O'Sullivan KJ, et al. - In this study including 21 pediatric subjects with cystic fibrosis, researchers assessed the performance of oscillating positive expiratory pressure therapy by these patients in order to determine adherence to target therapeutic pressures. Each participant reported a history of using an oscillating positive expiratory pressure device twice daily. These subjects had received standardized training and instructions from the same specialist physiotherapist. By means of a flow and pressure sensor located in-line between the participant's mouth and the device, they assessed the performance. Expirations were performed by the patients according to their normal routine. Target therapeutic pressure ranges were not achieved by the participants during expiration. Participants showed considerable variation despite standardized instruction and findings revealed overall poor technique during use, which compromised airway clearance impacts of oscillating positive expiratory pressure.