Study design (if review, criteria of inclusion for studies)
Cochrane reviews of randomised or quasi-randomised controlled trials (including cross-over trials)
people with CF diagnosed on the basis of clinical criteria and sweat testing or genotype analysis.
An airway clearance technique, either as a single technique or as a combination of techniques, compared with no intervention, with coughing, or with another airway clearance technique. The airway clearance techniques included: Conventional chest physiotherapy; Positive expiratory pressure (PEP) mask therapy; Active cycle of breathing techniques; Autogenic drainage; Airway oscillating devices; Mechanical percussive devices and external high frequency chest compression devices; Exercise; Other techniques.
Primary outcomes 1. Lung function (FEV1) 2. Patient preference 3. Quality of life (total scores or domain scores from validated instruments such as Cystic Fibrosis Questionnaire-Revised (Quittner 2009) or the Quality of Well-Being Scale) Secondary outcomes 1. Adverse events 2. Other measures of lung function i) FVC, ii) FEF25â75 3. Number of exacerbations 4. Sputum i) weight (dry or wet) ii) volume (dry or wet) 5. Lung clearance index (LCI)
We included six Cochrane Reviews, one of which compared any type of chest physiotherapy with no chest physiotherapy or coughing alone and the remaining five reviews included headâtoâhead comparisons of different airway clearance techniques. All the reviews were considered to have a low risk of bias. However, the individual trials included in the reviews often did not report sufficient information to adequately assess risk of bias. Many trials did not sufficiently report on outcome measures and had a high risk of reporting bias. We are unable to draw definitive conclusions for comparisons of airway clearance techniques in terms of FEV1, except for reporting no difference between PEP therapy and oscillating devices after six months of treatment, mean difference â1.43% predicted (95% confidence interval â5.72 to 2.87); the quality of the body of evidence was graded as moderate. The quality of the body of evidence comparing different airway clearance techniques for other outcomes was either low or very low.
There is little evidence to support the use of one airway clearance technique over another. People with cystic fibrosis should choose the airway clearance technique that best meets their needs, after considering comfort, convenience, flexibility, practicality, cost, or some other factor. More longâterm, highâquality randomised controlled trials comparing airway clearance techniques among people with cystic fibrosis are needed.