OBJECTIVES: NFBlSI-18 assesses advanced bladder cancer–associated quality of life (QOL) and symptoms with a total score and 4 subscores. The total scale (TOT) and physical disease–related symptoms subscale (DRS-P) are frequently used for clinical trials. We aimed to estimate the longitudinal psychometric properties of these scales.

METHODS: This was a prespecified interim analysis of the JAVELIN Bladder 100 trial (NCT02603432), which enrolled 700 patients with unresectable locally advanced or metastatic UC (mUC). TOT and DRS-P change scores (cycle 1 to end of treatment [EOT]) were calculated for each patient. Higher scores indicate improved QOL. With mixed-effects longitudinal models, we estimated trends on TOT and DRS-P based on progression-free survival (PFS) tertiles and best overall response (progressive disease [PD] vs stable disease [SD] vs complete response/partial response [CR/PR]). Change scores for TOT and DRS-P were each regressed on EQ-5D utility index (UI) and separately on visual analog scale (VAS) change scores to estimate meaningful group change. Responder definitions for individual change were estimated using the reliable change index.

RESULTS: Of enrolled patients, 433 (62%) and 420 (60%) had DRS-P and TOT assessments at EOT, respectively. Compared with PFS >7 months, patients with 0-2 and 3-7 months had lower score trends in TOT and DRS-P (p<0.001 for both). Compared with CR/PR, patients with PD and SD had lower score trends in TOT and DRS-P (p<0.001 for both). At the group level, a 0.10-point change in UI was associated with a 2.4-point change in TOT and a 1.2-point change in DRS-P. A 10.0-point change in VAS was associated with a 2.7-point change in TOT and 1.3-point change in DRS-P. At the individual level, responder thresholds in TOT and DRS-P were 8.3 and 5.1, respectively.

CONCLUSIONS: The NFBISI-18 TOT and DRS-P are responsive and clinically relevant for assessing QOL in mUC patients.