Airway clearance research in CF: the ‘perfect storm’ of strong preference and effortful participation in long-term, non-blinded studies

• Published in: Thorax Vol. 68; no. 8; pp. 701 - 702
• Main Author: Main, Eleanor
• Format: Journal Article
• Language: English
• Published: England BMJ Publishing Group Ltd and British Thoracic Society 01.08.2013; BMJ Publishing Group LTD
• Subjects: Bias; Chest Wall Oscillation - methods; Cystic Fibrosis; Cystic Fibrosis - therapy; Female; Humans; Laryngeal Masks; Male; Participation; Positive-Pressure Respiration - instrumentation; Preferences; Respiratory Infection; School dropout programs; School dropouts; Studies; Cystic Fibrosis; Respiratory Infection
• DOI: 10.1136/thoraxjnl-2012-203054
• ISSN: 0040-6376

Given the substantive cost and marketing behind HFCWO (over 200 times more expensive than PEP mask therapy), these results provide important and clinically useful information that clinicians will find very helpful in making cost-effective and best practice decisions about airway clearance for their patients. 7 In a landscape of ACT comparison literature, which invariably concludes that one technique or device is 'equivalent' to another, this is a noteworthy finding. 1-6 In addition however, apart from confirming the difficulty of reaching recruitment targets, this study illuminates effectively two other challenges facing airway clearance research, even in near-perfect conditions: forced expiratory volume in one second (FEV1) as a gold-standard outcome measure and participant dropouts related to preference. 7 Both contributed to the derailment of two recent long-term ACT studies and will jeopardise similar future studies unless they are carefully examined and addressed. 8 9 The primary outcome measure in McIlwaine's study provides a relevant and thoughtful antidote (long overdue) to FEV1 in airway clearance studies. [...]while random allocation almost entirely eliminates selection bias and other uncontrolled variables in treatment assignment, it is really only palatable for patients if there is genuine equipoise about the relative benefits, AND they do not know or care what they are getting OR if they only are required to endure the relative burden of treatment for a short time. 11 Neither of the latter conditions is met in long-term ACT research.