Public Health at National Institute for Health and Clinical Excellence (NICE) from 2012

Abstract

Professor Michael P Kelly, Director of the Centre for Public Health Excellence at NICE, looks at the work that NICE is doing for local government along with its return on investment activity in this changing landscape Programmes and interventions In 2005 National Institute for Health and Clinical Excellence (NICE) acquired a role to produce public health guidance in addition to its clinical portfolio. The idea was twofold: to use the platform of evidence based medicine to develop public health guidance; and, to produce guidance for a range of different audiences in the NHS and in other arenas where public health guidance might be helpful. Originally, two rather different types of guidance were planned - Programmes and Interventions. Public Health Programme guidance was modelled on clinical guidelines and tended to take a broad look at a public health problem and perhaps consider details of strategy, policy and delivery. The guidance produced on cardiovascular disease prevention; alcohol misuse prevention; promoting the health of looked after children; physical activity; the environment; and behaviour change were of this type. Public health intervention guidance was based on NICE's technology appraisals. The idea was to focus on a well-defined public health activity and to identify the most cost effective interventions. The guidance on promoting physical activity in primary care and those on interventions in primary care to prevent smoking or assist people quitting were of this type. In practice the distinction between Programmes and Interventions turned out to be difficult to work with. There were few interventions which were conveniently structured and delivered like technologies and still fewer where there was readily available comparative cost effective evidence to draw upon. Inevitably discussions expanded to include a policy, strategic or systematic context. In 2011 NICE published its thirty-sixth piece of public health guidance and has begun to develop new ways of defining problems and the sharp distinction between the two types of guidance is now less pronounced. New methods and processes will be coming on stream in 2012. Methodological challenges A number of interesting methodological challenges have had to be confronted by the NICE technical team and NICE's public health advisory committees. The public health evidence base is very broad and diverse methodologically. There are of course randomised controlled trials in some areas where NICE has been asked to take a look. But in many of the topic areas where NICE has sought out evidence, it has been found to be patchy in terms both of quality and of coverage. This has meant that new ways of thinking about the quality of evidence beyond a simple application of the hierarchy of evidence have had to be developed. This has been informative, not just as new forms of evidence synthesis have emerged, but the whole conception of the hierarchy of evidence has been put under the spotlight.1 The hierarchy of evidence is designed with one very simple and powerful idea in mind. It helps to identify evidence which is least likely to be biased. In evidence based medicine and health technology assessment where the need to calibrate the most effective sizes of drug interventions is imperative, the hierarchy as a measure of quality is very useful. This is because the hierarchy is about identifying those studies where the bias can be minimised. RCTs and syntheses of RCTs do well because they have been developed to control certain types of bias which distort the relationship between the independent and the dependent variable. The goal is to maximise internal validity. However, in the world of public health several differences apply which call into question the focus on internal validity alone. Public health actions frequently consist of long causal chains from the intervention and outcome, involving individual human behaviour in complex social settings. …