A questionnaire for the assessment of Biliary Symptoms

OBJECTIVES: Gallstone disease is common and causes high health care costs, but a measure of symptomatic biliary disease for outcome studies is lacking. We aimed to develop a reproducible, valid, discriminative, disease-specific measure of biliary symptoms. METHODS: We created the self-report Biliary Symptoms Questionnaire (BSQ) by combining possible biliary symptoms with validated items for gastroesophageal reflux disease (GERD), irritable bowel syndrome (IBS), and other disorders. We developed the final version through an iterative process and assessed reproducibility by the test-retest method, concurrent validity by comparing BSQ responses with symptoms obtained by structured interview, and discriminative validity by comparing BSQ-based diagnoses of biliary symptoms, GERD, and IBS with patients' final diagnoses. A shortened version (sBSQ) also underwent reproducibility testing. RESULTS: A total of 245 outpatients (mean age, 55.2 yr; 61% female) participated. Median completion times for the BSQ and sBSQ were 36 and 10 min, respectively. For the BSQ, median K values were 0.65 (range -0.03 to 0.95) for reproducibility and 0.61 (range 0.15-0.95) for concurrent validity. Using BSQ responses, investigators distinguished IBS and GERD 79-90% of the time. For the sBSQ, the median K value for reproducibility was 0.72 (range 0.32-0.86). CONCLUSIONS: The BSQ is reproducible and has good concurrent and discriminative validity for biliary symptoms. The abridged sBSQ has good reproducibility. These instruments may be useful in future outcome studies.