Rationale: Airway secretion clearance therapies are a cornerstone of cystic fibrosis care, however longitudinal comparative studies are rare. Our objectives were to compare three therapies [postural drainage and percussion: (postural drainage), flutter device (FD), and high frequency chest wall oscillation: (vest)], by studying (1) change in pulmonary function; (2) time to need for intravenous (IV) antibiotics, (3) use of pulmonary therapies, (4) adherence to treatment, (5) treatment satisfaction, and (6) quality of life.
Methods: Participants were randomly assigned to one of three therapies twice daily. Clinical outcomes were assessed quarterly over 3 years.
Results: Enrollment goals were not met, and withdrawal rates were high, especially in postural drainage (51%) and FD (26%), compared to vest (9%), resulting in early termination. FEV(1) decline, time to need IV antibiotics, and other pulmonary therapies were not different. The annual FEF(25-75%) predicted rate of decline was greater in those using vest (P = 0.02). Adherence was not significantly different (P = 0.09). Overall treatment satisfaction was higher in vest and FD than in postural drainage (P < 0.05). Health-related quality of life was not different. The rate of FEV(1) decline was 1.23% predicted/year.
Conclusions: The study was ended early due to dropout and smaller than expected decline in FEV(1). Patients were more satisfied with vest and FD. The longitudinal decline in FEF(25-75%) was faster in vest; we found no other difference in lung function decline, taken together this warrants further study. The slow decline in FEV(1) illustrates the difficulty with FEV(1) decline as a clinical trial outcome.