Preventing Delirium Takes a Village: Systematic Review and Meta-Analysis of Delirium Preventive Models of Care
BACKGROUND: Each hospital day of delirium incurs greater healthcare costs, higher levels of care, greater staff burden, and higher complication rates. Accordingly, administrators are incentivized to identify models of care that reduce delirium rates and associated costs.
PURPOSE: We present a systematic review and meta-analysis of delirium prevention models of care.
DATA SOURCES: Ovid MEDLINE, CINAHL, Cochrane Database of Systematic Reviews, EMBASE, and PsycINFO.
STUDY SELECTION: Eligible models of care were defined as provider-oriented interventions involving revision of professional roles, multidisciplinary teams, and service integration. Included studies implemented multidomain, multicomponent interventions, used a validated delirium instrument, and enrolled a control group to evaluate efficacy or effectiveness.
DATA EXTRACTION: We extracted data on study design, population, model of care, outcomes, and results.
DATA SYNTHESIS: A total of 15 studies were included. All but two studies reported reduction in delirium or its duration, and 11 studies reported statistically significant improvements. Using random effects models, the pooled odds ratios of delirium incidence were 0.56 (95% CI: 0.37-0.85) from three randomized controlled trials, 0.63 (95% CI 0.37-1.07) from four pre–post intervention studies, and 0.79 (95% CI: 0.46-1.37) from three additional nonrandomized studies.
CONCLUSIONS: Several models of care can prevent delirium. In general, higher quality studies were more likely to demonstrate statistical significance of an effect. The diverse models of care included here explored interventions adapted to specific care settings, especially by addressing setting-specific delirium risk factors. These care models illustrate a range of promising strategies that deserve growing recognition, refinement, and implementation.
© 2019 Society of Hospital Medicine
Delirium presents as an acute change in mentation characterized by reduced attention, clouding of awareness, and typically an altered level of arousal. It can be caused by a host of medical conditions, medications, or other psychoactive substances and is therefore encountered primarily in acute and postacute medical settings.1 More than a quarter of all hospitalized patients develop delirium,2 with rates up to 80% in the critically ill.3 Similarly, delirium occurs in more than one-third of patients who transition to postacute care.4 These high prevalence rates are alarming, especially because delirium is a risk factor for mortality, prolonged hospitalization, institutionalization, and overall higher cost of care.5 However, more than a quarter of delirium is preventable.6 Evidence-based guidelines for delirium uniformly call for multicomponent prevention strategies,7 and these are best delivered through collaborative models of care. In short, delirium impacts healthcare systems; therefore, interventions aimed at preventing delirium and its consequences ought to be systems-based.
Since the Institute of Medicine issued its 1999 report highlighting the critical role of medical errors in healthcare, healthcare systems have increasingly become team-based.8 “Medical care is inherently interdependent,”9 and this implies that delirium prevention rests not only on individuals but also on broader systems of care. Although nonpharmacological interventions are efficacious at preventing delirium,10 previous reviews have focused on specific interventions or multiple interventions rather than the systems of care needed to deliver them. Indeed, teams and the quality of their teamwork impact outcomes.11
Herein, we provide a systematic review and meta-analysis of integrated models of care designed to prevent delirium. What distinguishes this review from previous reviews of nonpharmacological interventions to prevent delirium is our focus on discrete models of care that involve collaboration among clinicians. Our goal is to identify the most promising models that deserve further development, investigation, and dissemination. Viewing delirium prevention through a collaborative care lens is consistent with efforts to achieve value-based care and may encourage drawing from the expanding literature outlining the benefits of mental healthcare integration.12,13 Specifically, a systems perspective highlights the potential for system-wide benefits such as reducing readmissions14,15 and cost savings.16
METHODS
This systematic review and meta-analysis follows PRISMA guidelines. A search of OVID, MEDLINE, CINAHL, Cochrane Database of Systematic Reviews, EMBASE, and PsycINFO was completed by a medical librarian for clinical studies in which models of care were implemented to prevent delirium using PICO (P patient, problem or population; I, intervention; C, comparison, control or comparator; O, outcome) inquiries. Search terms included delirium, acute confusional state, altered mental status, prevention, and control (“delirium”/exp OR “acute confusion”/exp OR “altered mental status”/exp) AND “prevention and control”/exp AND [English]/lim AND [embase]/lim).
