Background: This analysis aims to assess the association between population restrictive measures and the cumulative number of confirmed COVID-19 cases in the early phase of pandemic .
Methods: We compared mobility data extracted from the Mobility Reports provided by Google with the cumulative number of confirmed cases of COVID-19 of 15 countries provided by John Hopkins University . We compared the number of confirmed COVID-19 cases before and after the peak effect (PE) of population mobility restrictions in each country, defined as the highest percent reduction in mobility measurements .
Results: Time to PE of population mobility restrictions ranged between 16 and 45 days after the report of the index COVID-19 confirmed case in each country . The most frequent reductions in activities were retail & recreation, parks, and transit & stations, ranging from 30% to 90% . Despite this variability in PE among the countries, the predicted smooth effect after the PE of population mobility restrictions was observed in almost all countries .
Conclusions: These data suggest that the reduction in mobility was associated with a decrease in the cumulative total number of COVI-19 cases in each country, underscoring that the use of widely available real-time surveillance data might be a valuable resource during this pandemic