COVID‐19 pandemic‐related lockdown: response time is more important than its strictness

The rapid spread of SARS‐CoV‐2 and its threat to health systems worldwide have led governments to take acute actions to enforce social distancing. Previous studies used complex epidemiological models to quantify the effect of lockdown policies on infection rates. However, these rely on prior assumptions or on official regulations. Here, we use country‐specific reports of daily mobility from people cellular usage to model social distancing. Our data‐driven model enabled the extraction of lockdown characteristics which were crossed with observed mortality rates to show that: (i) the time at which social distancing was initiated is highly correlated with the number of deaths, r 2 = 0.64, while the lockdown strictness or its duration is not as informative; (ii) a delay of 7.49 days in initiating social distancing would double the number of deaths; and (iii) the immediate response has a prolonged effect on COVID‐19 death toll. Synopsis This study used mobility data obtained from Apple users around the world to explore the effect of lockdown on COVID‐19 related mortality. The results suggest that countries that enforced a strict lockdown could have obtained similar mortality figures with less stringent mobility restrictions. The time at which social distancing was initiated is highly correlated with the number of deaths. No association was observed between the lockdown strictness (or its duration) to the number of deaths. A delay of 7.49 days in social distancing initiation would double the number of deaths. The immediate response has a prolonged effect on COVID‐19 related mortality. Graphical Abstract This study used mobility data obtained from Apple users around the world to explore the effect of lockdown on COVID‐19 related mortality. The results suggest that countries that enforced a strict lockdown could have obtained similar mortality figures with less stringent mobility restrictions.