Susceptibility to COVID-19 Diagnosis in People with Down Syndrome Compared to the General Population: Matched-Cohort Study Using Primary Care Electronic Records in the UK

Background During the COVID-19 pandemic, people with Down syndrome (DS) have experienced a more severe disease course and higher mortality rates than the general population. It is not yet known whether people with DS are more susceptible to being diagnosed with COVID-19. Objective To explore whether DS is associated with increased susceptibility to COVID-19. Design Matched-cohort study design using anonymised primary care electronic health records from the May 2021 release of Clinical Practice Research Datalink (CPRD) Aurum. Setting Electronic health records from approximately 1400 general practices (GPs) in England. Participants 8854 people with DS and 34,724 controls matched for age, gender and GP who were registered on or after the 29th January 2020. Measurements The primary outcome was COVID-19 diagnosis between January 2020 and May 2021. Conditional logistic regression models were fitted to estimate associations between DS and COVID-19 diagnosis, adjusting for comorbidities. Results Compared to controls, people with DS were more likely to be diagnosed with COVID-19 (7.4% vs 5.6%, p <= 0.001, odds ratio (OR) = 1.35; 95% CI = 1.23-1.48). There was a significant interaction between people with DS and a chronic respiratory disease diagnosis excluding asthma and increased odds of a COVID-19 diagnosis (OR = 1.71; 95% CI = 1.20-2.43), whilst adjusting for a number of comorbidities. Conclusion Individuals with DS are at increased risk for contracting COVID-19. Those with underlying lung conditions are particularly vulnerable during viral pandemics and should be prioritised for vaccinations.