Survival and critical care use among people with dementia in a large English cohort.

Background: Admitting people with dementia to critical care units may not always lead to a clear survival benefit. Critical care admissions of people with dementia vary across countries. Little is known about the use and trends of critical care admissions of people with dementia in England.

Objective: To investigate critical care use and survival among people with dementia in a large London catchment area.

Methods: A retrospective cohort study using data from dementia assessment services in south London, UK (2007-20) linked with national hospitalisation data to ascertain critical care admissions. Outcomes included age-sex-standardised critical care use and 1-year post-critical care admission survival by dementia severity (binary: mild versus moderate/severe). We used logistic regression and Kaplan-Meier survival plots for investigating 1-year survival following a critical care admission and linear regressions for time trends.

Results: Of 19,787 people diagnosed with dementia, 726 (3.7%) had ≥1 critical care admission at any time after receiving their dementia diagnosis. The overall 1-year survival of people with dementia, who had a CCA, was 47.5% (n = 345). Dementia severity was not associated with 1-year survival following a critical care admission (mild dementia versus moderate-severe dementia odds of 1-year mortality OR: 0.90, 95% CI [0.66-1.22]). Over the 12-year period from 2008 to 2019, overall critical care use decreased (β = -0.05; 95% CI = -0.01, -0.0003; P = 0.03), while critical care admissions occurring during the last year of life increased (β = 0.11, 95% CI = 0.01, 0.20, P = 0.03).

Conclusions: In this cohort, while critical care use among people with dementia declined overall, its use increased among those in their last year of life. Survival remains comparable to that observed in general older populations.