Do reviews of healthcare interventions teach us how to improve healthcare systems?

Planners, managers and policy makers in modern health services are not without ingenuity - they will always try, try and try again. They face deep-seated or 'wicked' problems, which have complex roots in the labyrinthine structures though which healthcare is delivered. Accordingly, the interventions devised to deal with such stubborn problems usually come in the plural. Many different reforms are devised to deal with a particular stumbling block, which may be implemented sequentially, simultaneously or whenever policy fashion or funding dictates. This paper examines this predicament from the perspective of evidence based policy. How might researchers go about reviewing the evidence when they are faced with multiple or indeed competing interventions addressing the same problem? In the face of this plight a rather unheralded form of research synthesis has emerged, namely the 'typological review'. We critically review the fortunes of this strategy. Separating the putative reforms into series of subtypes and producing a scorecard of their outcomes has the unintended effect of divorcing them all from an understanding of how organisations change. A more fruitful approach may lie in a 'theory-driven review' underpinned by an understanding of dynamics of social change in complex organisations. We test this thesis by examining the primary and secondary research on the many interventions designed to tackle a particularly wicked problem, namely the inexorable rise in demand for healthcare.