COVID-19 case fatality and Alzheimer's disease

ABSTRACT

Objective: Our objective was to determine whether AD increases COVID-19 case fatality rate (CFR). Background: Previous studies have identified dementia as a risk factor for death from coronavirus disease 2019 (COVID-19). However, it is unclear whether Alzheimer's disease (AD) is an independent risk factor for COVID-19 mortality. Design/Methods: In a retrospective cohort study, we identified 387,841 COVID-19 patientes through TriNetX, and performed a multivariable logistic regression to determine the odds ratio of dying from COVID-19 between patients with and without AD. We accounted for differences between cohorts in three ways. First, we included age, gender, race, ethnicity, and 30 comorbidities from the Elixhauser comorbidity index in our regression. Second, we matched each AD COVID-19 case to control COVID-19 cases with the same age, gender, race, and Elixhauser Comorbidity Index, and then performed conditional logistic regression to account for residual confounding. Third, we performed propensity score matching followed by conditional logistic regression. We extended this analysis to vascular dementia, dementia with Lewy bodies (DLB) and frontotemporal dementia (FTD). Results: We found that AD patients had higher odds of dying from COVID-19 compared to patients without AD (Odds Ratio(OR) 1.20, 95% confidence interval(CI) 1.09-1.32, p<0.001). This result is corroborated by conditional logistic regression analyses with exact-matching and propensity score matching. Interestingly, we did not observe increased mortality from COVID-19 among patients with vascular dementia (OR 0.99, 95% CI 0.88-1.10, p=0.83), DLB or FTD. Conclusions: AD increases CFR associated with COVID-19, though vascular dementia does not. These data are relevant to the evolving global COVID-19 pandemic and future pandemics.