| Abstrakt: |
Background: Cognitive reserve helps maintain cognitive function in the face of accumulating brain pathology and potentially delays the onset of clinical dementia. However, there is a lack of research examining the role of cognitive reserve in delirium, particularly in the context of preexisting neurocognitive disorders. We aimed to investigate the interaction between years of education and baseline cognition in their association with delirium occurrence in hospitalized older adults. Methods: Prospective cohort study including acutely ill patients aged ≥60 admitted to the geriatrics unit of a university hospital in Sao Paulo, Brazil (2009‐2020). Candidates underwent comprehensive geriatric assessments in the first 24 hours of hospitalization. Delirium occurrence was defined using the CAM, completed daily during the hospital stay. Baseline cognition was determined using the CDR and the CDR‐SB. Years of education were used as a proxy for cognitive reserve. We investigated the association between delirium occurrence and years of education using logistic regression models; we then completed interaction analyses exploring the effect of baseline cognition on that association. Results: We included 3,863 participants (mean age = 80; female = 62%; mean years of education = 6). Overall, 1,346 (35%) participants experienced delirium during hospitalization. Additionally, 777 (20%) participants had normal baseline cognition (CDR = 0), 2,068 (54%) had mild cognitive impairment or mild dementia (CDR = 0.5‐1), and 1,018 (26%) had moderate or severe dementia, with a median CDR‐SB of 4. After adjusting for age and sex, we found that participants with ≥12 years of education were less likely to experience delirium (OR = 0.75, 95%, 95%CI = 0.59‐0.96, p = 0.022). However, we found that the association was significantly modified by baseline cognition (p = 0.024) (Figure 1) and that having more years of education was protective against delirium only in the absence of preexisting cognitive impairment (Figure 2). Conclusion: More years of education were protective against delirium occurrence in hospitalized older adults, but only in the absence of preexisting cognitive impairment. Our results suggest that after the onset of clinical neurocognitive disorders, previous markers of cognitive reserve no longer contribute to a lower risk of delirium. [ABSTRACT FROM AUTHOR] |
