Dementia worsens COVID-19 outcomes in community-dwelling older adults

Dementia is an important risk factor for coronavirus disease 2019 (COVID-19) outcomes in community-dwelling older adults, with its effect becoming stronger with increasing patient age, a recent study has found.

The study included 47,219 community-dwelling older adults with laboratory-confirmed COVID-19. Review of their electronic health records showed that 31,770 had an ambulatory care visit in the last 24 months. The main outcomes of interest included COVID-19 hospitalization, severe disease or admission into the intensive care unit, dialysis, intubation, stroke, and in-hospital death.

In patients aged 65–74 years, frailty was a strong risk factor, with an attributable fraction (AF) of 24 percent for intermediate frailty and 18 percent for high frailty. Hypertension and chronic kidney disease were likewise important risk factors in this age group, with AFs of 24 percent and 17 percent, respectively.

However, as participant age increased, the AF of most comorbidities decreased, while the contributions of heart failure, dementia, and high frailty increased. In patients ≥85 years of age, respective AFs were 7 percent, 10 percent, and 26 percent. When considering all other outcome measures, such as severe disease and in-hospital mortality, dementia was the only risk factor whose AF increased consistently with increasing participant age.

Moreover, patients who had no ambulatory care in the past 24 months were significantly more likely to be hospitalized (adjusted odds ratio [OR], 1.55, 95 percent confidence interval [CI], 1.47–1.63), experience severe outcomes (adjusted OR, 1.09, 95 percent CI, 1.03–1.16), or die while hospitalized (adjusted OR, 1.09, 95 percent CI, 1.02–1.16). Such an effect was magnified even further in older age groups.