Decline in 25% to 75% forced expiratory flow as an early predictor of chronic airway rejection in pediatric lung transplant recipients

All patients who developed BOS had a decline in FEF25-75 at or before the decline in FEV1. The reduction in FEF25-75 occurred statistically significantly earlier than the decline in FEV1, by an average of 168.5 days. This decline in FEF25-75 was also highly sensitive and specific for the diagnosis of BOS.