COVID-19 and Public Health Restrictions Disproportionately Affected the Vulnerable: A Population Study in Sydney, Australia

Background: There is growing evidence that the COVID-19 pandemic disproportionately affected minority and lower socioeconomic groups. These groups have limited access to healthcare and social security, work in high-risk jobs, and have higher rates of comorbidities associated with poor outcomes from COVID-19. This study quantifies the effect of individual demographics, socioeconomic factors, and public health measures on COVID-19 health outcomes in a large population.Method: Demographics, socioeconomic factors, and COVID-19 outcomes for all 600,000 residents of the Sydney Local Health District from June 2021 to February 2022 were identified from the state’s Notifiable Conditions Information Management System (NCIMS) and linked to Australian Census data. Logistic regression and Cox proportional hazards models were generated for the outcomes of testing, infection, hospitalisation, and death for different periods of public health restrictions. Findings: Overall, public health interventions were effective in protecting the entire population from COVID-19 infection, hospitalisation, and death.During strict public health measures, older individuals had a lower risk of infection, with those aged 80 years and over having half the risk of infection compared to the reference group of 30 to 39 years old (hazards ratio 0.47, 95%CI 0.45-0.49); and those living in areas of lower socioeconomic status (SES) had a higher risk of infection, with the lowest areas having seven times the risk compared to the highest areas (HR 7.15, 6.24-8.19). The risk of infection was also higher for males (HR 1.34 1.27-1.40); those living in areas with higher household sizes (HR 1.56, 1.36-1.78); and individuals who were born in South Asia (HR 1.18, 1.07-1.29), South East Asia (HR 1.20, 1.07-1.36) and the Middle East and North Africa (HR 1.67, 1.47-1.90). During relaxed restrictions, differences between sexes, age groups, regions of birth and household sizes attenuated, but remained significant. Individuals with lower SES had lower rates of COVID-19 testing (odds ratio 0.31, 0.30-0.33), and higher odds of hospitalisation (OR 2.02, 1.71-2.38) and death (OR 4.11, 2.66-6.37) due to COVID-19. Individuals born outside of Australia had lower odds of testing, but no difference in the odds of hospitalisation or death. Importantly, vaccines were preferentially given to at-risk people, and these were protective of hospitalisation (OR 0.67, 0.61-0.73) and death (OR 0.70, 0.58-0.85). The Delta variant of COVID-19 was associated with higher odds of hospitalisation (OR 5.00, 0.56-4.76) and death (OR 4.17, 4.76-3.45).Interpretation: Policies adopted during the height of the COVID-19 pandemic were insufficient to maintain social equity. Policy and decision-makers should enhance efforts to achieve equity in relation to public health measures adopted for disease control. The challenge is to strengthen, scale, and sustain community engagement and relationships initiated during COVID-19 outbreaks. This can be part of a broader agenda that aims at enhancing clinical governance and community capacity to address the health and social inequalities of priority communities.Funding Information: The first author (GU) is funded by a National Health Medical Research Centre Integrated Health and Social Health Centre for Research Excellence (APP1198477). Declaration of Interests: None declared.Ethics Approval Statement: Ethics approval for the current study was granted by the Research Ethics & Governance Office, Royal Prince Alfred Hospital, Sydney Local Health District (X20-0426, 2020/ETH02492, X21-0180, 2021/ETH00947).