SARS-CoV-2 susceptibility and COVID-19 illness course and outcome in people with pre-existing neurodegenerative disorders: systematic review with frequentist and Bayesian meta-analyses.
Level 3 - non-randomized controlled study
Systematic review and meta-analysis of observational studies
PubMed 37183681 · doi:10.1192/bjp.2023.43
What was done
A pre-registered systematic review with frequentist and Bayesian meta-analyses searched PubMed, Web of Science, and preprint servers through January 9, 2023. The review quantified associations between pre-existing neurodegenerative disorders (including mild cognitive impairment, dementia, Alzheimer's disease, and Parkinson's disease) and SARS-CoV-2 infection susceptibility, illness severity, hospital admission, intensive care unit (ICU) admission, and mortality. Effect sizes were measured as odds ratios (ORs).
What was found
The meta-analysis included 136 primary studies with 97,643,494 total participants and 268 effect-size estimates. Odds for positive SARS-CoV-2 testing were increased for dementia (OR = 1.83, 95% CI 1.16–2.87), Alzheimer's disease (OR = 2.86, 95% CI 1.44–5.66), and Parkinson's disease (OR = 1.65, 95% CI 1.34–2.04). Pre-existing dementia was associated with more severe COVID-19 illness (OR = 1.43, 95% CI 1.00–2.03) and increased risk of hospital admission along with Alzheimer's disease (pooled OR range 1.60–3.72). Conversely, ICU admission rates were reduced for patients with dementia (OR = 0.54, 95% CI 0.40–0.74). All evaluated neurodegenerative disorders, including mild cognitive impairment, were associated with higher COVID-19-related mortality (pooled OR range 1.56–2.27).
Why it matters
This large-scale meta-analysis demonstrates that patients with neurodegenerative disorders face substantially elevated risks across the entire trajectory of COVID-19, from infection susceptibility to mortality. Lower ICU admission rates alongside higher mortality suggest possible disparities or treatment limitations in critical care allocation for this vulnerable population.
Limits
The underlying primary studies were observational, which introduces potential confounding from age, institutionalization, comorbidities, and testing frequency. The abstract does not report individual sub-analyses controlling for vaccination status, specific viral variants, or distinct clinical settings.
Cited by
- supports Dementia is strongly associated with poor clinical outcomes in COVID-19.