2546: A cluster randomised controlled trial of Air Filtration to  prevent symptomatic winter Respiratory Infections  (including COVID-19) in care homes (AFRI-c)
Source: gov.uk (2025-08-04)

This study aims to find out if air filters can reduce winter respiratory infections (including COVID-19) in care home residents.

About the project

What the project aims to do

A randomised controlled trial 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. This study aims to find out if air filters can reduce winter respiratory infections (including COVID-19) in care home residents.

Why this project is important

COVID-19 is mostly spread by airborne droplets and infection has led to over one million deaths worldwide, with older care home residents especially vulnerable to infection. Between 2 March and 12 June 2020, there were 66,112 deaths in UK care home residents of which 29% were related to COVID-19. The number of people living in UK care homes is projected to nearly double in the next 20 years, from 380,000 to 700,000. Care homes have also been identified as ‘reservoirs’ of antimicrobial resistance, which is considered a major challenge to public health.

Aerosols and airborne droplets contain some of the most pathogenic respiratory viruses (such as COVID-19), bacteria, and gastrointestinal viruses (such as Norovirus). Once inhaled or swallowed, these pathogens can invade the respiratory system causing infection. Airborne particles may also land on surfaces and hands, increasing the chance of direct and indirect transmission. Reducing airborne pathogens could therefore prevent respiratory as well as urinary, gastrointestinal and skin infections, transmitted via contamination of hands and medical equipment in care homes.

Evidence shows that high efficiency particulate (HEPA) air filters can capture relevant airborne particles, but it is not known whether portable filters can prevent infections in care homes and other indoor settings. Research is urgently needed to help health and social care providers know whether portable HEPA filters are clinically and cost-effective in reducing respiratory (and other) infections in care homes.

Who the data is about

participant to meet the criteria for entry into the AFRI-c study

extant consent in place

registered in England

How the data will be used

The University of Bristol will recruit up to 74 care homes. Care homes will be allocated into 2 treatment groups. Approximately 10 participants in each care home will be approached for consent either to have an air filter in their private room and access to their medical records, or access to their medical records only (control group).

The participating care homes will collect de-personalised data about infection symptoms and falls or near falls. The researchers will also collect information regarding outbreaks within the care homes for all residents and staff from the UKHSA. With resident consent, identifiable information will be shared with the UKHSA (such as initials, NHS number, full name, date of birth) to link to relevant information (for example, covid test results and mortality data) from individual’s records.

How often data is needed

Annual release

How this project will benefit public health and the public

This study will potentially improve the environment of care homes for residents to reduce symptoms of infections in the future. The information gained from this research could also help to inform public health guidance and policy around infection control and air filter use in the future. In addition, involvement in the trial may help care home residents, their family or carers understand more about infection prevention and control strategies.

Planned project outputs and communication
- peer-reviewed scientific journals
- internal report (publication not intended)
- conference presentation
- website
- press release
Lawful processing of personal and special category personal data

Under the UK General Data Protection Regulation (UK GDPR), the data required for this project is classified as special category personal data. This means that, in order for the processing of this data to be lawful, there must be both a lawful basis for processing under Article 6 and a separate condition for processing under Article 9 of the UK GDPR.

Legal basis for using personal data (Article 6)

UK GDPR Article 6(e): processing is necessary for the performance of a task carried out in the public interest or in the exercise of official authority vested in the Controller.

Legal basis for using special category personal data (Article 9)

UK GDPR Article 9(2)(j): processing is necessary for archiving purposes in the public interest, scientific or historical research purposes or statistical purposes in accordance with Article 89(1) based on Union or Member State law which shall be proportionate to the aim pursued, respect the essence of the right to data protection and provide for suitable and specific measures to safeguard the fundamental rights and the interests of the data subject.

Common law duty of confidentiality

The data needed for this project includes Confidential Patient Information — meaning data that can both identify an individual and relate to their health or care, shared in a context where confidentiality is expected and protected.

Confidential Patient Information is subject to a strict duty of confidentiality. It can only be used with the patient’s explicit consent or under specific legal provisions that permit its use — for example, for medical research or public health purposes.

How is the duty of confidentiality set aside

Explicit informed consent.

National Data Opt-Out

Opt-out preferences will not be applied.

This is because the national data opt-out does not apply to anonymised data.

Digital Object Identifier

Not assigned for this release.

Organisatons Research Organisation Registry (ROR) ID

ROR ID (https://ror.org/0524sp257)