Psychosomatics 44:6, November-December 2003 471 Somatic Symptoms in Primary Care: Etiology and Outcome ADNAN A. KHAN, M.D., AYESHA KHAN, M.D. JAROSLAW HAREZLAK, M.S., WANZHU TU,PH.D. KURT KROENKE, M.D. Although somatic complaints are the predominant reason for seeking general medical care, their etiology and prognosis remain poorly understood. In a random sample of the records of all pa- tients visiting an urban primary care clinic during four 1-month periods, 289 patients had one or more somatic symptoms, a total of 433 symptoms. Using explicit criteria, physician raters classi- fied nearly half (48%) of the symptoms as either psychiatric or idiopathic in etiology. Reviewing follow-up notes for 12 months after the index visit, raters found that at least one-fourth of the symptoms persisted. Independent predictors of symptom persistence were prior visits for the same symptom, symptom type (i.e., headache or back pain), male gender, and greater medical comor- bidity (i.e., seven or more medical diagnoses). Developing better management strategies for prev- alent, medically unexplained, persistent somatic symptoms is a health care priority. (Psychosomatics 2003; 44:471–478) Received Jan. 27, 2003; accepted Feb. 25, 2003. From the Department of Medicine and Regenstrief Institute, Indiana University School of Med- icine, Indianapolis. Address reprint requests to Dr. Kroenke, Regenstrief Institute, Indiana University Medical Center, RG-6, 1050 Wishard Blvd., Indianapolis, IN 46202; kkroenke@regenstrief.org (e-mail). Copyright  2003 The Academy of Psychosomatic Medicine. S omatic symptoms account for more than half of all out- patient encounters, or an estimated 400 million clinic visits in the United States each year. 1 Although the prognosis for the majority of common symptoms as they present in primary care is favorable in terms of mortality or serious morbidity, these symptoms do account for substantial health care utilization and costs. 2 Moreover, inadequacies in our current understanding of the etiology and epidemiology of common symptoms results in diagnostic uncertainty, inef- fective management, inability to meet patients’ expectations, and frustration among providers. 3–5 The goals of this study were to establish by record review in a primary care practice the frequency of somatic symptoms, their probable etiology, and their outcome over 12 months. In particular, we wanted to determine which factors are associated with a physical etiology of a symptom at baseline and which variables pre- dict poor symptom outcome (i.e., persistence) at follow-up. METHOD Setting The study was conducted in the primary care clinic of Wishard Hospital, a 600-bed public teaching hospital that provides care for residents of Indianapolis. The clinic is staffed by internal medicine faculty and residents and has more than 40,000 patient visits annually. Encounter infor- mation, including information on prescriptions, diagnostic tests, referrals, and diagnoses, is captured in the electronic medical record of the Regenstrief Medical Record System. Patient Sample A record of all Wishard clinic visits is stored electron- ically in the Regenstrief Medical Record System. Patient lists were generated for all primary care clinic visits during the months of March, June, September, and December, 1997. These four months were selected to minimize poten- tial seasonal bias in symptom-related visits. The visits for each month were then randomly arranged in a list by using a computerized random number table. A total of 633