Warwick 2004.
| Study characteristics | ||
| Methods | RCT. Cross‐over design Location: single centre in USA. Duration: 2 weeks (2 study days in each week). |
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| Participants | 12 participants (all males) with CF. Mean (range) age 29.2 (19 ‐ 50) years. Consistent sputum producers; all volunteers with no illness within 6 weeks of study. | |
| Interventions | HFCWO versus CPT. HFCWO: 5 minutes at 6 frequencies, followed by 3 huffs and directed coughs at the end of each cycle; treatment time 36 ‐ 40 min. CPT: 10 hand positions, 3 huffs and directed cough after each position treatment lasting about 45 ‐ 50 min. All treatments preceded by nebulisers. |
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| Outcomes | Wet and dry sputum weight measured at end of each session, data reported at end of week 1 and end of week 2. | |
| Notes | As this study also appeared to compare the efficacy of 2 different therapists therefore we cannot be absolutely clear that the HFCWO was solely responsible for any and all improvements in sputum weight. In addition the hand positions used by the therapist were not defined and commonly we would use a variety of 13 postural drainage positions if this was the technique being evaluated. |
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| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Described as randomised but method not discussed. |
| Allocation concealment (selection bias) | Unclear risk | Not discussed. |
| Blinding (performance bias and detection bias) All outcomes | High risk | Not possible to blind participants or clinicians,but paper states "all the subjects were analysed as soon as possible by a single scientist (LGH) with no knowledge of subject source or therapy given" |
| Incomplete outcome data (attrition bias) All outcomes | Unclear risk | Complete data sets for all participants. |
| Selective reporting (reporting bias) | Low risk | No evidence of selective reporting. All parameters measured were discussed. |
| Other bias | High risk | Paper also reports that a natural competition between two different therapists was created. In addition the hand positions used by the therapist were not defined. |