Prevalence, Impact, and Prognosis of Multisomatoform Disorder in Primary Care: A 5-Year Follow-up Study

BACKGROUND: To determine the prevalence, impact, and prognosis of multisomatoform disorder (MSD) over a 5-year period in a primary care population. Although somatization is prevalent in primary care, patients rarely meet Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV) criteria for somatization disorder. MSD, defined as > or = 3 bothersome, medically unexplained somatic symptoms, has been proposed as a more inclusive disorder. METHODS: A total of 500 adults presenting to a primary care clinic with a physical symptom were screened with the Primary Care Evaluation of Mental Disorders. Symptom count was assessed with the Patient Health Questionnaire 15-item somatic symptom scale. Additional baseline measures included functional status and symptom characteristics. Follow-up surveys at 2 weeks, 3 months, and 5 years assessed functioning, symptom outcome, psychiatric diagnoses, and patient satisfaction. Physician surveys assessed encounter difficulty. Utilization was obtained from our health database. RESULTS: MSD had an 8% prevalence at both baseline (n = 38/500) and at 5 years (n = 33/387). MSD persisted in 21% of those with MSD at baseline, and developed in 7% of those without MSD at baseline. MSD at baseline was a predictor of MSD at 5 years (relative risk (RR) = 2.7, 1.5-5.1). MSD patients were more likely to have comorbid mental disorders (RR = 1.5, 1.1-2.3) and be rated "difficult" by their clinicians (p = .02). They also reported worse functional status at all time points assessed (p < .001 for all), were less likely to experience symptom improvement, and had higher utilization rates (34.1 versus 23.1 visits; p = .006). CONCLUSIONS: MSD identifies a group of patients who are less likely to experience symptom improvement and have significant functional impairment and higher utilization rates.