Risk factors for dementia in older intensive care unit (ICU) survivors

As the number of older intensive care unit (ICU) survivors grows, there is an urgent need to identify modifiable risk factors for post-ICU dementia.

We performed a secondary data analysis of 3144 ICU patients ≥ 50 years of age without a history of dementia or severe mental illness who were screened as part of the Pharmacological Management of Delirium (PMD) study. Delirium was assessed using the Confusion Assessment Method for the ICU. Dementia was identified using International Classification of Diseases Ninth and Tenth revision codes for dementia or prescription of anti-dementia medication.

Average age (standard deviation) was 65.2 ± 9.5 years; 50.4% were female; and 37.3% were Black. Analyses identified stroke (adjusted hazard ratio [HR] 2.49; 95% confidence interval [CI: 1.52, 4.07], P < 0.001), and depression (adjusted HR 3.03; 95% CI [1.80, 5.10], P < 0.001) as post-ICU risk factors for dementia.

Future studies will need to examine whether interventions targeting post-ICU stroke and depression can lower dementia incidence in ICU survivors.

Risk factors for post-intensive care unit (ICU) dementia were distinct from those of Alzheimer's disease. Cardiovascular risk factors were not associated with dementia in older ICU survivors. Post-ICU stroke was associated with a higher risk of dementia in older ICU survivors. Post-ICU depression was associated with a higher risk of dementia in older ICU survivors.