Somatic symptom index (SSI): a new and abridged somatization construct. Prevalence and epidemiological correlates in two large community samples.

An abridged somatization construct (the Somatic Symptom Index) derived from the Diagnostic Interview Schedule's somatization disorder items was tested on community epidemiological samples to examine its prevalence, risk factors, and predictive value. The construct had a high prevalence (range, 4.4% to 20% compared with .03% to 0.7% for the full DSM-III somatization disorder diagnosis), was related to low socioeconomic status, female gender, older chronological age, and Hispanic ethnic background. The presence of this construct determined preferential use of medical services and predicted high indices of disability. The Somatic Symptom Index may have practical utility for clinical and community studies of somatoform phenomena.