Somatization, psychiatric disorder, and stress in utilization of ambulatory medical services.

Examined the prediction from Mechanic's (1972) attribution theory of somatization that somatizers who are under stress will overuse ambulatory medical services. Two hundred fourteen volunteer patients from university ambulatory care clinics completed the Diagnostic Interview Schedule and the Life Experiences Inventory. We examined somatization, psychiatric diagnoses, and life stress-and the interaction of these factors-in predicting frequency of medical visits during the preceding year, after controlling for need (active medical problems) and predisposing factors. As hypothesized, life stress interacted with somatization in predicting number of medical visits; somatizers who were under stress made more visits to the clinics than did nonsomatizers or somatizers who were not under stress. Although stress affected somatizers most, stress was predictive of increased medical utilization for all patients. These results suggest that psychological services intended to reduce overutilization of outpatient medical services might best focus on stress reduction and be most beneficial to somatizers.