1386. Reduction in Expected Survival Associated with Nontuberculous Mycobacterial Pulmonary Infection

Abstract

BackgroundNontuberculous mycobacteria (NTM) are emerging agents of pulmonary disease, estimated to affect >80,000 people in the United States. While the spectrum of pulmonary NTM severity is broad, some published series report 5-year mortality of up to 40%.MethodsWe conducted a retrospective cohort study to examine mortality of patients with positive respiratory cultures for NTM in the Duke Health System from January 1, 1996 to June 30, 2015, compared with the expected mortality in the US population among a cohort with the same demographic composition. We included patients with ≥2 positive NTM respiratory cultures, or 1 positive culture plus an associated ICD diagnosis. Patients with disseminated NTM, HIV, cystic fibrosis, and solid-organ or hematopoietic cell transplants were excluded, as were isolates of Mycobacterium gordonae. Five specific comorbidities (cancer, chronic obstructive pulmonary disease, stroke, chronic renal failure, myocardial infarction) were assessed with ICD codes. Survival was measured from the date of first positive NTM culture and censored as of 6/30/2015.ResultsWe identified 653 patients who met the case definition. 451 (69%) were female; 548 (84%) were Caucasian, and the median age was 69 years (IQR 59–76). 544 (83.3%) patients had only Mycobacterium avium complex (MAC) isolates in cultures; 39 (6%) had only M. abscessus; 33 (5%) had both MAC and M. abscessus; 37 (5.7%) had other NTM isolates. Most patients (n = 410, 62.8%) had none of the evaluated comorbidities prior to NTM diagnosis. Median follow-up time was 1252 days (IQR 449–2688). Median survival in our cohort among persons with and without comorbidities was 1973 days (95% CI 1487–2995) and 3952 days (95% CI 3496–5186), respectively. Median expected survival in the demographically-matched population cohort was significantly longer at 5479 days (P<.0001). Mortality at 5 years was 47.9% (39.7–55.0) and 27.2% (95% CI 22.1–32.0) among NTM patients with and without comorbidities, respectively, vs. expected mortality of 5.7% in the general population.ConclusionNTM pulmonary infection in our cohort was associated with significantly lower survival than expected in the general population. The impact of NTM infection itself vs. other comorbidities on survival requires further study. Disclosures All authors: No reported disclosures.