Liu · Journal of Alzheimer's disease : JAD 2020 · systematic review and meta-analysis · n=10 studies (119,218 participants)

The Impact of Dementia on the Clinical Outcome of COVID-19: A Systematic Review and Meta-Analysis.

Cited 118 times in the scientific literature.

Level 3 - non-randomized controlled study

Systematic review and meta-analysis of observational cohort studies

PubMed 33285638 · doi:10.3233/JAD-201016 · record verified 2026-08-29

What was done

A systematic review and meta-analysis was conducted across PubMed, Embase, and Web of Science databases to assess the prevalence and mortality of pre-existing dementia in patients diagnosed with COVID-19. Pooled risk estimates were calculated using fixed- or random-effects models.

What was found

Across 10 included studies comprising 119,218 participants, the pooled incidence of dementia in COVID-19 patients was 9% (95% CI: 6% to 13%). Meta-analysis of 9 studies showed that mortality among individuals with dementia infected with COVID-19 was significantly higher than among those without dementia (OR: 5.17, 95% CI: 2.31 to 11.59).

Why it matters

This review identifies pre-existing dementia as a critical risk factor for COVID-19 mortality, highlighting the need to prioritize individuals with cognitive impairment for targeted preventive interventions and specialized care.

Limits

The meta-analysis exhibited substantial heterogeneity across studies and significant publication bias. The observational design of the underlying studies limits causal inference, and unmeasured confounders such as age, comorbidities, and care facility residence were not accounted for in the abstract.

Cited by