OBJECTIVES: To confirm the fitness-for-purpose of the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30-items (EORTC-QLQ-C30) and the Myeloma 20-item module (EORTC-QLQ-MY20) scores to demonstrate clinical benefit of Multiple Myeloma (MM) therapies.

METHODS: Psychometric and meaningful within-patient change (MWPC) analysis of EORTC-QLQ-C30 and MY20 scores were conducted using pooled, blinded data from six TOURMALINE-MM clinical trials of newly diagnosed or relapsed/refractory multiple myeloma patients (N=2,972). Analyses included classical test theory (CTT: internal consistency and test-retest reliability, construct validity and ability to detect change) and Rasch measurement theory (RMT).

RESULTS: Adequate CTT properties were demonstrated: Cronbach’s alpha reliability coefficients were >0.80; correlations between EORTC-QLQ scores with other measures (Eastern Cooperative Oncology Group—Performance Status, EQ-5D, brief pain inventory-short form worst pain item) ranged from moderate (0.40≤r<0.70) to high (r≥0.70). Effect sizes for change over 4 cycles of therapy in QLQ-C30 Physical Functioning (PF) and QLQ-MY20 Disease Symptom (DS) scores were 0.35 and -0.41 in patients categorized as improved, indicating some ability to detect improvement. RMT analysis identified a meaningful hierarchy in the items comprising QLQ-C30 PF, pain and fatigue scales and the QLQ-MY20 DS scale. Gaps were identified in coverage along the measured continuums for all scales, including imperfect coverage, floor and ceiling effects. MWPC estimates for the QLQ-MY20 DS score were -11.11 points (range: -5.56 to -16.67) for improvement and +5.56 (range: 5.56 to 11.11) for deterioration.

CONCLUSIONS: The EORTC-QLQ-C30 and EORTC-QLQ-MY20 scores showed adequate measurement properties in recent MM clinical trials based on the CTT framework. RMT analyses uncovered gaps in the coverage of the measured concepts that may limit the ability of these scales to detect subtle changes when used in clinical trials, especially among MM patients with mild severity of symptoms (e.g., pain) and impacts on quality of life.