Homnick 1998.

Study characteristics
Methods	Quasi‐RCT (alternate allocation). Cross‐over design. Location: single centre in USA. Duration: length of hospitalisation.
Participants	22 enrolled into study, the data for 33 hospitalisations (20 males, 13 females) presented. Mean (range) age: 12 (7‐ 44) years. CF confirmed by sweat test and/or genetic testing.
Interventions	4x daily flutter (each treatment was 15 min) versus 4x daily CPT (each treatment was 30 min).
Outcomes	Change from baseline FVC, FEV1, FEF25-75, FEV1/FVC, TLC, RV, RV/TLC. Measured at admission and discharge which was mean (SD) 8.9 (2.5) days of treatment in the flutter arm and 8.8 (2.4) days in the CPT arm.
Notes	Although 22 participants enrolled into the study, data were collected for 33 hospitalisations over the study period therefore baseline demographics may include some duplication of data. Subgroup analyses of 15 participants with only one admission and the initial admission of 7 were done with no change from overall outcome of the total 33 data sets analysed.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Initial participant randomised, but not stated how. Others followed alternating schedule.
Allocation concealment (selection bias)	High risk	Alternate assignment.
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Open label.
Incomplete outcome data (attrition bias) All outcomes	Low risk	No drop outs reported.
Selective reporting (reporting bias)	High risk	Although 22 participants enrolled into the study the data were collected for 33 hospitalisations over the study period therefore baseline demographics may include some duplication of data. Subgroup analyses of 15 participants with only one admission and the initial admission of 7 were done with no change from overall outcome of the total 33 data sets analysed.
Other bias	Low risk	Participants were monitored for side effects including haemoptysis, hypoxia and pneumothorax but none were identified.