Title: Air Filtration to reduce Respiratory Infections (including COVID-19) in care homes: the AFRI-c cluster randomised controlled trial with nested internal pilot, process and economic evaluations
Funder: Department of Health and Social Care

Abstract: Respiratory infections, such as COVID, coughs, colds and ‘flu (influenza) are common in all age groups, but elderly people in care homes are more vulnerable because they are frail, have multiple health conditions and infections are easily spread within the shared space._x000D_ _x000D_ As COVID has shown, respiratory infections in care home residents are also more serious, with many requiring hospital care and many not recovering. Less severe infections still require antibiotics, contributing to antibiotic resistance - itself considered a public health crisis._x000D_ _x000D_ Respiratory infections are mainly spread when people breathe in or swallow airborne droplets containing germs. These are produced when others cough or sneeze. Care homes are required to follow the NHS ‘Code of Practice on Infection, Prevention and Control (IPC)’, but this focuses on preventing infections spread directly from contaminated hands or bodily fluids, and indirectly through germs settling on furniture or medical equipment._x000D_ _x000D_ There are currently 220,000 people over 65 years living in UK care homes. This number is predicted to double by 2040, and as highlighted by the devastating effects of COVID in care homes, reducing the spread of infections in care homes is a research priority._x000D_ _x000D_ Air filtration seems an obvious solution since high efficiency particulate air (HEPA) filters can quickly remove germs from the air. For years, they have been built into hospital operating theatres and transplant wards to prevent infections. But their use has not been tested in standard hospital wards or in care homes before. Now that HEPA filters are built into portable units available for domestic use, they can be placed in these locations with relative ease._x000D_ _x000D_ We talked to residents, carers and staff at three care homes about the practicalities of putting air filters in communal areas and residents’ rooms. Residents told us getting old and staying healthy is a priority, that AFRI-c is a ‘no brainer’ and that air filters would need to be installed carefully to minimise the risk of falls. Staff liked that air filters would add to existing IPC measures without disrupting the ‘flow of care’. One air filter (made by PhilipsTM) was preferred because it was sturdier, had a night-time quiet mode, and a visible indicator of air cleanliness. Post-COVID, staff told us we should run the study remotely, with telephone and video support from the study team. They told us they feel confident this would be possible as they are now using Zoom and other online systems for many routine tasks._x000D_ _x000D_ After care homes agree to place air filters in communal areas for one winter (September to April), up to 10 residents will be consented to have an air filter in their room, and to work with staff to report the number of infections they experience for the same period. We will divide the care homes into two groups at random (so they are similar), with one group receiving the air filters, and the other continuing with usual care. The study team will support all aspects of the study, without physically visiting the homes._x000D_ _x000D_ Our experience suggests about 1 in 3 care homes and 1 in 3 residents will want to help. We will allow sufficient time to talk to relatives and friends of residents who do not have capacity (e.g. people with dementia) so they can take part. Our design also takes account of the 40% of residents expected to drop out of the study through moving away, illness or death.

Lay abstract: Aim:_x000D_ The overall aim is to investigate the clinical and cost effectiveness of portable HEPA air filters in reducing symptomatic winter respiratory infections (including COVID-19) in residents of older people’s care homes. _x000D_ _x000D_ BACKGROUND_x000D_ To date SARS-CoV-2 infection has led to over one million deaths worldwide, with elderly care home residents disproportionately affected. There are currently 220,000 people over 65 years living in UK care homes, and this number is predicted to double by 2040. Respiratory infections (including SARS-CoV-2) are mainly spread when people breathe in or swallow airborne droplets containing germs. _x000D_ _x000D_ Care homes are obliged to follow DH&SC ‘Code of Practice on the Prevention and Control of Infections’, but airborne transmission remains largely unmitigated. Portable high efficiency particulate (HEPA) air filtration units trap droplet and aerosolised bacteria and viruses, but research is urgently needed to help health and social care providers know whether portable HEPA filters are clinically and cost-effective in reducing symptomatic respiratory infections._x000D_ _x000D_ OBJECTIVES_x000D_ Primary objective: To investigate the effect of portable HEPA air filters in private residential, communal and staff only rooms on residents’ symptomatic winter respiratory infection episodes (including COVID-19) in care homes with air filters compared with residents in care homes without air filters._x000D_ _x000D_ Secondary objectives:_x000D_ 1. To determine the effect of air filters installed in private residential, communal and staff only rooms during the winter months versus no air filters on residents’: _x000D_ a. Respiratory infections (symptomatic days) _x000D_ b. Fever and/or delirium and/or acute deterioration in physical ability (episodes and symptomatic days) _x000D_ c. Gastro-intestinal infection (episodes & symptomatic days) _x000D_ d. Antibiotic use (courses prescribed/days consumed) _x000D_ e. Number of falls/near falls _x000D_ f. Possible SARS-CoV-2 and Influenza-like illness infection episodes _x000D_ g. PCR confirmed SARS-CoV-2 infections _x000D_ h. PCR (or other test) confirmed Influenza A&B infections _x000D_ i. Other microbiologically confirmed infections including Streptococcal, Meningococcal, Respiratory Syncytial Virus, Norovirus and Human Metapneumovirus infections _x000D_ j. GP diagnosed respiratory (including COVID), gastrointestinal, skin and urinary infections _x000D_ k. Perception of care home environment _x000D_ _x000D_ 2. To determine the effect of air filters versus no air filters installed during winter months on staff members’: _x000D_ a. Sickness days away from work _x000D_ b. Change over time in staff confidence in, and use of, infection prevention and control strategies. _x000D_ c. PCR confirmed SARS-CoV-2 infections _x000D_ d. PCR (or other test) confirmed Influenza A&B infections _x000D_ e. Other microbiologically confirmed infections including Streptococcal, Meningococcal, Respiratory Syncytial Virus, Norovirus and Human Metapneumovirus infections _x000D_ f. Perception of care home environment _x000D_ _x000D_ 3. To determine the cost-effectiveness of air filter use in reducing symptomatic respiratory infection episodes(to include hospital admissions, deaths and cause of death). _x000D_ _x000D_ 4. To identify the views of care homes, local authority and CCG commissioners on intervention maintenance, sustainability and possible dissemination. _x000D_ _x000D_ 5. In the intervention arm: _x000D_ a. To explore staff, resident and residents’ relatives' attitudes to and perceptions and experiences of air filters and determine factors influencing their use, including acceptability, satisfaction and potential benefits and harms. _x000D_ b. To assess the fidelity of the intervention. _x000D_ _x000D_ DESIGN_x000D_ A two-arm, 1:1 cluster randomisation controlled trial of portable HEPA air filters versus no air filters for reducing symptomatic winter respiratory infections (including COVID-19) in care home residents with mixed method process and economic evaluation. _x000D_ _x000D_ PROJECT TIMETABLE_x000D_ The funding start date for this trial is 01 July 2021 and the study duration is expected to be 42 months, to 31st December 2024._x000D_ _x000D_ ANTICIPATED IMPACT AND DISSEMINATION_x000D_ Preventing infections could improve resident and staff quality of life, resident quantity of life, and the efficient use of health and social care resources, all expected to increase as the population ages. We will create a dissemination plan our collaborators and PPI, outputs to include: plain English summaries; publications/ presentations in high impact journals/ conferences; online webinars for care home managers, CCG and local authority commissioners.

Research activity codes: 3.2 INTERVENTIONS TO ALTER PHYSICAL AND BIOLOGICAL ENVIRONMENTAL RISKS
Health categories: INFECTION