Effectiveness of multicomponent nonpharmacological delirium interventions: a meta-analysis

Abstract

Importance: Delirium, an acute disorder with high morbidity and mortality, is often preventable through multicomponent nonpharmacological strategies. The efficacy of these strategies for preventing subsequent adverse outcomes has been limited to small studies to date.

Objective: To evaluate available evidence on multicomponent nonpharmacological delirium interventions in reducing incident delirium and preventing poor outcomes associated with delirium.

Data sources: PubMed, Google Scholar, ScienceDirect, and the Cochrane Database of Systematic Reviews from January 1, 1999, to December 31, 2013.

Study selection: Studies examining the following outcomes were included: delirium incidence, falls, length of stay, rate of discharge to a long-term care institution (institutionalization), and change in functional or cognitive status.

Data extraction and synthesis: Two experienced physician reviewers independently and blindly abstracted data on outcome measures using a standardized approach. The reviewers conducted quality ratings based on the Cochrane risk-of-bias criteria for each study.

Main outcomes and measures: We identified 14 interventional studies. The results for outcomes of delirium incidence, falls, length of stay, and institutionalization were pooled for the meta-analysis, but heterogeneity limited our meta-analysis of the results for change in functional or cognitive status. Overall, 11 studies demonstrated significant reductions in delirium incidence (odds ratio [OR], 0.47; 95% CI, 0.38-0.58). Four randomized or matched trials reduced delirium incidence by 44% (OR, 0.56; 95% CI, 0.42-0.76). The rate of falls decreased significantly among intervention patients in 4 studies (OR, 0.38; 95% CI, 0.25-0.60); in 2 randomized or matched trials, the rate of falls was reduced by 64% (OR, 0.36; 95% CI, 0.22-0.61). Length of stay and institutionalization also trended toward decreases in the intervention groups, with a mean difference of -0.16 (95% CI, -0.97 to 0.64) day shorter and the odds of institutionalization 5% lower (OR, 0.95; 95% CI, 0.71-1.26). Among higher-quality randomized or matched trials, length of stay trended -0.33 (95% CI, -1.38 to 0.72) day shorter, and the odds of institutionalization trended 6% lower (OR, 0.94; 95% CI, 0.69-1.30).

Conclusions and relevance: Multicomponent nonpharmacological delirium prevention interventions are effective in reducing delirium incidence and preventing falls, with a trend toward decreasing length of stay and avoiding institutionalization. Given the current focus on prevention of hospital-based complications and improved cost-effectiveness of care, this meta-analysis supports the use of these interventions to advance acute care for older persons.

Conflict of interest statement

Conflict of Interest: All the co-authors fully disclose they have no financial interests, activities, relationships and affiliations. The co-authors also declare they have no potential conflicts from the three years prior to submission of this manuscript.

Figures

Figure 1. Literature Identification, Review and Selection for Inclusion in Meta-analysis

The study followed the approaches outlined by the PRISMA flow diagram and checklist, Meta-analysis of Observational Studies in Epidemiology (MOOSE) consensus statement and the Cochrane Handbook for Systematic Reviews of Interventions. Databases searched included PubMed, Google Scholar, ScienceDirect and the Cochrane Database of Systematic Reviews from January 1999 – December 2013. For search terms, we used a combination of controlled vocabulary and keyword terms representing delirium prevention, delirium intervention, targeted multi-component intervention, multi-component intervention, non-pharmacologic intervention, and Hospital Elder Life Program. Utilizing our systematic literature search strategy, 2334 articles were found. Of these, 2098 were excluded based on our screening criteria for relevance, language, age range, or non-human study subjects. A further 189 were excluded after full review yielding 46 articles which met our initial screening criteria. Upon further review, 32 of these did not meet our second-level inclusion criteria which required delirium prevention (not treatment), validated delirium assessment methods, multi-component non-pharmacologic interventions.

Figure 2. Primary Outcomes

Incidence of Delirium Eleven studies measured incidence of delirium. Three RMTs and five non-RMTs demonstrated significant reductions in the incidence of delirium. Overall, the meta-analysis involving 3751 patients showed that the odds of delirium were 53% lower in the intervention group compared with controls (OR 0.47, 95% CI 0.38–0.58). The number needed to treat in the combined sample was 14.3 (95% CI 11.1–20.0). There was low heterogeneity, I2 = 18% with p < 0.00001. Weighting was assigned according to the inverse of the variance. Odds ratios less than 1 indicate decreased delirium incidence. RMT indicates randomized or matched trials; CI indicates confidence interval. Falls Four studies examined the number of falls per patient-days. Individually, only Stenvall et al., an RMT, demonstrated significant reductions in the number of falls. Combined, the meta-analysis involving 1038 patients showed that the odds of falling were 62% lower among intervention subjects (OR 0.38, 95% CI 0.25–0.60). This represents the equivalent of 4.26 falls prevented per 1000 patient-days – or 2.79 falls per 1000 patient-days among intervention subjects compared to 7.05 falls per 1000 patient-days among control subjects. There was low heterogeneity, I2 = 0.00% with p < 0.0001. Weighting was assigned according to the inverse of the variance. Odds ratios less than 1 indicate decreased rate of falls. RMT indicates randomized or matched trials; CI indicates confidence interval.

Figure 3. Secondary Outcomes

Length of Stay Nine studies measured length of stay. Individually, only two studies, Bo et al., a non-RMT, and Lundstrom 2007, an RMT, demonstrated significant reductions in length of stay. Overall, the meta-analysis involving 3358 patients showed that the mean difference was −0.16 days shorter in the intervention group with a trend towards significance (95% CI −0.97–0.64). Heterogeneity was moderate, I2 = 64% with p = 0.006). Weighting was assigned according to the inverse of the variance. Mean differences less than 0 indicate decreased length of stay, in days. RMT indicates randomized or matched trials; CI indicates confidence interval. Institutionalization Four studies examined the rate of institutionalization in a senior residential or nursing home facility post-hospital discharge. Overall, the meta-analysis involving 1176 patients showed that the odds of discharge to long-term care were 5% lower (OR 0.95, 95% CI 0.71–1.26) in the intervention group, but the results did not achieve statistical significance. Heterogeneity was low, I2 = 0.00% with p = 0.69 among intervention subjects, but there was little to no significant effect. Weighting was assigned according to the inverse of the variance. Odds ratios less than 1 indicate decreased rate of institutionalization. RMT indicates randomized or matched trials; CI indicates confidence interval.