The aerosol spread of SARS-CoV-2 has been a major challenge for healthcare facilities and there has been increased use of supplementary air filtration to mitigate SARS-CoV-2 transmission. Appropriately sized supplementary room air filtration systems could greatly reduce aerosol levels throughout ward spaces. Portable air filtration systems, such as those combining high efficiency particulate air (HEPA) filters and ultraviolet (UVC) light sterilisation, may be a scalable solution for removing respiratory viruses such as SARS-CoV-2. This rapid review aimed to assess the effectiveness of supplementary air cleaning devices in health service settings such as hospitals and dental clinics (including, but not limited to HEPA filtration, UVC light and mobile UVC light devices) to reduce the transmission of SARS-CoV-2.One systematic review (Daga et al. 2021), three observational studies (Conway Morris et al. 2022, Thuresson et al. 2022, Sloof et al. 2022), one modelling study, (Buchan et al. 2020) and two experimental studies (Barnewall & Bischoff 2021, Snelling et al. 2022) were found. Outcome measures included symptom scores, presence of SARS-CoV-2 RNA in sample counts, general particulate matter counts, viral counts, and relative risk of SARS-CoV-2 exposure. From real world settings, the systematic review assessed the effectiveness of HEPA filtration in dental clinics (Daga et al. 2021), two additional observational studies assessed HEPA and UV light in UK hospital settings (Conway Morris et al. 2022, Sloof et al. 2022) and one observational study included mobile HEPA-filtration units in Swedish hospitals (Thuresson et al. 2022). Studies were published from 2020 onwards.Real world evidence suggests supplementary air systems have the potential to reduce SARS-CoV-2 in the air and subsequently reduce transmission or infection rates but further research, with study designs having lower risk of bias, is required. HEPA filters alongside UVC light could provide the most notable reductions in SARS-CoV-2 counts, although the supporting evidence relates to HEPA/UVC filtration, and this review does not provide evidence on the effectiveness of other potential supplementary air filtration systems that could be used. Evidence is limited on the optimum air changes per hour needed and the positioning of air filtration units in rooms.Funding statementThe Wales Centre for Evidence Based Care was funded for this work by the Wales COVID-19 Evidence Centre, itself funded by Health & Care Research Wales on behalf of Welsh Government.

The use of personal protective equipment (PPE) is a cornerstone of infection prevention and control guidelines and was of increased importance during the COVID-19 pandemic. Adherence with prescribed guidelines for the use of PPE and their applicability to the working practices of staff in general practitioner (GP) and ambulance settings have been a growing concern. The aim of this rapid review was to assess the barriers, facilitators, and potential adverse outcomes of the use of PPE in these specific settings. Included studies were published from 2020 to November 2022. We identified four systematic reviews, a rapid review, a retrospective chart review, and a prospective quantitative survey study. Outcome measures were broadly focused on physical adverse outcomes from the use of PPE, but also included barriers and facilitators to the use of PPE in varied healthcare settings. The five reviews covered a broad range of health and care settings, which included GP and ambulance settings, but not as a specific focus. Both the retrospective chart review and the prospective survey study took place in an ambulance or emergency response setting. Overall confidence in the body of evidence is low. Extended use of PPE is associated with an increased occurrence of adverse physiological events, such as pressure ulcers and de novo headaches. Evidence indicates that adherence with PPE guidance is primarily influenced by organisational communication and workplace cultures. In ambulance settings, adherence may also be affected by dispatch codes and indicative symptoms reported during the initial call. Policy implications: As there is evidence to suggest that usage of PPE increases risk of adverse effects in healthcare workers, this should be at the forefront of considerations when developing or reviewing new and existing infection prevention and control measures. If new policy regarding the use and implementation of PPE is to be developed, effective communication and dissemination should be a priority, as this was identified as a barrier to adherence. This review has identified a significant paucity of evidence in the settings of interest and is reliant on examining evidence that represents a large variety of health and care settings. It is important to acknowledge there may be some issues specific to Ambulance and GP settings that are not covered by this review. This does impact the validity of this reviews conclusions.