McIlwaine 1991.

Study characteristics
Methods	Single‐centre (Vancouver, Canada), randomised cross‐over study with 3 arms 18 participants with CF randomly allocated into 3 groups (CCPT, PEP or AD) at start of trial, although participants were ultimately to perform each treatment at home for 2 months. There was a 4‐week washout period between each 2‐month treatment cycle, consisting of CCPT.
Participants	18 participants with CF (diagnostic criteria not described) Age and gender not reported in publication Unpublished data stated age range 11–27 years; mean age 17.3 years. Pulmonary severity ranged from mild to severe (FVC range, 38–117% of predicted value and Shwachman score, 50–94).
Interventions	CCPT: standard PD with percussion PEP: applied with a mask combined with huffing, in a seated position, which utilised collateral ventilation AD: utilising airflow and breathing control to move secretions, in which respiratory rate, amplitude and effort were modulated to mobilise and clear secretions No details of prescription reported (duration, frequency); no details of dropouts or withdrawals.
Outcomes	Outcomes not explicitly declared. Apparent from results that sputum "net weight" was measured, although it is unclear when this was done or how it was measured (or whether single or repeated treatments). Pulmonary function tests (FVC, FEV1, FEF25–75, FEV1/FVC) performed at baseline and at the beginning and end of each 2‐month intervention period. All 3 abstracts report on "more independence, less discomfort, more 'sense of control'" and "less interruption of daily life", although how and when this was measured was not reported.
Notes	Study reported in 3 abstracts (Davidson 1988, McIlwaine 1988, McIlwaine 1991), the most recent of which is the primary reference for this study, from the 17th European CF conference, although some details were extracted from the other abstracts. An unpublished draft of the full manuscript for this study was provided to the Cochrane Cystic Fibrosis and Genetic Disorders Editorial Base, which provided material additional details. Jadad score: 1/5.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not reported. Quote: "Using a random cross‐over design, patients were divided into groups." Numbers in each group and order of treatments not described.
Allocation concealment (selection bias)	Unclear risk	Not described.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not feasible (participants), not described (personnel).
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not described.
Incomplete outcome data (attrition bias) All outcomes	High risk	No withdrawals or dropouts reported in any of the abstracts. In unpublished draft of full manuscript, it is apparent 4 participants did not complete the study and were excluded from the analysis: 1 hospitalised during first treatment period (PD) due to an exacerbation (ABPA); 1 withdrew at the end of the 1st treatment period after requiring prednisone to control an allergic reaction to an antibiotic; 2 participants refused to cross over after the 1st treatment period (AD group) due to perceived greater effectiveness at mobilising sputum.
Selective reporting (reporting bias)	High risk	No numeric data provided for any outcome in the study, and outcomes for pulmonary function simply described as non‐significant. 2/3 abstracts indicated that AD produced "significantly more sputum" than CCPT, but no data on actual values or magnitude of difference provided.
Other bias	High risk	Each participant used each technique for 2 months, and had 1 month of washout between techniques. The washout was CCPT, which was 1 of the 3 techniques. Unclear what impact this may have had. Unclear how multiple repeated pulmonary function values were performed or analysed. Unclear how "independence, discomfort, sense of control or interruption to daily life" were measured, although these were reported in all 3 abstracts. Supported in part by grants from the BC Lung Association, BC Health Care Research Foundation and the Vancouver Foundation, Canadian Pacific Airlines & Astra Meditech (Manufacturer of PEP masks).