[Evidence summary:] What is the impact of COVID-19 on people with disabilities in terms of mortality and development of severe illness? [v1.0]

The Health Protection Surveillance Centre states that data from international COVID-19 outbreaks has identified significant levels of mortality and morbidity in high-risk groups. Particular attention is required when considering how the needs of vulnerable people are managed to support prevention, identification and clinical management scenarios arising within them1. Disability alone may not be related to higher risk for getting COVID-19 or having severe illness. Most people with disabilities are not inherently at higher risk of becoming infected with or having severe illness from COVID-19. However, some people with disabilities might be at a higher risk of infection or severe illness because of their underlying medical conditions2, 3. People with developmental or behavioural disorders who have serious underlying medical conditions may be at risk of serious illness4. BMJ Best Practice reports that in the UK, the death rate from COVID-19 is higher in people with learning disabilities than in the general population. People with learning disabilities were over-represented threefold amongst people who died from COVID-19, with a larger disparity in younger age groups5. Robust evidence associating specific underlying conditions with severe illness in children is limited6. Conditions which may be associated with increased risk of severe disease in children include medical complexity, severe genetic disorders, and severe neurological disorders. Down Syndrome has also been proposed to predispose to severe disease6. Individuals with Down Syndrome deceased with COVID-19 are younger than individuals without Down Syndrome. The burden of co-occurring medical conditions and increased risk of complications can influence COVID-19 prognosis in individuals with Down Syndrome. Specific strategies to prevent and mitigate the effects of COVID-19 in the population with Down Syndrome are needed19. Risk factors and co-occurring medical conditions can contribute to more severe clinical presentations of COVID-19 in this population23. Leading signs/symptoms of COVID-19 and risk factors for severe disease course are similar to the general population. However, individuals with Down Syndrome present significantly higher rates of mortality, especially from age 4010. Cuyper’s findings suggest that a pandemic may disproportionally affect people with intellectual disabilities while population data may not immediately raise warnings. Early detection of diverging patterns and faster implementation of tailored strategies therefore require collection of good quality data8. People with intellectual and developmental disabilities living in residential group homes may be at greater risk of severe COVID-19 outcomes. However, a full understanding of the severity of this risk will not be possible until all relevant data on COVID-19 outcomes among this population is publicly shared12. Multiple sclerosis (MS) patients have been considered a higher-risk population for COVID-19 due to the high prevalence of disability and disease-modifying therapy use; however, there is little data identifying clinical characteristics of MS associated with worse COVID-19 outcomes9. In their multicentre prospective cohort study, Chaudhry et al found that MS patients with more severe COVID-19 courses tended to be older, were more likely to suffer from progressive phenotype, and had a higher degree of disability7. The data from a descriptive study looking at COVID-19 deaths in people with intellectual disability in the UK and Ireland provides insight into possible factors for deaths in people with intellectual disabilities. Some of the factors varied between the mild and moderate-toprofound intellectual disability groups. This highlights an urgent need for further systemic inquiry and study of the possible cumulative impact of these factors and co-occurring medical conditions given the possibility of COVID-19 resurgence.