Risk factors for rate of decline in FEV₁ in adults with cystic fibrosis

Background: Previously we assessed risk factors for FEV₁ decline in children and adolescents using the Epidemiologic Study of Cystic Fibrosis (J Pediatr 2007;151:134-139); the current study assessed risk factors in adults. Methods: Risk factors for FEV₁ decline over 3-5.5years for ages 18-24 and ≥25years were assessed using mixed-model regression. Results: Mean rates of FEV₁ decline (% predicted/year) were -1.92 for ages 18-24y (n=2793) and -1.45 for ages ≥25y (n=1368). For the 18-24y group, B. cepacia, pancreatic enzyme use, multidrug-resistant P. aeruginosa, cough, mucoid P. aeruginosa, and female sex predicted greater decline; low baseline FEV₁ and sinusitis predicted less decline. For the ≥25y group, only pancreatic enzyme use predicted greater decline; low baseline FEV₁ and sinusitis predicted less decline. Conclusions: Risk factors for FEV₁ decline in adults <25years are similar to those previously identified in children and adolescents; older adults had few statistically significant risk factors.