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.