Summary of findings 2.

Oscillating devices compared with breathing techniques for cystic fibrosis

Oscillating devices compared with breathing techniques for cystic fibrosis
Patient or population: adults and children with cystic fibrosis Settings: outpatients and hospitalised patients Intervention: oscillating devices Comparison: breathing techniques
Outcomes	Illustrative comparative risks* (95% CI)		Relative effect (95% CI)	No of participants (studies)	Quality of the evidence (GRADE)	Comments
	Assumed risk	Corresponding risk
	Breathing techniques	Oscillating devices1
FEV₁: % predicted or L Follow‐up: less than 1 week to 1 year	6 out of 7 studies reported no statistically significant differences between oscillating devices and breathing techniques in terms of FEV₁ (% predicted or L). 1 study reported a significant advantage for active cycle of breathing techniques compared to HFWCO in terms of FEV₁ (L).		NA	184 (7 studies)	⊕⊕⊝⊝ low3,4
FEF25‐75 Follow‐up: 5 days	There were no statistically significant differences between oscillating devices and breathing techniques in terms of FEF25‐75.		NA	7 (1 study)	⊕⊝⊝⊝ very low5,6
FVC Follow‐up: less than 1 week to 1 year	4 out of 5 studies reported no statistically significant differences between oscillating devices and breathing techniques in terms of FVC. 1 study reported a significant advantage for active cycle of breathing techniques compared to HFWCO in terms of FVC % predicted.		NA	154 (6 studies)	⊕⊕⊝⊝ low3,4
Sputum: volume (g) Follow‐up: up to 1 month	The mean sputum volume in the breathing technique group was 3.6 g.	The mean sputum volume in the oscillating device group was 0.9 g higher (1.72 g lower to 3.52 g higher).	NA	14 (1 study)	⊕⊕⊝⊝ low5,7
Sputum: weight (dry or wet) (g) Follow‐up: up to 2 weeks	3 out of 5 studies reported no statistically significant difference between oscillating devices and breathing technique in terms of sputum weight (g). 2 out of 5 studies reported that a significantly greater weight of sputum was yielded using breathing techniques compared to oscillating devices.		NA	92 (5 studies)	⊕⊕⊝⊝ low3,4
Frequency of exacerbations2 Follow‐up: NA	Outcome not reported in any study.		NA	NA	NA
Participant‐reported satisfaction with treatment intervention Follow‐up: up to 2 weeks	Some differences were reported between treatment groups in single domains of satisfaction questionnaires or measurement scales (in favour of or against oscillating devices). Overall across the 5 studies, no consistent differences were reported in terms of satisfaction of any treatment intervention.		NA	92 (5 studies)	⊕⊕⊝⊝ low3,4
*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. 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). CI: confidence interval; FEF25‐75 : mid‐expiratory flow; FEV₁: forced expiratory volume at one second;FVC: forced vital capacity; HFCWO: high frequency chest wall oscillation;L: litres; MD: mean difference; NA: not applicable.
GRADE Working Group grades of evidence High quality: Further research is very unlikely to change our confidence in the estimate of effect. Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low quality: 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 quality: We are very uncertain about the estimate.

1. The oscillating devices included in the trials under this comparison were HFCWO, flutter and cornet.

2. Frequency of exacerbations were measured as defined by Rosenfeld as a consequence of the treatment intervention (Rosenfeld 2001).

3. Downgraded once due to risk of bias; judgements of high risk of bias across some of the included studies due to reasons such as lack of blinding of participants clinicians and outcome assessors, incomplete outcome data and selective reporting (see Risk of bias in included studies for further information)

4. Downgraded once due to imprecision: many included studies had very small sample sizes, short treatment durations and employed cross‐over designs. As results were not presented from paired analyses for these studies, we treated the cross‐over trials as if they were parallel trials which is a conservative approach as it does not take into account within‐patient correlation. Sensitivity analyses indicates that results were robust to this approach.

5. Downgraded once due to risk of bias: the single included study was at high risk of bias due to lack of blinding and reported limited information regarding other aspects of the methodological design

6. Downgraded once due to serious imprecision: a single cross‐over study recruiting only seven participants over a 5‐day period contributed to the outcome and no numerical data were available.

7. Downgraded once due to imprecision: a single cross‐over study recruiting only 14 participants contributed to the outcome.