Shielding those at highest risk from Covid-19 during the first wave of the pandemic may not have been as effective at protecting them from infection and death as hoped, according to a new study.
The research – led by the University of GlasgowLocated in Glasgow, Scotland, the University of Glasgow is a public research university that was founded in 1451 making it the fourth-oldest university in the English-speaking world. As a research-intensive university, it is a member of the Russell Group, Universitas 21, and the Guild of European Research-Intensive Universities. ”>University of Glasgow and published in Scientific Reports – found that, between March and May 2020, patients advised to shield in NHS Greater Glasgow and Clyde (NHSGGC) experienced higher rates of infection and death than those not advised to shield.
Many western countries, including Scotland, used shielding (extended self-isolation) of people presumed to be at high risk from COVID-19First identified in 2019 in Wuhan, China, Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It has spread globally, resulting in the 2019–20 coronavirus pandemic.”>COVID-19 to protect them and reduce healthcare demand.
The study looked at data from over 1.3 million patients registered with GP practices in NHSGGC. Of this group, 27,747 individuals had been advised to shield (self-isolate for extended periods of time), and a further 353,085 individuals had not been advised to shield but were categorized by the researchers as at medium risk of Covid-19 due to health conditions such as diabetes.
The authors found that, compared to low-risk individuals (the remaining 934,239 people in the study), people who had been advised to shield were eight times more likely to have confirmed infections.
Those advised to shield were also five times more likely to die following confirmed infection, whilst moderate-risk individuals were four times more likely to have confirmed infections than the low-risk group, and five times more likely to die following confirmed infection.
In the shielded group, there were 299 (1.1%) confirmed infections and 140 (0.51%) deaths from Covid-19. In the moderate risk group, there were 1,859 (0.53 %) confirmed infections and 803 (0.23%) deaths; and in the low-risk group, there were 1,190 (0.13% confirmed infections) and 84 (0.01%) deaths from Covid-19.
The study also showed that an age of 70 and over accounted for 49.55% of deaths.
Professor Jill Pell, Director of the University of Glasgow’s Institute of Health and Wellbeing, said: “Our study highlights that to effectively protect high-risk individuals, shielding should be used alongside other population-wide measures such as physical distancing, face coverings, and hand hygiene.
“Our study also showed that shielding may be of limited value in reducing burden on health services because, in spite of the shielding strategy, high-risk individuals were at increased risk of death. We believe that, to be effective as a population strategy, shielding criteria would have needed to be widely expanded to include other criteria, such as the elderly.”
The study linked GP, prescribing, laboratory, hospital, and death records and compared COVID-19 outcomes among shielded and non-shielded individuals in the West of Scotland.
Reference: “Comparison of COVID-19 outcomes among shielded and non-shielded populations” by Bhautesh D. Jani, Frederick K. Ho, David J. Lowe, Jamie P. Traynor, Sean P. MacBride-Stewart, Patrick B. Mark, Frances S. Mair and Jill P. Pell, 27 July 2021, Scientific Reports.