Developing methodologies for evaluating community-wide health promotion

There has been growing recognition that health promotion programs which target whole communities are more likely to be effective in changing health behaviour. However, studies evaluating the impact of community-wide health promotion programs rarely use adequate methodology. Randomised control trials where multiple whole communities are randomly assigned to control and intervention groups are optimum if evaluators hope to validly attribute changes in health behaviour to the intervention. However, such trials present a number of difficulties including cost and feasibility limitations and the evolving nature of statistical techniques. This paper proposes applying a fairly well-accepted phased evaluation approach to the evaluation of community participation programs, using three defined phases. Phase 1 consists of small-scale studies to develop the measures and assess acceptability and feasibility of the intervention; Phase 2 consists of studies in a small number of communities designed to trial the intervention in the real world; Phase 3 studies use an appropriate number of entire communities to provide valid evidence of efficacy of the intervention. It is suggested that criteria be resolved to identify adequate studies at each stage and that advantages and limitations of Phase 1 and 2 studies be clearly identified. The paper describes the major design, sampling and analysis considerations for a Phase 3 study.