Experiencing delirium within 30 days of hospitalization is linked to higher risks for mild cognitive impairment (MCI) and dementia, as well as to faster cognitive decline among adults, including those without prior cognitive impairment, according to a new study.
The research, published online on November 2 in JAMA Neurology, was led by Allyson K. Palmer, MD, PhD, of the Mayo Clinic in Rochester, Minnesota. The study utilized data from the Mayo Clinic Study of Aging (MCSA), a prospective, population-based study in Olmsted County, Minnesota. Researchers employed a validated natural language processing tool to identify delirium in hospital notes, emergency department visits, and follow-up notes from the 30 days after hospitalization.
Among the 3,501 study participants who were free of dementia at enrollment, delirium was recorded in 2.1% of cases. The outcomes for these individuals were starkly different from those without delirium. Of those who experienced delirium, 64% developed MCI and 24% developed dementia. In contrast, among participants without delirium, 30.4% developed MCI and 6.2% developed dementia.
After adjusting for factors like age, sex, education, and APOE epsilon 4 status, the risks remained significantly higher for those with delirium. The adjusted hazard ratio for developing MCI was 3.67 (P < .001), and for dementia, it was 5.39 (P < .001). Cognitive decline, measured by MMSE scores, was also more pronounced. MMSE scores fell an average of -2.51 points at 10 years for those with delirium, compared to -0.64 points for those without.
The study also found that the timing of the delirium episode was a critical factor. Delirium recorded within 7 days of hospitalization was strongly linked to dementia, with an adjusted hazard ratio of 12.91 (95% CI, 4.07-40.99). This association weakened but remained significant when delirium was recorded up to 180 days after hospitalization (aHR, 5.14; 95% CI, 3.02-8.75).
The authors emphasized the importance of clinical intervention. Clinicians should prioritize delirium prevention and early management during hospitalization, implement structured postdischarge follow-up, and counsel patients and their families regarding the potential long-term impact of delirium on cognitive health,
they wrote.
The study had several limitations, including a potential underestimation of delirium incidence, possible participation and survival bias, and potential errors in the algorithm used to analyze complex language notes. The single-county, predominantly non-Hispanic White cohort may also limit the generalizability of the findings. The research was funded by the Mayo Clinic Robert and Arlene Kogod Center on Aging and the National Institute on Aging. Source Source
