Prognostic factors associated with long-term mortality in 1445 patients with nontuberculous mycobacterial pulmonary disease: a 15-year follow-up study

Limited data are available regarding the prognostic factors for patients with nontuberculous mycobacterial pulmonary disease (NTM-PD). We investigated the prognostic factors associated with long-term mortality in NTM-PD patients after adjusting for individual confounders, including etiologic organism and radiological form. A total of 1445 patients with treatment-naive NTM-PD who were newly diagnosed between July 1997 and December 2013 were included. The etiologic organisms were as follows: Mycobacterium avium (n=655), M. intracellulare (n=487), M. abscessus (n=129), and M. massiliense (n=174). The factors associated with mortality in NTM-PD patients were analysed using a multivariable Cox model after adjusting for demographic, radiological, and etiological data. The overall 5-, 10-, and 15-year cumulative mortality rates for the NTM-PD patients were 12.4%, 24.0%, and 36.4%, respectively. On multivariable analysis, the following factors were significantly associated with mortality in NTM-PD patients: old age, male gender, low body mass index, chronic pulmonary aspergillosis, pulmonary or extrapulmonary malignancy, chronic heart or liver disease, and erythrocyte sedimentation rate. The etiologic organism was also significantly associated with mortality: M. intracellulare (adjusted hazard ratio [aHR]=1.40; 95% confidence interval [CI]=1.03–1.91); M. abscessus (aHR=2.19; 95% CI=1.36–3.51; and M. massiliense (aHR=0.99, 95% CI=0.61–1.64) compared to M. avium. Mortality was also significantly associated with the radiological form of NTM-PD, for cavitary nodular bronchiectatic form (aHR=1.70; 95% CI=1.12–2.59) and for fibrocavitary form (aHR=2.12; 95%CI=1.57–3.08), compared to non-cavitary nodular bronchiectatic form. The long-term mortality in patients with NTM-PD was significantly associated with the etiologic NTM organism, cavitary disease, and certain demographic characteristics.