Air Filtration to reduce Respiratory Infections in older people’s care homes: the AFRI cluster randomised controlled trial with nested internal pilot, qualitative and economic evaluations

 

Funding

National Institute for Health and Care Research (NIHR) Health Technology Assessment (HTA) Ref. NIHR129783.

What is the problem?

Respiratory infections, such as coughs, colds and ‘flu (influenza) are common in all age groups, but elderly people who live in care homes are more vulnerable because they are frail, have multiple health conditions and infections can easily spread within the shared living space.
For the same reasons, infections in care home residents are also more serious, with many requiring GP care and antibiotics, contributing to antibiotic resistance. Others need hospital care and many do not recover.

Respiratory infections are mainly spread when people breathe in or swallow airborne droplets
containing germs. These are produced when others cough, sneeze or vomit, and this is the most
difficult infection route to control. Care homes are required to follow the NHS ‘Code of Practice on the Prevention and Control of Infections’, but this focuses mainly on preventing infections which are spread from contaminated hands or bodily fluids, and indirectly with germs on furniture or medical equipment.

There are currently 220,000 people over 65 years living in care homes in the UK. This number is
predicted to double by 2040, so it is not surprising that reducing the spread of infections in care homes is a research priority.

What is the aim of the research?

Air filtration seems an obvious solution since high efficiency particulate air (HEPA) filters quickly
remove germs from the air and are now inside some portable units available for domestic use. For years, HEPA filters have been built into hospital operating theatres and bone marrow transplant wards to prevent infections. And ultraviolet treatment has been shown to reduce germs in the air, and infections in hospital wards. However, the effects of air filtration have not been tested in standard hospital wards or in care homes before.

 

How will this be achieved?

We talked to residents, carers and staff at three care homes about the practicalities of putting air filters in communal areas and residents’ rooms. They told us getting old and staying healthy is a priority, that the AFRI study 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 infection control measures without disrupting the ‘flow of care’. One model (made by Philips) was preferred to another manufacturer’s because it was sturdier, had a night-time quiet mode, and a visible indicator of air cleanliness. None of the staff was aware of residents already using air filters.

After consenting care homes to install air filters in communal areas for one winter (September to April), we will invite residents to consent to air filters in their rooms and to tell us how many infections they experience. We will divide the care homes into two groups at random (so they are as similar as possible), with one group receiving the air filters, and the other continuing with usual care. The study team will visit all the care homes weekly to measure infections (because staff told us they would not have time to do this).

Our experience suggests about 1 in 3 care homes and 1 in 3 residents will want to help. Bristol
Commissioners are responsible for 186 care homes and will endorse AFRI to these homes. We have allowed several months 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.

Who is leading the research?

Professor Alastair D Hay, Professor of Primary Care, Bristol Medical School.

Further information:

For more information or to get involved in this project, please contact bnssg.research@nhs.net.

The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care.