A systematic review of studies examining the rate of lung function decline in patients with cystic fibrosis.

A systematic review was performed (i) to describe the reported overall rate of progression of CF lung disease quantified as FEV1%predicted decline with age, (ii) to summarise identified influencing risk factors and (iii) to review methods used to analyse CF lung disease progression data. A search of publications providing FEV1%predicted values over age was conducted in PUBMED and EMBASE. Baseline and rate of FEV1%predicted decline were summarised overall and by identified risk factors. Thirty-nine studies were included and reported variable linear rates of lung function decline in patients with CF. The overall weighted mean FEV1%predicted over age was graphically summarised and showed a nonlinear, time-variant decline of lung function. Compared to their peers, Pseudomonas aeruginosa infection and pancreatic insufficiency were most commonly associated with lower baseline and more rapid FEV1%predicted declines respectively. Considering nonlinear models and drop-out in lung disease progression, analysis is lacking and more studies are warranted.