The association between a statewide stay-at-home order and motor vehicle injury rates among population sub-groups in West Virginia

Abstract

Objective Little is known about the relationship between Stay-At-Home orders issued by state governments due to the COVID-19 pandemic and their impacts on motor vehicle-related injuries. The purpose of this study was to determine whether the presence of a Stay-At-Home order was associated with lower rates of motor vehicle-related injuries requiring emergency medical treatment among population sub-groups in West Virginia (i.e., males, females, 0-17, 18-25, 26-45, 46-65, ≥66 years old). Methods A Stay-At-Home order was in effect in West Virginia from March 23-May 4, 2020. Counts of individuals who incurred motor-vehicle-related injuries that required emergency medical treatment were obtained from the Centers for Disease Control and Prevention’s National Syndromic Surveillance Program from January 1 thru September 6 of 2019 and 2020. Counts were obtained by week-year and by population sub-group in West Virginia. The presence of the Stay-At-Home order was binary coded by week. Negative binomial regression was used to assess the relationship between the presence of a Stay-At-Home and injury rates. 2019 population sub-group estimates were obtained from the United States Census Bureau and used as offsets in the models. Models were also adjusted for year and vehicle miles traveled by week-year. Results There were 23,418 motor-vehicle related injuries during the study period. The presence of the Stay-At-Home order was associated with 44% less injuries overall [Incident Rate Ratio (IRR)=0.56, 95% CI 0.48, 0.64]. Females experienced fewer injuries than males (IRR = 0.49 vs 0.63, respectively) and the number of injuries decreased with age (p-value 0.031) when comparing time periods when the Stay-At-Home was in effect compared to times when it was not. Conclusions West Virginia’s Stay-At-Home order was associated with lower motor-vehicle injury rates requiring medical treatment across all population sub-groups. Most population sub-groups likely altered their travel behaviors which resulted in lower motor-vehicle injury rates. These findings may inform future policies that impose emergency travel restrictions in populations.