Screening practices for nontuberculous mycobacteria at US cystic fibrosis centers

Current guidelines recommend at least once yearly screening for nontuberculous mycobacteria (NTM) in Cystic Fibrosis (CF), however screening practices remain widely variable. This study evaluates current practices among United States CF centers with specific focus on clinical predictive factors for NTM screening.

The CF Patient Registry (CFFPR) was queried for CF patients ages 10 and older with NTM cultures completed between 2010-2014. Predictors for screening were assessed using univariate and multivariate logistic regression. Centers were evaluated by groups based on screening rates for analysis of clinical drivers of screening.

From 2010-2014 a total of 22,739 patients were identified with 17,177 (75.5%) tested for NTM during this time. In the overall cohort, those who were tested for NTM had lower pulmonary function (70.7% vs 83.9%), higher annual average of visits with pulmonary exacerbations (1.0 vs 0.3), and higher rate of coinfection with Pseudomonas aeruginosa (PA) as well as Methicillin resistant Staphylococcus aureus (MRSA). Among CF centers, pulmonary function, exacerbations, and coinfections with PA and MRSA were predictive of NTM screening in the lower screening cohort while pulmonary function was not predictive of screening in the highest screening cohort. Those programs who screened at a higher rate were successful in identifying NTM in more CF patients.

NTM screening practices vary widely among United States CF centers with many centers testing only on clinical changes. With higher rates of testing shown as successful in identifying more patients with NTM, routine screening should be emphasized in CF care going forward.