Features of somatization predict the onset of chronic widespread pain - Results of a large population-based study

Objective. Chronic widespread pain, the clinical hallmark of the fibromyalg ia syndrome, is associated with other physical and psychological symptoms b oth in patients studied in a clinical setting and in those identified in th e community. The present study was undertaken to examine the hypothesis tha t psychological and physical indicators of the process of somatization pred ict the development of new chronic widespread pain. Methods. In this population-based prospective study, 1,658 adults ages 18-6 5 years completed a detailed pain questionnaire, which included a pain draw ing. They also completed the following psychosocial instruments: General He alth Questionnaire, Somatic Symptom Checklist, Fatigue Questionnaire, and I llness Attitude Scales. Individuals were followed up at 12 months, at which time 1,480 (93% of subjects still living at their baseline address) provid ed data on pain status, using the same instruments. Results. At baseline, 825 subjects were classified as pain free and 833 as having pain not satisfying criteria for chronic widespread pain. Of those, 18 (2%) and 63 (8%), respectively, were classified as having chronic widesp read pain at followup. After adjustment for age and sex, there were strong relationships between baseline test scores and subsequent risk of chronic w idespread pain (odds ratio for the Somatic Symptom Checklist 3.3; odds rati o for the Illness Behavior subscale of the Illness Attitude Scales 9.0). Al l 95% confidence intervals excluded unity. These associations were independ ent of baseline pain status. Conclusion. Subjects who are free of chronic widespread pain are at increas ed future risk of its development if they display other aspects of the proc ess of somatization. Data from this population-based prospective study lend powerful support to the hypothesis that chronic widespread pain can be one manifestation of the somatization of distress.