Delirium is a common and distressing complication of a range of stressor events including infection, new medications and environment change that is often experienced by older people with frailty and dementia. Older people living in institutional long-term care (LTC) are at high risk of delirium, which increases the risk of admission to hospital, development of or worsening of dementia, and mortality. Delirium is also associated with substantial healthcare costs. Although it is possible to prevent delirium in the hospital setting by providing multicomponent delirium prevention interventions it is currently unclear whether interventions to prevent delirium in LTC are effective.
To assess the effectiveness of interventions for preventing delirium in older people in long term care.
We searched ALOIS (www.medicine.ox.ac.uk/alois) – the Cochrane Dementia and Cognitive Improvement Group’s Specialised Register – on 23 April 2013. The search was as sensitive as possible to identify all studies on ALOIS relating to delirium. We ran additional separate searches in major healthcare databases, trial registers, the Cochrane Central Register of Controlled Trials (CENTRAL) and grey literature sources, to ensure that the search was as comprehensive as possible.
We included randomised controlled trials (RCTs) and cluster-randomised controlled trials (cluster-RCTs) of single- and multicomponent non-pharmacological and pharmacological interventions for preventing delirium in older people (aged 65 years and over) in permanent LTC residence.
Data collection and analysis
Two independent review authors examined the titles and abstracts of citations identified by the search for eligibility and extracted data, with any disagreements settled by consensus. Primary outcomes were prevalence, incidence and severity of delirium. Secondary outcomes included new diagnosis of dementia, activities of daily living, quality of life and adverse outcomes. We used risk ratios (RRs) as measures of treatment effect for dichotomous outcomes and hazard ratios (HR) for time to event data.
We included two trials that recruited 3636 participants. Both were complex single-component non-pharmacological delirium prevention interventions. Risk of bias for many items was unclear due to inadequate reporting. Notably, there was no evidence of blinding of trial participants or assessors in either trial. One small cluster-RCT (n = 98) of a hydration-based intervention reported no reduction in delirium incidence in the intervention group compared to control (RR 0.85, 95% confidence interval (CI) 0.18 to 4.00, analysis not adjusted for clustering, very low quality evidence). Results were imprecise and there were serious limitations evident in trial design. One large cluster-RCT (n = 3538) of a computerised system to identify medications that may contribute to delirium risk and trigger a pharmacist-led medication review reported a large reduction in delirium incidence (12-month HR 0.42, CI 0.34 to 0.51, moderate quality evidence) but no clear evidence of reduction in hospital admissions (HR 0.89, CI 0.72 to 1.10, moderate quality evidence), in mortality (HR 0.88, CI 0.66 to 1.17, moderate quality evidence) or in falls risk (HR 1.03, CI 0.92 to 1.15, moderate quality evidence).
Our review identified very limited evidence on interventions for preventing delirium in older people in LTC. Introduction of a software-based intervention to identify medications that could contribute to delirium risk so that a pharmacist-led medication review and monitoring plan can be initiated may reduce incidence of delirium for older people in institutional LTC. This is based on one large RCT in the United States and may not be practical in other countries which do not have comparable information technology services available in care homes. Our review identified only one ongoing pilot trial of a multicomponent delirium prevention intervention and no trials of pharmacological agents. Future trials of computerised medication management systems and multicomponent non-pharmacological and pharmacological delirium prevention interventions for older people in LTC are needed to help inform the provision of evidence-based care for this vulnerable group.
Plain language summary
Interventions for preventing delirium in older people in institutional long-term care (LTC)
We reviewed the evidence about the effectiveness of interventions for preventing delirium in older people living in long-term care (LTC).
LTC is the name used for residential homes, which provide personal care, supervision with medications and some help with day to day activities, and nursing homes, which provide 24-hour nursing care. Delirium is a common and serious illness for older people living in LTC. People with delirium usually become more confused over a few hours or a couple of days. Some people with delirium become quiet and sleepy but others become agitated and disorientated, so it can be a very distressing condition. It can also increase the chances of being admitted to hospital and developing dementia, and LTC residents who develop delirium are at increased risk of death.
Importantly, studies of people in hospital have shown that it is possible to prevent around a third of cases of delirium by providing an environment and care plan that target the main risk factors for delirium. For example: providing better lighting and signs to avoid disorientation; avoiding unnecessary use of catheters to help prevent infection; avoiding medications which increase delirium risk.
This review has searched for and assessed research on preventing delirium in older people living in LTC.
The evidence is current to 04/2013. We found two studies that included 3636 participants. Both studies were done in the United States.
The first study tested whether delirium can be prevented by calculating how much fluid an older person in a care home needs each day and ensuring that hydration was provided by giving regular drinks. 98 people participated in the study, which lasted four weeks.
The second study tested the effect of a computer programme which searched prescriptions for medications that might increase the chance of developing delirium so that a pharmacist could adjust or stop them. 3538 people participated in the study, which lasted 12 months.
The first study found that the hydration intervention did not reduce delirium. However, this was a small study of short duration with serious design problems.
The second study found that the computerised medication search programme and pharmacist review reduced delirium but there was no clear reduction in hospital admissions, deaths or falls. One problem with the findings of this study is that it might not be possible to use this computer programme in different countries that do not have similar computer systems.
Quality of the evidence
There is very low-quality evidence on the effectiveness of hydration interventions for reducing the incidence of delirium in older people in LTC. It is therefore not possible to draw firm conclusions.
There is moderate-quality evidence that a computerised medication search programme and pharmacist review may reduce the incidence of delirium in older people in LTC.
There is no clear evidence that a computerised medication search programme and pharmacist review reduces hospitalisation, mortality or falls for older people in LTC.
As this review only found a very small number of research studies, we have recommended that further research should be conducted testing different ways of preventing delirium for older people living in LTC. This may help improve the quality of care for this vulnerable group.
There was no source of external funding for this review.
Conflicts of interest
NS is chief investigator for a National Institute for Health Research (NIHR) Research for Patient Benefit (RfPB) grant to investigate the effects of a delirium prevention intervention for older people in long term care.
JY is a co-applicant for a National Institute for Health Research (NIHR) Research for Patient Benefit (RfPB) grant to investigate the effects of a delirium prevention intervention for older people in long term care.
AC, RH and AH declare that they have no known conflicts of interest.