Validation of a patient‐reported outcomes symptom measure for patients with nontransfusion‐dependent thalassemia (NTDT‐PRO(©))

This study demonstrates the quantitative characteristics of the first patient‐reported outcome (PRO) tool developed for patients with nontransfusion‐dependent β‐thalassemia (NTDT), the NTDT‐PRO(©). A multicenter validation study was performed over 24 weeks, involving 48 patients from Italy, Lebanon, Greece, and Thailand. Most patients were female (68.8%), with a median age of 34.5 years (range, 18‐52); 66.7% were diagnosed with β‐thalassemia intermedia, and median time since diagnosis was 22 years (range, 0‐43). The NTDT‐PRO comprises 6 items across 2 domains (Tiredness/Weakness and Shortness of Breath [SoB]), and was valid and reliable, with good consistency. At baseline, most patients reported symptoms as present via the NTDT‐PRO, and were highly compliant, ≥90% completing the NTDT‐PRO tool. In a pairwise correlation analysis, all items were positively correlated. Correlations between NTDT‐PRO and existing tools—36‐Item Short Form Health Survey version 2 (SF‐36v2) and Functional Assessment of Cancer Therapy‐Anemia (FACT‐An)—were assessed at weeks 1, 3, and 12; robust correlations were seen between SoB and SF‐36v2‐Vitality (r (s) = −0.53), and between SoB and Fact‐An‐Fatigue Experience (r (s) = −0.66) at week 1. Internal consistency was high for both Tiredness/Weakness (Cronbach alpha, 0.91) and SoB (Spearman‐Brown coefficient, 0.78); intraclass correlation coefficients were high (Tiredness/Weakness, 0.88 and 0.97; SoB, 0.92 and 0.98), demonstrating stability. Further studies are required to fully support the validity of this tool, this study demonstrated the usefulness of the NTDT‐PRO in the clinical setting and for longitudinal clinical research, particularly in trials where patient health‐related quality of life is expected to change.