Gaps in Cystic Fibrosis Care Are Associated with Reduced Lung Function in the U.S. Cystic Fibrosis Foundation Patient Registry

Document Type


Publication Date



Critical Care Medicine, Pulmonology

Journal Title

Annals of the American Thoracic Society


RATIONALE: Cystic Fibrosis (CF) is a genetic disease leading to progressive lung function loss and early mortality. Many clinical and demographic variables are associated with lung function decline, but little is known about the effects of prolonged periods of missed care. OBJECTIVES: To determine if missed care in the US Cystic Fibrosis Foundation Patient Registry (CFFPR) is associated with decreased lung function at follow-up visits. METHODS: De-identified US Cystic Fibrosis Foundation Patient Registry (CFFPR) data for 2004-2016 was analyzed, with the exposure of interest being ≥ 12-month gap in CF registry data. We modeled percent predicted forced expiratory volume in one second (FEV1PP) using longitudinal semiparametric modeling with natural cubic splines for age (knots at quantiles) and with subject-specific random effects, adjusted for gender and cystic fibrosis transmembrane conductance regulator (CFTR) genotype, race, and ethnicity and included time-varying covariates for gaps in care, insurance type, underweight BMI, CF-related diabetes status, and chronic infections. RESULTS: 24,328 individuals with 1,082,899 encounters in the CFFPR met inclusion criteria. 8,413 (35%) individuals in the cohort had at least a single ≥ 12-month episode of discontinuity, whereas 15,915 (65%) had continuous care. 75.8% of all encounters preceded by a 12-month gap occurred in patients 18 years or older. Compared to those with continuous care, those with a discontinuous care episode had a lower follow-up FEV1PP at the index visit (-0.81%; 95% CI -1.00, -0.61), after adjustment for other variables. The magnitude of this difference was much greater (-2.1%; 95% CI -1.5, -2.7) in young adult F508del homozygotes. CONCLUSIONS: There was a high rate of ≥ 12-month gap in care, especially in adults, documented in the CFFPR. Discontinuous care identified in the US CFFPR was strongly associated with decreased lung function, especially in adolescents and young adults homozygous for the F508del CFTR mutation. This may have implications for identifying and treating people with lengthy gaps in care and have implications for CFF care recommendations.