Area-level socioeconomic deprivation, non-national residency, and Covid-19 incidence: A longitudinal spatiotemporal analysis in Germany

Abstract

Background: Socioeconomic conditions affect the dynamics of the Covid-19 pandemic. We analysed the association between area-level socioeconomic deprivation, proportion of non-nationals, and incidence of Covid-19 infections in Germany.

Methods: Using linked nationally representative data at the level of 401 German districts from three waves of infection (January-2020 to May-2021), we fitted Bayesian spatiotemporal models to assess the association between socioeconomic deprivation, and proportion of non-nationals with Covid-19 incidence, controlling for age, sex, vaccination coverage, settlement structure, and spatial and temporal effects. We estimated risk ratios (RR) and corresponding 95% credible intervals (95% CrI). We further examined the deprivation domains (education, income, occupation), interactions between deprivation, sex and the proportion of non-nationals, and explored potential pathways from deprivation to Covid-19 incidence.

Findings: Covid-19 incidence risk was 15% higher (RR=1·15, 95%-CrI=1·06-1·24) in areas classified with the highest deprivation quintile (Q5) compared to the least deprived areas (Q1). Medium-low (Q2), medium (Q3), and medium-high (Q4) deprived districts showed 6% (1·06, 1·00-1·12), 8% (1·08, 1·01-1·15), and 5% (1·05, 0·98-1·13) higher risk, respectively, compared to the least deprived. Districts with higher proportion of non-nationals showed higher incidence risk compared to districts with lowest proportion, but the association weakened across the three waves. During the first wave, an inverse association was observed with highest incidence risk in least deprived areas (Q1). Deprivation interacted with sex, but not with the proportion of non-nationals.

Interpretation: Socioeconomic deprivation, and proportion of non-nationals are independently associated with the incidence of Covid-19. Regional planning of non-pharmaceutical interventions and vaccination strategies would benefit from consideration of area-level deprivation and non-national residency.

Funding: The study was funded by the German Ministry of Health (ZMV I 1 - 25 20 COR 410).

Keywords: Bayesian spatiotemporal analysis; COVID-19; Education; Equity; Income; Infectious disease modelling; Migration; Occupation; SARS-CoV-2; Socioeconomic deprivation; Socioeconomic inequalities.

Figure 1

Crude incidence rates (CIR) per 100,000 population by deprivation quintiles. Time pattern of Covid-19 crude incidence rate (CIR) per 100,000 population stratified by deprivation quintiles. Area-level socioeconomic deprivation quintiles: lowest deprivation (Q1, solid blue line), medium-low deprivation (Q2, dashed light blue line), medium deprivation (Q3, solid grey line), medium-high deprivation (Q4, solid red line) and highest deprivation (Q5, dashed dark red line). Wave 1 (green): week 02-2020 to 27-2020 (January 2020 to June 2020), Wave 2 (blue): week 28-2020 to 05-2021 (July 2020 to January 2021), Wave 3 (red): week 06-2021 to 20-2021 (February 2021 to May 2021).

Figure 2

Stratified crude incidence rate (CIR) per 100,000 population by deprivation quintiles, sex and age. Time pattern of Covid-19 crude incidence rate (CIR) per 100,000 population stratified by deprivation quintiles, and panels sex (female, male) and age-groups (0-4, 5-14, 15-34, 35-59, 60-79, and 80+ years). Area-level socioeconomic deprivation quintiles: lowest deprivation (Q1, solid blue line), medium-low deprivation (Q2, dashed light blue line), medium deprivation (Q3, solid grey line), medium-high deprivation (Q4, solid red line) and highest deprivation (Q5, dashed dark red line). Wave 1 (green): week 02-2020 to 27-2020 (January 2020 to June 2020), Wave 2 (blue): 28-2020 to 05-2021 (July 2020 to January 2021), Wave 3 (red): 06-2021 to 20-2021 (February 2021 to May 2021).

Figure 3

Relative risks (RR) for Covid-19 infections of area deprivation quintiles and non-nationals quintiles by waves. Relative risks (RR) and corresponding 95% credible intervals (95%-CrI, blue error bars) for Covid-19 infections associated with socioeconomic deprivation (reference: Q1 low deprivation), proportion of non-nationals (reference: non-national Q1) by infection waves (Wave 1 to 3) and total study period (Total), displayed on a log-scale. Reference categories refer to a RR equal to 1. A RR greater than 1 indicates a higher incidence risk in the respective quintile compared to lowest quintile (Q1). Wave 1: week 02-2020 to 27-2020 (January 2020 to June 2020), Wave 2: 28-2020 to 05-2021 (July 2020 to January 2021), Wave 3: 06-2021 to 20-2021 (February 2021 to May 2021), Total period: week 02-2020 to 20-2021 (January 2020 to May 2021).

Figure 4

Relative risks (RR) for Covid-19 infections of area deprivation domains by waves. Relative risks (RR) and corresponding 95% credible intervals (95%-CrI, blue error bars) for Covid-19 infections associated with socioeconomic deprivation domains education, income, and occupation by infection waves (Wave 1 to 3) and total study period (Total), displayed on a log-scale. A RR greater than 1 indicates a higher incidence risk for areas with higher domain-specific deprivation in education, income, and occupation, respectively. Wave 1: week 02-2020 to 27-2020 (January 2020 to June 2020), Wave 2: 28-2020 to 05-2021 (July 2020 to January 2021), Wave 3: 06-2021 to 20-2021 (February 2021 to May 2021), Total period: week 02-2020 to 20-2021 (January 2020 to May 2021).

Figure 5

Changes in risk estimates of area deprivation between adjusted models. Absolute (Δ) and proportional changes (%) in relative risk (RR, blue bars) estimates in deprivation quintiles Q2 (medium-low deprivation) to Q5 (high deprivation) between incrementally adjusted mixed-models for considered fixed-effects for the total study period (reference: Q1 low deprivation, referring to a RR equal to 1).