Background: The task of matching fluctuating demand with available capacity is one of the basic challenges in all large-scale service industries. It is a particularly pressing concern in modern health-care systems, as increasing demand (ageing populations, availability of new treatments, increased patient knowledge, etc.) meets stagnating supply (capacity and funding restrictions on staff and services, etc.). As a consequence, a very large portfolio of demand management strategies has developed based on quite different assumptions about the source of the problem and about the means of its resolution.
Methods: This report presents a substantial review of the effectiveness of main strategies designed to alleviate demand pressures in the area of planned care. The study commences with an overview of the key ideas about the genesis of demand and capacity problems for health services. Many different diagnoses were uncovered: fluctuating demand meeting stationary capacity; turf protection between different providers; social rather than clinical pressures on referral decisions; self-propelling diagnostic cascades; supplier-induced demand; demographic pressures on treatment; and the informed patient and demand inflation. We then conducted a review of the key ideas (programme theories) underlying interventions designed to address demand imbalance. We discovered that there was no close alignment between purported problems and advocated solutions. Demand management interventions take their starting point in seeking reforms at the levels of strategic decision-making, organisational re-engineering, procedural modifications and behavioural change. In mapping the ideas for reform, we also noted a tendency for programme theories to become ‘whole-system’ models; over time policy-makers have advocated the need for concerted action on all of these fronts.
Findings: The remainder and core of the report contains a realist synthesis of the empirical evidence on the effectiveness on a spanning subset of four major demand management interventions: referral management centres (RMCs); using general practitioners with special interests (GPwSIs) at the interface between primary and secondary care; general practitioner (GP) direct access to clinical tests; and referral guidelines. In all cases we encountered a chequered pattern of success and failure. The primary literature is replete with accounts of unanticipated problems and unintended effects. These programmes ‘work’ only in highly circumscribed conditions. To give brief examples, we found that the success of RMCs depends crucially on the balance of control in their governance structures; GPwSIs influence demand only after close negotiations on an agreed and intermediate case mix; significant efficiencies are created by direct GP access to tests mainly when there is low diagnostic yield and high ‘rule-out’ rates; and referral guidelines are more likely to work when implemented by staff with responsibility for their creation.
Conclusions: The report concludes that there is no ‘preferred intervention’ that has the capacity to outperform all others. Instead, the review found many, diverse, hard-won, local and adaptive solutions. Whatever the starting point, success in demand management depends on synchronising a complex array of strategic, organisational, procedural and motivational changes. The final chapter offers practitioners some guidance on how they might ‘think through’ all of the interdependencies, which bring demand and capacity into equilibrium. A close analysis of the implementation of different configurations of demand management interventions in different local contexts using mixed methods would be valuable to understand the processes through which such interventions are tailored to local circumstances. There is also scope for further evidence synthesis. The substitution theory is ubiquitous in health and social care and a realist synthesis to compare the fortunes of different practitioners placed at different professional boundaries (e.g. nurses/doctors, dentists/dental care practitioners, radiologists/radiographers and so on) would be valuable to identify the contexts and mechanisms through which substitution, support or short-circuit occurs.
Funding: The National Institute for Health Research Health Services and Delivery Research programme.
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