Title: EvaluatioN of Hospital Admission avoidaNCE Services (ENHANCE): a mixed-methods realist-informed study of initiatives in England
Funder: Department of Health and Social Care

Abstract: Research Question: How are the mechanisms of hospital admission avoidance interventions causally linked to the contexts in which they operate, and which outcome measures should be prioritised to support high-quality evaluation and further research? Background:Urgent and emergency care services are under extraordinary and sustained pressure, with acute hospital bed occupancy rates regularly exceeding safe and efficient thresholds. The NHS Long Term Plan and wider health policy advocates the delivery of more acute care closer to home, recognising the potential adverse impacts of unscheduled hospital admissions on quality of life and clinical outcomes, particularly on the frailest and those who experience socio-economic disadvantage. A broad range of Hospital Admission Avoidance Interventions (HAAIs) exist across a range of settings, but with significant inequity of provision. The heterogeneity of contexts means comparative evaluation of HAAIs using standard experimental methods is highly problematic, with a lack of clarity about which outcomes should be prioritised, and for whom. Consequently, many HAAIs do not endure, or struggle with effective implementation in different settings despite apparent promise. This combines to make commissioning, researching and evaluating HAAIs very challenging, with evidence loss and disconnect between stakeholder priorities. Aims: To develop a theory-rooted understanding of the causal association between contexts, mechanisms and outcomes in HAAIs, to support robust real-world evaluation and inform the design of future experimental research. Objectives: Produce an evidence-informed taxonomy to support comparative evaluation of services; Determine which clinical, patient reported and economic outcome measures are causally connected with different HAAI mechanisms, and prioritise which should be used in an evaluation toolkit for commissioners and policy-makers; Acquire a deep understanding of context to inform subsequent HAAI trial designs.Methods:Through three interconnected work packages, this project uses the uniting lens of a 'Realist' approach to develop a robust, theory-rooted understanding of how contextual factors are causally associated with the mechanisms and outcomes of HAAIs. A realist review will systematically combine existing academic, grey and policy literature with key informant insights, to develop initial programme theories underpinning the successful operation of HAAIs, including intended and unintended consequences. These theories will be tested and refined through a detailed case-study analysis of six HAAIs in England, selected for maximal variation of service architectures and as representing a diverse range of contexts. Realist interviews will be conducted with patients, carers, and clinicians. Ethnographic methods will be used to deeply explore the context and mechanisms of these varied programmes. Cognitive and psychometric methods will be used, along with care diaries, to explore how the range of commonly identified patient reported, clinical, quality of life and economic outcome measures are theoretically connected to real-world contexts and the actual priorities of all stakeholders. Innovative PPI methods will be used to capture patient and carer perspectives in the generation of programme theories. Outputs and Impact:This project will produce knowledge products with immediate utility in the NHS to support consistent, evidence informed evaluation of HAAIs. For research, the contextual appreciation of service architectures will support future experimental design, including novel approaches to trials.

Lay abstract: Being admitted to hospital is a major upheaval, with consequences that impact some groups in society more than others. We know that being older, from a disadvantaged social background, or having multiple long-term health problems increases the chance of being admitted urgently to hospital. For the most frail, it can take a considerable amount of time to recover from a hospital stay. For younger and more active people, an unexpected hospital stay may have significant impacts on caring or work responsibilities. Urgent care services are under extreme strain at the moment. The demand on emergency services and hospital beds often outstrips supply, with concerns about long waiting times and challenges in providing efficient, effective care.These combined issues mean those who plan healthcare services are interested in other ways of treating urgent medical needs that do not require hospital admission. This might involve additional care support in someone's home during an illness, or receiving input from professionals such as physiotherapists. Some services provide tests and medical treatments at home usually associated with hospital stay, such as antibiotics via a drip or ultrasound scans. Some services involve home visits or advice calls from specialist doctors and nurses, or aim to support people at home as they reach the end of their life. These services are neither evenly accessible across the country nor available to everyone, creating inequality. There is significant variation in which services are funded, mainly because no one is really sure which services are 'best' or 'most effective'. Presently, it is very difficult to directly compare one service with another to determine what works best. In healthcare research, trials are often used to decide if one treatment is better than another. Trials aim to keep as many things 'the same' between two groups as possible. They usually have a well-developed theory about why one treatment might work best, and a clear idea of what to measure to prove it. None of this is easy to achieve when researching services to help prevent hospital admissions. Different people prioritise and value different aspects of urgent care. For some, staying out of hospital at all costs is the priority. For others, maintaining independence is key. People are prepared to accept different 'trade offs'. Carers may have a different perspective. The availability of local health and social care services might have a major impact on whether hospital admission is seen as the best option. Individual circumstances are often so different that the same service might work really well for one person but not another, and it might not be clear why. We call this 'contextual variation'. This makes it very difficult for researchers to compare services, and for healthcare managers to decide what to fund. This project will try to understand these issues in much more detail. Using an approach called 'realist evaluation', we will explain how the diversity of services work for people in different situations. We will turn to previous research, policy documents, reports and experts to develop theories. We will test these theories by looking closely at several very different services in England that aim to prevent hospital admissions. We will interview patients, carers and staff. We will conduct detailed observations of the services to understand how and who they work for. We will look at different ways the benefits (and drawbacks) are measured, and study how connected these measures are with what actually matters to patients and carers. By understanding and describing 'contextual variation', we aim to be able to design trials that can compare services fairly, and improve equal access to initiatives that work best for all patients.

Research activity codes: 8.1 ORGANISATION AND DELIVERY OF SERVICES
Health categories: GENERIC HEALTH RELEVANCE