The Othmer and DeSouza test for screening of somatisation disorder: is it useful in general practice?

Abstract

BACKGROUND: Somatisation disorder is an underdiagnosed and difficult problem for family physicians. Early diagnosis of somatisers is a very important factor in improving health outcomes. AIM: To assess the validity of the Othmer and DeSouza test (a seven-item questionnaire) used by general practitioners as a screening instrument for the diagnosis of somatisation disorder in primary care. DESIGN OF STUDY: A cross-sectional study of patients presenting with unexplained multiple chronic physical symptoms. SETTING: A total of 149 patients were selected for the study by 29 family physicians in the primary health care centres of the Basque Health Service in the metropolitan area of Bilbao, Bizkaia, Spain. METHODS: Participating patients completed the Othmer and DeSouza test, carried out by family physicians. Their answers were compared with the results of the Schedules for Clinical Assessment in Neuropsychiatry (SCAN). This psychiatric interview was administered blind to 144 patients by trained psychiatrists. RESULTS: A total of 19% of patients were diagnosed as having somatisation disorder by the SCAN psychiatric interview. The discriminating capacity of the Othmer and DeSouza test for all possible screening thresholds (> or = 1, > or = 2, ... > or = 6 symptoms) was very low and positive predictive values ranged between 19% and 33%. With respect to negative predictive values, even in the absence of affirmative responses to all seven questions, the pretest probability of being a non-somatiser case remained unchanged. CONCLUSION: Our data indicate that the Othmer and DeSouza test does not present clinically useful predictive values in primary care patients with suggestive symptoms of somatisation disorder.