The techniques were chosen for each participant Apoptosis Compound Library according to perceived efficacy and participant preference, and aligned with the recommended application of the selected techniques ( McIlwaine and Van Ginderdeuren 2009). Subjects performed this airway clearance regimen for each session with or without an assistant as required. The duration and type of airway clearance techniques

were established in the days prior to randomisation and were maintained across the three study days. Timing regimens: When participants were allocated to inhale hypertonic saline before or after airway clearance techniques, they were advised to commence the second intervention as soon as the first intervention was complete. When participants were allocated to inhale hypertonic saline during airway clearance techniques, participants and the treating therapist decided collaboratively if this would be performed by simultaneous administration or by alternating short periods of inhalation and techniques, eg, 10–15 breaths of hypertonic saline followed by airway clearance techniques, performed in cycles until the treatment session was completed. However, participants using mouthpiece positive expiratory pressure as their airway clearance technique were not permitted

to administer hypertonic saline simultaneously as this alters the inhaled dose and the Osimertinib distribution of its deposition ( Laube et al 2005). Alternating administration of these two interventions was always used instead. Participants received other usual care on all three study days, including all other routine therapies. Other inhaled therapies (eg, dornase alpha, corticosteroids) were administered at a consistent time of day that was more than one hour from any of the three study periods. Typically, dornase alpha was inhaled in the morning or evening, according to patient preference (Bishop et al 2011, Dentice and Elkins 2011). Lung function was measured using a standard

spirometere according to American Thoracic Society guidelines (American Thoracic Society 1995). The spirometric measures recorded were FEV1 and forced vital capacity (FVC), with each calculated in litres and as a percentage of the predicted value (Knudson et al 1983). The spirometric measures were recorded prior to the second treatment session each day. Participants then had a bronchodilator, and all then inhaled hypertonic saline either before, during, or after airway clearance techniques, as allocated for that day. The spirometric measures were recorded again 2 hr after the baseline measurement, and the change in FEV1 and FVC over this 2-hr period for each of the study days was calculated. The physiotherapist who recorded the spirometric measures was kept unaware of the timing regimens allocated to all participants. The perceived effectiveness, tolerability, and satisfaction with each timing regimen were reported by participants at the end of the day after all treatments using that regimen had been experienced.