Homnick 1998.

Study characteristics
Methods	Single‐centre (Michigan, USA), preliminary, open‐label, alternate assignment comparative trial 22 adults and children with CF confirmed by sweat test or genetic testing, or both, were alternately allocated to either Flutter device or CCPT during hospitalisation for an acute exacerbation. 7/22 participants were admitted more than once during the study period (data collected during 33 hospital admissions). Duration: maximum 11 days per admission (mean 8.9 days) during an acute exacerbation
Participants	Participants diagnosed with CF by sweat or genetic testing. 22 participants contributed data during 33 admissions to hospital for pulmonary exacerbations, 15 participants admitted once, 7 participants admitted ≥ 2 times Age range 7–44 years Exclusion criteria included history of severe reaction to aerosolised bronchodilator (significant tachycardia or wheezing), or to CCPT, (increased wheezing, chest pain, or discomfort); history of tobacco use; inability to undertake pulmonary function testing; history of significant haemoptysis (> 240 mL/day on any occasion or > 100 mL/day for several days) or pneumothorax within 1 year of study entry. CCPT (n = 17): mean age 12 years; range 7–21 years Flutter (n = 16): mean age 16.1 years; range 8–44 years
Interventions	Participants received supervised Flutter therapy or standard, manual CCPT 4 times per day during hospitalisation; all participants received rhDNase 2.5 mg once daily. Respiratory therapists were registered and trained and the same in both groups. Flutter device: 15 min 4 times per day (preceded by albuterol nebuliser 2.5–5 mg in either 2 mL normal saline solution or 20 mg (2 mL) sodium cromoglycate); Flutter device was directly supervised by respiratory therapists using manufacturer's recommendations. CCPT: (standard manual) 30 min 4 times per day (preceded by albuterol nebuliser 2.5–5 mg in either 2 mL normal saline solution or 20 mg (2 mL) sodium cromoglycate); CCPT was administered by respiratory therapists using CF Foundation guidelines incorporated into a hospital protocol.
Outcomes	Complete pulmonary function tests (FEV1, FVC, FEF25–75, FEV1/FVC, RV, RV/TLC) performed in lung function laboratory using ATS standards at baseline (admission), weekly, and upon discharge from the hospital. Clinical score determined at the time of hospital admission and at discharge. Participants monitored for complications, including haemoptysis, hypoxaemia and pneumothorax. Shwachman score, a CF severity scoring system, a clinical score (modified Case Western) were all performed at baseline. Mean length of hospitalisation, mean number of respiratory treatments during the hospitalisation and adverse events were measured.
Notes	Study reported in 1 abstract (Homnick 1996, n = 14) and 1 full‐text manuscript (Homnick 1998, n = 22), which is the primary reference for this study. Jadad score: 0/5.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Not reported: initial participant "randomised," then alternate allocation.
Allocation concealment (selection bias)	High risk	Alternate allocation.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	No blinding: not feasible (participants), open‐label (personnel).
Blinding of outcome assessment (detection bias) All outcomes	High risk	Non‐blinded: open‐label study.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Analysis of 33 hospitalisations in 22 participants. Multiple enrolment to increase sample size. Although authors stated no participants withdrew from the study, it was unclear if any declined further participation in hospitalisations subsequent to their first admission.
Selective reporting (reporting bias)	Unclear risk	Pulmonary function tests after 1st week were measured but not reported.
Other bias	High risk	Difference in baseline ages between groups (16 years with Flutter device vs 12 years with CCPT), and almost significant improvement in clinical score in favour of CCPT group not discussed. CCPT treatments were twice as long as Flutter device treatments (30 min with CCPT vs 15 min with Flutter), with uncertain consequences. The 22 participants were measured during 33 admissions, with repeated measures on 7/22 participants, some of whom were admitted more than twice (and who may, therefore, have been over‐represented). Apparently, subgroup analysis of first 22 admissions produced similar results although data not shown. Unclear how subsequent admissions were dealt with in terms of group allocation.