Abstract Rationale Patients with nontuberculous mycobacterial (NTM) pulmonary disease (PD) often experience debilitating symptoms and reduced quality of life (QoL). While antibiotic treatment is intended to improve QoL by reducing infection burden, drugs used against NTM are often poorly tolerated. The QoL-Bronchiectasis, NTM (QoL-B,NTM) module uses a preliminarily validated patient-reported outcome (PRO) measure to simultaneously assess symptom burden and evaluate treatment effectiveness. This study aimed to characterize PRO measures during a pilot EBA trial of azithromycin for Mycobacterium avium complex (MAC)-PD. Methods This prospective single-arm trial enrolled adults in the US diagnosed with MAC-PD from 2021 to 2025. Participants received oral azithromycin for 2 weeks, followed by addition of rifampin and ethambutol for 6 weeks. QoL-B,NTM was administered at baseline and three follow-up visits until study completion at week 8. Changes in domain scores between visits were calculated. QOL-B,NTM scores range from 0 to 100, with higher scores indicating better QoL. The proportion of participants achieving a minimal clinically important difference (MCID), defined as the smallest score change perceived as clinically significant, an improvement of ≥ 8.0 points, was also assessed. Results Ten participants were enrolled in the study, with a median age of 73 years IQR:67,73. The majority were white (80%) and 60% were female. Nine participants completed four visits, while one completed three due to an unrelated death.The overall proportion of participants achieving MCID from baseline to last visit did not exceed 40% across all scores and did not show any statistically significant difference between the visits. The median increase in individual QoL-B respiratory symptom scores from baseline to last visit was 7 IQR:3,7, and mycobacterial burden declined over the course of treatment. Most participants exhibited fluctuations in their scores or minimal change overall.The change in the respiratory symptom domain from baseline to the last visit had a strong inverse correlation with the change in the role functioning domain change (Spearman’s rho=-.61) and a moderately inverse correlation with the change in NTM symptoms (Spearman’s rho=-.59). Additionally, the change in NTM symptoms was moderately correlated with the change in health perception scores (Spearman’s rho=.58). Conclusions In this small cohort of patients with MAC-PD, QoL scores did not change significantly from baseline through week 8, despite microbiologic response. These preliminary findings emphasize the dynamic nature of QoL-B,NTM and highlight the need for larger studies to establish the optimal PRO tools and frequency of measurement in NTM treatment trials. This abstract is funded by: K23 AI159145, Fisher Center Discovery Award, CHEST Foundation
Ignatius et al. (2026) studied this question.