Hospital Delirium Linked to Subsequent Cognitive Decline

TOPLINEExperiencing delirium within 30 days of hospitalization was linked to higher risks for mild cognitive impairment (MCI) and dementia as well as to faster cognitive decline among adults, including those without cognitive impairment, a study showed. METHODOLOGYResearchers conducted a cohort study using data from the MCSA, a prospective, population-based study conducted among individuals residing in Olmsted County, Minnesota, with neuropsychological testing about every 15 months and expert consensus diagnoses.The study included 3501 MCSA participants who had at least one hospitalization and were free of dementia at enrollment or before first hospitalization (median age, 74.1 years; 47.9% women; 26% apolipoprotein E [APOE] epsilon 4 carriers). Researchers used a validated natural language processing tool to flag delirium in notes from hospital stays, related emergency department visits, and follow-up notes from the 30 days after hospitalization.Outcomes were incident MCI, incident dementia, and cognitive trajectories longitudinally assessed using Mini-Mental State Examination (MMSE) scores converted from Short Test of Mental Status scores. The MCI analysis included only participants who were free of MCI at enrollment; those with baseline MCI remained in the dementia and cognitive trajectory analyses.The analysis was adjusted for age, sex, education, and APOE epsilon 4 status. The median follow-up was 7.2 years. TAKEAWAYDelirium was recorded in 2.1% of participants, of whom 64% and 24% developed MCI and dementia, respectively. Among participants without delirium, 30.4% and 6.2% developed MCI and dementia, respectively.Incidence rates per 100 person-years were higher among individuals with vs without delirium for MCI (19.3 vs 4.2) and dementia (12.4 vs 1.2). After adjustment, the risks were higher among individuals with delirium within 30 days of hospitalization than those without delirium for MCI (adjusted hazard ratio [aHR], 3.67; P < .001) and dementia (aHR, 5.39; P < .001).MMSE scores fell faster among individuals with delirium than among those without: -0.75 vs -0.24 points at 1 year, -2.28 vs -0.43 at 5 years, and -2.51 vs -0.64 at 10 years. Differences were largest for Trail Making Test Part B and category fluency.Delirium recorded within 7 days of hospitalization was strongly linked to dementia (aHR, 12.91; 95% CI, 4.07-40.99), with the association attenuating at 180 days of hospitalization (aHR, 5.14; 95% CI, 3.02-8.75).IN PRACTICE"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," the authors wrote.SOURCEThe study was led by Allyson K. Palmer, MD, PhD, Mayo Clinic, Rochester, Minnesota. It was published online on November 2 in JAMA Neurology.LIMITATIONSThe study was limited by potential underestimation of delirium incidence, possibility of participation and survival bias, and potential errors made by the algorithm in notes with complex language. The single-county, predominantly non-Hispanic White cohort may have limited the generalizability of the findings.DISCLOSURESThe study was funded by the Mayo Clinic Robert and Arlene Kogod Center on Aging Clinical Application Theme Pilot Award. The MCSA was supported by the National Institute on Aging. Disclosure information for the study investigators is available in the original study publication.This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.