Sara J. Cromer, MD{1,2,3}; Chirag M. Lakhani, PhD{2,3}; Deborah J Wexler, MD, MSc{1,2}; Sherri-Ann M. Burnett-Bowie, MD, MPH{2,4}; Miriam Udler, MD, PhD{1,2,3}; Chirag J. Patel, PhD{2}

Drs. Cromer and Lakhani contributed equally to this article

  1. Diabetes Unit, Massachusetts General Hospital, Boston, MA 02114
  2. Harvard Medical School, Boston, MA 02115
  3. Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, MA 02142
  4. Endocrine Unit, Massachusetts General Hospital, Boston, MA 02114


Background: The SARS-CoV-2 pandemic has disproportionately affected racial and ethnic minority communities across the United States. We sought to disentangle individual and census tract-level sociodemographic and economic factors associated with these disparities.

Methods and Findings: All adults tested for SARS-CoV-2 between February 1 and June 21, 2020 were geocoded to a census tract based on their address; hospital employees and individuals with invalid addresses were excluded. Individual (age, sex, race/ethnicity, preferred language, insurance) and census tract-level (demographics, insurance, income, education, employment, occupation, household crowding and occupancy, built home environment, and transportation) variables were analyzed using linear mixed models predicting infection, hospitalization, and death from SARS-CoV-2.

Among 57,865 individuals, per capita testing rates, individual (older age, male sex, non-White race, nonEnglish preferred language, and non-private insurance), and census tract-level (increased population density, higher household occupancy, and lower education) measures were associated with likelihood of infection. Among those infected, individual age, sex, race, language, and insurance, and census tract-level measures of lower education, more multi-family homes, and extreme household crowding were associated with increased likelihood of hospitalization, while higher per capita testing rates were associated with decreased likelihood. Only individual-level variables (older age, male sex, Medicare insurance) were associated with increased mortality among those hospitalized.

Conclusions: This study of the first wave of the SARS-CoV-2 pandemic in a major U.S. city presents the cascade of outcomes following SARS-CoV-2 infection within a large, multi-ethnic cohort. SARS-CoV-2 infection and hospitalization rates, but not death rates among those hospitalized, are related to census tract-level socioeconomic characteristics including lower educational attainment and higher household crowding and occupancy, but not neighborhood measures of race, independent of individual factors.

GitHub Repository

GitHub Repository that includes scripts used for analysis. We do not include data files, database credentials, or some geocoding code because it contains personally identifiable information.