The impact of population mobility on COVID-19 incidence and socioeconomic disparities at the sub-city level in 314 Latin American cities

Kephart, J. L.; Delclos-Alio, X.; Bilal, U.; Sarmiento, O. L.; Barrientos-Gutierrez, T.; Ramirez-Zea, M.; Quistberg, D. A.; Rodriguez, D. A.; Diez Roux, A. V.

Background: Little is known about the impact of changes in mobility at the sub-city level on subsequent COVID-19 incidence or the contribution of mobility to socioeconomic disparities in COVID-19 incidence. Methods: We compiled aggregated mobile phone location data, COVID-19 confirmed cases, and features of the urban and social environments to analyze linkages between population mobility, COVID-19 incidence, and educational attainment at the sub-city level among cities with >100,000 inhabitants in Argentina, Brazil, Colombia, Guatemala, and Mexico from March to August 2020. We used mixed effects negative binomial regression to examine longitudinal associations between changes in weekly mobility (lags 1-6 weeks) and subsequent COVID-19 incidence at the sub-city level, adjusting for urban environmental factors. Findings: Among 1,031 sub-cities representing 314 cities in five Latin American countries, 10% higher weekly mobility was associated with 8.5% (95% CI 7.4% to 9.5%) higher weekly COVID-19 incidence the following week. This association gradually declined as the lag between mobility and COVID-19 incidence increased and was not different from the null at a six-week lag. We found evidence that suggests differences in mobility reductions are a driver of socioeconomic disparities in COVID-19 incidence. Interpretation: Lower population movement within a sub-city is associated with lower risk of subsequent COVID-19 incidence among residents of that sub-city. Implementing policies that reduce population mobility at the sub-city level may be an impactful COVID-19 mitigation strategy that takes equity into consideration and reduces economic and social disruption at the city or regional level.