Application of the BDS Checklist within a patient sample from a psychosomatic outpatient clinic in Germany

Aims: Bodily Distress Syndrome (BDS) is a clinical diagnosis for functional disorders in primary care. Based on empirical research, it comprises of four determining factors: cardiopulmonary, gastrointestinal, musculoskeletal and general symptoms. These symptoms have been translated into a self-report questionnaire (the BDS checklist). We aimed at replicating the proposed four factor model of the instrument within a German psychosomatic outpatient sample. In addition, we aimed to compare the four subgroups regarding symptom prevalence, psychopathology and quality of life and investigate how well the total number of symptoms predicts physical and mental quality of life. Methods: In this cross-sectional study, N=413 participants were recruited from a psychosomatic outpatient clinic. The four factor model of the BDS Checklist was evaluated with both exploratory and confirmatory factor analysis. Chi-squared tests and analyses of covariance were used to explore the differences between symptom cluster groups. Multiple linear regression analyses were conducted to predict mental and physical quality of life. Results: Exploratory Factor Analysis identified four main factors. Confirmatory factor analyses replicated a four-factorial structure which reflects the four symptoms clusters (n=338. CFI>.951. TLI>.946. RMSEA=.098. 90% CI: .092-.104). Patients assigned to the general Cluster (n=57) showed significantly higher levels of depression and general anxiety as well as lower scores in mental quality of life compared to patients from the gastrointestinal (n=24) and musculoskeletal (n=55) clusters. Patients from the musculoskeletal cluster showed lower physical quality of life than the other groups. Age, health anxiety and number of BDS symptoms significantly predicted physical quality of life, whereas age, education and depression predicted mental quality of life. Conclusion: The BDS checklist proves to be a useful self-rating questionnaire to screen for somatic symptoms from four predominant symptom clusters. It may be used for case finding in patients with BDS in both clinical practice and in research.