The effects of Alzheimer's and Parkinson's disease on 28-day mortality of COVID-19

We compared the prognosis of inpatients with a known diagnosis of Alzheimer's or Parkinson's disease who have COVID-19 infection with other hospitalized patients with COVID-19. Our cohort study started in October 2020 and ended in May 2021 and included inpatients with COVID-19 infection who were admitted to hospitals. From a total of 67,871 patients with a confirmed diagnosis of COVID-19, a sample of 3732 individuals were selected of which 363 had Alzheimer's, and 259 had Parkinson's disease. All patients had both positive RT-PCR test and positive chest CT for COVID-19. The outcome was dead within 28 days of admission and the predictors were a large number of demographic and clinical features, and comorbidities recorded at patients’ bedside. Mortality were 37.5%, 35.1%, and 29.5% in patients with Alzheimer's disease, Parkinson's disease; and in other patients, respectively. The hazard ratio for Alzheimer's disease was 1.27 (95% CI, 1.06–1.53, p = 0.010) and for Parkinson's disease was 1.17 (95% CI, 0.94–1.46, p = 0.171). Age was a predictor of mortality, hazard ratio = 1.04 (95% CI, 1.03–1.05, p < 0.001). Patients with Alzheimer's disease and COVID-19 infection were older and more likely to have a loss of consciousness on admission (both p ≤ 0.001). We concluded that inpatients with Alzheimer's disease have an increased risk for 28-day mortality from COVID-19 and healthcare settings should be ready to provide critical care for them such as early intubation and immediate O(2) therapy. However, Parkinson's disease does not significantly predict higher mortality of COVID-19.