Coronavirus: social distancing has greatest impact in densely populated areas
14 July 2020
Social distancing measures introduced by the UK government to reduce the spread of coronavirus have been most effective in areas of high population density, according to research by Dr Peter Tammes from the University of Bristol’s Centre for Academic Primary Care.
The study, published in BJGP Open, looked at weekly coronavirus incidence rates per 100,000 population in 149 upper tier local authorities in England between 16 March and 19 April 2020, the five-week period after social distancing measures were introduced.
Local authorities were divided into quartiles according to population density. Quartile 1 included those with the lowest population density and quartile 4 those with the highest population density.
Using data from the Public Health England Dashboard, which provides daily cumulative counts of laboratory-confirmed cases of COVID-19, the study found that:
- incidence rates of coronavirus peaked in the week of 30 March to 5 April
- local authorities in the quartile with the highest population density had higher coronavirus incidence rates (46.2 per 100,000), adjusted for age, ethnicity, life expectancy and socioeconomic class, than those in the lower density quartiles (Q1: 33.3 per 100,000; Q2: 35.9) at this time
- thereafter, as social distancing measures took effect, incidence rates dropped most in most densely populated local authorities to a rate of 22.4 per 100,000 in the week of 13-19 April, compared to 31.4 per 100,000 in quartile 1, 34.2 per 100,000 in quartile 2, and 43.2 per 100,000 in quartile 3 in the same period.
Dr Tammes, Senior Research Associate in Primary Health Care at the Centre for Academic Primary Care, said: “This study shows that social distancing measures have the greatest effect in reducing the spread of coronavirus in the most densely populated areas. This is important to note as it points to a greater risk of rapid and dramatic resurgence of the virus in these areas as lockdown eases and social distancing rules are relaxed.
“More research is needed to understand why areas of high population density benefit most from social distancing measures. This may inform policy to ease social distancing restrictions safely.”
The study was funded by the University of Bristol’s COVID-19 research support fund.
Paper: Social distancing, population density, and spread of COVID-19 in England: a longitudinal study by Peter Tammes. Published in BJGP Open. 7 July 2020.
About the Centre for Academic Primary Care
The Centre for Academic Primary Care (CAPC) at the University of Bristol is a leading centre for primary care research in the UK, one of nine forming the NIHR School for Primary Care Research. It sits within Bristol Medical School, an internationally recognised centre of excellence for population health research and teaching. Follow us on Twitter: @capcbristol.
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