Delirium in elderly patients and the risk of postdischarge mortality, institutionalization, and dementia: a meta-analysis.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of observational cohort studies
PubMed 20664045 · doi:10.1001/jama.2010.1013
What was done
A systematic search across MEDLINE, EMBASE, PsycINFO, and CINAHL (1981–April 2010) identified observational studies of elderly patients with delirium evaluating mortality, institutionalization, or dementia after at least 3 months of follow-up. From 2,939 initial references, 51 relevant articles were identified. Study quality was evaluated using STROBE criteria. Primary analyses pooled high-quality studies controlling for age, sex, comorbid illness/severity, and baseline dementia using random-effects models.
What was found
In primary analyses adjusted for key confounders: - Mortality (7 studies, mean follow-up 22.7 months): 271/714 (38.0%) with delirium vs 616/2243 (27.5%) controls; adjusted hazard ratio (HR) 1.95 (95% CI, 1.51–2.52; I² = 44.0%). - Institutionalization (7 studies, mean follow-up 14.6 months): 176/527 (33.4%) with delirium vs 219/2052 (10.7%) controls; odds ratio (OR) 2.41 (95% CI, 1.77–3.29; I² = 0%). - Dementia (2 studies, mean follow-up 4.1 years): 35/56 (62.5%) with delirium vs 15/185 (8.1%) controls; OR 12.52 (95% CI, 1.86–84.21; I² = 52.4%).
Why it matters
This meta-analysis demonstrates that delirium is not merely a marker of severe acute illness, but is independently associated with long-term mortality, institutional placement, and dementia in elderly patients.
Limits
All included studies were observational, meaning residual confounding remains possible. The dementia analysis included only 2 studies with a small sample (56 delirium patients, 185 controls), resulting in very wide confidence intervals. Moderate heterogeneity was present for the mortality (I² = 44.0%) and dementia (I² = 52.4%) outcomes. The search was limited to English and Dutch publications.
Cited by
- supports Patients who develop delirium are three times more likely to subsequently develop dementia.