Use of airway clearance therapy in children hospitalised with acute lower respiratory tract infections in a South African paediatric hospital.

This was a single-hospital retrospective folder review, so it describes routine practice rather than testing whether airway clearance therapy works. Clinicians, not the study, chose who received ACT, and children receiving ACT were more likely to have bacterial organisms, chronic comorbidities, neuromuscular disorders, previous respiratory hospitalisation or ventilation, so worse outcomes cannot be separated from sicker patients. The study design cannot determine causality between ACT and longer hospital stay or mortality. 93 folders were missing, and duplicate admissions were handled by collecting demographic data only for the first admission, which may affect descriptive counts. Culture results were available in only 245 admissions (17.0%), and sampling was not standardised, so organism proportions may overestimate some pathogens and miss others. The presumed nosocomial group may be biased because many children in that category were identified through physiotherapy referral rather than diagnostic code search. Written informed consent was waived because the study was retrospective.

Do not read the association between ACT and longer hospital stay or mortality as proof that ACT harmed children. The children who received ACT were more likely to have bacterial organisms, comorbidities and ventilation, and this study cannot determine cause.