Development and validation of a patient-reported outcome measure to assess symptom burden after chimeric antigen receptor T-cell therapy

This cross-sectional study aimed to develop and validate a patient-reported outcomes (PROs) assessment tool to assess symptom burden and daily functioning in patients after chimeric antigen receptor (CAR) T-cell therapy, the MD Anderson Symptom Inventory (MDASI-CAR). The items were generated based on literature review, content elicitation interviews with patients, and clinician's review. The patients completed the MDASI core and module, single-item quality-of-life (QoL) measure and Patient-Reported Outcomes Measurement Information System-29 (PROMIS-29). The psychometric validation analysis was based on the acceptability after item reduction process. The final 10 MDASI-CAR module items included tremors, fever/chills, headache, balance, dizziness, attention, difficulty speaking, coughing, sexual dysfunction, and diarrhoea with high internal consistency (Cronbach's alpha: MDASI Core, 0.865; MDASI Interference, 0.915; CAR-T module, 0.746). The MDASI-CAR has excellent known-group validity that was demonstrated by differentiate patients based on patient's performance status (Cohen's d for MDASI core = -1.008, interference = -0.771, module = -0.835). Criterion validity was demonstrated by the significant correlations between the MDASI-CAR composite score, the single QoL item and the relevant domains on PROMIS-29 (all p < 0.05). This study established the MDASI-CAR module as a reliable and valid PRO tool for monitoring symptom burden after CAR T-cell therapy in patients with haematological malignancies. The findings need to be validated with a longitudinal design.