A pragmatic cluster randomised controlled trial of air filtration to prevent symptomatic winter respiratory infections (including COVID-19) in care homes (AFRI-c) in England: Trial protocol

PLoS One. 2024 Jul 23;19(7):e0304488. doi: 10.1371/journal.pone.0304488. eCollection 2024.

Abstract

Background: Respiratory tract infections are readily transmitted in care homes. Airborne transmission of pathogens causing respiratory tract illness is largely unmitigated. Portable high-efficiency-particulate-air (HEPA) filtration units capture microbial particles from the air, but it is unclear whether this is sufficient to reduce infections in care home residents. The Air Filtration to prevent symptomatic winter Respiratory Infections (including COVID-19) in care homes (AFRI-c) randomized controlled trial will determine whether using HEPA filtration units reduces respiratory infection episodes in care home residents.

Methods: AFRI-c is a cluster randomized controlled trial that will be delivered in residential care homes for older people in England. Ninety-one care homes will be randomised to take part for one winter period. The intervention care homes will receive HEPA filtration units for use in communal areas and private bedrooms. Normal infection control measures will continue in all care homes. Anonymised daily data on symptoms will be collected for up to 30 residents. Ten to 12 of these residents will be invited to consent to a primary care medical notes review and (in intervention homes) to having an air filter switched on in their private room. The primary outcome will be number of symptomatic winter respiratory infection episodes. Secondary outcomes include specific clinical measures of infection, number of falls / near falls, number of laboratory confirmed infections, hospitalisations, staff sickness and cost-effectiveness. A mixed methods process evaluation will assess intervention acceptability and implementation.

Discussion: The results of AFRI-c will provide vital information about whether portable HEPA filtration units reduce symptomatic winter respiratory infections in older care home residents. Findings about effectiveness, fidelity, acceptability and cost-effectiveness will support stakeholders to determine the use of HEPA filtration units as part of infection control policies.

Publication types

  • Clinical Trial Protocol

MeSH terms

  • Aged
  • Air Filters*
  • COVID-19* / epidemiology
  • COVID-19* / prevention & control
  • COVID-19* / transmission
  • England / epidemiology
  • Humans
  • Nursing Homes
  • Randomized Controlled Trials as Topic
  • Respiratory Tract Infections* / epidemiology
  • Respiratory Tract Infections* / prevention & control
  • SARS-CoV-2 / isolation & purification
  • Seasons*

Grants and funding

This trial is funded by the National Institute for Health and Social Care (NIHR) Public Health Research (PHR) Programme NIHR129783 (https://fundingawards.nihr.ac.uk/award/NIHR129783). The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care. Versuni (previously Philips) provided the air filtration units at a discounted rate. Neither the funder nor Versuni (previously Philips) nor the Sponsor (University of Bristol) have any involvement in the design of the trial, data collection, analysis or interpretation of the data, decision to publish or preparation of the manuscript. The following authors received the award from the NIHR: DR, EH, GM, NT, TW, DM, KS, CM, RK, AH.