Background

Nontuberculous mycobacterial lung disease (NTMLD) is a life-threatening pulmonary infection with increasing prevalence in Japan. Asthma is a common comorbidity, but data are limited on the added illness burden of NTMLD in patients with asthma.

Objective

To assess the incremental hospitalization burden of NTMLD in patients with asthma.

Methods

A retrospective study was conducted with the Japan Medical Data Center claims data 2015?2020. Patients with asthma with NTMLD (cases) were matched 1:3 by age and sex to patients with asthma without NTMLD (controls). Incremental burden was assessed by comparing hospitalizations (all-cause, respiratory, and asthma) over a 1-year post-index (NTMLD diagnosis date) period with univariate and multivariate analyses adjusting for pre-index comorbidities.

Results

A total of 257 cases were matched to 771 controls: mean (SD) age on index date 54 (11) years, 65% female. Bronchiectasis (11.7% vs 0.4%) and COPD (38.1% vs 9.6%) were more common in cases during the 1-year pre-index period. Univariate analyses showed greater hospitalization burden in cases vs controls (17% vs 2% had respiratory-related hospitalizations) (Figure 1A). The burden was also reflected in the multivariate analyses.

Conclusion

The substantial incremental hospitalization burden associated with NTMLD in patients with asthma in Japan highlights the urgent need for appropriate management of NTMLD.