The impact of lockdown measures on COVID-19: a worldwide comparison

Papadopoulos, Dimitris I; Donkov, Ivo; Charitopoulos, Konstantinos; Bishara, Samuel

Objective We aimed to determine which aspects of the COVID-19 national response are independent predictors of COVID-19 mortality and case numbers. Design Comparative observational study between nations using publically available data Setting Worldwide Participants Covid-19 patients Interventions Stringency of 11 lockdown policies recorded by the Blavatnik School of Government database and earliness of each policy relative to first recorded national cases Main outcome measures Association with log10 National deaths (LogD) and log10 National cases (LogC) on the 29th April 2020 corrected for predictive demographic variables Results Early introduction was associated with reduced mortality (n=137) and case numbers (n=150) for every policy aside from testing policy, contact tracing and workplace closure. Maximum policy stringency was only found to be associated with reduced mortality (p=0.003) or case numbers (p=0.010) for international travel restrictions. A multivariate model, generated using demographic parameters (r2=0.72 for LogD and r2=0.74 for LogC), was used to assess the timing of each policy. Early introduction of first measure (significance p=0.048, regression coefficient {beta}=-0.004, 95% confidence interval 0 to -0.008), early international travel restrictions (p=0.042, ({beta}=-0.005, -0.001 to -0.009) and early public information (p=0.021, {beta}=-0.005, -0.001 to -0.009) were associated with reduced LogC. Early introduction of first measure (p=0.003, {beta}=-0.007, -0.003 to -0.011), early international travel restrictions (p=0.003, {beta}=-0.008, -0.004 to-0.012), early public information (p=0.003, {beta}=-0.007, 0.003 to -0.011), early generalised workplace closure (p=0.031, {beta}=-0.012, -0.002 to -0.022) and early generalised school closure (p=0.050, {beta}=-0.012, 0 to -0.024) were associated with reduced LogC. Conclusions At this stage in the pandemic, early institution of public information, international travel restrictions, and workplace closure are associated with reduced COVID-19 mortality and maintaining these policies may help control the pandemic.