Epidemiological characteristics and outcomes of COVID-19 cases: mortality inequalities by socio- economic status, Barcelona, Spain, 24 February to 4 May 2020

Background: Population-based studies characteris-ing outcomes of COVID-19 in European settings are limited, and effects of socio-economic status (SES) on outcomes have not been widely investigated. Aim: We describe the epidemiological characteristics of COVID-19 cases, highlighting incidence and mortal-ity rate differences across SES during the first wave in Barcelona, Catalonia, Spain. Methods: This popula-tion-based study reports individual-level data of lab-oratory-confirmed COVID-19 cases diagnosed from 24 February to 4 May 2020, notified to the Public Health Agency of Barcelona and followed until 15 June 2020. We analysed end-of-study vital status and the effects of chronic conditions on mortality using logistic regression. Geocoded addresses were linked to basic health area SES data, estimated using the composed socio-economic index. We estimated age-standard-ised incidence, hospitalisation, and mortality rates by SES. Results: Of 15,554 COVID-19-confirmed cases, the majority were women (n = 9,028; 58%), median age was 63 years (interquartile range: 46-83), 8,046 (54%) required hospitalisation, and 2,287 (15%) cases died. Prevalence of chronic conditions varied across SES, and multiple chronic conditions increased risk of death (>= 3, adjusted odds ratio: 2.3). Age-standardised rates (incidence, hospitalisation, mortality) were high-est in the most deprived SES quartile (incidence: 1,011 (95% confidence interval (CI): 975-1,047); hospitali-sation: 619 (95% CI: 591-648); mortality: 150 (95% CI: 136-165)) and lowest in the most affluent (inci-dence: 784 (95% CI: 759-809); hospitalisation: 400 (95% CI: 382-418); mortality: 121 (95% CI: 112-131)). Conclusions: COVID-19 outcomes varied markedly across SES, underscoring the need to implement effec-tive preventive strategies for vulnerable populations.

Automated summary

This study examines the epidemiological characteristics of COVID-19 cases in Barcelona, with a focus on the impact of socio-economic status on incidence and mortality rates. Findings suggest that individuals in lower SES groups had higher rates of infection, hospitalization, and death, highlighting the importance of implementing targeted preventive strategies for vulnerable populations.