Diel R, et al. - A systematic review of the published literature on five-year all-cause mortality in patients with Mycobacterium avium complex (MAC) lung disease was performed, and the mortality rates were pooled to give an overall estimate of five-year mortality from these studies. Most studies in patients with MAC pulmonary disease, despite high heterogeneity, document a five-year all-cause mortality exceeding 25%, indicating poor prognosis. As per findings, more effective management and additional prospective mortality data collection are required.