Assessment of content validity for patient-reported outcome measures used in patients with non-muscle invasive bladder cancer: a systematic review

Abstract

Non-muscle invasive bladder cancer (NMIBC) is a chronic condition requiring ongoing treatment and endoscopic examinations that are frequent and can be life-long. To ensure the comprehensive assessment of the benefits and harms of treatments for NMIBC, the impact on important and relevant patient-reported outcomes (PROs) should be determined. We systematically reviewed the NMIBC PRO literature to determine the suitability of available PRO measures (PROMs) for use in evaluating patient outcomes in NMIBC research. We searched six electronic databases, reference lists, and key authors. Two reviewers independently applied inclusion and quality criteria and extracted findings. PROM domains, item content, and content coverage and relevance were determined for identified PROMs. Content validity was assessed against an empirically derived NMIBC-specific conceptual framework that includes 11 PRO domains and 19 sub-domains. Seventeen studies assessed PROs related to NMIBC and treatment impact. From these studies, 11 PROMs were identified, including three generic, three cancer-specific, and five symptom-specific. None of the PROMs cover all PRO domains important in NMIBC as assessed against our conceptual framework. The EORTC QLQ-C30 plus the NMIBC24 module was best aligned to the conceptual model, but failed to represent six outcomes important to NMIBC patients. Currently, some outcomes important in NMIBC are inadequately covered by generic and cancer-specific measures despite similar conceptual models. This review identified gaps in the literature regarding assessment of symptoms and other PROs considered important by NMIBC patients. Careful consideration of PROM item content is required when selecting outcome measures for use in future NMIBC clinical trials to ensure that appropriate measures are used to assess outcomes that matter to patients.