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Symptom attribution and symptom reporting in Australian Gulf War veterans
Symptom attribution and symptom reporting in Australian Gulf War veterans Breanna K. Wright, Alexander C. McFarlane, David M. Clarke, Malcolm R. Sim, Helen L. Kelsall PII: DOI: Reference:
S0022-3999(15)00248-2 doi: 10.1016/j.jpsychores.2015.04.012 PSR 9012
To appear in:
Journal of Psychosomatic Research
Received date: Revised date: Accepted date:
3 December 2014 6 April 2015 23 April 2015
Please cite this article as: Wright Breanna K., McFarlane Alexander C., Clarke David M., Sim Malcolm R., Kelsall Helen L., Symptom attribution and symptom reporting in Australian Gulf War veterans, Journal of Psychosomatic Research (2015), doi: 10.1016/j.jpsychores.2015.04.012
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ACCEPTED MANUSCRIPT Symptom attribution and symptom reporting in Australian Gulf War veterans RUNNING HEADER: Wright et al.
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Breanna K Wright1, Alexander C McFarlane2, David M Clarke3, Malcolm R Sim4 and Helen L Kelsall5.
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Affiliations
PhD Candidate, Department of Epidemiology & Preventive Medicine, Monash University, Australia
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Director of the Centre for Traumatic Stress Studies, Centre for Traumatic Stress, University of Adelaide, Australia Professor, Department of Psychiatry, Monash University, Australia
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Director, Monash Centre for Occupational & Environmental Health, Department of Epidemiology & Preventive Medicine, Monash University, Australia Senior Research Fellow, Department of Epidemiology & Preventive Medicine, Monash University, Australia
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Corresponding author:
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Breanna Wright
Monash Centre for Occupational and Environmental Health (MonCOEH) Department of Epidemiology & Preventive Medicine
Melbourne, VIC 3004
Ph: +61 3 9903 0311
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Australia
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The Alfred Centre, Commercial Road
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Monash University
Email: [email protected]
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Word Count: 4996
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ACCEPTED MANUSCRIPT Abstract Objective: To better understand the consistent elevated symptom reporting by Gulf War
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veterans; we compared Australian Gulf War veterans and military-comparison group on
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symptom attributional styles and the relationship with total number and grouping of somatic
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and psychological symptoms.
Method: Postal questionnaires were completed by Australian Gulf War veterans (n=697) and
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military-comparison group (n=659) in 2000-2002 and 2011-2012. Data were collected on deployments, military-psychological stressors, symptom reporting, symptom factors and
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attributional style (normalising, psychologising, somatising, mixed-attribution). Results: Gulf War veterans did not differ in attributional style from comparison group
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(p>0.05); normalising was the predominant style. Groups were combined for analyses.
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Psychologisers reported the highest overall symptoms (mean(M)=10.95, standard
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deviation(SD)=9.15), the most psychophysiological (M=1.71, SD=2.82), cognitive (M=5.79, SD=5.09) and arthro-neuromuscular symptoms (M=1.53, SD=1.73). Psychologisers and
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somatisers reported significantly more symptoms across overall symptoms, all three symptom factors and psychological distress than normalisers. Normalisers consistently reported fewest overall symptoms (M=2.85, SD=4.49), psychophysiological (M=0.40, SD=0.98), cognitive (M=1.14, SD=2.22), and arthro-neuromuscular symptoms (M=0.72, SD=1.31). Persistent symptoms, rather than remitted, between baseline and follow-up were associated with increased rates of psychologising and mixed-attribution compared with normalising. For incident symptoms a similar pattern was observed, some symptoms also showed increased rates of somatising. Conclusions: In veterans, psychologising was associated with higher symptom reporting, while somatisers and mixed-attribution also demonstrated higher reporting than normalisers.
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ACCEPTED MANUSCRIPT Symptom persistence and incidence were associated with symptom attribution. The findings indicate that attributional style is associated with patterns of symptom reporting and
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highlights both past and present symptoms may influence attributional style.
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Keywords:
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Symptom reporting, symptom factors, symptom attribution, attributional style, veterans, Gulf
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War.
Introduction Excess symptom reporting in Gulf War veterans has been the subject of extensive research and debate; it has been widely established that Gulf War veterans from several countries deployed to the 1990-1991 Gulf War including the Unites States, United Kingdom and Australia report symptoms at a higher rate than their non-deployed or military-era 3
ACCEPTED MANUSCRIPT counterparts [1-7], although no group or pattern of symptoms have been identified as specific to Gulf War veterans [8]. Further to this, many veterans attribute their symptoms to their
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involvement in the Gulf War; one study reported 46% of Gulf War veterans attributed their
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symptoms ‘definitely’ to the Gulf War and a further 18% thought it was ‘probable’ that their
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symptoms were due to the Gulf War [9].
The most commonly reported symptoms include fatigue, cognitive difficulties, headaches,
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myalgia, mood disturbances, sleep problems and psychological distress [10]; which cross numerous body systems with a high rate of comorbidity [11]. Gulf War veterans appear to
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have a relatively stable number of symptoms that they report, whilst the severity of the symptoms varies over time [12]. A study of Australian Gulf War veterans conducted a factor
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analysis of reported symptoms that revealed three factors; psychophysiological distress,
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cognitive distress and arthro-neuromuscular distress [13]. The factors identified generally reflect similar symptom reporting across Gulf War and other veteran populations [14-16], as
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well as a general hospital population [17]. While multiple demographic, military service, psychological factors, and Gulf War-related chemical, medical and environmental exposures
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have been associated with increased symptom reporting in Gulf War veterans [18-22], these risk factors are not thought to provide a full explanation. To try to elucidate the rates of symptom reporting, we investigated the role of symptom attribution in these levels of distress. How individuals understand and attribute their symptoms plays an important role in their overall symptom experience, reporting and treatment-seeking behaviours [23]. As the constellation of symptoms Gulf War veterans may experience do not fall into a diagnostic category, an explanatory label for their symptoms may have been sought [24]. The Centers for Disease Control definition of the descriptively labelled ‘multisymptom illness’ is in itself based solely on reporting symptoms from two of three clusters of self-reported symptoms [4, 24]. Symptoms in these clusters are often chronic and recent research indicates that they may 4
ACCEPTED MANUSCRIPT also be relevant for contemporary veterans [25]. Thus, how veterans understand their symptoms and their causes is important, particularly in how it might affect their illness
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behaviour and help-seeking. How individuals understand symptoms may be different from
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how they understand diagnosed medical conditions because symptoms are not necessarily
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subsumed by an illness schema [26]. In the absence of a diagnosed medical condition, symptoms are likely to play a larger role in how veterans view their health and the types of treatments they pursue. Furthermore, treatment may not be sought for symptoms until they
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reach a particular threshold [27]. Thus, a number of veterans may be experiencing symptoms
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but who have not sought a diagnosis [26] or who perhaps were beneath the diagnostic cut-off [28]. Even for veterans who have received a diagnosis, symptoms are still the primary
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indicator on which interpretation and decisions are made [29]. By considering the
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relationship with symptoms rather than diagnosed medical conditions, we can better understand the role of the individuals’ interpretation.
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There are patterns in the way that people think about the cause of their symptoms; research has identified three attributional styles; normalising (generally downplaying symptoms or
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attributing them to an environmental cause) is generally the most prevalent style, psychologising (attributing symptoms to psychological distress or stress) and somatising (attributing symptoms as due to an organic or physical cause) [30]. Although attributional style is likely associated with an enduring tendency in individuals, it has been associated with past experience [30]. Robbins et al (1991) found that there was good test-retest reliability in attributional style but also noted that there can be variability over time; Robbins describes attributional style as ‘moderately stable’. [30] Symptom attribution has shown associations with current symptoms severity, for example psychologisers report greater depressive symptoms [23]. Previous physical illness or psychological problems may also influence how new symptoms are interpreted. Patients with 5
ACCEPTED MANUSCRIPT a history of chronic psychiatric problems have reported more psychologising attributions and fewer normalising attributions [30]. Furthermore, chronic physical illness has been associated
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with more somatising attributions [30]. Thus, whilst there are likely stable elements to
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attributional style, it should be considered a somewhat fluid concept. As Gulf War veterans
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frequently report symptoms across a range of body systems, it is important to consider the diversity of symptoms, how symptom attribution may affect symptom experience and how both past and current symptoms can influence how symptoms are understood and
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interpretation of new symptoms.
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We considered the concept of symptom attribution to be useful in investigating both the frequency and pattern of symptom reporting in a cohort of Gulf War veterans and military-era
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comparison group; and aimed to investigate the following research questions:
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1. What is the predominant attributional style in Gulf War veterans and the comparison
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group and are Gulf War veterans more likely to be psychologisers or somatisers? 2. Are the total number of symptoms reported and the symptom factor scores (psychophysiological, cognitive distress and arthro-neuromuscular) elevated in
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psychologisers or somatisers? 3. Is the persistence or incidence of symptoms from baseline to follow-up associated with attributional style?
Methods Participants The Australian Gulf War Veterans’ Health Study (2000-2002) involved 1456 Gulf War veterans (80.5% of eligible cohort) and 1588 (56.8%) of an era-military comparison group who were mainly Naval personnel [19]. A follow-up study was undertaken in 2011-12. After removing participants who had refused further research, reported as deceased or had no valid 6
ACCEPTED MANUSCRIPT mailing address, 1330 Gulf War veterans and 1449 comparison group members were invited to participate at follow-up. Of those, 715 (54%) Gulf War veterans and 675 (47%)
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comparison group members participated. Those who completed the self-report questionnaire
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included; 712 Gulf War veterans and 674 comparison group members. The current analysis
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was restricted to male participants (due to the very small number of female participants; 2.2%). The final study sample for this analysis was 1356: 697 Gulf War and 659 comparison group members. The Human Research Ethics Committees of Monash University, Australian
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Department of Defence and Australian Department of Veterans’ Affairs approved the
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baseline and follow-up studies; all participants provided voluntary informed consent. Measures
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Participants completed a self-administered postal questionnaire at baseline and follow-up. Deployment status was defined as having ever been on an active deployment of at least one
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week between 1991 and 2012 and those who had never deployed during this period. In addition, information on military psychological stressors was collected at baseline.
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The assessment of military psychological stressors through the 44-item Military Service Experience Questionnaire (MSEQ) administered at baseline, captures actual military events as well as personal appraisals of threat, fear or discomfort [31]. Common themes captured by the MSEQ include; fear of entrapment, fear of death, exposure to death or suffering of others and feelings of helplessness. Responses were scored on a three-point Likert scale; 1 – Not experienced, 2 – Yes, Mildly so, and 3 – Yes, Strongly so. For the present analysis, the total number of MSEQ items experienced was tallied (total scores ranging from 0-44) and divided into four categories; 0-4, 5-8, 9-12, >12 [19]. The MSEQ demonstrated good internal consistency; α = .85) [31].
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ACCEPTED MANUSCRIPT A 63-item self-report symptom questionnaire assessed the presence of symptoms in the past month. A previous factor analysis of symptoms reported at baseline revealed a three-factor
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solution; psychophysiological, cognitive and arthro-neuromuscular [13]. For the purposes of
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the current analysis, the scores on these three factors (count of those symptoms rated
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moderate or severe) were used for both the baseline and follow-up time points. The total possible range for the three factor scores were; psychophysiological (0-23), cognitive (0-20) and arthro-neuromuscular (0-6). Persistent symptoms were defined as those that were
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reported as moderate or severe at both baseline and follow-up; remitted were present at
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baseline but not at follow-up; incident were not reported at baseline but were reported at follow-up and never reported were neither reported at baseline nor follow-up. The symptoms
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presented for the persistent and incident symptom analyses were the ten most prevalent
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symptoms reported at follow-up by all participants and had a minimum endorsement of 50% of respondents at follow-up; these symptoms were chosen for the present analysis to allow
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exploration of the common symptoms experienced by Gulf War veterans and to ensure adequate power to detect relationships
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Attributional style was assessed at follow-up only, by the Symptom Interpretation Questionnaire (SIQ). The SIQ lists 13 common hypothetical bodily symptoms or sensations [30], attached to each symptom are three possible explanations, each one corresponding to one of the three styles of attribution: psychologising, somatising, or normalising. Participants were asked to indicate which of the three possible causes they think it is probably due to, giving each participant a numerical score from 0-13 along the three attributional dimensions. Participants were classified as predominantly normalisers, psychologisers, or somatisers if they scored 7 or more on that attributional dimension, those who did not score at least 7 for any style were categorised as no predominance [32]. No predominance indicates a combination of mostly psychologising and somatising with some normalising attributions and 8
ACCEPTED MANUSCRIPT thus will be interpreted as a mixed-attribution style. Validation research has shown that these scores remain reasonably consistent over time, supporting the theory that they may reflect
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underlying health beliefs [30, 32].
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The 12-item General Health Questionnaire (GHQ-12) was used assess non-psychotic
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psychological distress [33]. We employed the Likert method of scoring where responses are given a weight of 0, 1, 2 or 3, with the total range of scores from 0 to 36.
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Statistical Analyses
Bivariate analysis with chi-square was used to test if there was a difference in attributional
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style by study group and deployment status. The relationship between attributional style and overall number of symptoms, as well as the GHQ-12, was assessed with a one-way
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independent Analysis of Co-Variance (ANCOVA) which controlled for the effect of military
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psychological stressors and post-hoc t-tests with Bonferroni adjustment; adjusted p-value =
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0.008. Multivariate Analysis of Co-variance (MANCOVAs) were implemented to investigate the relationship between symptom factor scores and attributional style; post-hoc ANCOVAs were used to investigate where the statistical differences existed. Chi-square tests were again
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used to investigate the relationship between persistent and incident symptoms and attributional style; with multinominal logistic regression used to investigate post-hoc differences where normalisers were used as the reference group. Missing data were no more than 10% on any variable. and listwise deletion was used for analyses. Data analysis was performed using SPSS version 21.
Results Participants in the present analyses ranged in age from 38 to 72 years old, with a mean age of 50.1 years (SD=6.45), 77.3% were in the Navy with 14.0% and 8.7% in the Air Force and
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ACCEPTED MANUSCRIPT Army respectively. Regarding active deployments, 67.8% of all veterans had deployed between 1991 and 2012 and 17.5% were still serving in the ADF at follow-up.
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Utilising baseline data, evaluation of non-response bias indicated that those who participated
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at follow-up were older and more likely to be a supervisory rank. Comparison group
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members who participated at follow-up were also more likely to have served in the Air Force and to have scored slightly lower on general mental health and wellbeing using the Short-
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Form 12 mental component score at baseline. These observed differences may mean that the reported health results may vary slightly from what would have been observed with full
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participation, but general mental health and wellbeing was not considered likely to have had an important impact on the magnitude of differences observed in reported symptoms at
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follow-up [34].
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Bivariate analysis revealed that there was no significant difference between Gulf War
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veterans and comparison group members across their predominant symptom attributional style; the percentage of participants in each attributional style (see Table 1) did not differ by study group; 2 (3, N=1302) = 5.87, p = 0.12, Cramer’s V=0.07. Normalising was the
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principal style in both Gulf War veterans and the comparison group. There was also no significant difference in attributional style between those who had been on an active deployment between 1991 and 2012 compared with those who had not deployed; 2 (3, N=1275) = 2.01, p = 0.57, Cramer’s V=0.04. Thus, Gulf War veterans and comparison group members were combined for all subsequent analyses. Table 1. Attributional style by study group.
Attributional Style Psychologisers Somatisers
Study Group Comparison Gulf War group % % 7.4 4.8 7.4
6.4
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70.1
Mixed-attribution
20.5
18.6
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Normalisers
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There was, however, a difference in attribution style for military psychological stressors
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(MSEQ) 2 (9, N=1273) = 36.14, p < 0.001, Cramer’s V=0.11. Post-hoc analyses using multinominal logistic regression revealed that with increasing military psychological stressors, participants were more likely to be psychologisers and for the highest exposure
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category more likely to have a mixed-attribution than to be normalisers.
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For symptom reporting, we first investigated if the total number of symptoms reported by participants varied by attributional style. After controlling for the effects of military
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psychological stressors, an overall difference was found (F(3, 1154) = 42.067; p<0.001). The
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means and standard deviations of total number of symptoms at follow-up by attributional style are presented in Table 2. Post-hoc analyses revealed that psychologisers reported a
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higher number of symptoms than somatisers (p<0.001), normalisers (p<0.001) and mixedattribution (p<0.001). Somatisers reported a higher average number of symptoms than
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normalisers (p=0.002), but were not statistically different from mixed-attribution (p>0.05). Normalisers reported significantly fewer symptoms than mixed-attribution (p<0.001). Table 2. Attributional style and unadjusted means and standard deviations of symptoms. Factor scores
Mean total Attributional
number of Athro-
Style
GHQ
Symptoms Psychophysiological
Cognitive
neuromuscular
(0-23)
(0-20)
(0-6)
(0-63)a
(0-36)
Psychologisers
10.95 (9.15)
1.71 (2.82)
5.79 (5.09)
1.53 (1.73)
20.00 (7.96)
Somatisers
5.55 (7.13)
1.19 (2.57)
2.36 (1.00)
1.39 (1.80)
12.44 (5.87)
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ACCEPTED MANUSCRIPT Normalisers
2.85 (4.49)
0.40 (0.98)
1.14 (2.22)
0.72 (1.31)
10.84 (4.45)
5.61 (7.33)
0.94 (1.88)
2.63 (3.60)
1.14 (1.64)
14.65 (5.77)
Mixedattribution
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a Total possible range denoted in brackets
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The second analysis for symptom reporting used a MANCOVA to investigate the relationship between symptom factor scores and attributional style, controlling for military psychological stressors (see Table 2). There was a statistically significant difference across the three factor
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scores (psychophysiological distress, cognitive distress and arthro-neuromuscular distress) by attributional style (see Table 2); F(9, 3081) = 22.369, p<0.001; Wilk’s = 0.857. Further,
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attributional style was significantly associated with all three factor scores; psychological distress (F(3, 1268) = 21.085; p<0.001), cognitive distress (F(3, 1268) = 61.695; p<0.001)
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and arthro-neuromuscular distress (F(3, 1268) = 6.05; p<0.001). Post-hoc analyses adjusted for military psychological stressors revealed that for the
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psychophysiological distress factor, psychologisers reported statistically more symptoms than normalisers (p<0.001) and mixed-attribution (p=0.001) but were not statistically different
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from somatisers. Somatisers reported statistically more symptoms than normalisers (p<0.001) but not from mixed-attribution (p>0.05). Normalisers reported statistically fewer symptoms than mixed-attribution (p<0.001). Similarly, adjusted post-hoc analyses revealed that for the cognitive distress factor, mean symptom reporting by psychologisers was statistically higher than somatisers (p<0.001), normalisers (p<0.001) and mixed-attribution (p<0.001). Somatisers reported statistically more symptoms than normalisers (p=0.001) but were not statistically different from mixedattribution (p>0.05). Normalisers reported statistically fewer symptoms than mixedattribution (p<0.001).
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ACCEPTED MANUSCRIPT And finally, for the arthro-neuromuscular distress factor, adjusted mean symptom reporting by psychologisers was statistically higher than normalisers (p<0.001), but not somatisers
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(p>0.05) or mixed-attribution (p>0.05). Somatisers reported statistically more symptoms than
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normalisers (p<0.001) but not from mixed-attribution (p>0.05). Normalisers reported
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statistically fewer symptoms than mixed-attribution (p<0.001).
The association between attributional style and psychological distress (GHQ-12), adjusted for
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military psychological stressors, was assessed using an ANCOVA. An overall difference in attributional style by psychological distress was found; (F(3, 1263) = 87.956; p<0.001).
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Adjusted post-hoc tests using Bonferroni revealed that psychologisers reported higher psychological distress than all other attributional styles (all p<0.001). Somatisers reported
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significantly higher psychological distress than normalisers (p>0.008) and lower than mixed-
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attribution (p>0.008). Finally, normalisers reported lower GHQ-12 scores than all other
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attributional styles (all p<0.001).
The investigation of the relationship between symptoms over time and attributional style was divided into those who reported symptoms at baseline and those who did not. For those who
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reported symptoms as moderate or severe at baseline, Tables 3 depicts symptoms that were reported as persistent (P) or remitted (R) at follow-up and the associations with attributional style. There was a statistical difference in attributional style between those who reported the symptoms as persistent rather than remitted for five of the ten symptoms. Of the statistically significant differences, the general pattern was for those in the persistent group to be more likely to be psychologisers or mixed-attribution than to be normalisers. Only for the unrefreshed sleep symptom was the persistent group also more likely to be somatisers.
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ACCEPTED MANUSCRIPT For example, looking at unrefreshed sleep, the overall chi-square statistic is significant indicating that there is a difference in attributional style between the persistence or remittance
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of symptoms. The post-hoc multinomial logistic regression showed that participants who
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reported persistent unrefreshed sleep were more likely to be psychologisers, somatisers or
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mixed-attribution than to be normalisers.
Sleep difficulties
P
9.5*
R
1.2*
P
79.2
17.4*
7.1
59.3
24.0*
5.4
79.0
14.4*
9.3*
7.8
56.1
26.8
3.7*
2.2
83.1
11.0
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R
2.8*
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0.7*
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Fatigue
R
Headaches
P
8.0
8.9
61.1
22.0
R
5.9
5.1
69.9
19.1
P
8.2*
7.4
62.1
22.3
R
3.8*
5.2
73.9
17.1
P
6.6
7.8
63.7
21.9
R
3.8
6.0
70.7
19.5
P
9.9*
6.7
57.2
26.2*
R
1.5*
8.5
74.5
15.5*
P
7.6
9.6
59.4
23.4
R
4.7
6.5
71.0
17.8
P
7.7
9.4
60.6
22.3
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Muscle ache/pains
Low back pain
Irritable/outbursts
Stiffness in joints
Ringing in ears
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Table 3. Persistent (P) or remitted (R) symptoms from baseline to follow-up and attributional style. Attributional Style (%) ChiMixeda Symptom Square p Psychologising Somatising Normalising attribution Unrefreshed sleep P 9.7* 7.2* 58.9 24.3* 25.319 0.000
25.709
0.000
33.301
0.000
4.173
0.243
10.311
0.016
2.961
0.398
27.323
0.000
4.830
0.185
4.959
0.175
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1.9
70.4
24.1
P
6.0
5.7
66.2
22.1
R
8.7
6.5
66.8
17.9
2.448
0.485
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Flatulence/burping
R
a
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Ten most commonly reported symptoms at follow-up * Indicates which attributional styles were statistically different between persistent and remitted groups for each symptom at p<0.05. P=Persistent. R=Remitted. Normalising is the reference Group.
For those who did not report the ten most commonly reported symptoms at baseline (Table 4),
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attributional style across incident (I) and never reported (N) symptoms at follow-up were
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compared. There was a statistically significant difference between incident and never reported for seven of the ten symptoms. For symptoms in which there was a statistically
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significant difference, the general pattern was for those who reported incident symptoms to
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be more likely to be psychologisers or mixed-attribution than to be normalisers. For four
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symptoms, the incident group was also more likely to be somatisers than normalisers.
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Table 4. Incidence (I) and never reported (N) symptoms from baseline to follow-up and attributional style. Attributional Style (%) ChiMixeda Symptoms Square p Psychologising Somatising Normalising attribution Unrefreshed sleep I 5.3* 9.1 63.9 21.6* 20.093 0.000
Fatigue
Sleep difficulties
Muscle ache/pains
Headaches
N
1.6*
7.1
80.4
10.9*
I
5.6*
9.5*
61.2
23.7*
N
1.7*
5.5*
81.7
11.1*
I
6.5*
8.1
63.8
21.5*
N
1.4*
6.6
80.7
11.2*
I
4.3
6.0
71.2
18.4
N
4.6
6.0
71.1
18.3
I
5.5
6.0
67.5
21.0
28.059
0.000
27.095
0.000
0.032
0.999
2.644
0.450
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Ringing in ears
a
I
7.9
5.7
70.2
16.2
N
4.8
6.5
69.8
19.0
I
10.6*
7.2
58.9
N
2.0*
6.5
77.8
I
6.8
8.1*
N
4.7
4.5*
I
8.5*
8.5*
N
4.1*
I
6.5
N
4.6
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T
16.9
23.3*
3.210
0.360
34.605
0.000
10.964
0.012
12.729
0.005
10.847
0.013
13.7*
63.5
21.6
74.1
16.6
63.1
20.0
5.4*
72.5
17.9
11.6*
59.8
22.1
6.2*
71.6
17.6
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Flatulence/burping
71.1
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Stiffness in joints
7.9
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Irritable/outbursts
4.1
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Low back pain
N
Ten most commonly reported symptoms at follow-up
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* Indicates which attributional styles were statistically different between incident and never reported groups for each symptom at p<0.05. I=Incident. N=Never reported. Normalising is the reference group.
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For example, looking at unrefreshed sleep, the overall chi-square statistic is significant indicating that there is a difference across attributional style for incidence of symptoms. The
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post-hoc multinomial logistic regression showed that participants who reported incident unrefreshed sleep were more likely to be psychologisers or mixed-attribution than to be normalisers. There was no difference in rates of somatising.
Discussion In summary, our study found that having deployed to the Gulf War or having ever actively deployed were not related to attributional style. However, increasing number of military psychological stressors were mildly associated with an increased likelihood of having a psychologising style or mixed-attribution style, providing novel insight into the relationship between stress and attributional style. Across all symptom measures, psychologisers reported
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ACCEPTED MANUSCRIPT the greatest number of symptoms and normalisers the least, consistent with previous research in other populations [23, 32]. Whilst not all longitudinal symptom results were significant,
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persistence and incidence of symptoms tended to be associated with a psychologising or
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mixed-attribution styles; and for incident symptoms, some symptoms also showed an
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association with higher rates of somatising compared with normalising.
Military psychological stressors were associated with a psychologising style and the highest
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category associated with mixed-attribution. This finding indicates that exposure to military psychological stressors could influence the vigilance that individuals have towards their
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distress and symptoms. This could be of particular interest in this population as at the time of the Gulf War there was general concern regarding potential exposure to chemical warfare
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[18], which was identified as a significant stressor [31]. Australian Gulf War veterans
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reported some chemical and environmental exposures [35] and a number of military psychological stressors [31] more frequently than a military-era comparison group. Thus,
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there were substantial health concerns for Gulf War veterans. Increasing military psychological stressors were also associated with symptom reporting in Australian Gulf War
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veterans [21], and combat experience has also been associated with higher rates of vague somatic complaints in US personnel deployed to Iraq [36]. Thus, combat exposures may affect awareness of and attention to symptom experience and individuals’ inclination to report symptoms. Attributional style potentially plays a moderating role in this relationship. These findings could have implications for the general experience of stress; concern or worry may heighten awareness and detection of symptoms and result in attributing symptoms to causes other than transient. Life stressors may induce heightened concern over the experience of symptoms. Cameron et al found that during periods of ongoing life stress, individuals were less tolerant of ambiguous symptoms and more likely to interpret them as caused by illness, more serious and for them to lead to greater healthcare utilisation [37]. Although controlling 17
ACCEPTED MANUSCRIPT for military psychological stressors did not change the significance of the results in the current analyses, it may be that the relationships are moderated for some attributional styles,
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possibly psychologising and mixed-attribution.
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The increased symptom reporting by psychologisers was most notable for psychological
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symptoms, as observed on the psychophysiological factor, cognitive distress factor and psychological distress; whilst the arthro-neuromuscular factor was only significant for the
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greatest symptom reporting difference, between psychologisers and normalisers. Psychologisers may demonstrate greater vigilance or sensitivity to symptoms, particularly
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those that are psychological. However, it has also been suggested that patients with psychological disorders such as anxiety or depression, may have a lower threshold for
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physical symptoms because they interfere with the adaptive process most people with chronic
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illnesses go through which allows for some level of habituation [38]. It is possible that a history of psychological symptoms may lead to a psychologising style and an increased
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sensitivity to all symptoms, but particularly to psychological ones. This pattern may suggest that psychologisers more readily identify psychological symptoms, are more disposed to
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report their distress or that those who have experienced psychological symptoms (either in the past or presently) are more likely to be psychologisers. Although a psychologising style was not elevated in Gulf War veterans, they have consistently reported excess psychological symptoms compared with comparison groups over the past 20 years [19, 22, 34]. Thus, identifying those with a tendency to psychologise may be an important step in managing their long-term symptoms. Somatisers generally reported significantly fewer symptoms than psychologisers and significantly more symptoms than normalisers. Our findings are consistent with research that has found that somatisers report fewer psychological symptoms and are less psychologically distressed than psychologisers, but they are also more likely to attribute physical causes to 18
ACCEPTED MANUSCRIPT their symptoms than normalisers [39]. Somatisers were not significantly different from mixed-attribution on any of the symptom factors. A mixed-attribution style appeared to be
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relatively similar to somatisers in their symptom profile, which may suggest similarity
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between the styles in their increased reporting compared with the predominant normalising
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style.
Normalisers reported significantly fewest symptoms overall and on all three factors compared
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with all other attributional styles. Normalisers also reported lower psychological distress than psychologisers and mixed-attribution. Our finding that normalisers reported fewest symptoms
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across multiple measures extends previous research that found they had lower psychological distress [32]. This is an important finding as it suggests that normalisers either do not
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acknowledge symptoms or signs of distress or, alternatively, that they may be failing to report
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the symptoms that they do experience. If normalisers do not acknowledge or underreport their symptoms, their levels of both somatic and psychological distress are susceptible to being
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overlooked by healthcare professionals, and healthcare professionals may need to be alert to this tendency to ensure that they are seeking and receiving appropriate healthcare.
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The longitudinal findings in our study indicate that individuals may initially attribute symptoms to situational or environmental factors, but when the normalising attribution becomes insufficient to account for symptoms or persistence of symptoms, individuals may begin to consider other causes [39]. Thus, attributional style influences symptom experience and reporting but it should also be acknowledged that both past and present experience of symptoms may interact with attributional style as well. Further to this, our findings in regard to incident and persistent symptoms provide additional support for some influence on attributional style, indicating that the presence of a new symptom or symptoms means that a person may look to other explanations such as
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ACCEPTED MANUSCRIPT psychologising or somatising rather than a normalising explanation. Moreover, the persistence of symptoms may also be associated with an increased likelihood to look for other
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explanations, particularly psychologising, to account for enduring symptoms. But it is
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important to bear in mind that attributional style may also be influencing the patterns of
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symptom reporting. The increased rates of psychologising and mixed-attribution for persistent and incident symptoms, tended to be in relation to sleep and irritability symptoms,
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and also highlight the decrease in normalising with these symptoms. The findings discussed above provide insight into the experience of Gulf War veterans’
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health over the past 20 years. Gulf War veterans have been found consistently to report more symptoms than military-era and non-deployed comparison groups in epidemiological studies
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[1-7]. Their symptom history may have potentially influenced their attributional style.
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However, we found no difference in attributional style between the Gulf War veterans and the military comparison group in this study. However, attributional style was associated with
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the likelihood and patterns of reporting symptoms. All veterans who reported symptoms demonstrated alterations in their attributional style. These differences provide insight into
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patterns of symptom reporting and this may potentially have implications for how they seek treatment for symptoms. Methodological strengths of this study include a large sample size and military population, which has not, to our knowledge, been investigated previously regarding symptom attributional styles. This study is also unique in its access to longitudinal data, in addition to the use of a range of symptom measures to provide a comprehensive symptom profile of the study population. However, there are some limitations to consider. The Symptom Interpretation Questionnaire was not available at both time points and so investigation of change in attributional style over time was not possible. Symptom reporting was collected at two time points over ten years and so whilst the longitudinal data provides insight into the 20
ACCEPTED MANUSCRIPT patterns of symptom incidence and persistence, it is possible that during the ten year interval there were intermittent symptoms that were not captured by the current data and symptoms
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that may have remitted and returned. Both symptom reporting and attributional style are
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reliant on self-report data. It is possible that self-reported symptoms may have over- or under-
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estimated the symptoms experienced. It is also important to note that in relation to symptom interpretation the symptom experience as reported by individuals in particularly relevant. The participants may or may not have received a medical diagnosis for the symptoms they
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reported which may have influenced how they view their symptoms and potentially their
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attributional style. The analyses in this paper were limited to male veterans due to the low number of females in the study. The relationship between attributional style and symptom
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reporting in female veterans should be explored in future research; there is evidence to
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suggest that gender is associated with symptom experience and attribution style [23, 30, 40]. In conclusion, the Gulf War veteran population investigated appears to be similar in its
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attributional style profile to a military comparison group and to other populations that have been reported previously [32]. This suggests that they do not have a predominant attributional
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style that would explain the increased symptom reporting observed in this study population and possibly in Gulf War veteran overseas populations more generally. The pattern of those likely to report the greatest and least number of symptoms was similar in both the Gulf War veteran and comparison group: psychologisers and normalisers respectively. Attributional style is an important consideration in understanding symptom experience, and by investigating its role in reporting, our understanding of symptom patterns has been improved. Normalisers may underreport symptoms and healthcare professionals may need to be alert to this. Understanding symptoms is a complex phenomenon, it cannot be explained by a single concept; however, the current findings provide further insight into symptom reporting patterns and profiles of Australian veterans. 21
ACCEPTED MANUSCRIPT Acknowledgements Financial support for the studies on which this research was based was received from the
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Australian Department of Veterans' Affairs. The views expressed in this article are those of
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the authors and are not necessarily those of the Australian Government. Conflict of Interest
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The authors declare that there is no conflict of interest.
Kelsall HL, McKenzie DP, Sim MR, Leder K, Forbes AB, Dwyer T. Physical,
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1.
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ACCEPTED MANUSCRIPT Conflict of Interest
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The authors have no conflicts of interest to declare.
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ACCEPTED MANUSCRIPT Highlights: Normalising was the predominant attributional style in Australian veterans.
Psychologisers reported the highest and Normalisers the lowest number of symptoms
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Psychologising and mixed-attribution styles.
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Persistence and Incidence of symptoms demonstrated a relationship with
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across all symptom groups.
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S0022-3999(15)00248-2 doi: 10.1016/j.jpsychores.2015.04.012 PSR 9012
To appear in:
Journal of Psychosomatic Research
Received date: Revised date: Accepted date:
3 December 2014 6 April 2015 23 April 2015
Please cite this article as: Wright Breanna K., McFarlane Alexander C., Clarke David M., Sim Malcolm R., Kelsall Helen L., Symptom attribution and symptom reporting in Australian Gulf War veterans, Journal of Psychosomatic Research (2015), doi: 10.1016/j.jpsychores.2015.04.012
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT Symptom attribution and symptom reporting in Australian Gulf War veterans RUNNING HEADER: Wright et al.
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Breanna K Wright1, Alexander C McFarlane2, David M Clarke3, Malcolm R Sim4 and Helen L Kelsall5.
1
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Affiliations
PhD Candidate, Department of Epidemiology & Preventive Medicine, Monash University, Australia
2
3
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Director of the Centre for Traumatic Stress Studies, Centre for Traumatic Stress, University of Adelaide, Australia Professor, Department of Psychiatry, Monash University, Australia
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Director, Monash Centre for Occupational & Environmental Health, Department of Epidemiology & Preventive Medicine, Monash University, Australia Senior Research Fellow, Department of Epidemiology & Preventive Medicine, Monash University, Australia
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5
Corresponding author:
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Breanna Wright
Monash Centre for Occupational and Environmental Health (MonCOEH) Department of Epidemiology & Preventive Medicine
Melbourne, VIC 3004
Ph: +61 3 9903 0311
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Australia
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The Alfred Centre, Commercial Road
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Monash University
Email: [email protected]
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Word Count: 4996
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ACCEPTED MANUSCRIPT Abstract Objective: To better understand the consistent elevated symptom reporting by Gulf War
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veterans; we compared Australian Gulf War veterans and military-comparison group on
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symptom attributional styles and the relationship with total number and grouping of somatic
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and psychological symptoms.
Method: Postal questionnaires were completed by Australian Gulf War veterans (n=697) and
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military-comparison group (n=659) in 2000-2002 and 2011-2012. Data were collected on deployments, military-psychological stressors, symptom reporting, symptom factors and
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attributional style (normalising, psychologising, somatising, mixed-attribution). Results: Gulf War veterans did not differ in attributional style from comparison group
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(p>0.05); normalising was the predominant style. Groups were combined for analyses.
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Psychologisers reported the highest overall symptoms (mean(M)=10.95, standard
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deviation(SD)=9.15), the most psychophysiological (M=1.71, SD=2.82), cognitive (M=5.79, SD=5.09) and arthro-neuromuscular symptoms (M=1.53, SD=1.73). Psychologisers and
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somatisers reported significantly more symptoms across overall symptoms, all three symptom factors and psychological distress than normalisers. Normalisers consistently reported fewest overall symptoms (M=2.85, SD=4.49), psychophysiological (M=0.40, SD=0.98), cognitive (M=1.14, SD=2.22), and arthro-neuromuscular symptoms (M=0.72, SD=1.31). Persistent symptoms, rather than remitted, between baseline and follow-up were associated with increased rates of psychologising and mixed-attribution compared with normalising. For incident symptoms a similar pattern was observed, some symptoms also showed increased rates of somatising. Conclusions: In veterans, psychologising was associated with higher symptom reporting, while somatisers and mixed-attribution also demonstrated higher reporting than normalisers.
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ACCEPTED MANUSCRIPT Symptom persistence and incidence were associated with symptom attribution. The findings indicate that attributional style is associated with patterns of symptom reporting and
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highlights both past and present symptoms may influence attributional style.
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Keywords:
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Symptom reporting, symptom factors, symptom attribution, attributional style, veterans, Gulf
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War.
Introduction Excess symptom reporting in Gulf War veterans has been the subject of extensive research and debate; it has been widely established that Gulf War veterans from several countries deployed to the 1990-1991 Gulf War including the Unites States, United Kingdom and Australia report symptoms at a higher rate than their non-deployed or military-era 3
ACCEPTED MANUSCRIPT counterparts [1-7], although no group or pattern of symptoms have been identified as specific to Gulf War veterans [8]. Further to this, many veterans attribute their symptoms to their
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involvement in the Gulf War; one study reported 46% of Gulf War veterans attributed their
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symptoms ‘definitely’ to the Gulf War and a further 18% thought it was ‘probable’ that their
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symptoms were due to the Gulf War [9].
The most commonly reported symptoms include fatigue, cognitive difficulties, headaches,
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myalgia, mood disturbances, sleep problems and psychological distress [10]; which cross numerous body systems with a high rate of comorbidity [11]. Gulf War veterans appear to
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have a relatively stable number of symptoms that they report, whilst the severity of the symptoms varies over time [12]. A study of Australian Gulf War veterans conducted a factor
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analysis of reported symptoms that revealed three factors; psychophysiological distress,
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cognitive distress and arthro-neuromuscular distress [13]. The factors identified generally reflect similar symptom reporting across Gulf War and other veteran populations [14-16], as
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well as a general hospital population [17]. While multiple demographic, military service, psychological factors, and Gulf War-related chemical, medical and environmental exposures
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have been associated with increased symptom reporting in Gulf War veterans [18-22], these risk factors are not thought to provide a full explanation. To try to elucidate the rates of symptom reporting, we investigated the role of symptom attribution in these levels of distress. How individuals understand and attribute their symptoms plays an important role in their overall symptom experience, reporting and treatment-seeking behaviours [23]. As the constellation of symptoms Gulf War veterans may experience do not fall into a diagnostic category, an explanatory label for their symptoms may have been sought [24]. The Centers for Disease Control definition of the descriptively labelled ‘multisymptom illness’ is in itself based solely on reporting symptoms from two of three clusters of self-reported symptoms [4, 24]. Symptoms in these clusters are often chronic and recent research indicates that they may 4
ACCEPTED MANUSCRIPT also be relevant for contemporary veterans [25]. Thus, how veterans understand their symptoms and their causes is important, particularly in how it might affect their illness
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behaviour and help-seeking. How individuals understand symptoms may be different from
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how they understand diagnosed medical conditions because symptoms are not necessarily
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subsumed by an illness schema [26]. In the absence of a diagnosed medical condition, symptoms are likely to play a larger role in how veterans view their health and the types of treatments they pursue. Furthermore, treatment may not be sought for symptoms until they
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reach a particular threshold [27]. Thus, a number of veterans may be experiencing symptoms
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but who have not sought a diagnosis [26] or who perhaps were beneath the diagnostic cut-off [28]. Even for veterans who have received a diagnosis, symptoms are still the primary
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indicator on which interpretation and decisions are made [29]. By considering the
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relationship with symptoms rather than diagnosed medical conditions, we can better understand the role of the individuals’ interpretation.
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There are patterns in the way that people think about the cause of their symptoms; research has identified three attributional styles; normalising (generally downplaying symptoms or
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attributing them to an environmental cause) is generally the most prevalent style, psychologising (attributing symptoms to psychological distress or stress) and somatising (attributing symptoms as due to an organic or physical cause) [30]. Although attributional style is likely associated with an enduring tendency in individuals, it has been associated with past experience [30]. Robbins et al (1991) found that there was good test-retest reliability in attributional style but also noted that there can be variability over time; Robbins describes attributional style as ‘moderately stable’. [30] Symptom attribution has shown associations with current symptoms severity, for example psychologisers report greater depressive symptoms [23]. Previous physical illness or psychological problems may also influence how new symptoms are interpreted. Patients with 5
ACCEPTED MANUSCRIPT a history of chronic psychiatric problems have reported more psychologising attributions and fewer normalising attributions [30]. Furthermore, chronic physical illness has been associated
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with more somatising attributions [30]. Thus, whilst there are likely stable elements to
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attributional style, it should be considered a somewhat fluid concept. As Gulf War veterans
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frequently report symptoms across a range of body systems, it is important to consider the diversity of symptoms, how symptom attribution may affect symptom experience and how both past and current symptoms can influence how symptoms are understood and
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interpretation of new symptoms.
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We considered the concept of symptom attribution to be useful in investigating both the frequency and pattern of symptom reporting in a cohort of Gulf War veterans and military-era
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comparison group; and aimed to investigate the following research questions:
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1. What is the predominant attributional style in Gulf War veterans and the comparison
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group and are Gulf War veterans more likely to be psychologisers or somatisers? 2. Are the total number of symptoms reported and the symptom factor scores (psychophysiological, cognitive distress and arthro-neuromuscular) elevated in
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psychologisers or somatisers? 3. Is the persistence or incidence of symptoms from baseline to follow-up associated with attributional style?
Methods Participants The Australian Gulf War Veterans’ Health Study (2000-2002) involved 1456 Gulf War veterans (80.5% of eligible cohort) and 1588 (56.8%) of an era-military comparison group who were mainly Naval personnel [19]. A follow-up study was undertaken in 2011-12. After removing participants who had refused further research, reported as deceased or had no valid 6
ACCEPTED MANUSCRIPT mailing address, 1330 Gulf War veterans and 1449 comparison group members were invited to participate at follow-up. Of those, 715 (54%) Gulf War veterans and 675 (47%)
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comparison group members participated. Those who completed the self-report questionnaire
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included; 712 Gulf War veterans and 674 comparison group members. The current analysis
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was restricted to male participants (due to the very small number of female participants; 2.2%). The final study sample for this analysis was 1356: 697 Gulf War and 659 comparison group members. The Human Research Ethics Committees of Monash University, Australian
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Department of Defence and Australian Department of Veterans’ Affairs approved the
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baseline and follow-up studies; all participants provided voluntary informed consent. Measures
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Participants completed a self-administered postal questionnaire at baseline and follow-up. Deployment status was defined as having ever been on an active deployment of at least one
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week between 1991 and 2012 and those who had never deployed during this period. In addition, information on military psychological stressors was collected at baseline.
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The assessment of military psychological stressors through the 44-item Military Service Experience Questionnaire (MSEQ) administered at baseline, captures actual military events as well as personal appraisals of threat, fear or discomfort [31]. Common themes captured by the MSEQ include; fear of entrapment, fear of death, exposure to death or suffering of others and feelings of helplessness. Responses were scored on a three-point Likert scale; 1 – Not experienced, 2 – Yes, Mildly so, and 3 – Yes, Strongly so. For the present analysis, the total number of MSEQ items experienced was tallied (total scores ranging from 0-44) and divided into four categories; 0-4, 5-8, 9-12, >12 [19]. The MSEQ demonstrated good internal consistency; α = .85) [31].
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ACCEPTED MANUSCRIPT A 63-item self-report symptom questionnaire assessed the presence of symptoms in the past month. A previous factor analysis of symptoms reported at baseline revealed a three-factor
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solution; psychophysiological, cognitive and arthro-neuromuscular [13]. For the purposes of
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the current analysis, the scores on these three factors (count of those symptoms rated
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moderate or severe) were used for both the baseline and follow-up time points. The total possible range for the three factor scores were; psychophysiological (0-23), cognitive (0-20) and arthro-neuromuscular (0-6). Persistent symptoms were defined as those that were
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reported as moderate or severe at both baseline and follow-up; remitted were present at
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baseline but not at follow-up; incident were not reported at baseline but were reported at follow-up and never reported were neither reported at baseline nor follow-up. The symptoms
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presented for the persistent and incident symptom analyses were the ten most prevalent
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symptoms reported at follow-up by all participants and had a minimum endorsement of 50% of respondents at follow-up; these symptoms were chosen for the present analysis to allow
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exploration of the common symptoms experienced by Gulf War veterans and to ensure adequate power to detect relationships
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Attributional style was assessed at follow-up only, by the Symptom Interpretation Questionnaire (SIQ). The SIQ lists 13 common hypothetical bodily symptoms or sensations [30], attached to each symptom are three possible explanations, each one corresponding to one of the three styles of attribution: psychologising, somatising, or normalising. Participants were asked to indicate which of the three possible causes they think it is probably due to, giving each participant a numerical score from 0-13 along the three attributional dimensions. Participants were classified as predominantly normalisers, psychologisers, or somatisers if they scored 7 or more on that attributional dimension, those who did not score at least 7 for any style were categorised as no predominance [32]. No predominance indicates a combination of mostly psychologising and somatising with some normalising attributions and 8
ACCEPTED MANUSCRIPT thus will be interpreted as a mixed-attribution style. Validation research has shown that these scores remain reasonably consistent over time, supporting the theory that they may reflect
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underlying health beliefs [30, 32].
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The 12-item General Health Questionnaire (GHQ-12) was used assess non-psychotic
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psychological distress [33]. We employed the Likert method of scoring where responses are given a weight of 0, 1, 2 or 3, with the total range of scores from 0 to 36.
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Statistical Analyses
Bivariate analysis with chi-square was used to test if there was a difference in attributional
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style by study group and deployment status. The relationship between attributional style and overall number of symptoms, as well as the GHQ-12, was assessed with a one-way
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independent Analysis of Co-Variance (ANCOVA) which controlled for the effect of military
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psychological stressors and post-hoc t-tests with Bonferroni adjustment; adjusted p-value =
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0.008. Multivariate Analysis of Co-variance (MANCOVAs) were implemented to investigate the relationship between symptom factor scores and attributional style; post-hoc ANCOVAs were used to investigate where the statistical differences existed. Chi-square tests were again
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used to investigate the relationship between persistent and incident symptoms and attributional style; with multinominal logistic regression used to investigate post-hoc differences where normalisers were used as the reference group. Missing data were no more than 10% on any variable. and listwise deletion was used for analyses. Data analysis was performed using SPSS version 21.
Results Participants in the present analyses ranged in age from 38 to 72 years old, with a mean age of 50.1 years (SD=6.45), 77.3% were in the Navy with 14.0% and 8.7% in the Air Force and
9
ACCEPTED MANUSCRIPT Army respectively. Regarding active deployments, 67.8% of all veterans had deployed between 1991 and 2012 and 17.5% were still serving in the ADF at follow-up.
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Utilising baseline data, evaluation of non-response bias indicated that those who participated
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at follow-up were older and more likely to be a supervisory rank. Comparison group
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members who participated at follow-up were also more likely to have served in the Air Force and to have scored slightly lower on general mental health and wellbeing using the Short-
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Form 12 mental component score at baseline. These observed differences may mean that the reported health results may vary slightly from what would have been observed with full
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participation, but general mental health and wellbeing was not considered likely to have had an important impact on the magnitude of differences observed in reported symptoms at
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follow-up [34].
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Bivariate analysis revealed that there was no significant difference between Gulf War
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veterans and comparison group members across their predominant symptom attributional style; the percentage of participants in each attributional style (see Table 1) did not differ by study group; 2 (3, N=1302) = 5.87, p = 0.12, Cramer’s V=0.07. Normalising was the
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principal style in both Gulf War veterans and the comparison group. There was also no significant difference in attributional style between those who had been on an active deployment between 1991 and 2012 compared with those who had not deployed; 2 (3, N=1275) = 2.01, p = 0.57, Cramer’s V=0.04. Thus, Gulf War veterans and comparison group members were combined for all subsequent analyses. Table 1. Attributional style by study group.
Attributional Style Psychologisers Somatisers
Study Group Comparison Gulf War group % % 7.4 4.8 7.4
6.4
10
ACCEPTED MANUSCRIPT 64.8
70.1
Mixed-attribution
20.5
18.6
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Normalisers
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There was, however, a difference in attribution style for military psychological stressors
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(MSEQ) 2 (9, N=1273) = 36.14, p < 0.001, Cramer’s V=0.11. Post-hoc analyses using multinominal logistic regression revealed that with increasing military psychological stressors, participants were more likely to be psychologisers and for the highest exposure
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category more likely to have a mixed-attribution than to be normalisers.
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For symptom reporting, we first investigated if the total number of symptoms reported by participants varied by attributional style. After controlling for the effects of military
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psychological stressors, an overall difference was found (F(3, 1154) = 42.067; p<0.001). The
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means and standard deviations of total number of symptoms at follow-up by attributional style are presented in Table 2. Post-hoc analyses revealed that psychologisers reported a
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higher number of symptoms than somatisers (p<0.001), normalisers (p<0.001) and mixedattribution (p<0.001). Somatisers reported a higher average number of symptoms than
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normalisers (p=0.002), but were not statistically different from mixed-attribution (p>0.05). Normalisers reported significantly fewer symptoms than mixed-attribution (p<0.001). Table 2. Attributional style and unadjusted means and standard deviations of symptoms. Factor scores
Mean total Attributional
number of Athro-
Style
GHQ
Symptoms Psychophysiological
Cognitive
neuromuscular
(0-23)
(0-20)
(0-6)
(0-63)a
(0-36)
Psychologisers
10.95 (9.15)
1.71 (2.82)
5.79 (5.09)
1.53 (1.73)
20.00 (7.96)
Somatisers
5.55 (7.13)
1.19 (2.57)
2.36 (1.00)
1.39 (1.80)
12.44 (5.87)
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ACCEPTED MANUSCRIPT Normalisers
2.85 (4.49)
0.40 (0.98)
1.14 (2.22)
0.72 (1.31)
10.84 (4.45)
5.61 (7.33)
0.94 (1.88)
2.63 (3.60)
1.14 (1.64)
14.65 (5.77)
Mixedattribution
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T
a Total possible range denoted in brackets
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The second analysis for symptom reporting used a MANCOVA to investigate the relationship between symptom factor scores and attributional style, controlling for military psychological stressors (see Table 2). There was a statistically significant difference across the three factor
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scores (psychophysiological distress, cognitive distress and arthro-neuromuscular distress) by attributional style (see Table 2); F(9, 3081) = 22.369, p<0.001; Wilk’s = 0.857. Further,
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attributional style was significantly associated with all three factor scores; psychological distress (F(3, 1268) = 21.085; p<0.001), cognitive distress (F(3, 1268) = 61.695; p<0.001)
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and arthro-neuromuscular distress (F(3, 1268) = 6.05; p<0.001). Post-hoc analyses adjusted for military psychological stressors revealed that for the
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psychophysiological distress factor, psychologisers reported statistically more symptoms than normalisers (p<0.001) and mixed-attribution (p=0.001) but were not statistically different
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from somatisers. Somatisers reported statistically more symptoms than normalisers (p<0.001) but not from mixed-attribution (p>0.05). Normalisers reported statistically fewer symptoms than mixed-attribution (p<0.001). Similarly, adjusted post-hoc analyses revealed that for the cognitive distress factor, mean symptom reporting by psychologisers was statistically higher than somatisers (p<0.001), normalisers (p<0.001) and mixed-attribution (p<0.001). Somatisers reported statistically more symptoms than normalisers (p=0.001) but were not statistically different from mixedattribution (p>0.05). Normalisers reported statistically fewer symptoms than mixedattribution (p<0.001).
12
ACCEPTED MANUSCRIPT And finally, for the arthro-neuromuscular distress factor, adjusted mean symptom reporting by psychologisers was statistically higher than normalisers (p<0.001), but not somatisers
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(p>0.05) or mixed-attribution (p>0.05). Somatisers reported statistically more symptoms than
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normalisers (p<0.001) but not from mixed-attribution (p>0.05). Normalisers reported
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statistically fewer symptoms than mixed-attribution (p<0.001).
The association between attributional style and psychological distress (GHQ-12), adjusted for
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military psychological stressors, was assessed using an ANCOVA. An overall difference in attributional style by psychological distress was found; (F(3, 1263) = 87.956; p<0.001).
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Adjusted post-hoc tests using Bonferroni revealed that psychologisers reported higher psychological distress than all other attributional styles (all p<0.001). Somatisers reported
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significantly higher psychological distress than normalisers (p>0.008) and lower than mixed-
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attribution (p>0.008). Finally, normalisers reported lower GHQ-12 scores than all other
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attributional styles (all p<0.001).
The investigation of the relationship between symptoms over time and attributional style was divided into those who reported symptoms at baseline and those who did not. For those who
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reported symptoms as moderate or severe at baseline, Tables 3 depicts symptoms that were reported as persistent (P) or remitted (R) at follow-up and the associations with attributional style. There was a statistical difference in attributional style between those who reported the symptoms as persistent rather than remitted for five of the ten symptoms. Of the statistically significant differences, the general pattern was for those in the persistent group to be more likely to be psychologisers or mixed-attribution than to be normalisers. Only for the unrefreshed sleep symptom was the persistent group also more likely to be somatisers.
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ACCEPTED MANUSCRIPT For example, looking at unrefreshed sleep, the overall chi-square statistic is significant indicating that there is a difference in attributional style between the persistence or remittance
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of symptoms. The post-hoc multinomial logistic regression showed that participants who
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reported persistent unrefreshed sleep were more likely to be psychologisers, somatisers or
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mixed-attribution than to be normalisers.
Sleep difficulties
P
9.5*
R
1.2*
P
79.2
17.4*
7.1
59.3
24.0*
5.4
79.0
14.4*
9.3*
7.8
56.1
26.8
3.7*
2.2
83.1
11.0
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R
2.8*
D
0.7*
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Fatigue
R
Headaches
P
8.0
8.9
61.1
22.0
R
5.9
5.1
69.9
19.1
P
8.2*
7.4
62.1
22.3
R
3.8*
5.2
73.9
17.1
P
6.6
7.8
63.7
21.9
R
3.8
6.0
70.7
19.5
P
9.9*
6.7
57.2
26.2*
R
1.5*
8.5
74.5
15.5*
P
7.6
9.6
59.4
23.4
R
4.7
6.5
71.0
17.8
P
7.7
9.4
60.6
22.3
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Muscle ache/pains
Low back pain
Irritable/outbursts
Stiffness in joints
Ringing in ears
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Table 3. Persistent (P) or remitted (R) symptoms from baseline to follow-up and attributional style. Attributional Style (%) ChiMixeda Symptom Square p Psychologising Somatising Normalising attribution Unrefreshed sleep P 9.7* 7.2* 58.9 24.3* 25.319 0.000
25.709
0.000
33.301
0.000
4.173
0.243
10.311
0.016
2.961
0.398
27.323
0.000
4.830
0.185
4.959
0.175
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ACCEPTED MANUSCRIPT 3.7
1.9
70.4
24.1
P
6.0
5.7
66.2
22.1
R
8.7
6.5
66.8
17.9
2.448
0.485
T
Flatulence/burping
R
a
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Ten most commonly reported symptoms at follow-up * Indicates which attributional styles were statistically different between persistent and remitted groups for each symptom at p<0.05. P=Persistent. R=Remitted. Normalising is the reference Group.
For those who did not report the ten most commonly reported symptoms at baseline (Table 4),
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attributional style across incident (I) and never reported (N) symptoms at follow-up were
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compared. There was a statistically significant difference between incident and never reported for seven of the ten symptoms. For symptoms in which there was a statistically
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significant difference, the general pattern was for those who reported incident symptoms to
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be more likely to be psychologisers or mixed-attribution than to be normalisers. For four
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symptoms, the incident group was also more likely to be somatisers than normalisers.
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Table 4. Incidence (I) and never reported (N) symptoms from baseline to follow-up and attributional style. Attributional Style (%) ChiMixeda Symptoms Square p Psychologising Somatising Normalising attribution Unrefreshed sleep I 5.3* 9.1 63.9 21.6* 20.093 0.000
Fatigue
Sleep difficulties
Muscle ache/pains
Headaches
N
1.6*
7.1
80.4
10.9*
I
5.6*
9.5*
61.2
23.7*
N
1.7*
5.5*
81.7
11.1*
I
6.5*
8.1
63.8
21.5*
N
1.4*
6.6
80.7
11.2*
I
4.3
6.0
71.2
18.4
N
4.6
6.0
71.1
18.3
I
5.5
6.0
67.5
21.0
28.059
0.000
27.095
0.000
0.032
0.999
2.644
0.450
15
ACCEPTED MANUSCRIPT
Ringing in ears
a
I
7.9
5.7
70.2
16.2
N
4.8
6.5
69.8
19.0
I
10.6*
7.2
58.9
N
2.0*
6.5
77.8
I
6.8
8.1*
N
4.7
4.5*
I
8.5*
8.5*
N
4.1*
I
6.5
N
4.6
IP
T
16.9
23.3*
3.210
0.360
34.605
0.000
10.964
0.012
12.729
0.005
10.847
0.013
13.7*
63.5
21.6
74.1
16.6
63.1
20.0
5.4*
72.5
17.9
11.6*
59.8
22.1
6.2*
71.6
17.6
D
Flatulence/burping
71.1
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Stiffness in joints
7.9
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Irritable/outbursts
4.1
MA
Low back pain
N
Ten most commonly reported symptoms at follow-up
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* Indicates which attributional styles were statistically different between incident and never reported groups for each symptom at p<0.05. I=Incident. N=Never reported. Normalising is the reference group.
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For example, looking at unrefreshed sleep, the overall chi-square statistic is significant indicating that there is a difference across attributional style for incidence of symptoms. The
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post-hoc multinomial logistic regression showed that participants who reported incident unrefreshed sleep were more likely to be psychologisers or mixed-attribution than to be normalisers. There was no difference in rates of somatising.
Discussion In summary, our study found that having deployed to the Gulf War or having ever actively deployed were not related to attributional style. However, increasing number of military psychological stressors were mildly associated with an increased likelihood of having a psychologising style or mixed-attribution style, providing novel insight into the relationship between stress and attributional style. Across all symptom measures, psychologisers reported
16
ACCEPTED MANUSCRIPT the greatest number of symptoms and normalisers the least, consistent with previous research in other populations [23, 32]. Whilst not all longitudinal symptom results were significant,
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persistence and incidence of symptoms tended to be associated with a psychologising or
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mixed-attribution styles; and for incident symptoms, some symptoms also showed an
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association with higher rates of somatising compared with normalising.
Military psychological stressors were associated with a psychologising style and the highest
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category associated with mixed-attribution. This finding indicates that exposure to military psychological stressors could influence the vigilance that individuals have towards their
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distress and symptoms. This could be of particular interest in this population as at the time of the Gulf War there was general concern regarding potential exposure to chemical warfare
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[18], which was identified as a significant stressor [31]. Australian Gulf War veterans
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reported some chemical and environmental exposures [35] and a number of military psychological stressors [31] more frequently than a military-era comparison group. Thus,
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there were substantial health concerns for Gulf War veterans. Increasing military psychological stressors were also associated with symptom reporting in Australian Gulf War
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veterans [21], and combat experience has also been associated with higher rates of vague somatic complaints in US personnel deployed to Iraq [36]. Thus, combat exposures may affect awareness of and attention to symptom experience and individuals’ inclination to report symptoms. Attributional style potentially plays a moderating role in this relationship. These findings could have implications for the general experience of stress; concern or worry may heighten awareness and detection of symptoms and result in attributing symptoms to causes other than transient. Life stressors may induce heightened concern over the experience of symptoms. Cameron et al found that during periods of ongoing life stress, individuals were less tolerant of ambiguous symptoms and more likely to interpret them as caused by illness, more serious and for them to lead to greater healthcare utilisation [37]. Although controlling 17
ACCEPTED MANUSCRIPT for military psychological stressors did not change the significance of the results in the current analyses, it may be that the relationships are moderated for some attributional styles,
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possibly psychologising and mixed-attribution.
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The increased symptom reporting by psychologisers was most notable for psychological
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symptoms, as observed on the psychophysiological factor, cognitive distress factor and psychological distress; whilst the arthro-neuromuscular factor was only significant for the
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greatest symptom reporting difference, between psychologisers and normalisers. Psychologisers may demonstrate greater vigilance or sensitivity to symptoms, particularly
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those that are psychological. However, it has also been suggested that patients with psychological disorders such as anxiety or depression, may have a lower threshold for
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physical symptoms because they interfere with the adaptive process most people with chronic
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illnesses go through which allows for some level of habituation [38]. It is possible that a history of psychological symptoms may lead to a psychologising style and an increased
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sensitivity to all symptoms, but particularly to psychological ones. This pattern may suggest that psychologisers more readily identify psychological symptoms, are more disposed to
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report their distress or that those who have experienced psychological symptoms (either in the past or presently) are more likely to be psychologisers. Although a psychologising style was not elevated in Gulf War veterans, they have consistently reported excess psychological symptoms compared with comparison groups over the past 20 years [19, 22, 34]. Thus, identifying those with a tendency to psychologise may be an important step in managing their long-term symptoms. Somatisers generally reported significantly fewer symptoms than psychologisers and significantly more symptoms than normalisers. Our findings are consistent with research that has found that somatisers report fewer psychological symptoms and are less psychologically distressed than psychologisers, but they are also more likely to attribute physical causes to 18
ACCEPTED MANUSCRIPT their symptoms than normalisers [39]. Somatisers were not significantly different from mixed-attribution on any of the symptom factors. A mixed-attribution style appeared to be
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relatively similar to somatisers in their symptom profile, which may suggest similarity
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between the styles in their increased reporting compared with the predominant normalising
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style.
Normalisers reported significantly fewest symptoms overall and on all three factors compared
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with all other attributional styles. Normalisers also reported lower psychological distress than psychologisers and mixed-attribution. Our finding that normalisers reported fewest symptoms
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across multiple measures extends previous research that found they had lower psychological distress [32]. This is an important finding as it suggests that normalisers either do not
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acknowledge symptoms or signs of distress or, alternatively, that they may be failing to report
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the symptoms that they do experience. If normalisers do not acknowledge or underreport their symptoms, their levels of both somatic and psychological distress are susceptible to being
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overlooked by healthcare professionals, and healthcare professionals may need to be alert to this tendency to ensure that they are seeking and receiving appropriate healthcare.
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The longitudinal findings in our study indicate that individuals may initially attribute symptoms to situational or environmental factors, but when the normalising attribution becomes insufficient to account for symptoms or persistence of symptoms, individuals may begin to consider other causes [39]. Thus, attributional style influences symptom experience and reporting but it should also be acknowledged that both past and present experience of symptoms may interact with attributional style as well. Further to this, our findings in regard to incident and persistent symptoms provide additional support for some influence on attributional style, indicating that the presence of a new symptom or symptoms means that a person may look to other explanations such as
19
ACCEPTED MANUSCRIPT psychologising or somatising rather than a normalising explanation. Moreover, the persistence of symptoms may also be associated with an increased likelihood to look for other
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explanations, particularly psychologising, to account for enduring symptoms. But it is
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important to bear in mind that attributional style may also be influencing the patterns of
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symptom reporting. The increased rates of psychologising and mixed-attribution for persistent and incident symptoms, tended to be in relation to sleep and irritability symptoms,
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and also highlight the decrease in normalising with these symptoms. The findings discussed above provide insight into the experience of Gulf War veterans’
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health over the past 20 years. Gulf War veterans have been found consistently to report more symptoms than military-era and non-deployed comparison groups in epidemiological studies
D
[1-7]. Their symptom history may have potentially influenced their attributional style.
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However, we found no difference in attributional style between the Gulf War veterans and the military comparison group in this study. However, attributional style was associated with
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the likelihood and patterns of reporting symptoms. All veterans who reported symptoms demonstrated alterations in their attributional style. These differences provide insight into
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patterns of symptom reporting and this may potentially have implications for how they seek treatment for symptoms. Methodological strengths of this study include a large sample size and military population, which has not, to our knowledge, been investigated previously regarding symptom attributional styles. This study is also unique in its access to longitudinal data, in addition to the use of a range of symptom measures to provide a comprehensive symptom profile of the study population. However, there are some limitations to consider. The Symptom Interpretation Questionnaire was not available at both time points and so investigation of change in attributional style over time was not possible. Symptom reporting was collected at two time points over ten years and so whilst the longitudinal data provides insight into the 20
ACCEPTED MANUSCRIPT patterns of symptom incidence and persistence, it is possible that during the ten year interval there were intermittent symptoms that were not captured by the current data and symptoms
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that may have remitted and returned. Both symptom reporting and attributional style are
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reliant on self-report data. It is possible that self-reported symptoms may have over- or under-
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estimated the symptoms experienced. It is also important to note that in relation to symptom interpretation the symptom experience as reported by individuals in particularly relevant. The participants may or may not have received a medical diagnosis for the symptoms they
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reported which may have influenced how they view their symptoms and potentially their
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attributional style. The analyses in this paper were limited to male veterans due to the low number of females in the study. The relationship between attributional style and symptom
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reporting in female veterans should be explored in future research; there is evidence to
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suggest that gender is associated with symptom experience and attribution style [23, 30, 40]. In conclusion, the Gulf War veteran population investigated appears to be similar in its
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attributional style profile to a military comparison group and to other populations that have been reported previously [32]. This suggests that they do not have a predominant attributional
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style that would explain the increased symptom reporting observed in this study population and possibly in Gulf War veteran overseas populations more generally. The pattern of those likely to report the greatest and least number of symptoms was similar in both the Gulf War veteran and comparison group: psychologisers and normalisers respectively. Attributional style is an important consideration in understanding symptom experience, and by investigating its role in reporting, our understanding of symptom patterns has been improved. Normalisers may underreport symptoms and healthcare professionals may need to be alert to this. Understanding symptoms is a complex phenomenon, it cannot be explained by a single concept; however, the current findings provide further insight into symptom reporting patterns and profiles of Australian veterans. 21
ACCEPTED MANUSCRIPT Acknowledgements Financial support for the studies on which this research was based was received from the
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Australian Department of Veterans' Affairs. The views expressed in this article are those of
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the authors and are not necessarily those of the Australian Government. Conflict of Interest
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The authors declare that there is no conflict of interest.
Kelsall HL, McKenzie DP, Sim MR, Leder K, Forbes AB, Dwyer T. Physical,
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1.
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ACCEPTED MANUSCRIPT Conflict of Interest
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The authors have no conflicts of interest to declare.
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ACCEPTED MANUSCRIPT Highlights: Normalising was the predominant attributional style in Australian veterans.
Psychologisers reported the highest and Normalisers the lowest number of symptoms
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Psychologising and mixed-attribution styles.
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Persistence and Incidence of symptoms demonstrated a relationship with
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across all symptom groups.
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