PT  - JOURNAL ARTICLE
AU  - Taher, Ali T
AU  - Musallam, Khaled M
AU  - Viprakasit, Vip
AU  - Kattamis, Antonis
AU  - Lord-Bessen, Jennifer
AU  - Yucel, Aylin
AU  - Guo, Shien
AU  - Pelligra, Christopher
AU  - Shields, Alan L
AU  - Shetty, Jeevan K
AU  - Miteva, Dimana
AU  - Bueno, Luciana Moro
AU  - Cappellini, Maria Domenica
TI  - Psychometric evaluation of the NTDT-PRO questionnaire for assessing symptoms in patients with non-transfusion-dependent beta-thalassaemia
AID  - 10.1136/bmjopen-2022-066683
DP  - 2023 Mar 01
TA  - BMJ Open
PG  - e066683
VI  - 13
IP  - 3
4099  - http://bmjopen.bmj.com/content/13/3/e066683.short
4100  - http://bmjopen.bmj.com/content/13/3/e066683.full
SO  - BMJ Open2023 Mar 01; 13
AB  - Objectives The non-transfusion-dependent beta-thalassaemia-patient-reported outcome (NTDT-PRO) questionnaire was developed for assessing anaemia-related tiredness/weakness (T/W) and shortness of breath (SoB) among patients with NTDT. Psychometric properties were evaluated using blinded data from the BEYOND trial (NCT03342404).Design Analysis of a phase 2, double-blind, randomised, placebo-controlled trial.Setting USA, Greece, Italy, Lebanon, Thailand and the UK.Participants Adults (≥18 years) (N=145) with NTDT who had not received a red blood cell transfusion within 8 weeks prior to randomisation, with mean baseline haemoglobin level ≤100 g/L.Measures NTDT-PRO daily scores from baseline until week 24, and scores at select time points for the 36-Item Short Form Health Survey version 2 (SF-36v2), Functional Assessment of Chronic Illness Therapy–Fatigue (FACIT-F) and Patient Global Impression of Severity (PGI-S).Results Cronbach’s alpha at weeks 13–24 was 0.95 and 0.84 for the T/W and SoB domains, respectively, indicating acceptable internal consistency reliability. Among participants self-reporting no change in thalassaemia symptoms via the PGI-S between baseline and week 1, intraclass correlation coefficients were 0.94 and 0.92 for the T/W and SoB domains, respectively, indicating excellent test–retest reliability. In a known-groups validity analysis, least-squares mean T/W and SoB scores at weeks 13–24 were worse in participants with worse scores for the FACIT-F Fatigue Subscale (FS), SF-36v2 vitality or PGI-S. Indicating responsiveness, changes in T/W and SoB domain scores were moderately correlated with changes in haemoglobin levels, and strongly correlated with changes in SF-36v2 vitality, FACIT-F FS, select FACIT-F items and the PGI-S. Improvements in least-squares mean T/W and SoB scores were higher in participants with greater improvements in scores on other PROs measuring similar constructs.Conclusions The NTDT-PRO demonstrated adequate psychometric properties to assess anaemia-related symptoms in adults with NTDT and can be used to evaluate treatment efficacy in clinical trials.Data are available upon reasonable request. All data relevant to the study are included in the article or uploaded as supplemental information.