Psychometric Analysis of the EORTC QLQ-NMIBC24 Using Data from a Global Phase 2 Randomized Trial of Erdafitinib[1] in Participants with High-Risk Non-Muscle-Invasive Bladder Cancer (NMIBC)

Author(s)

Kristi Bertzos, PhD1, Carrie Houts, PhD2, André De Champlain, PhD1, Anthony Raborn, PhD2;
1Janssen Global Services, LLC, Horsham, PA, USA, 2Vector Psychometric Group, LLC, Chapel Hill, NC, USA
OBJECTIVES: The European Organization for Research and Treatment of Cancer (EORTC) QLQ-NMIBC24 is a disease-specific, PROM designed to supplement the EORTC QLQ-C30 when evaluating health-related quality of life in adults with non-muscle-invasive bladder cancer (NMIBC). Although evidence supports the measurement properties of the QLQ-NMIBC24 (e.g., Blazeby et al., 2014), it has not been field-tested in a global population. The objective of this research was to evaluate the psychometric properties of the QLQ-NMIBC24 in a global sample of NMIBC patients.
METHODS: A randomized, Phase 2 trial enrolled 107 adults with intermediate- or high-risk NMIBC in 15 countries. Analyses of the QLQ-NMIBC24 focused on data from screening and the first three treatment cycles. Dimensionality of the QLQ-NMIBC24 items was assessed using factor analysis. Classical test theory (CTT) methods assessed internal consistency and test-retest reliability. Validity was assessed by convergent and discriminant correlational, known-groups, and sensitivity to change analyses. Meaningful score difference (MSD) thresholds were also investigated.
RESULTS: A unidimensional factor model applied to the Urinary Symptoms domain showed adequate fit (TLI = 1.00, RMSEA = 0.04) after accounting for residual correlations between two items. CTT analyses showed high internal consistency for both the Urinary Symptoms (alpha = 0.83) and Future Worries (alpha = 0.86) domains. All domains displayed acceptable test-retest reliability in a stable sample of participants, except for Malaise (ICC = .19). Different methods of validation analyses showed that the QLQ-NMBIC24 scores generally behaved as expected. Distribution-based MSD thresholds were around 10 points for all but the Male Sexual Problems domain.
CONCLUSIONS: This is the first investigation of the psychometric properties and MSD thresholds for the QLQ-NMIBC24 in a global sample. Results provide additional support for the reliability and validity of inferences that can be made using QLQ-NMIBC24 domain scores in adults living with NMIBC.
[1] Erdafitinib (JNJ-42756493) was discovered in collaboration with Astex Pharmaceuticals

Conference/Value in Health Info

2025-05, ISPOR 2025, Montréal, Quebec, CA

Value in Health, Volume 28, Issue S1

Code

CO147

Topic

Clinical Outcomes

Topic Subcategory

Clinical Outcomes Assessment

Disease

SDC: Oncology

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