Dementia and outcomes from coronavirus disease 2019 (COVID-19) pneumonia: A systematic review and meta-analysis

Background: The number of positive and death cases from coronavirus disease 2019 (COVID-19) is still increasing until now. One of the most prone individuals, even in normal situations is patients with dementia. Currently, no study provides clear evidence regarding the link between dementia and COVID-19. This study aims to analyze the relationship between dementia and poor outcomes of COVID-19 infection. Materials and Methods: We systematically searched the PubMed and Europe PMC database using specific keywords related to our aims until October 25th, 2020. All articles published on COVID-19 and dementia were retrieved. The quality of the study was assessed using the Newcastle Ottawa Scale (NOS) tool for observational studies. Statistical analysis was done using Review Manager 5.4 software. Results: A total of 24 studies with 46,391 dementia patients were included in this meta-analysis. This meta analysis showed that dementia was associated with composite poor outcome [RR 2.67 (95% CI 2.06 - 3.47), p < 0.00001, I-2 = 99%, random-effect modeling] and its subgroup which comprised of risk of COVID-19 infection [RR 2.76 (95% CI 1.43 - 5.33), p = 0.003, I-2 = 99%, random-effect modeling], severe COVID-19 [RR 2.63 (95% CI 1.41 - 4.90), p = 0.002, I-2 = 89%, random-effect modeling], and mortality from COVID-19 infection [RR 2.62 (95% CI 2.04 - 3.36), p < 0.00001, I-2 = 96%, random-effect modeling]. Conclusions: Extra care and close monitoring should then be provided to patients with dementia to minimize the risk of infections, preventing the development of severe and mortality outcomes.