Dementia and the risk of death in elderly patients with COVID-19 infection: Systematic review and meta-analysis

Objectives: The COVID-19 infection represents a global public health emergency worldwide. Several risk factors have been associated with a poor prognosis among COVID-19 patients. We aimed to perform a systemic review and meta-analysis to evaluate the mortality risk in elderly patients with dementia and COVID-19 infection. Methods: Literature search was based on Cochrane Library, Embase, PubMed, and Google Scholar to locate articles published between December 2019 and July 2020, presenting the number of survived versus deceased patients with dementia and COVID-19 infection. Results: A total of 233 articles were retrieved: 158 were excluded for not meeting the inclusion criteria, leaving 75 articles to assess for eligibility. After evaluation of the full-text articles, eight met the inclusion criteria and were thus included into the final analysis (6493 patients – mean age: 69.6 years). Among COVID-19 patients, the prevalence of dementia was higher in non-survivors compared with survivors (17.5% vs. 5.4%, p < 0.001). The pooled analysis performed using a random-effect model showed an increase in the risk of death in COVID-19 patients with dementia (odds ratio: 3.75; 95% confidence interval: 2.54–5.54, p < 0.0001, I2 = 49.5%). The Egger's regression test confirmed that there were not statistically evidences of publication bias (t = 0.059; p = 0.954). Conclusions: Our preliminary results suggest that patients with COVID-19 infection and dementia have a higher mortality risk in the short-term period compared with infected non-demented individuals. Due to their intrinsic frailty, dementia patients may require a more aggressive treatment and prompt isolation to improve their short-term outcome.