The therapeutic impact of maximum chemotherapy possession days during three consecutive months in non-tuberculous mycobacterial lung disease: A real-world experience

Purpose: Adherence to guideline recommendations in the treatment of non-tuberculous mycobacterial lung disease (NTM-LD) is often difficult. Thus, this study aimed to investigate the impact of the integrity of NTM-LD treatment on treatment outcomes. Materials and methods: The participants were screened from the National Taiwan University Hospital-Integrative Medical Database (NTUH-iMD) and the Taiwan National Health Insurance Research Database (NHIRD). The longest treatment duration during 3 consecutive months was defined as maximum chemotherapy possession days (MCPDs) and was categorized as low (28–55 days), medium (56–90 days), and maximum (≥91 days). We analyzed microbiological cure and 3-year mortality using MCPDs. Results: Low, medium, and maximum MCPD groups had 83 (19.2 %), 94 (21.8 %), and 255 (59.0 %) participants in the NTUH-iMD cohort (N = 432) and 1203 (26.5 %), 1251 (27.6 %), and 2084 (45.9 %) participants in the NHIRD cohort (N = 4538), respectively. In the NTUH-iMD cohort, multivariable analysis showed that adjusted hazard ratios (aHRs) of 3-year mortality were 0.51 (95 % CI: 0.29–0.90) and 0.29 (0.18–0.49) in medium and maximum MCPD groups compared with the low MCPD group. The trends of survival benefit by maximum MCPDs were also found in the NHIRD cohort. The maximum MCPD group had 45.9 % participants with microbiologic cure, which was significantly higher than in medium and low MCPD groups (27.7 % and 4.0 %, respectively; p < 0.001). Conclusion: Maximum MCPD for NTM-LD increased microbiological cure and reduced 3-year mortality by 71 % compared with low MCPD group. Maintaining NTM-LD treatment integrity as possible might positively impact disease outcomes.