Community versus individual risk of SARS-CoV-2 infection in two municipalities of Louisiana, USA: An assessment of Area Deprivation Index (ADI) paired with seroprevalence data over time

Abstract

Objective: Determine whether an individual is at greater risk of severe acute respiratory distress syndrome coronavirus 2 (SARS-CoV-2) infection because of their community or their individual risk factors.

Study design and setting: 4,752 records from two large prevalence studies in New Orleans and Baton Rouge, Louisiana were used to assess whether zip code tabulation areas (ZCTA)-level area deprivation index (ADI) or individual factors accounted for risk of infection. Logistic regression models assessed associations of individual-level demographic and socioeconomic factors and the zip code-level ADI with SARS-CoV-2 infection.

Results: In the unadjusted model, there were increased odds of infection among participants residing in high versus low ADI (both cities) and high versus mid-level ADI (Baton Rouge only) zip codes. When individual-level covariates were included, the odds of infection remained higher only among Baton Rouge participants who resided in high versus mid-level ADI ZCTAs. Several individual factors contributed to infection risk. After adjustment for ADI, race and age (Baton Rouge) and race, marital status, household size, and comorbidities (New Orleans) were significant.

Conclusions: While higher ADI was associated with higher risk of SARS-CoV-2 infection, individual-level participant characteristics accounted for a significant proportion of this association. Additionally, stage of the pandemic may affect individual risk factors for infection.

Fig 1. Association of area-based deprivation index (ADI) with probability of infection (splines, 2 knots).

ADI ranges for low, mid, and high were (35.7–61.7), (61.7–83.6), and (83.6–112.9) for Baton Rouge and (7.3–59.5), (59.5–86.6), and (86.6–112.9) for New Orleans (denoted by dashed lines in the top panel).

Fig 2. Association between ADI and SARS-CoV-2 infection in Baton Rouge and New Orleans.

Results are presented as odds ratios; error bars represent 95% Confidence Intervals. The unadjusted model accounts for bivariate associations between each variable and COVID-19 positivity. Model 1 accounts for all individual-level variables that were measured in both Baton Rouge and New Orleans (Age, race, sex, comorbidities, household size, and marital status). Model 2 accounts for all individual-level variables that were measured in Baton Rouge (Age, race, sex, comorbidities, household size, and marital status, BMI, work environment, job type). BMI, work environment, and job type were not collected in New Orleans. ADI ranges for low, mid, and high were (35.7–61.7), (61.7–83.6), and (83.6–112.9) for Baton Rouge and (7.3–59.5), (59.5–86.6), and (86.6–112.9) for New Orleans.