How do we know that health promotion is having an impact on preventing ill health, improving health status and reducing health inequalities? At this point it is worth reiterating two references from Chapter One:

With a plethora of criticisms about the seemingly innate problem of discovering whether health education and health promotion interventions are effective, it becomes questionable whether investment in such projects is justifiable. Yet the commitment to health promotion as a worthwhile preventative strategy remains a central element in the repertoire of healthcare systems in the UK and abroad. However, if these criticisms have any validity, how might they be countered?

Berridge (2010) appears to point the way to a significantly different methodological approach to evaluating the effectiveness of health promotion in action: ‘Historical evaluation of health promotion … cannot tell us what works best, what is cost-effective … or advise us on the best technique for assessment’ (p 22); ‘Health promotion needs to establish methodological rigour and scientific credibility if it is to achieve recognition as a discipline’ (p 30).

The question of developing an evidence-based discipline in the context of health matters has not been confined to health education and health promotion. It has been preceded by a debate about the benefits of evidence-based medical practice. Cochrane's (1972) innovative methodology was inspired by what was seen as the fallibility of the medical profession in forecasting, with any degree of accuracy, the probable impact of their treatment on a patient's health and wellbeing. Cochrane was an early exponent of a much more rigorous method of testing the efficacy of clinical interventions. He promoted the need for randomised controlled trials (RCTs), in which experimental and control groups are used so that the key variable – treatment of some kind – can be isolated and checked for its effect (Palfrey, 2000). However, this scientific approach did not convince everyone concerned with medical interventions.