The impact of nontuberculous mycobacteria species on non-cancer mortality in patients with nontuberculous mycobacterial lung disease

<b>Purpose:</b> Patients with nontuberculous mycobacterial lung disease (NTM-LD) have increasing mortality. However, the impact of all NTM species on the risk of mortality remains unclear, especially for death by non-cancer causes. <b>Methods:</b> This was a retrospective cohort study from 2006 to 2018 in a tertiary hospital. We enrolled patients who fulfilled the microbiologically diagnostic criteria of NTM-LD Mortality causes within eight years after diagnosis were identified and Cox proportional hazard regression was performed for risk factors of mortality. <b>Results:</b> A total of 1652 subjects with NTM-LD were included. Among them, 723 (43.8%) were infected by Mycobacterium avium complex (MAC), 408 (24.7%) by M. abscessus complex (MABC), 120 (7.3%) by M. kansasii (MK), 304 (18.4%) by other rapid growing mycobacteria (RGM) and 97 (5.9%) by other slow growing mycobacteria (SGM) groups. The 8-year all-cause mortality was 35.8% for all and highest in the MK-LD group (46.7%), followed by the MABC-LD and MAC-LD groups. The adjusted hazard ratios were 2.15 (95% confidence interval:1.37–3.38) in the MK-LD, 1.84 (1.24–2.73) in the MABC-LD, and 1.61 (1.10–2.37) in the MAC-LD groups for all-cause mortality, compared with the SGM group. Kaplan–Meier survival curves showed that all-cause mortality, non-cancer mortality, and mortality due to chronic airway diseases were significantly correlated with NTM species (all p&lt;0.05 by log rank test). <b>Conclusions:</b> High eight-year mortality rates were found in patients with NTM-LDs according to different NTM species. Notably, the difference was significant in non-cancer causes and mortality in chronic airway disease.