A systematic review and meta-analysis of the percentage of revised diagnoses in functional somatic symptoms

• Doctors may be hesitant to diagnose functional somatic symptoms (FSS), due to the risk to miss a somatic disease.
• Diagnostic tests are often ordered in patients with a low pretest probability to rule out somatic disease or to reassure the patient.
• The overall pooled proportion for misdiagnosis in patients with FSS found at diagnostic check-up is 8.8%.
• The overall pooled proportion for misdiagnosis in patients with FSS during naturalistic follow-up is 0.5%.

BackgroundFunctional somatic symptoms (FSS) are bodily complaints of unclear etiology, which are (currently) not fully explained by well-recognized somatic pathology. Doctors are often hesitant to diagnose FSS, due to the risk to miss a somatic disease. The purpose of this study is to review available literature on the percentage of patients diagnosed with FSS reported to have an underlying somatic disease that explains their symptoms previously labeled as FSS.MethodsWe performed a systematic search of Medline, Embase and PsycINFO databases and reference lists of selected articles. We included studies published between January 1980 and July 2014 without language restrictions. Studies that measured the percentage of underlying somatic diseases after a diagnostic evaluation or naturalistic follow-up period in adult patients initially diagnosed with FSS were included. As primary outcome measure the weighted percentage of revised diagnoses was calculated using meta-analyses.ResultsSix diagnostic evaluation studies (total N = 1804 patients) and 16 follow-up studies (total N = 2440 patients) were included. The percentage of revised diagnosis in patients initially diagnosed with FSS was 8.8% (95% CI 1.0 to 22.2, p = 0.007) in diagnostic evaluation studies and 0.5% (95% CI 0.01 to 1.5, p = 0.03) in follow-up studies. Partially or possibly related diagnoses were rarely found. No specific somatic diagnosis seemed to be missed systematically.ConclusionsThe percentage of underlying somatic diseases in patients previously diagnosed with FSS is relatively small but unneglectable.