Changes in Treatment Patterns and Outcomes of Mycobacterium Avium Complex Pulmonary Disease

Abstract Background: Despite the rising incidence of non-tuberculous mycobacterial pulmonary disease (NTM-PD) over the past decade, no studies have yet examined changes in patient characteristics, treatment patterns, or outcomes over time. This study focuses on Mycobacterium avium complex (MAC)-PD, the most common NTM-PD, to assess these trends. Methods: Patients diagnosed with and treated for MAC-PD at Seoul National University Hospital from July 1, 2009, to June 30, 2024, were included. Patients were categorized into three groups based on treatment initiation period (Group 1: 2009-2014, Group 2: 2015-2019, Group 3: 2020-2024). Baseline demographic characteristics, radiographic severity scores, drugs used, and treatment outcomes were analyzed. Results: A total of 543 patients were analyzed (Group 1: 94, Group 2: 217, Group 3: 232). Radiographic severity scores increased over time from 4.16 (IQR 0.01-12.0) to 5.75 (IQR 0.01-13.1). Azithromycin use rose from 14.9% to 98.3% (p for trend <0.001), amikacin from 1.1% to 12.1% (p for trend <0.001), and clofazimine from 1.1% to 41.8% (p for trend <0.001). Meanwhile, clarithromycin use declined from 79.8% to 1.7% (p for trend <0.001) and rifampin from 97.2% to 26.7%. Culture conversion rates within six months improved over time, from 55.9% to 74.6% (p for trend <0.001). Conclusion: Treatment for MAC-PD has shifted toward greater use of clofazimine and amikacin, with declining use of rifampin, and treatment outcomes have improved.