Summary of findings 8. Autogenic drainage versus intrapulmonary percussive ventilation (200 bpm).

AD compared with IPV (200 bpm)for CF
Patient or population: adults with CF Settings: hospital admission for respiratory exacerbation Intervention: AD Comparison: IPV (200 bpm) with AD
Outcomes	Illustrative comparative risks* (95% CI)		Relative effect (95% CI)	No of participants (studies)	Certainty of the evidence (GRADE)	Comments
	Assumed risk	Corresponding risk
	IPV plus AD	AD
FEV1% predicted (change from baseline)   Follow‐up: 10 days	Change in FEV1 % predicted was 3.8% higher in the AD group (0.57% lower to 8.17% higher) than in the IPC group.		N/A	4 (1)	⊕⊝⊝⊝ very lowa,b	The included trial is a cross‐over trial which has been analysed as a parallel trial; this means that the participants have been counted twice.
QoL	This outcome was not reported.
Participant preference	This outcome was not reported.
Exercise tolerance (modified shuttle test)	This outcome was not reported.
Adverse events	This outcome was not reported.
Number of admissions to hospital	See comments.					Inclusion criteria for participants in the Dingemans study included hospitalisation for a respiratory infection (Dingemans 2018).
Need for extra treatment	See comments.					All 4 participants were already receiving intravenous antibiotics as part of their medical management as inpatients during the course of this study (Dingemans 2018).
*The basis for the assumed risk (e.g. the median control group risk across studies) is the event rate or mean risk in the control group unless otherwise stated. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). AD: autogenic drainage; CF: cystic fibrosis; CI: confidence interval; FEV1: forced expiratory volume in 1 second; IPV: intrapulmonary percussive ventilation; NA: not applicable; QoL: quality of life.
GRADE Working Group grades of evidence High certainty: further research is very unlikely to change our confidence in the estimate of effect. Moderate certainty: further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low certainty: further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. Very low certainty: we are very uncertain about the estimate.

a. Downgraded once due to imprecision caused by a very small number of participants.

b. Downgraded twice due to risk of bias from the design of the study. The study uses a cross over design whereby participants are randomised to a different treatment at each subsequent admission. It is unlikely that baseline values will be the same at the start of each treatment period. There is also a high risk of reporting bias and selective reporting of results.