The determinants of survival among adults with cystic fibrosis—a cohort study

BACKGROUND: Cystic fibrosis (CF) is one of the most common autosomal recessive diseases. Factors contributing to disease exacerbations and survival rate of CF patients are type of mutation in the CFTR gene, poor nutritional status, lung failure, and infection development by Pseudomonas aeruginosa. The study aimed to evaluate the relationship between the severity of mutation, nutritional status, lung function, and Pseudomonas aeruginosa prevalence and survival rate in adult patients with cystic fibrosis. METHODS: A study of 124 (68 ♀ and 56 ♂) adults with CF aged 18–51 years were evaluated for (a) type of mutation in the CFTR gene, (b) nutritional status (BMI), (c) lung function (FEV(1)%), and (d) Pseudomonas aeruginosa prevalence. For statistical calculations, Kaplan-Meier analysis of survival, chi-squared test for multiple samples, and logistic regression were used. RESULTS: The type of mutation (χ(2) = 12.73, df = 3, p = 0.005), FEV(1)% (χ(2) = 15.20, df = 2, p = 0.0005), Pseudomonas aeruginosa prevalence (χ(2) = 11.48, df = 3, p = 0.009), and BMI (χ(2) = 31.08, df = 4, p < 0.000) significantly differentiated the probability of survival of patients with CF. The shortest life expectancy was observed in patients with a severe type of mutation on both alleles, FEV(1)% < 40, subjects in whom Pseudomonas culture was extensively drug-resistant or pandrug-resistant, and patients whose BMI was lower than 18.5 kg/m(2). The period from 30 to 40 years of age was the most critical in CF adults’ lifespan. The risk of adults with CF death doubled with Pseudomonas aeruginosa prevalence (OR = 2.06, 95% CI 1.29; 2.28) and eightfold when the bacteria acquired antibiotic resistance (OR = 8.11, 95% CI 1.67; 38.15). CONCLUSIONS: All factors included in the study were significantly related to the survival rate of patients with cystic fibrosis.