Care homes that are heavily reliant on agency staff may be two-and-a-half times more likely to spread Covid-19 to their residents, a study found.
In homes where bank staff made up 10% of the total staff, the risk of infection for residents increased by 2.5 times compared with those with sufficient staff and by 1.5 times compared with being understaffed.
The use of agency workers posed the biggest infection-risk impact in smaller care homes.
The research by Strathclyde University confirms existing observational evidence cited in The Lancet that the use of agency staff increases the risk of infection for residents compared to staff who work within a single facility.
The model did not account for potentially reduced compliance with measures in understaffed scenarios and lower quality care.
While testing of agency staff was found to be an important risk mitigation measure, the modelling revealed that forming bubbles of care homes and restricting agency staff to only working within a bubble had limited impact on the spread of Covid.
Dr Itamar Megiddo of the Department of Management Science, co-author of the study, said: “Care homes are heavily reliant on agency/bank staff due to staff shortages.
“Consistent with other Covid-19 prevalence surveys in care homes in the UK, our findings would support policies for limiting the movement of staff working across multiple care homes if their testing compliance is low.
“While regular testing with high compliance can help reduce infections, the risk of spread is still higher in homes using agency staff.
“At the same time, we need to recognise that these staff are necessary to maintain quality of care and of the life of residents; an element our study did not explore.”