A Cochrane review [Abstract] 1 included 35 studies with a total of 1 138 subjects. Data were not published in sufficient detail in most of these studies to perform meta-analysis. One long-term study (7 months) compared oscillatory devices with either conventional physiotherapy or breathing techniques and found statistically significant differences in some lung function parameters in favour of oscillating devices. One study identified an increase in frequency of exacerbations requiring antibiotics whilst using high frequency chest wall oscillation when compared to positive expiratory pressure. There were some small but significant changes in secondary outcome variables such as sputum volume or weight, but not wholly in favour of oscillating devices. Participant satisfaction was reported in 11 studies, but this was not specifically in favour of an oscillating device, as some participants preferred breathing techniques or techniques used prior to the study interventions. The results for the remaining outcome measures were not examined or reported in sufficient detail to provide any high level evidence.
Comment: The quality of evidence is downgraded by study quality (inadequate or unclear allocation concealment) and by inconsistency (heterogeneity in interventions and outcomes, variability in results across studies).
Primary/Secondary Keywords