Effectiveness of non-pharmaceutical interventions on COVID-19 transmission in 190 countries from 23 January to 13 April 2020.


This study included 1,908,197 confirmed COVID-19 cases from 190 countries between 23 January and 13 April 2020. The implemented NPIs were categorized into four types: mandatory face mask in public, isolation or quarantine, social distancing and traffic restriction (referred to as mandatory mask, quarantine, distancing, and traffic hereafter, respectively).

To evaluate and compare the effectiveness of four types of non-pharmaceutical interventions (NPIs) in containing the time-varying effective reproduction number (Rt) of COVID-19.

The implementations of mandatory mask, quarantine, distancing and traffic were associated with changes (95%confidence interval, CI) of -15.14% (-21.79% to -7.93%), -11.40% (-13.66% to -9.07%), -42.94% (-44.24% to -41.60%) and -9.26% (-11.46% to -7.01%) in the Rt of COVID-19 compared with those without the implementation of the corresponding measures. Distancing and the simultaneous implementation of two or more types of NPIs seemed to be associated with a greater decrease in the Rt of COVID-19.

Our study indicates that NPIs can significantly contain the COVID-19 pandemic. Distancing and the simultaneous implementation of two or more NPIs should be the strategic priorities for containing COVID-19.

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