Title: Developing tools for preventing delirium in primary care
Funder: Department of Health and Social Care

Abstract: Delirium involves an acute decline in cognitive function. Delirium often develops following potentially avoidable triggers, especially in patients with cognitive impairments. Risk factors in hospital settings are well studied and there is RCT evidence that intervention to reduce risk factors can reduce delirium incidence by up to 35% in hospital settings. Avoidable factors in community acquired delirium have been little studied. However, our practitioner input suggests that acute confusion and consequent failure of carer and community provision contributes to up to half of urgent hospital admissions to care of the elderly wards. Given the success of hospital delirium prevention there is now a need to clarify the scope for preventing community acquired delirium. Recruiting patients with, or at risk of, delirium to a clinical study would be challenging and expensive. Electronic clinical records, such as the NIHR part-funded Clinical Practice Research Database (CPRD) provide cost-effective analysis opportunities for studying delirium in the community. In pilot work in CPRD primary care and linked hospital episode data from 2000 to 2014, we identified 20,000 patients with recorded episodes of delirium, half of which were noted in primary care records only. The aims of this project are therefore: To estimate the prevalence of potentially avoidable factors for delirium in primary care To estimate health care resources used and associated costs, to establish the potential savings that might flow from successful risk reduction To evaluate statistical associations between potential predisposing and precipitating factors and episodes of delirium, to identify the best predictors To develop risk classification algorithms for implementation in electronic medical record systems, to identify high risk patients with potentially avoidable factors To validate the predictive performance of the algorithms To pave the way to a trial of prevention of delirium in primary care Delirium specific algorithms will supplement planned general frailty markers, which in our pilot work were not good predictors of delirium. Risk prediction could help target interventions, likely including focussed medication reviews, assessment of predisposing factors (e.g. nutrition, mobility and sleep problems) and rapid treatment of infections, plus the support of carers. Being able to identify individuals at highest risk will be critical to cost-effective intervention services. We plan to use CPRD primary care, hospital episode and death certificate data to characterise current practice and identify predictive and avoidable factors. The applicant team have extensive experience with CPRD and are well supported with patient involvement and practitioner input. We also have input from the lead of a US based randomised trial of improved community care for patients after hospital acquired delirium. Our 18 month project will produce: essentially the first data on the characteristics of those who developed delirium recorded in primary care records, plus comparisons with hospital diagnosed cases the first data on risk factors in primary care diagnosed delirium information on resource use and costs of care, to enable design of an intervention trial validated algorithms to identify level and nature of delirium risk, which will be implementable at low cost through GP software systems. The new information produced in our project is also likely to help improve the recording of delirium, and we will build in scope for recalibration of the algorithms as recording improves. These outputs will pave the way to trials of community prevention of delirium, which could lead to substantial increases in quality of life for cognitively vulnerable older people and substantial reductions in acute hospital care costs.

Lay abstract: Delirium involves a sudden onset of confusion, memory loss, inability to focus and difficulty speaking. It is relatively common in older people living in the community, estimated to be diagnosed in up to 2% of individuals 65 years and older, equating to approximately 200,000 cases every year in the UK. Delirium often precipitates hospital admission and results in loss of quality of life, and increased death rates and healthcare costs. Most research on delirium has focused on hospitalised patients. Risk factors include alcohol consumption, smoking, malnutrition, inappropriate prescription of certain drugs, and underlying conditions such as physical illness and dementia. Intervention studies in hospital settings have achieved significant successes and recent reviews estimate that up to a third of cases of delirium are preventable. However there is little data on delirium in older people living in the community and no trials of prevention have been reported in primary care. We propose using anonymised patient medical records to improve our understanding of the causes of delirium in the community and to develop tools to help prevent delirium. We will use the government run Clinical Practice Research Datalink data of already collected medical records: this has national ethics approval for analysis. Our main aim is to develop tools to help general practices identify patients at higher risk of delirium, so that risk factors (e.g. certain medications) can be avoided. These prediction tools will also help to target information to carers about how to cope if an episode of delirium does develop. The tools will aim to identify those at higher risk of first episodes of delirium, and also to identify avoidable or precipitating factors in those who have had previous episodes. Such tools would be of great value for aiding GPs to provide personalised care to their patients at risk of delirium.

Research activity codes: 7.3 MANAGEMENT AND DECISION MAKING;8.4 RESEARCH DESIGN AND METHODOLOGIES (HEALTH SERVICES)
Health categories: MENTAL HEALTH