Preventing delirium: should non-pharmacological, multicomponent interventions be used? A systematic review and meta-analysis of the literature

Background: delirium is a complex neuropsychiatric syndrome that is common among elderly inpatients. It has been associated with increased mortality, longer hospital stays, cognitive and functional decline and increased institutionalisation rates. Multicomponent interventions, a series of non-pharmacological strategies frequently handled by nursing staff, might be useful for prevention. Objectives: to assess the efficacy of multicomponent interventions in preventing incident delirium in the elderly. Methods: a systematic review of randomised trials was undertaken. Two independent reviewers performed iterative literature searches in seven databases without language restrictions. Grey literature repositories were considered as well. The quality of included trials was assessed by using the criteria established by the Cochrane Collaboration. When possible, data were synthesised into a meta-analysis. Heterogeneity was assessed using the chi(2) and I-2 tests. Findings: a total of 21,788 citations were screened, and seven studies of diverse quality were included in the review, comprising 1,691 participants. Multicomponent interventions significantly reduced incident delirium (relative risk [RR] 0.73, 95% confidence interval [CI] 0.63-0.85, P < 0.001) and accidental falls during the hospitalisation (RR 0.39, 95% CI 0.21, 0.72, P = 0.003), without evidence of differential effectiveness according to ward type or dementia rates. Non-significant reductions in delirium duration, hospital stay and mortality were found as well. Interpretation: multicomponent interventions are effective in preventing incident delirium among elderly inpatients. Effects seemed to be stable among different settings. Due to the limited amount of data, potential benefits in survival need to be confirmed in further studies. Future research should be aimed at contrasting different multicomponent programmes to select the most useful interventions.