Is hospitalization a risk factor for cognitive decline in older age adults?
Level 3 - non-randomized controlled study
Systematic review and meta-analysis of longitudinal observational cohort studies
PubMed 32985398 · doi:10.1017/S1041610220001763
What was done
Authors conducted a systematic review and meta-analysis following PRISMA guidelines to evaluate post-hospitalization cognitive decline (PHCD) in older adults across general acute illness hospitalizations (AIH). They screened 6,566 titles, qualitatively synthesized 46 longitudinal observational reports, and conducted a meta-analysis on 7 eligible studies. Methodological quality was assessed using the Newcastle-Ottawa Scale.
What was found
Qualitative synthesis suggested cognitive decline following AIH, particularly in memory and processing speed domains, with increasing age and illness severity identified as consistent risk factors. Meta-analysis of 7 studies with 41,453 participants demonstrated significant cognitive decline following hospitalization (Cohen's d = -0.25, 95% CI [-0.02, -0.49], I^2 = 35%).
Why it matters
This study provides evidence that cognitive decline after hospitalization is not confined to ICU admissions or delirium cases, but may be a broader complication across general acute medical admissions in older populations.
Limits
The included literature consists entirely of observational cohorts, several of which were noted as vulnerable to bias. Only 7 of 46 reviewed studies provided data eligible for meta-analysis, and clinical trajectory, underlying etiology, and confounding by pre-existing cognitive impairment could not be fully resolved from the abstract data.