OBJECTIVES: To evaluate psychometric properties of the patient-reported Quality of Life-Bronchiectasis-Respiratory Domain (QOL-B-RD) in adults with newly diagnosed or recurrent MAC lung disease (MAC-LD) who had not initiated antibiotics for their current MAC infection.

METHODS: Data analyzed were from ARISE (NCT04677543; baseline and longitudinal data) and ENCORE (NCT04677569; baseline data) double-blind, randomized, active-control trials assessing the impact of once-daily amikacin liposome inhalation suspension (ALIS) treatment on respiratory symptoms in MAC-LD. In ARISE, treatment was administered for 6 months, followed by 1 month off treatment. Modern psychometric methods (MPMs) were employed to test item properties and establish an empirical scoring algorithm. Classical measurement properties evaluated included reliability (internal consistency, test-retest reliability [TRTR]), convergent and known-groups validity, and responsiveness (meaningful within-patient change [MWPC]). MPMs, internal consistency (Cronbach’s alpha), convergent validity (Pearson correlations), and known-groups validity were analyzed at baseline (N=229 patients [ARISE: n=97, ENCORE: n=132]). Convergent validity was assessed between the QOL-B-RD and the EXACT tool, E-RS scale, SGRQ, and FACIT-Fatigue. Known-groups validity compared QOL-B-RD scores across PGI-S Respiratory severity groups. TRTR was estimated via intraclass correlation coefficient (ICC[A,1]) among patients reporting no change in PGI-S Respiratory between screening and baseline. Anchor-based MWPC thresholds were estimated between baseline and end of study (month 7) and supplemented with empirical cumulative distribution curves (N=99 ARISE patients).

RESULTS: MPMs supported relevance of all items and a sum score for the QOL-B-RD. The QOL-B-RD demonstrated strong internal consistency (Cronbach’s alpha: 0.79, 95% CI: 0.75–0.83), TRTR (ICC[A,1]: 0.69), and convergent validity (EXACT: -0.70, E-RS: -0.70, SGRQ: -0.71, FACIT-Fatigue: 0.49). Known-groups validity was demonstrated across PGI-S Respiratory groups. MWPC analyses supported a 14.81-point change from baseline as a proposed clinically meaningful within-patient improvement.

CONCLUSIONS: The findings demonstrate the QOL-B-RD has adequate reliability, validity, and responsiveness for assessing respiratory symptoms in adults with newly diagnosed or recurrent MAC-LD.