Air purifiers for reducing the incidence of acute respiratory infections in Australian residential aged care facilities : A study protocol for a randomised control trial

Introduction: Adults living in Residential Aged Care Facilities (RACFs) are highly susceptible to seasonal respiratory infections. Evidence indicates that the aerosols contaminated with virus particles in closed indoor spaces may play a significant role in the transmission of respiratory infections. In this protocol paper, we outline details of a planned RCT which aims to evaluate the effectiveness of portable in room air purifiers in reducing the risk of ARIs among residents in Australian RACFs.

This study uses a multi-centre double-blind randomised crossover design. Three RACFs in a regional area of New South Wales will be invited to participate in the study. Air purifiers with or without high-efficiency particulate absorbing (HEPA) filters will be placed in the rooms of residents who are enrolled in the trial. The primary outcome will be a reduction in the incidence of ARI and the secondary outcomes will be the time to first infection, number of emergency department admissions, hospital admissions, and medical consultations due to an ARI.

Conclusion: To our knowledge, this will be the first RCT using air purifiers in resident rooms to identify their effect in reducing ARIs in RACFs. If our findings indicate some potential benefit for in-room air purification, it will help provide support and justification for larger trials, which may include a facility wide approach to air purification.