Risk factors for 30-day COVID-19 mortality among people living with dementia in Alberta, Canada: a retrospective cohort study.

BACKGROUND

People living with dementia (PLWD) were disproportionately impacted by the COVID-19 pandemic, experiencing high mortality rates in the initial waves. However, factors contributing to their increased risk of death following COVID-19 infection remain unclear. Given that PLWD are a heterogenous population with varying susceptibility to negative health outcomes, this study aimed to identify independent factors associated with 30-day COVID-19 mortality among PLWD and vulnerable subgroups of PLWD.

METHODS

We conducted a retrospective cohort analysis using administrative data from March 1st 2020 to December 1st 2020, in Alberta, Canada. We examined the association between an outcome variable created to examine mortality in the 30-days following COVID-19 infection and factors related to the demographics and health (e.g., age, comorbidities), health service use (e.g., past physician utilization), and environment (e.g., community or long-term care) of PLWD in our study cohort and subgroups of our study cohort based on age, sex, and living setting (community, long-term care).

RESULTS

Among our study cohort of PLWD (N = 1526), 28% of individuals died within 30 days following COVID-19 infection. After adjusting for confounders, increasing age (AOR = 2.38, 95% CI: 1.12-5.06), male sex (AOR = 2.30, 95% CI: 1.76-3.01), and living in long-term care (AOR = 5.91, 95% CI: 4.49-7.79) were associated with a higher risk of 30-day COVID-19 mortality. Additionally, congestive heart failure, diabetes with complications, and renal failure were linked to mortality among certain subgroups of PLWD.

CONCLUSIONS

The 30-day COVID-19 case fatality rate was high among PLWD. PLWD who were older, male, and living in long-term care were at the greatest risk. The findings of this study demonstrate that specific groups of PLWD, based on both demographic and site-of-care-related factors, would benefit most from improved attention in future infectious disease public health planning.