Bauer 1994.

Study characteristics
Methods	Single‐centre (Alabama, USA), parallel design RCT for 54 participants (3 dropped out) Participants randomly allocated to receive either manual or mechanical chest percussion 3 times per day for approximately 12 days during admission to hospital for acute pulmonary exacerbation. 27 of the original participants were admitted a 2nd time during the study and agreed to participate in the opposite arm of the study (cross‐over analysis) (5 dropped out, 22 analysed).
Participants	54 participants aged > 6 years agreed to participate and could perform adequate spirometry and signed consent forms. 3 dropped out: 1 'dismissed' after 2 days of hospitalisation, 1 not compliant with the protocol, and 1 complained that manual percussion was painful. Therefore, 51 participants participated fully in the study, providing the data for analysis. 27 participants were admitted a 2nd time during the study and agreed to participate in the opposite arm of the study (cross‐over analysis). Of these 27 participants, 5 were excluded: 2 were dismissed early, 1 was non‐compliant and 2, assigned to mechanical percussion, requested to return to manual percussion because of personal preference. Therefore, 22 participants participated fully in both arms of the study (cross‐over group). Manual percussion: (n = 36, including cross‐over): mean age 17 (SEM 1.4) years; 18 males; mean days in hospital 12.5 (SEM 0.5) days Mechanical percussion: (n = 37, including cross‐over): mean age 15.9 years (SEM 1.4); 19 males; mean days in hospital 11.4 (SEM 0.5) days
Interventions	Participants were randomly assigned to receive either manual or mechanical percussion for the entire hospitalisation. Participants admitted to the hospital twice during the course of the study were allowed to participate a 2nd time but were non‐randomly assigned to receive the form of percussion not received during the first participation. No participant was allowed to participate more than twice. Percussion was performed 3 times per day by respiratory care practitioners who recorded each session in the hospital chart, noting time, positions, cough and secretion assessments, oximetry readings and complications. Each percussion session was performed in 2 upright positions (upper portion of the back and upper anterior portion of the chest), 4 flat positions (mid‐portion of the chest, anterior portion of the back, left and right sides), and 4 Trendelenburg positions (lower portion of the chest, anterior portion of the back, left and right sides). Manual percussion: 30 min with cupped hands Mechanical percussion: 30 min with Vibracare percussor or a model 9000 percussor 25–35 Hz, with (quote) "sufficient pressure to change the voice."
Outcomes	Hospital duration, participant preference, FVC, FEV1, FEF25–75, weight.
Notes	Study reported in 1 abstract (Bauer 1990) and 1 full‐text manuscript (Bauer 1994), which is the primary reference for this study. No details were extracted from the abstract. Jadad score: 2/5.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not reported: (quote) "Patients were randomly allocated."
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	Unclear risk	3/54 participants dropped out of the first phase (51 analysed) and 5/27 participants dropped out in the second phase (22 analysed). 1 early discharge, 1 non‐compliant, 1 complained manual percussion painful.
Selective reporting (reporting bias)	Low risk	All outcome measures were reported.
Other bias	High risk	Final analysis combined and included data from 22 participants on repeated admissions. Participants who were less well and required more‐frequent admissions may thus have been over‐represented in this population sample. Although unpaired t‐test used on combined analysis, data were paired for 22 participants within the analysis.