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Illness behavior and chronic headache
Pain, 10 (1981) 221--229 © Elsevier/North-Holland Biomedical Press
221
ILLNESS BEHAVIOR AND CHRONIC HEADACHE STEFAN DEMJEN and DONALD BAKAL*
Department of Psychology, The University of Calgary, Calgary, Alberta T2N 1N4 (Canada) (Received 12 August 1980, accepted 5 November 1980)
SUMMARY
Illness behavior was examined in chronic headache sufferers within the context of the psychobiological or severity model of headache. A Procrustes factor analytic procedure demonstrated the appropriateness of using the existing IBQ factor structure with'chronic headache patients. The dimensions of illness behavior were not found to be related to headache diagnosis (muscle contraction, migraine, combined) nor to topographical properties of head pain which are used to infer diagnosis (forehead, bilateral, sides, unilateral). Headache patients who experienced the greatest amount of headache activity during a 21-day self-observation period were found to view their disorder in somatic as opposed to psychological terms. A comparison of patients with continuous pain and patients with episodic pain provided additional support for the somatic-psychological distinction. Patients with continuous head pain viewed their disorder in somatic terms and also scored higher cn the dimension of denial than did patients with episodic pain. Taken together these data demonstrated the utility of examining psychological components of the chronic headache syndrome from a severity perspective.
INTRODUCTION
The present study examined the significance of the concept of illness behavior [7, 8] for understanding the severity and the symptomatology associated with chronic headache. The hypothesis that illness behavior may play a direct role in the development and maintenance of chronic headache was suggested by the psychobiological or severity model of headache ~1, 2, 4]. Within the model severe headache disorders, including headaches associated
* Address correspondence to: Dr. D. Bakal.
|
222
with migrainous symptoms, reflect the outcome of two inextricable processes: (a) the individual's failure to cope with less severe headaches, accompanied by (b) an increasing involvement and automaticity of the underlying psychological and physiological processes. Several lines of evidence support the validity of conceptualizing the origins of chronic muscle contraction and migraine headache along a severity dimension. Two independent studies [4, 9] have demonstrated that occasional headache sufferers are familiar with the symptoms which are used in clinical settings to diagnose muscle contraction and migraine headache; the only difference being that occasional headache sufferers experience their symptoms less frequently. Similar observations have been made in large-scale epidemiological studies [10, 11]. In addition, a comparison of the head pain locations mud symptoms experienced by chronic muscle contraction and migraine headache patients revealed that the two groups were virtually identical in their headache characteristics [3]. It was hypothesized that percepts and cognitions associated with chronic headache represent a significant component of the psychobiological processes which maintain the disorder. Chronic headache sufferers are known to experience attack~ in the absence of physical and/or psychological antecedents which cause attacks in occasional headache sufferers [2J. Furthermore, chronic headache sufferers, especially those who experience attacks on a daily or near-daily basis, often reject the notion that psychological stress is the cause of their problem and, if anything, they feel that experienced stress is the result of their uncontrollable headaches. Consequently, it seemed necessary to shift attention from searching for psychological antecedents of headache to identifying psychological processes which mediate headache. The concept of illness behavior was ideally suited for this purpose because of its emphasis on the patient's psychological transactions with his/her physical symptoms.
METHOD
Subjects The data ~resented in this study were obtained from chronic headache patients who were referred to a headache research unit by family practitioners and neurologist.s. Each patient received a neurological examination ar.d a diagnosis before being accepted to the project. Ninety-four patients (79 females, 15 males} were used in the factor analytic portion of the study. Thirty.two patients had received a diagnosis of migraine headache based on the criteria that at least 3 of the following symptoms were present: unilateral pain, nausea, vomiting, visual disturbances, and lif.ht sensitivity. The mean age of the migraine group was 37.3 years and the r man duration of reported problem headache was 15.4 years. Forty-two of the 94 patients had received a diagnosis of muscle contraction headache. These patients complained of headaches which were typified by feelings of tightnes~ and pressure, bilateral
223 in onset, and generally localized around the forehead and back of head. The mean age of the muscle contraction group was 32.6 years and the mean duration of reported problem headache was 10.1 years. The remaining 20 patients had received a diagnosis of combined muscle contraction-migraine headache which was based on the criterion that they experienced muscle contraction and migraine symptoms either separately or in combination across their headache attacks. The mean age of the combined headache group was 37.9 years and the mean duration of reported problem headache was 15.4 years. Procedure Illness behavior was assessed with the Illness Behavior Questionnaire (IBQ) designed by Pilowsky and Spence [7]. The IBQ consists of 7 subscales which reflect different aspects of Ulness behavior: (1) general hypochondriasis, (2) conviction of disease, (3) psychological versus somatic focus of illness, (4) affective inhibition, (5) affective disturbance, (6) denial of life problems not related to pain, and (7) irritability. The original factor structure was derived using patients with a broad range of pain complaints which included head pain, back pain, chest pain, and abdominal pain. An initial objective of the present study was to determine the extent to which the factor structure of the IBQ based on headache sufferers approximated the factor structure obtained by Pilowsky and Spence [7]. The goodness-of-fit of the present data to the original Pilowsky and Spence solution was assessed using a Procrustes procedure developed by Cliff [5]. The procedure involves the development of an orthogonal transformation matrix which rotates the obtained principal components matrix to a position of maximal fit with a theoretical or a criterion matrix. A major advantage of using a Procrustes procedure is that it provides an analytic criterion in terms of congruence coefficients for assessing similarities between factor structures. Cliff's solution also contains an orthogonality restriction which reduces the probability that the congruence coefficients result from chanc,~. Topographical headache data were collected with the Headache Frequency Record [3] which is a serf-monitoring device that permits the daily recording of headache activity in terms of head pain locations, intensity, and associated symptoms. Two indices of headache severity were also derived from the self-observation data and were used in the illness behavior comparisons. Patients referred to the headache research unit were required to complete the IBQ during the initial contact session. Instructions were given to answer the it~ms with specific reference to their headache discrder. After completing the questionnaire, patients received instruction in the self-observation and monitoring of headache activity. Patients were instruc~d to use all location numl~rs necessary to describe the pain and to write them in the cell showing the time of day and pain intensity (from 0, no pain; to 5, intense, incapacitating pain). Each patient monitored his/her headache activity on a daily basis for a 3-week period. Patients were encouraged to mail each card within 24 h of completion.
224 RESULTS
Procrustes analysis Responses to the 52-item version of the IBQ were collected from 94 chronic headache patients. Three general information variables (age, sex, estimated length of disorder) used by Pilowsky and Spence were also included. Initially,product.moment correlations were generated among the 55 items and the resulting matrix was factor analyzed by a principal components method with unities in the diagonal. Eighteen factors were extracted and entered, along with the 12 factors identifiedby Pilowsky and Spence*, into the Procrustes solution.The degree of concordance between the two solutions wa3 examined only for the 7 subscales which currently comprise the IBQ inventory. The congruence coefficients obtained between the IBQ factors and the Procrustes factors were as follows: scale I (generalhypochondriasis) with Proc. 1, r = 0.65; scale 2 (disease conviction) with Proc. 2, r = 0.70; scale 3 (psychological vs. somatic perception of illness)with Proc. 3, r = 0.69; scale 4 (affectiveinhibition) with Proc. 4, r = 0.65; scale 5 (affective disturbance) with Proc. 5, r = 0.79; scale 6 (denial) with Proc. 9, r = 0.74; scale 7 (irritability)wi~h Proc. 12, r = 0.65. The congruence coefficients indicated that a moderate degree of equivalence was demonstrated between the two solutions. Table I contains the item loadings for each subscale for the two solutions. Pilowsky and Spence [9] reported IBQ subscale means for 100 patients with intractable pain. These patients failed to respond to medical treatment and they also had pain complaints which were not supported by organic pathology. Comparisons were made between their data and the data obtained in the present study. The ~neans and standard deviations for the 2-patient groups are presented in Table II. t-Test comparisons revealed significant differences on 5 of the 7 II~Q subscales. Headache sufferers scored higher on general hypochondriasis, psychological versus somatic perception of illnessand irritability.The irritabilityscale differencem a y have been due to the younger age of the headaches group (age <~ 40 scores positively on this scale). Intractable pain patients scored higher on the subscales of disease conviction and denial. Illnessbehavior and head pain characteristics Corresponding IBQ questionnaire3 and pretreatment headache frequency records were available from 75 patients. In order to determine whether illness behaviors were related to diagnosis, the patients were grouped into muscle contraction (n = 32), migraine (n = 25), and combined muscle contraction-migraine (n = 18) groups on the basisof the diagnosis contained in their medical referral.Seven separate 1-way analyses of variance using IBQ subscale scores as the dependent variable were performed. The resultant
* A complete listing of the factor loadings was graciously provided by Dr. Pilowsky.
225 TABLE I IBQ ITEM LOADINGS OBTAINED F R O M PROCRUSTES SOLUTIONS Item
Scale 1. General hypocho,~driasis 9. annoyed at being told look fine 20. hypersensitive to pain 21. afraid of illness 24. worry about health excessively 29. feel jealous about other's health 36. bothered b y silly thoughts 32. upset b y w a y others view illness 37. often think might fall i!! 38. worry about getting diseases
P!LOWSKY
AND
Pilowsky and Spence
SPENCE [7] A N D
Procrustes
0.55 0.57 0.51 0.73 0.71 0.49 0.45 0.55 0.42
0.11 0.37 047 0.6;~ 0.58 0.44 0.30 ~.41 0.26
Scale 2. Disease conviction 2. believe that something is wrong with body 3. illness interferes with life 7. believe doctor when he says nothing is wrong 35. sleeping well 41. bothered b y many different symptoms
0.56 0.49 --0.48 -0.43 0.48
0.29 -0.50 -0.33 0.37
Scale 3. Psychological vs. somatic focusing 11. illness is punishment for past wrong-doing 16. bothered b y many pains and aches 44. believe that something is wrong with mind 46. bad health is biggest life difficulty
0.62 --0.53 0.55 --0.56
0.37 --0.28 0.39 --0.35
Scale 4. Affective inhibition 22. can easily express personal feelings 36. tend to bottle up feelings when angry
---0.59 0.63
--0.57 0.43
Stole 5. Affective disturbance 12. have trouble with nerves 18. become anxious easily 47. get sad easily
0.75 0.69 0.52
0.64 0.44 0.30
Scale 6. Denial 27. have life problems 31. have financial problems 43. have family problems
0.77 0.57 0.68
0.58 0.52 0.59
--0.61 0.41 0.73 0.62
--0.46 0.59 0.44 0.21
Scale 7; Irritability 4. easy to get on with when ill 17. illness affects interpersonal .~htions 51. get angry easily age 40
C.IJ
226 TABLE II IBQ COMPARISONS FOR CHRONIC HEADACHE PATIENTS AND INTRACTABLE PAIN PATIENTS Scale Groups
1
2
3
4
5
6
7
Headache patients
Mean S.D.
2.07 1.87
2.53 1.31
1.17 0.85
0.88 0.76
1.82 1.~3
1.83 1.15
2.22 1.24
Intractable pain patients
Mean S.D.
1.35 2.02
3.28 1.68
9.44 0.81
0.88 0.81
1.43 2.21
2.38 0.94
1.38 1.37
t ratio
2.56* 3.50* 5.98* 0.00
2.29
3.67* 4.42*
* P ' ~ 0.01.
F ratios were all non-significant (P > 0.05) indicating that illness behaviors were not related to headache diagnosis. From the Headache FreqL~ncy Record, an average daily headache hour score was calculated from the 21-day self.observation period. A related score, daily headache index, was derived by multiplying the hour scores by the rated intensity of pain. Correlation coefficients were computed between the IBQ subscales and the two measures of headache severity. Scale 3 (psychological versus somatic perception of illness) correlated significantly with daily headache hours ( r = --0.25, P <~ 0.01) and with daily headache index (r = --0.30, P < 0.01). Headache patients who viewed their disorder in somatic terms experienced greater headache activity than patients who viewed their disorder in psychological terms. The patients were next divided on the basis of their hourly headache scores into a group who experienced less than 15 h of head pain per day (n = 60) and into a group who experienced 15.0 or greater hours of head pain per day (n = 15). The cut-off point for the division was used in a previous study to demarcate episodic from continuous head pain [2]. Headache patients with episodic pain scored significantly higher on scale 3 than patients with continuous pain (t = 2.21, df = 73, P < 0.03), indicating that patients with the greatest number of headache hours, especially those with continuous or near-continuous pain, tended to view their disorder in somatic rather than psychological terms. Patients with continuous head pain also scored significantly higher on the denial subscale than patients with episodic head pain (t = 2.52, df = 73, P < 0.02). Relationships between the IBQ and topogranhical properties of headache were examined next. Initially the 18 headache locations represented on the Headache Frequency Record were reduced to 5 basic head regions involved in muscle contraction and migraine head pain. Bilateral pain from the neck and back and top of head along with bilateral pain from the forehead were regions chosen to reflect the pain of muscle contraction headache. Migraine head pain was represented by unilateral pain in the region of the eye and
227 unilateral pain from the forehead. A fifth area was included for bilateral pain from the eyes and sides of the head. The degree of involvement of the various areas across headache attacks was expressed as a proportion based on the number of headache hours an area was present relative to the total number of hours of head pain experienced. For example, if a patient experienced 20 h of headache with unilateral pain present during 10 h, the respective region received a score of 0.5. Similar proportions based on days rather than hours were derived for the symptom data. If a patient reported the symptom of throbbing during 6 of 18 headache days, throbbing received a value of 0.33. There were no significant relationships (P ~ 0.05) between the proportion scores reflecting the head pain locations and the individual IBQ subscales, a finding which was consistent with the demonstrated absence of relationship between headache diagnosis and illness behaviors. Two symptom proportion scores correlated significantly (P ~ 0.01) with scale 3. Throbbing correlated ---0.25 and nausea correlated - 0 . 3 0 with scale 3 which indicated that patients who experienced these two symptoms with the greatest frequency viewed their headache disorder in somatic terms.
DISCUSSION In the original factor analytic study of the IBQ, Pilowsky and Spence [7] used patients with a heterogeneous source of pain complaints. The present study demonstrated, using a Procrustes goodness-of-fit factor analytic procedure, that similar dimensions of illness behavior were also characteristic of chronic headache sufferers. The degree of approximation to the Pilowsky and Spence solution was less than perfect since the correlations between the theoretical and obtained factors ranged from 0.69 to 0.79 and not from 0.89 to 0.99 as might be expected with an ideal approximation. However, all 7 theoretical dimensions of illness behavior and virtually all of the critical items were identified. The approximation was sufficient to warrant using the same dimensions to study the significance of illness behavior in chronic headache sufferers. Chronic headache sufferers were observed to differ from the intractable pain patients used by Pilowsky and Spence [8] in several respects. Headache sufferers scored significantly higher on general hypochondriasis and psychological versus somatic perception of illness. Headache sufferers scored significantly lower on disease conviction and denial. These differences suggest that chronic headache sufferers, compared to intractable pain patients, have a stronger psychological focus for their disorder and a greater willingness to discuss psychological problems. The IBQ differences between the chronic headache sufferers and the intractable pain patients may have been related, if not determined, by the quality of pain which was characteristic of each group. The pain experienced by the intractable pain patients, although not specified, was likely continuous in nature, whereas the pain experienced by the majority of headache sufferers
228
was episodic in nature. Headache suffererswith continuous or near-continuous pain were found to resemble the intractable pain patients along two dimensions of illness behavior. Both groups viewed their pain in somatic as opposed to psychological terms and both groups scored high on the scale measuring denial of general life problems. It is interestingto note that these characteristicsare similarto the psychological characteristicsoften attributed to patients with psychogenic headache. Although the diagnostic category israrelyused, one of itsprimary featuresispain that isdiffuseand continuous in nature [12]. This category of headache is also believed to occur in the absence of mediating physiological mechanisms. A more integrated view would be to assume that there are psychobiological processes which control continuous headache and that the condition of continuous pain reflectsthe outcome of the patient'sfailure to cope with less severe headache which at an earliertime was episodic in nature. The dimensions of illness behavior assessed by the IBQ were not found to be differentiallyrelated to the diagnostic categoriesof muscle contraction and migraine headache or to head pain locations indicativeof these diagnostic categories. It was demonstrated, however, that as headache activityincreased both muscle contraction and migraine headache patients showed a tendency to shift from a psychological to a somatic view of their disorder. The shift was -alsoaccompanied by an increase in the reported frequency of headaches associated with throbbing and nausea which are symptoms used in the diagnosis of migraine. The observation that patients with the most severe headache activity haw~ a somatic view of their condition m a y reflect not only their failure to cope with less severe attacks, but m a y also reflectthe appearance of mechanisms which have become increasingly autonomous from specificpsychological triggers. A final commentary is in order concerning the numerous studies which have attempted to characterize and/or differentiate headache patients in terms of psychopathology. A recent study by Kudrow and Sutkus [6] is illustrative of this approach. They examined MMPI characteristics of several diagnostic categories of headache sufferers, including migraineurs, muscle contraction headache sufferers, and cluster headache sufferers. Using an index of psychopathology derived from several MMPI scales, they demonstrated that psychopathology was largely absent in the migraineurs and was quite marked in muscle contraction headache sufferers. Although interesting, their finding might lead to the conclusion that psychological variables are not critical for understanding headache patients with migraine symptoms. However, it was demonstrated in the present study there are psychological components of the chronic headache syndrome and that these components contribute to the maintenance of the disorder independent of diagnosis. ACKNOWLEDGEMENT
This study was supported by a grant from the Alberta Mental Health Advisory Council.
229 REFERENCES
1 Bakal, D.A., Headache. In: R.H+ Woody (Ed.), Encyclopedia of Clinical Assessment, Vol. 1, Josscy-Bass, San Francisco, Calif., 1980, pp. 308--318. 2 Bakal, D.A., Demjen, S. and Kaganov, J.A., Cognitive behavioral treatment of chronic headache, Headache, in press. 3 Bakal, D.A. and Kaganov, J.A., Muscle contraction and migraine headache: psychophysiologic comparison, Headache, 17 (1977) 208--215. 4 Bakal, D.A. and Kaganov, J.A., Symptom characteristics of chronic and non-chronic headache sufferers, Headache, 19 (1979) 285--289. 5 Cliff, N., Orthogonal rotation to congruence, Psychometrika, 31 (1966) 33--42. 6 Kudrow, L. and Sutkus, B.J., MMPI pattern specificity in primary headache disorders, Headache, 19 (1979) 18--24. 7 Pilowsky, I. and Spence, N.D., Patterns of illness behaviour in patients with intractable pain, J. psychosom. Res., 1.9 (1975) 279--287. 8 Pilowsky, L and Spence, N.D., Pain and illness behaviour: a comparative study, J. psychosom. Res., 20 (1976) 131--134. 9 Thompson, J.K., Haber, J.D., Figueroa, J.L. and Adams, H.E., A replication and generalization of the "psychobiological" model of headache, Headache, 20 (1980) 199-203. 10 Waters, W.E., The Pontypridd headache survey, Headache, 14 (1974) 81--90. 11 Waters, W.E., The prevalence of migraine, Headache, 18 (1978) 53--54. 12 Wcatherhead, A.D., Psychogenic headache, Headache, 20 (1980) 47--54.
221
ILLNESS BEHAVIOR AND CHRONIC HEADACHE STEFAN DEMJEN and DONALD BAKAL*
Department of Psychology, The University of Calgary, Calgary, Alberta T2N 1N4 (Canada) (Received 12 August 1980, accepted 5 November 1980)
SUMMARY
Illness behavior was examined in chronic headache sufferers within the context of the psychobiological or severity model of headache. A Procrustes factor analytic procedure demonstrated the appropriateness of using the existing IBQ factor structure with'chronic headache patients. The dimensions of illness behavior were not found to be related to headache diagnosis (muscle contraction, migraine, combined) nor to topographical properties of head pain which are used to infer diagnosis (forehead, bilateral, sides, unilateral). Headache patients who experienced the greatest amount of headache activity during a 21-day self-observation period were found to view their disorder in somatic as opposed to psychological terms. A comparison of patients with continuous pain and patients with episodic pain provided additional support for the somatic-psychological distinction. Patients with continuous head pain viewed their disorder in somatic terms and also scored higher cn the dimension of denial than did patients with episodic pain. Taken together these data demonstrated the utility of examining psychological components of the chronic headache syndrome from a severity perspective.
INTRODUCTION
The present study examined the significance of the concept of illness behavior [7, 8] for understanding the severity and the symptomatology associated with chronic headache. The hypothesis that illness behavior may play a direct role in the development and maintenance of chronic headache was suggested by the psychobiological or severity model of headache ~1, 2, 4]. Within the model severe headache disorders, including headaches associated
* Address correspondence to: Dr. D. Bakal.
|
222
with migrainous symptoms, reflect the outcome of two inextricable processes: (a) the individual's failure to cope with less severe headaches, accompanied by (b) an increasing involvement and automaticity of the underlying psychological and physiological processes. Several lines of evidence support the validity of conceptualizing the origins of chronic muscle contraction and migraine headache along a severity dimension. Two independent studies [4, 9] have demonstrated that occasional headache sufferers are familiar with the symptoms which are used in clinical settings to diagnose muscle contraction and migraine headache; the only difference being that occasional headache sufferers experience their symptoms less frequently. Similar observations have been made in large-scale epidemiological studies [10, 11]. In addition, a comparison of the head pain locations mud symptoms experienced by chronic muscle contraction and migraine headache patients revealed that the two groups were virtually identical in their headache characteristics [3]. It was hypothesized that percepts and cognitions associated with chronic headache represent a significant component of the psychobiological processes which maintain the disorder. Chronic headache sufferers are known to experience attack~ in the absence of physical and/or psychological antecedents which cause attacks in occasional headache sufferers [2J. Furthermore, chronic headache sufferers, especially those who experience attacks on a daily or near-daily basis, often reject the notion that psychological stress is the cause of their problem and, if anything, they feel that experienced stress is the result of their uncontrollable headaches. Consequently, it seemed necessary to shift attention from searching for psychological antecedents of headache to identifying psychological processes which mediate headache. The concept of illness behavior was ideally suited for this purpose because of its emphasis on the patient's psychological transactions with his/her physical symptoms.
METHOD
Subjects The data ~resented in this study were obtained from chronic headache patients who were referred to a headache research unit by family practitioners and neurologist.s. Each patient received a neurological examination ar.d a diagnosis before being accepted to the project. Ninety-four patients (79 females, 15 males} were used in the factor analytic portion of the study. Thirty.two patients had received a diagnosis of migraine headache based on the criteria that at least 3 of the following symptoms were present: unilateral pain, nausea, vomiting, visual disturbances, and lif.ht sensitivity. The mean age of the migraine group was 37.3 years and the r man duration of reported problem headache was 15.4 years. Forty-two of the 94 patients had received a diagnosis of muscle contraction headache. These patients complained of headaches which were typified by feelings of tightnes~ and pressure, bilateral
223 in onset, and generally localized around the forehead and back of head. The mean age of the muscle contraction group was 32.6 years and the mean duration of reported problem headache was 10.1 years. The remaining 20 patients had received a diagnosis of combined muscle contraction-migraine headache which was based on the criterion that they experienced muscle contraction and migraine symptoms either separately or in combination across their headache attacks. The mean age of the combined headache group was 37.9 years and the mean duration of reported problem headache was 15.4 years. Procedure Illness behavior was assessed with the Illness Behavior Questionnaire (IBQ) designed by Pilowsky and Spence [7]. The IBQ consists of 7 subscales which reflect different aspects of Ulness behavior: (1) general hypochondriasis, (2) conviction of disease, (3) psychological versus somatic focus of illness, (4) affective inhibition, (5) affective disturbance, (6) denial of life problems not related to pain, and (7) irritability. The original factor structure was derived using patients with a broad range of pain complaints which included head pain, back pain, chest pain, and abdominal pain. An initial objective of the present study was to determine the extent to which the factor structure of the IBQ based on headache sufferers approximated the factor structure obtained by Pilowsky and Spence [7]. The goodness-of-fit of the present data to the original Pilowsky and Spence solution was assessed using a Procrustes procedure developed by Cliff [5]. The procedure involves the development of an orthogonal transformation matrix which rotates the obtained principal components matrix to a position of maximal fit with a theoretical or a criterion matrix. A major advantage of using a Procrustes procedure is that it provides an analytic criterion in terms of congruence coefficients for assessing similarities between factor structures. Cliff's solution also contains an orthogonality restriction which reduces the probability that the congruence coefficients result from chanc,~. Topographical headache data were collected with the Headache Frequency Record [3] which is a serf-monitoring device that permits the daily recording of headache activity in terms of head pain locations, intensity, and associated symptoms. Two indices of headache severity were also derived from the self-observation data and were used in the illness behavior comparisons. Patients referred to the headache research unit were required to complete the IBQ during the initial contact session. Instructions were given to answer the it~ms with specific reference to their headache discrder. After completing the questionnaire, patients received instruction in the self-observation and monitoring of headache activity. Patients were instruc~d to use all location numl~rs necessary to describe the pain and to write them in the cell showing the time of day and pain intensity (from 0, no pain; to 5, intense, incapacitating pain). Each patient monitored his/her headache activity on a daily basis for a 3-week period. Patients were encouraged to mail each card within 24 h of completion.
224 RESULTS
Procrustes analysis Responses to the 52-item version of the IBQ were collected from 94 chronic headache patients. Three general information variables (age, sex, estimated length of disorder) used by Pilowsky and Spence were also included. Initially,product.moment correlations were generated among the 55 items and the resulting matrix was factor analyzed by a principal components method with unities in the diagonal. Eighteen factors were extracted and entered, along with the 12 factors identifiedby Pilowsky and Spence*, into the Procrustes solution.The degree of concordance between the two solutions wa3 examined only for the 7 subscales which currently comprise the IBQ inventory. The congruence coefficients obtained between the IBQ factors and the Procrustes factors were as follows: scale I (generalhypochondriasis) with Proc. 1, r = 0.65; scale 2 (disease conviction) with Proc. 2, r = 0.70; scale 3 (psychological vs. somatic perception of illness)with Proc. 3, r = 0.69; scale 4 (affectiveinhibition) with Proc. 4, r = 0.65; scale 5 (affective disturbance) with Proc. 5, r = 0.79; scale 6 (denial) with Proc. 9, r = 0.74; scale 7 (irritability)wi~h Proc. 12, r = 0.65. The congruence coefficients indicated that a moderate degree of equivalence was demonstrated between the two solutions. Table I contains the item loadings for each subscale for the two solutions. Pilowsky and Spence [9] reported IBQ subscale means for 100 patients with intractable pain. These patients failed to respond to medical treatment and they also had pain complaints which were not supported by organic pathology. Comparisons were made between their data and the data obtained in the present study. The ~neans and standard deviations for the 2-patient groups are presented in Table II. t-Test comparisons revealed significant differences on 5 of the 7 II~Q subscales. Headache sufferers scored higher on general hypochondriasis, psychological versus somatic perception of illnessand irritability.The irritabilityscale differencem a y have been due to the younger age of the headaches group (age <~ 40 scores positively on this scale). Intractable pain patients scored higher on the subscales of disease conviction and denial. Illnessbehavior and head pain characteristics Corresponding IBQ questionnaire3 and pretreatment headache frequency records were available from 75 patients. In order to determine whether illness behaviors were related to diagnosis, the patients were grouped into muscle contraction (n = 32), migraine (n = 25), and combined muscle contraction-migraine (n = 18) groups on the basisof the diagnosis contained in their medical referral.Seven separate 1-way analyses of variance using IBQ subscale scores as the dependent variable were performed. The resultant
* A complete listing of the factor loadings was graciously provided by Dr. Pilowsky.
225 TABLE I IBQ ITEM LOADINGS OBTAINED F R O M PROCRUSTES SOLUTIONS Item
Scale 1. General hypocho,~driasis 9. annoyed at being told look fine 20. hypersensitive to pain 21. afraid of illness 24. worry about health excessively 29. feel jealous about other's health 36. bothered b y silly thoughts 32. upset b y w a y others view illness 37. often think might fall i!! 38. worry about getting diseases
P!LOWSKY
AND
Pilowsky and Spence
SPENCE [7] A N D
Procrustes
0.55 0.57 0.51 0.73 0.71 0.49 0.45 0.55 0.42
0.11 0.37 047 0.6;~ 0.58 0.44 0.30 ~.41 0.26
Scale 2. Disease conviction 2. believe that something is wrong with body 3. illness interferes with life 7. believe doctor when he says nothing is wrong 35. sleeping well 41. bothered b y many different symptoms
0.56 0.49 --0.48 -0.43 0.48
0.29 -0.50 -0.33 0.37
Scale 3. Psychological vs. somatic focusing 11. illness is punishment for past wrong-doing 16. bothered b y many pains and aches 44. believe that something is wrong with mind 46. bad health is biggest life difficulty
0.62 --0.53 0.55 --0.56
0.37 --0.28 0.39 --0.35
Scale 4. Affective inhibition 22. can easily express personal feelings 36. tend to bottle up feelings when angry
---0.59 0.63
--0.57 0.43
Stole 5. Affective disturbance 12. have trouble with nerves 18. become anxious easily 47. get sad easily
0.75 0.69 0.52
0.64 0.44 0.30
Scale 6. Denial 27. have life problems 31. have financial problems 43. have family problems
0.77 0.57 0.68
0.58 0.52 0.59
--0.61 0.41 0.73 0.62
--0.46 0.59 0.44 0.21
Scale 7; Irritability 4. easy to get on with when ill 17. illness affects interpersonal .~htions 51. get angry easily age 40
C.IJ
226 TABLE II IBQ COMPARISONS FOR CHRONIC HEADACHE PATIENTS AND INTRACTABLE PAIN PATIENTS Scale Groups
1
2
3
4
5
6
7
Headache patients
Mean S.D.
2.07 1.87
2.53 1.31
1.17 0.85
0.88 0.76
1.82 1.~3
1.83 1.15
2.22 1.24
Intractable pain patients
Mean S.D.
1.35 2.02
3.28 1.68
9.44 0.81
0.88 0.81
1.43 2.21
2.38 0.94
1.38 1.37
t ratio
2.56* 3.50* 5.98* 0.00
2.29
3.67* 4.42*
* P ' ~ 0.01.
F ratios were all non-significant (P > 0.05) indicating that illness behaviors were not related to headache diagnosis. From the Headache FreqL~ncy Record, an average daily headache hour score was calculated from the 21-day self.observation period. A related score, daily headache index, was derived by multiplying the hour scores by the rated intensity of pain. Correlation coefficients were computed between the IBQ subscales and the two measures of headache severity. Scale 3 (psychological versus somatic perception of illness) correlated significantly with daily headache hours ( r = --0.25, P <~ 0.01) and with daily headache index (r = --0.30, P < 0.01). Headache patients who viewed their disorder in somatic terms experienced greater headache activity than patients who viewed their disorder in psychological terms. The patients were next divided on the basis of their hourly headache scores into a group who experienced less than 15 h of head pain per day (n = 60) and into a group who experienced 15.0 or greater hours of head pain per day (n = 15). The cut-off point for the division was used in a previous study to demarcate episodic from continuous head pain [2]. Headache patients with episodic pain scored significantly higher on scale 3 than patients with continuous pain (t = 2.21, df = 73, P < 0.03), indicating that patients with the greatest number of headache hours, especially those with continuous or near-continuous pain, tended to view their disorder in somatic rather than psychological terms. Patients with continuous head pain also scored significantly higher on the denial subscale than patients with episodic head pain (t = 2.52, df = 73, P < 0.02). Relationships between the IBQ and topogranhical properties of headache were examined next. Initially the 18 headache locations represented on the Headache Frequency Record were reduced to 5 basic head regions involved in muscle contraction and migraine head pain. Bilateral pain from the neck and back and top of head along with bilateral pain from the forehead were regions chosen to reflect the pain of muscle contraction headache. Migraine head pain was represented by unilateral pain in the region of the eye and
227 unilateral pain from the forehead. A fifth area was included for bilateral pain from the eyes and sides of the head. The degree of involvement of the various areas across headache attacks was expressed as a proportion based on the number of headache hours an area was present relative to the total number of hours of head pain experienced. For example, if a patient experienced 20 h of headache with unilateral pain present during 10 h, the respective region received a score of 0.5. Similar proportions based on days rather than hours were derived for the symptom data. If a patient reported the symptom of throbbing during 6 of 18 headache days, throbbing received a value of 0.33. There were no significant relationships (P ~ 0.05) between the proportion scores reflecting the head pain locations and the individual IBQ subscales, a finding which was consistent with the demonstrated absence of relationship between headache diagnosis and illness behaviors. Two symptom proportion scores correlated significantly (P ~ 0.01) with scale 3. Throbbing correlated ---0.25 and nausea correlated - 0 . 3 0 with scale 3 which indicated that patients who experienced these two symptoms with the greatest frequency viewed their headache disorder in somatic terms.
DISCUSSION In the original factor analytic study of the IBQ, Pilowsky and Spence [7] used patients with a heterogeneous source of pain complaints. The present study demonstrated, using a Procrustes goodness-of-fit factor analytic procedure, that similar dimensions of illness behavior were also characteristic of chronic headache sufferers. The degree of approximation to the Pilowsky and Spence solution was less than perfect since the correlations between the theoretical and obtained factors ranged from 0.69 to 0.79 and not from 0.89 to 0.99 as might be expected with an ideal approximation. However, all 7 theoretical dimensions of illness behavior and virtually all of the critical items were identified. The approximation was sufficient to warrant using the same dimensions to study the significance of illness behavior in chronic headache sufferers. Chronic headache sufferers were observed to differ from the intractable pain patients used by Pilowsky and Spence [8] in several respects. Headache sufferers scored significantly higher on general hypochondriasis and psychological versus somatic perception of illness. Headache sufferers scored significantly lower on disease conviction and denial. These differences suggest that chronic headache sufferers, compared to intractable pain patients, have a stronger psychological focus for their disorder and a greater willingness to discuss psychological problems. The IBQ differences between the chronic headache sufferers and the intractable pain patients may have been related, if not determined, by the quality of pain which was characteristic of each group. The pain experienced by the intractable pain patients, although not specified, was likely continuous in nature, whereas the pain experienced by the majority of headache sufferers
228
was episodic in nature. Headache suffererswith continuous or near-continuous pain were found to resemble the intractable pain patients along two dimensions of illness behavior. Both groups viewed their pain in somatic as opposed to psychological terms and both groups scored high on the scale measuring denial of general life problems. It is interestingto note that these characteristicsare similarto the psychological characteristicsoften attributed to patients with psychogenic headache. Although the diagnostic category israrelyused, one of itsprimary featuresispain that isdiffuseand continuous in nature [12]. This category of headache is also believed to occur in the absence of mediating physiological mechanisms. A more integrated view would be to assume that there are psychobiological processes which control continuous headache and that the condition of continuous pain reflectsthe outcome of the patient'sfailure to cope with less severe headache which at an earliertime was episodic in nature. The dimensions of illness behavior assessed by the IBQ were not found to be differentiallyrelated to the diagnostic categoriesof muscle contraction and migraine headache or to head pain locations indicativeof these diagnostic categories. It was demonstrated, however, that as headache activityincreased both muscle contraction and migraine headache patients showed a tendency to shift from a psychological to a somatic view of their disorder. The shift was -alsoaccompanied by an increase in the reported frequency of headaches associated with throbbing and nausea which are symptoms used in the diagnosis of migraine. The observation that patients with the most severe headache activity haw~ a somatic view of their condition m a y reflect not only their failure to cope with less severe attacks, but m a y also reflectthe appearance of mechanisms which have become increasingly autonomous from specificpsychological triggers. A final commentary is in order concerning the numerous studies which have attempted to characterize and/or differentiate headache patients in terms of psychopathology. A recent study by Kudrow and Sutkus [6] is illustrative of this approach. They examined MMPI characteristics of several diagnostic categories of headache sufferers, including migraineurs, muscle contraction headache sufferers, and cluster headache sufferers. Using an index of psychopathology derived from several MMPI scales, they demonstrated that psychopathology was largely absent in the migraineurs and was quite marked in muscle contraction headache sufferers. Although interesting, their finding might lead to the conclusion that psychological variables are not critical for understanding headache patients with migraine symptoms. However, it was demonstrated in the present study there are psychological components of the chronic headache syndrome and that these components contribute to the maintenance of the disorder independent of diagnosis. ACKNOWLEDGEMENT
This study was supported by a grant from the Alberta Mental Health Advisory Council.
229 REFERENCES
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