Further investigation of the role of personality, lifestyle and arthritic severity in predicting pain

Journal

of Psyhosommc

Research, Vol. 30. No. 3, pp. 327-337,

Printed inGreatBritain.

FURTHER INVESTIGATION

0022-3999/86 $3.00+ .OO Pergamon Journals Ltd.

1986.

OF THE ROLE OF PERSONALITY,

LIFESTYLE AND ARTHRITIC SEVERITY IN PREDICTING PAIN* PETER A.

LICHTENBERG,

CLIFFORD H.

SWENSEN

and MICHAEL W. SKEHAN

(Received 11 April 1985; accepted in revisedform

17 October 1985)

Abstract-Lichtenberg et al. (1984) presented empirical research on elderly osteoarthritics that indicated that personality, specifically hypochondriasis, was the most powerful predictor of pain as compared with arthritic severity and recent life stress. This study investigated further the role of psychological predictors and arthritic severity ratings in accounting for perceived pain. The study included 70 subjects with an average age of 68 years. The results indicated that hypochondriasis was the predictor most highly related to pain. Arthritic severity ratings and other psychological predictors were also significantly related to pain. In a multiple regression analysis arthritic severity predicted 13 percent of pain variance whereas the psychological predictors accounted for an additional 41 percent of the variance. Age of the individual was related to several psychological variables. New possibilities for therapeutic intervention are discussed.

INTRODUCTION LICHTENBERG, Skehan and Swensen [l] demonstrated that hypochondriasis was a better predictor of perceived pain than was arthritic severity in a sample of 40 osteoarthritics. Hypochondriasis was significantly correlated with pain (r= 0.61; p = 0.001) while arthritic severity was not (r= 0.00; p = 0.49). This finding suggested that pain was related to psychological factors independent of the severity of the arthritic condition. The present study was designed to, in part, replicate the previous investigation and to investigate whether other important psychological factors would be significantly related to pain independent of arthritic severity. In addition to collecting information on hypochondriasis, measures of daily hassles, health behaviors, social activity and financial satisfaction were included. These predictors were chosen after a review of of the literature in gerontology, health psychology, and rheumatology revealed that they were important components of an elderly arthritic’s life. What follows is a summary of existing literature in which variables have been related to general health status. Lichtenberg et al. [l] found that major life stress was significantly associated with pain (r= 0.31; p = 0.024, n = 40). After the effects of age were controlled statistically, however, major life stress was unassociated with pain (r= 0.20; p = 0.08; n = 40). This indicated that major stress was not a good predictor of pain in the elderly arthritics studied. Recent research in health psychology has led to speculation that ‘daily hassles’, a class of environmental stressors that are stable, repetitive and chronic are more highly related to mental and physical health than is major stress 12, 31. Hassles are defined as the irritating, frustrating, distressing demands that to some degree characterize everyday transactions with the environment. These include ordinary troubles of family life, trouble with work and components of the physical environment (excessive noise, pollution). Delongis et a/. reported that daily hassles added variance to that accounted for by major life events in the prediction of physical health. Life

*This work was completed in partial fulfillment for the requirements by Peter Lichtenberg at Purdue University, Psychology Department, 327

for Doctor of Philosophy West Lafayette, Indiana,

degree U.S.A.

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events, however, did not add to the variance accounted for by daily hassles. A measure of daily hassles replaced the life events measure in this study. Rheumatologists and geropsychologists have emphasized the importance of exercise, nutrition and weight control. Range of motion exercises have been an important part of arthritis treatment. A lack of adequate physical exercise in the elderly can produce physical conditions that worsen arthritis. Among the changes due to a lack of exercise are joint weakness, joint stiffness and increased joint flexion 14, 51. Weg [6] found that the diets of most elderly were high in sugars and low in proteins. An especially important function of diet in osteoarthritics is to reduce weight-especially in cases where the weight bearing joints are involved (such as with our subjects who all were experiencing knee osteoarthritis). There has not been any previous empirical evidence investigating the relationship between health behaviors and chronic pain. Therefore measures of the physical health behaviors such as exercise and diet were included in the present investigation. Research in social gerontology has demonstrated that social activity and financial satisfaction are important variables associated with the overall health of an individual. Research on the relationship between social activity and health has found that high activity had a positive relationship with general good health and vice versa 17-91. Previous research on chronic pain with younger adults revealed that an increase in activity led to a reduction in pain ]lO]. A measure of social activity was included in this investigation in order to determine its relationship to pain. Lipman [ 1 l] reported that perceived financial satisfaction was the second highest ranked problem among elderly subjects. He linked subjects’ financial dissatisfaction to insecurity about health. Recent research revealed that financial satisfaction was only indirectly related to income level 1121. Indeed, financial satisfaction was more strongly associated with health than was income [ 131 indicating that how a subject perceives his financial situation is more highly related to health than his income level. Thus a rating of financial satisfaction was included in this study. The relationship between personality and pain in younger adults is well documented (14, 151. Early research demonstrated a relationship between personality variables on the Minnesota Multiphasic Personality Inventory (MMPI) and low back pain. Subjects were found to have ‘conversion V’ profiles (elevated scores on Hypochondriasis, Depression and Hysteria with Depression being the lowest). Our research with elderly arthritics found an equal elevation for all three scales and no evidence for the ‘conversion V’ profile. Hypochondriasis held the strongest relationship to pain (r = 0.61; p = 0.001; n = 40) and accounted for 37 percent of pain variance. All three personality scales were highly related to one another, and thus only Hypochondriasis was used in the present study. Lunghi et al. 1161 also demonstrated a positive association between personality and global pain ratings in hip osteoarthritics. The purpose of this study was to investigate the relative contributions of physiological and psychological predictors in predicting pain on older adults. The guiding research questions in the study were: (1) do psychological predictors have a significant relationship with pain independent of the subject’s arthritic severity? and (2) how much unique pain variance is accounted for by psychological predictors (independently and as a group) independent of arthritic severity?

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METHOD

Subjects This investigation included 70 subjects. The subjects were volunteer patients of a local rheumatologist. Of the 78 people asked to participate, 70 agreed to serve as subjects. Fifty-nine of the subjects were women and 11 were men. Forty-three subjects were married, 22 were widowed, 2 were divorced and 3 subjects never married. The great majority of subjects were of northern European descent. Subjects ranged from 48 to 89 yr of age. Two subjects were between 42 and 49 yr old, 20 subjects were between 50 and 59, 16 were between 60 and 69, 21 subjects were between 70 and 79, and all subjects were between 80 and 89 yr of age. The average age for subjects was 68.

Procedure All subjects were asked by their physician if they would be willing to participate in a study to learn more about pain in arthritics. Subjects were subsequently interviewed in their homes. The psychometric material consisted of the following: (a) The McGill Pain Questionnaire (MPQ) was used to measure subjects’ perceived pain [17]. The psychometric properties of the MPQ were presented earlier in Lichtenberg et al. [ 11. (b) The Hypochondriasis scale was abstracted from the Minnesota Multiphasic Personality Inventory (MMPI) [18]. Refer to Lichtenberg et al. [l] for information on the psychometric properties of the scale. In the present study adequate internal consistency reliabilities were found for hypochondriasis (0.78). (c) The Daily Hassles Scale (1981) was presented by Kanner et al. [3]. The scale consists of 117 hassles in the areas of work, health, family, friends and the environment. Subjects answered ‘yes’ or ‘no’ as to whether a certain item had been a hassle during the last month (e.g. not enough personal energy; trouble making decisions; the weather). A hassles frequency score was computed for each subject by counting up the number of hassles reported. Kanner et al. reported an adequate test-retest reliability correction (r = 0.79) and an internal consistency reliability of (r=O.95) using a sample size of 100. (d) Physical health behaviors were measured by Cicirelli’s (1982) promotive and self-destructive health behavior questionnaires 1191. These measures were previously employed by Cicirelli with a population of elderly individuals. Promotive health behaviours were addressed by a 25 item questionnaire asking subjects to rate the degree to which they engaged in these behaviors on a 5 point scale (never, rarely, occasionally, often, always). Areas covered by the scale included: (1) diet (e.g. stay within 10 pounds of ideal weight; eat some fruits and vegetables daily; consume only a small amount of salt in and on foods); (2) exercise (e.g. get some kind of exercise each day; do certain stretch exercises at least 3 times per week); and (3) general state of mind (e.g. try to do something for others regularly; avoid thinking too much about own health symptoms; find something to joke and laugh about each day). Self-destructive behaviors were assessed by an 11 item questionnaire that again had subjects rate on a 5 point scale the extent to which they engaged in these behaviors. Items included overeating, drinking too much alcohol; overexerting; staying up too late and not getting adequate sleep or rest; avoiding exercise. Internal consistency indexes of 0.80 and 0.81 were found in the present study for the promotive and self-

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destructive questionnaires respectively. These were comparable to those found by Cicirelli. (e) Measures of social activity in the elderly have typically included two separate dimensions-formal vs. informal participation [20]. Recently, Markides and Martin devised a single activity scale to measure both dimensions [8]. Formal activity included items such as church attendance, number of organizations belonged to, whereas informal activity included items such as going on a picnic, farthest distance travelled during last two weeks. The Markides and Martine scale was used in the present study. This scale, like the other activity scales used in gerontological research was experimental and did not have reliability data. The scale has been shown to be sensitive to the effects of life satisfaction in the elderly [8]. (f) Financial satisfaction was measured by a single 5 point rating: (1) extremely satisfied, (2) satisfied, (3) neither satisfied nor dissatisfied, (4) not satisfied, (5) extremely dissatisfied. This format has been used in previous gerontological research 191. (g) Chronological age of the subject was recorded. (h) A severity rating of the knee osteoarthritis was made by the patient’s physician. As in the previous Lichtenberg et al. research, this was a functional classification according to American Rheumatology Association standards for osteo and rheumatoid arthritis [22J and was based upon the degree of joint deformity, the subject’s range of motion, and radiographic evidence of degenerative joint disease. Arthritic severity was rated on a five point scale (none, slight, moderate, somewhat severe, very severe). Test-retest reliability, using a 12 month interval between ratings was 0.72 for a sample of 34 cases.

Statistical procedures The mean, standard deviation and range were computed for each variable. Correlational and multiple regression analyses were used to test the research questions. Pearson product moment correlations allow one to find the relationship between each individual predictor and the criterion, pain. The Pearson correlation is a robust test and thus this parametric technique was used to discover the relationship between and financial satisfaction (which are predictors such as arthritic severity, nonparametric data) with pain. This practice has long been used in gerontological studies 17-9, 12, 201. Pearson product moment correlations reveal only those relationships that are linear. The multivariate analysis (correlational) suited the present study better than univariate analysis because it allowed the investigator to discover whether certain relationships were no longer significant when one or more important factors are controlled. In the present study, for example, the effects the arthritic severity had on the relationship between each psychological predictor and the criterion, pain were controlled for through partial correlations. A hierarchical multiple regression analysis was computed in order to determine how much unique pain variance was accounted for by the group of psychological predictors above and beyond that accounted for by arthritic severity. This unique variance was determined through a semi-partial correlation in which the effects of arthritic severity were removed from the psychological predictors but not from the criterion, pain. Unique variance is thus the correlation squared between the part of

Further

psychological the criterion.

investigation

predictors

of personality,

lifestyle

and arthritic

that could not be estimated

severity

in predicting

for arthritic

pain

331

severity and all of

RESULTS

Reported in Table I are the mean, standard deviation and range for each variable. These data are presented here in the hopes of spurring further research that can provide normative data for elderly osteorthritics. The mean raw score for Hypochondriasis was 24.15 and was almost identical to the one found in our previous research [l]. Similarly, the mean score derived on the MPQ (30.61) and arthritic severity (3.33) were almost identical to that found in our earlier study. The mean daily hassles score was 16.61 and it was slightly lower than that found in previous research [24]. Promotive health behaviors had a mean of 97.81, destructive health behaviors a mean of 20.17 and social activity a mean score of 10.56. The mean financial satisfaction score was 2.33. TABLE I.--MEAN,

STANDARDDEVIATION

AND RANGE FOR EACHVARIABLE

Variable

Mean

Standard deviation

Range

Pain Arth Sev HS D Hassle Activ Prom Behav Des Behav Finsat Age Duratn

30.61 3.33 11.66 25.84 16.61 10.56 97.81 20.07 2.33 67.66 13.83

12.55 1.03 5.37 7.74 7.52 4.56 9.69 3.18 0.96 10.84 10.13

9-60 2-5 3-26 15-61 l-43 2-20 69-117 13-28 l-5 42-89 l-40

n = 70 Pain = McGill Pain Questionnaire Score Arth Sev = Physician’s rating of arthritic severity HS = MMPI Hypochondriasis Score D = MMPI Depression Score Hassle = Daily Hassles Score Activ = Social Activity Score Prom Behav = Promotive Health Behaviors Score Des Behav = Destructive Health Behaviors Score Finsat = Financial Satisfaction rating Age = Age of subjects Duratn = Length of time with arthritic pain.

Pearson product moment correlations were computed among several variables principally to discover which predictor held the strongest relationship with the criterion, pain (see Table II). A review of the correlational analyses indicated that hypochondriasis evidenced the strongest relationship to pain (r= 0.59; p = 0.001; n = 70) and accounted for 35 percent of pain variance. Daily hassles held the second strongest relationship to pain (r= 0.47; p = 0.001; n = 70) and accounted for 22 percent of pain variance. Pain was significantly correlated with other psychological predictors; financial satisfaction (r = 0.40; p = 0.001; n = 70), destructive behaviors (r= 0.40; p=O.OOl; n=70), promotive behaviors (r= -0.39; p=O.OOl; n=70) and social activity (r= 0.30; p = 0.006; n = 70).

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PETER A. LICHTENBERG et al.

Further

investigation

of personality,

lifestyle

and arthritic

severity

in predicting

pain

333

The Pearson correlations indicated that arthritic severity was significantly related to pain in the present investigation (r = 0.36; p = 0.001; n = 70) and accounted for 13 percent of the pain variance. This finding makes one question whether the relationship between hypochondriasis and pain, for example, is due to the effects of the physical arthritic severity. Partial correlational analyses were used to explore the change in relationship between predictor and pain when arthritic severity was statistically controlled (see Table III). TABLE

III.-PARTIAL

CORRELATIONS

OF VARIABLES WITH Partial

Zero-order

Variables Arth

Sev

HS Hassle Activ Prom

Behav

Des Behav Finsat

correlation

PAIN

correlation

controlling

arthritic

for severity

0.36; p=O.OOl 0.59: p=O.OOl 0.47* p=O.OOl - 0.30* p=O.O06 - 0.39* p=O.OOl 0.40*

0.58* p=O.OOl 0.49* p=O.OOl - 0.25* p=o.o17 - 0.38* p=O.OOl 0.42*

p=O.OOl

p=o.o01

0.40* p=O.OOl

0.41* p=O.OOl

*p < 0.05 n = 70 Arth Sev = Physician’s rating of arthritic severity HS = MMPI Hypochondriasis Score D = MMPI Depression Score Hassle = Daily Hassles Score Activ = Social Activity Score Prom Behav = Promotive Health Behaviors Score Des Behav = Destructive Health Behaviors Score Finsat = Financial Satisfaction rating.

A review of the partial correlational analyses demonstrated that the relationship between pain and hypochondriasis did not depend upon arthritic severity and decreased only very slightly after partialling out arthritic severity (r= 0.58; p = 0.001; n = 70). Similarly, the relationships between the other psychological predictors and pain remained virtually unchanged after controlling for arthritic severity by partial correlations: daily hassles (r= 0.49; p = 0.001; n = 70), activity (r= - 0.25; p = 0.017; n = 70), promotive behavior (r= 0.38; p = 0.001; n = 70), destructive behavior (r= 0.42; p = 0.001; n = 70) and financial satisfaction (r= 0.41; p = 0.001; n = 70). These results indicated that the relationship between each psychological predictor and pain was independent of the effects of arthritic severity. Psychological predictors were thus found to have significant relationships with pain that were not associated with the severity of their osteoarthritic disease. Hierarchical multiple regression analysis was used to determine the amount of unique variance accounted for by psychological predictors above and beyond that accounted for by arthritic severity. As can be seen in Table IV, arthritic severity was

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PETER A. LICHTENBERG et al.

entered by itself on the first step of the equation. This predictor accounted for 13 percent of the pain variance. The six psychological predictors were next entered into the equation, together, on the second step of the regression analysis. The psychological predictors accounted for an additional 41 percent of pain variance beyond the effects of arthritic severity. This data indicated that when combined, the psychological predictors accounted for a sizeable portion of the pain variance independent of arthritic severity. The relationship between age of the subject and the other variables was studied via correlational analyses (see Table II) in order to better understand the aging osteoarthritic. Age was unrelated to perceived pain in the present study (r= - 0.12; p-0.17; n =70). Age was also unrelated to hypochondriasis (r= 0.01; p= 0.476; n = 70). The results indicated that as people grow older, severity of arthritics increased (r= 0.36; p = 0.001; n = 70) as did promotive health behaviors (r= 0.21; p = 0.039; n = 70) and satisfaction with finances (r= - 0.40; p = 0.001; n = 70). Older individuals reported significantly fewer daily hassles (r= - 0.21; p = 0.039; n = 70), engaged in fewer destructive health behaviors (r= 0.21; p= 0.039; n = 70) and were involved in less activity (r= -0.28; p=O.O09; n = 70).

DISCUSSION

This investigation was bounded by procedural limitations. The method of subject sampling for this study was non-random. Therefore, the generalizability of these results is limited. Previous research in chronic pain has focused on the difference between those with an observable organic condition and those without one. This distinction has been part of the tradition that classified pain as ‘organic’ or ‘functional’ 1231. These researchers used univariate statistical designs and did not allow for testing the relative contributions of physical and psychological factors. The multivariate design used in this study and in our previous study has demonstrated converging evidence that psychological factors held relationships with pain that were independent of objective physical severity ratings. These findings suggest new ideas for treatment of chronic pain in the elderly. Psychological variables, specifically hypochondriasis, daily hassles, health behaviors, financial satisfaction, and social activity appeared to be potentially important factors in lowering the threshold for perceived pain. High pain scores are associated with abnormal concerns over bodily functions and vague somatic complaints. Complaints by high scores included loss of appetite, insomnia, dizziness, general listlessness, weight concerns, lack of personal energy and concern with day to day responsibilities, such as shopping or preparing meals. High pain scores were found to be overweight and often obese. Their diets consisted less of fruits, vegetables or whole grain foods and more of fatty foods or foods with high sugar content. High pain scorers rarely performed flexing exercises and often engaged in unhealthy behaviors, such as overeating, and overexerting. They often were unable to keep a positive outlook on life. High pain scorers were less involved in community activities and rarely pursued their own enjoyment through informal activities, such as travelling and enjoying recreation. Finally, high pain scorers were often dissatisfied with their present situation. These

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different psychological factors may have an interactive relationship with one another and with pain which cause the other psychological factors to become exaggerated. In contrast, low pain scores were associated with cheerfulness and a positive evaluation of lifestyle. These individuals were active in their social community, enjoyed leisure activities, were bothered by fewer daily hassles and reported better health habits. Exercise, good nutrition, weight control and a positive outlook on life were more highly reported in these individuals. Interventions with those reporting higher perceived pain could focus on aiding individuals in lowering the amount of their hypochondriacal concerns, increasing promotive health behaviors such as proper exercise, better nutrition, and decreasing destructive health behaviors, such as overexerting or overeating. Furthermore, interventions could aid individuals in lowering the amount of their daily stress and increasing their social activity. These factors may lead to a more positive attitude and improvement of their arthritic condition. Interpretation of the findings indicated that increasing age may not be related to lower reports of pain and lower hypochondriacal concerns. Age was unrelated to pain and hypochondriasis in the present study, but was significantly related to both variables in our previous study. Stress decreased with age in both studies. The relationship among these variables should be clarified through further research on pain in the elderly.

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