Association Between Dementia and Clinical Outcome After COVID-19: A Nationwide Cohort Study with Propensity Score Matched Control in South Korea
Abstract Despite a high prevalence of dementia in older adults hospitalized with severe acute respiratory syndrome coronavirus 2 infection (COVID-19), research investigating association between preexisting diagnoses of dementia and prognosis of COVID-19 is scarce. We explored a nationwide cohort with a total of 2,800 subjects older than 50 years who were diagnosed with COVID-19 between January and April 2020. Among them, 223 patients had underlying dementia (dementia group). We matched 1:1 for each dementia-non-dementia group pair yielding 223 patients without dementia (no dementia group) using propensity score matching. The primary outcome measure was group difference in mortality after COVID-19. Mortality rate after COVID-19 were significantly higher in dementia group than in no dementia group (33.6% vs. 20.2%, p=0.002). In addition, dementia group had higher proportion of patients requiring invasive ventilatory support than no dementia group (34.1% vs. 22.0%, p=0.006). Multivariable analysis showed that dementia group had a higher risk of mortality than no dementia group (odds ratio=3.05, p<0.001). We also found that patients in dementia group had a higher risk of needing invasive ventilatory support than those in no dementia group. Our results suggest that system including strengthen quarantines are required for patients with dementia during the COVID-19 pandemic.