Antimicrobial Treatment of Mild Mycobacterium avium Complex Pulmonary Disease Predicted to Increase Survival and Quality-Adjusted Life Years: A Microsimulation Decision Analysis Model.

BACKGROUND

Mycobacterium avium complex pulmonary disease (MAC-PD) can lead to chronic lung disease, which can necessitate intensive antimicrobial therapy. In patients with mild MAC-PD, uncertainty exists regarding whether guideline-based antimicrobial treatment should be used as compared with watchful waiting.

RESEARCH QUESTION: What are the long-term consequences of initiation of antimicrobial treatment compared with watchful waiting in patients with mild MAC-PD?

STUDY DESIGN AND

METHODS

We simulated a cohort of 70-year-old Canadian individuals with nodular bronchiectatic MAC-PD with a macrolide-susceptible specimen and normal lung function. We used a lifetime model to compare guideline-based treatment with observation for patients with MAC-PD, accounting for common adverse events, culture conversion rates, and disease recurrences from prior literature. Our outcomes were quality-adjusted life years (QALYs) and life years. The primary analysis was a probabilistic Monte Carlo simulation to estimate the mean and 95% uncertainty intervals (UIs) for each outcome under treatment and observation, as well as the treatment to observation difference. Additional outcomes included deterministic analysis and 1-way and 2-way deterministic sensitivity analyses.

RESULTS

In the primary analysis, the cohort of individuals receiving antimicrobial treatment showed a mean of 15.9 QALYs (95% UI, 12.4-19.3 QALYs), whereas those under observation showed 13.4 QALYs (95% UI, 9.0-16.4 QALYs), with a treatment to observation difference of 2.5 QALYs (95% UI, 0.8-4.7 QALYs). Similarly, those receiving treatment showed a mean 18.3 life years (95% UI, 19.2-25.5 life years), and those under observation showed 15.8 life years (95% UI, 17.3-22.2 life years). The treatment to observation difference was 2.5 years (95% UI, 1.0-4.2 years). Increase in QALYs and life years was consistent across almost all sensitivity analyses.

INTERPRETATION: In a simulated cohort, guideline-based treatment increased QALYs and life years in patients with mild MAC-PD. Our findings can support patients and physicians in deciding on treatment approach.