—Physical distancing interventions are associated with a reduced incidence of COVID-19 globally, according to a study published online July 15 in The BMJ.
Nazrul Islam, M.B.B.S., M.P.H., Ph.D., from the University of Oxford in the United Kingdom, and colleagues conducted a natural experiment using an interrupted time series analysis involving data from 149 countries or regions to examine the correlation between physical distancing interventions (closures of schools, workplaces, and public transport; restrictions on mass gatherings and public events; and restrictions on movement) and the incidence of COVID-19 globally.
The researchers found that implementation of any physical distancing intervention correlated with a reduction in COVID-19 incidence (incidence rate ratio [IRR], 0.87). When the other four distancing interventions were in place, there was no correlation for closure of public transport with any additional reduction in COVID-19 incidence (pooled IRR with and without public transport closure, 0.85 and 0.87, respectively).
Similar overall effectiveness was suggested using data from 11 countries when school closures, workplace closures, and restrictions on mass gatherings were in place (pooled IRR, 0.85). Compared with a delayed implementation of lockdown after other physical distancing interventions were in place, earlier implementation of lockdown was associated with a larger decrease in COVID-19 incidence (pooled IRR, 0.86 versus 0.90).
“As the pandemic continues to evolve, it will be crucial to repeat and extend this analysis to assess the impacts of interventions in the longer term, as well as to study combinations and sequence of the lifting of physical distancing restrictions,” the authors write.