Objectives: To compare COVID-19 infection, severe infection, mortality, case-fatality, and excess deaths, among adults with intellectual disabilities and those without.
Design: Record-linkage of all adults recorded with intellectual disabilities in Scotland Census, 2011, and a 5% sample of other adults, to COVID-19 test results (Electronic Communication of Surveillance in Scotland), hospitalisations (Scottish Morbidity Record 01), and deaths (National Records of Scotland).
Setting: General population; 24th January 2020 - 15th August 2020
Participants: Successful linkage of 94.8% provided data on 17,173 adults with, and 195,859 without, intellectual disabilities.
Outcomes: Crude rates of COVID-19 infection, severe infection (hospitalisation/death), mortality, and case-fatality; age-, sex- and deprivation-standardised severe infection and mortality ratios; annual all-cause mortality for 2020 and 2015-2019.
Results: Adults with intellectual disabilities had higher rates of COVID-19 infection (957/100,000 versus 513/100,000); severe infection (549/100,000 versus 237/100,000); mortality (259/100,000 versus 114/100,000); and case-fatality (30% versus 24%). Poorer COVID-19 outcomes remained after standardising for age, sex, and deprivation: standardised severe infection ratio 2.59 (95% CI 1.80, 3.39) and mortality ratio 3.20 (95% CI 2.16, 4.25). These were higher among 55-64 year olds: 7.12 (95% CI 3.73, 10.50) and 16.16 (95% CI7.69, 24.63) respectively. Among adults with intellectual disabilities, all-cause mortality was only slightly higher in 2020 than the previous five years: standardised mortality ratios 2.49 (95% CI 2.17, 2.81) and 2.38 (95% CI 2.26, 2.49) respectively.
Conclusions: Adults with intellectual disabilities were more likely to be infected with COVID-19, and had worse outcomes once infected, particularly those under 65 years. Non-pharmaceutical interventions directed at formal and informal carers are essential to reduce transmission and all adults with intellectual disabilities should be immediately prioritised for vaccination regardless of age.