Validation of the EORTC QLQ-BIL21 questionnaire for measuring quality of life in patients with cholangiocarcinoma and cancer of the gallbladder.

<bold>Background: </bold>There is no specific quality of life (QoL) measurement tool to quantify QoL in patients with biliary tract cancer. Quality of life measurement is an increasingly crucial trial end point and is now being incorporated into clinical practice.<bold>Methods: </bold>This International Multicentre Phase IV Validation Study assessed the QLQ-BIL21 module in 172 patients with cholangiocarcinoma and 91 patients with cancer of the gallbladder. Patients completed the questionnaire at baseline pretherapy and subsequently at 2 months. Following this, the psychometric properties of reliability, validity, scale structure and responsiveness to change were analysed.<bold>Results: </bold>Analysis of the QLQ-BIL21 scales showed appropriate reliability with Cronbach's α-coefficients >0.70 for all scales overall. Intraclass correlations exceeded 0.80 for all scales. Convergent validity >0.40 was demonstrated for all items within scales, and discriminant validity was confirmed with values <0.70 for all scales compared with each other. Scale scores changed in accordance with Karnofsky performance status and in response to clinical change.<bold>Conclusions: </bold>The QLQ-BIL21 is a valid tool for the assessment of QoL in patients with cholangiocarcinoma and cancer of the gallbladder. [ABSTRACT FROM AUTHOR]