Cluster analyses of pain patients' responses to the SCL-90R.

This study sought to identify distinct subgroups of chronic pain patients based on responses to the Symptom Checklist 90-revised (SCL-90R), a measure of psychological distress. Two scoring methods were used: the standard scoring that accompanies the manual, and a scoring method based upon factor scores obtained in an earlier study using low back pain patients. Two separate cluster analyses assigned patients into 2 groups: one based on standard scores and one based on factor scores. Results of this study support the hypothesis that distinct and replicable subgroups of chronic pain patients can be identified using the SCL-90R. Depending upon group membership, patients significantly differed on measures of qualitative pain and quantitative pain report, depressive symptoms, medication usage, and pain-related behaviors. This study supports the use of SCL-90R factor scoring with pain patients as greater differentiation between clusters was found for pain report and pain-related behavior when this method was used. Guidelines for clinical application of SCL-90R cluster groups is provided.

A psychosocial and behavioral comparison of reflex sympathetic dystrophy, low back pain, and headache patients.

Based primarily on anecdotal evidence, patients with reflex sympathetic dystrophy (RSD) have often been suspected of having a high degree of psychosocial disturbance prior to the onset of symptoms as well as in reaction to the disorder. In the present study, patients presenting to a pain center with RSD were compared to patients with low back (LBP) and headache pain (HAP) on a variety of self-reported demographic, behavioral, pain, and mood measures. Typical of most patients experiencing chronic pain, all three groups demonstrated elevations indicative of pain, emotional distress, and behavioral disturbance. However, although the RSD patient group reported the highest level of pain intensity, the most employment disruption, and contained the highest percentage of patients receiving financial compensation, this same group paradoxically reported less emotional distress on the Symptom Checklist-90R than did LBP and HAP patients. This paradox may be due to the lesser chronicity of the RSD patients as well as to their apparently experiencing a more sympathetic response from doctors, employers, and insurance carriers than their LBP and HAP counterparts. On balance, the present data do not support the hypothesis the RSD patients, relative to other pain patients, are uniquely disturbed in psychosocial functioning.

Pain complaint and the weather: weather sensitivity and symptom complaints in chronic pain patients.

Chronic pain patients frequently report that weather conditions affect their pain; however, no standardized measures of weather sensitivity have been developed. We describe the development and use of the Weather and Pain Questionnaire (WPQ) which assess patient sensitivity to meteorologic variables defined by the National Weather Service (e.g., temperature, precipitation). Seventy chronic pain patients (59% females) with an average age of 43 years completed the WPQ. The instrument was revised using factor analysis to produce a Weather Sensitivity Index (WSI) (48% of variance) with high internal consistency (0.93) and test-retest reliability (r = 0.89). Reporting patterns suggested that patients could reliably identify which meteorologic variables influenced their pain but could not reliably determine which physical symptoms were consistently affected. The most frequently reported meteorologic variables which affect pain complaint were temperature (87%) and humidity (77%). The most frequently reported physical complaints associated with the weather were joint and muscle aches (82% and 79%, respectively). Patients labeled as being 'weather sensitive', defined by greater than median scores on the WPQ, reported significantly greater pain intensity, greater chronicity of pain problems, and more difficulties sleeping than patients with low scores on the WPQ. No differences in gender, education level, disability status, or global psychological distress were found. Results are discussed with respect to physiological and psychological mediating variables.

Health locus of control, gender differences and adjustment to persistent pain.

Locus of control (LOC) beliefs, long thought important in adjustment to persistent pain, were studied among 160 subjects (67 males and 93 females) referred to a comprehensive pain rehabilitation program. The subscale structure of the Multidimensional Health Locus of Control (MHLC) was factorially replicated in our sample. Three unique MHLC profile clusters were identified for both males and females. Among men, cluster assignment was related to age only. The younger male patients reported a stronger internal attributional style. Older male patients relied more heavily on both chance and powerful other factors. Among women, cluster assignment was related to the use of coping strategies. For example, patients with high internal scores only, reflecting a strong internal orientation towards self-management of health care needs, were more likely to utilize Information-Seeking, Self-Blame, and Threat Minimization coping strategies than patients with high scores on both the Internal and Powerful Other factors. It appears that the presence of both Internal and Powerful Other health attributional styles is associated with less frequent use of cognitive self-management techniques. In understanding the LOC scores it is important to rely on pattern analysis of scores. Implications for clinical treatment are discussed.