Factors associated with lung function response with oral antibiotic treatment of pulmonary exacerbations in cystic fibrosis.

Pulmonary exacerbations treated with oral antibiotics (oPEx) have a significant effect on lung function decline in people with cystic fibrosis (CF). However, factors associated with lung function response with oPExs are not well defined. We performed a retrospective cohort study of pediatric and adult patients with CF followed in the Toronto CF Database. Lung function response was measured both as the change in forced expiratory volume in 1 second (FEV1) from Day 0 of antibiotic therapy to end of treatment as well as from baseline to end of treatment. Drop from baseline to Day 0 FEV1 was strongly associated with lung function response (p<0.001). Greater FEV1 improvements were associated with longer antibiotic treatment durations. Older, female patients had less improvements in FEV1 at end of treatment compared to younger, male patients.