This study aimed to evaluate the psychometric properties of the EORTC QLQ-NMIBC24 and to propose distribution-based minimal clinically important difference (MCID) thresholds in patients with low-grade, intermediate-risk NMIBC (LG-IR-NMIBC).
Patients with LG-IR-NMIBC from two phase 3 trials (ATLAS, n = 270; ENVISION, n = 240) completed the EORTC QLQ-C30 (ENVISION only) and QLQ-NMIBC24 questionnaires at baseline, Week 6, and Month 3. Psychometric evaluation of the QLQ-NMIBC24 in the LG-IR-NMIBC population included internal consistency, item convergence, known-groups validity, test-retest reliability and responsiveness to clinical change.
Item-item (0.40-0.96) and item-scale correlations (0.44-0.96) indicated good convergent validity across most domains. Internal consistency was acceptable for all multi-item domains (Cronbach's α 0.78-0.93) except Malaise, which showed lower reliability (Cronbach's α 0.34-0.67). Known-groups comparisons supported the instrument's ability to distinguish patients by physical function (effect sizes up to 1.63) and sex-related domains. Test-retest reliability was generally good for Urinary Symptoms and Sexual Function (ICC 0.79-0.82). Selected domains (Urinary Symptoms, Sexual Intimacy, Malaise) demonstrated responsiveness to clinical change. Distribution-based MCID estimates varied across domains (4.37-16.29), providing potential thresholds for meaningful changes in HRQoL scores. Anchor-based analyses using QLQ-C30 change scores were explored, but correlations with QLQ-NMIBC24 domains (r = -0.37 to 0.01) did not meet the minimum threshold (0.37).
The QLQ-NMIBC24 demonstrates valid, reliable, and interpretable measurement properties in patients with LG-IR-NMIBC. Although sensitivity varied across domains, the findings support its use in clinical trials and potentially routine practice. Distribution-based MCID thresholds provide guidance for interpreting meaningful HRQoL changes, though further studies using anchor-based methods are warranted.
Research and reports in urology. 2026 Mar 18*** epublish ***
Charles C Peyton, Rahul Dhanda, Tom Burke, Victoria Tsurutis, Nikky Ugwuoke, Anagha Nadkarni, Brent Burger, Veronica Lee, Michael J Louie, Angela M Stover
Department of Urology, University of Alabama at Birmingham, Birmingham, AL, USA., Urogen Pharma, Princeton, NJ, USA., Prime HCD, London, UK., Department of Health Policy and Management, University of North Carolina, Chapel Hill, NC, USA.