PIN74 The Impact of Social Distancing on Sars-COV-2 Mortality: A US Analysis

Objectives: Social distancing (SocD) has been rapidly adopted as SARS-CoV-2 infection cases increased This study’s aim was to evaluate the association between the SocD stringency and mortality from SARS-CoV-2 infections Methods: Number of new COVID-19 fatalities and tests performed per day per state was obtained from The COVID Tracking Project Social distancing activity was obtained from Unacast Unacast creates SocD scores using an average of three dimensions based on cellular location data for 15-17 million people per day: the extent of person-to-person encounters, changes in average distance traveled and visitation to non-essential venues compared to a pre-COVID-19 period SocD scores were categorized in this study as follows: <2 (reference), 2-2 9 (lower), 3-3 9 (medium), 4-5 (high) Poisson regression models were built to evaluate the impact of SocD score category on COVID-19 daily mortality, adjusting for population density and daily testing volume The association between SocD_score category and new fatalities were modeled using a 1- to 10-week lag time Results: Models with only 1-week lag showed positive associations between all SocD_score categories and increasing fatalities, the highest mortality proportion ratio (MPR) being observed for the median SocD_score category (MPR: 3 80, 95%CI: 2 07-7 00), suggesting that populations likely adopted higher SocD measures with increasing fatalities in the prior week For the most stringent SocD_score category: models using 2- to 10-week lags showed SocD to be protective for mortality (MPR at 2 weeks: 0 79, 95%CI: 0 46-1 35, minimum MPR observed at week 11: 0 20, 95%CI: 0 10-0 40) For the lower and medium category of SocD_scores, it took 11 weeks to see a protective effect between SocD and fatalities Conclusions: A protective effect of social distancing versus COVID-19 fatalities was shown after 2 weeks for the most stringent, and after 11 weeks, for the more relaxed, SocD measures Further research on other confounders (eg mask usage) is required