The evaluation of the effectiveness of health education interventions in clinical practice: a continuing methodological challenge

Aim. This paper examines the methodological issues arising from an evaluation of the effectiveness of a health education project undertaken to increase Hong Kong Chinese women's knowledge of the prevention of cervical cancer and the uptake of screening. Background. The significance of health promotion to the prevention of diseases currently affecting contemporary society has become increasingly recognized. Within the context of health promotion health education continues to provide an important preventive strategy. Indeed the leading causes of mortality such as coronary heart disease and cancer lend themselves well to health education interventions. However the evaluation of the effectiveness of health education remains complex and raises some important methodological issues. Design. The project used a health education intervention as the major preventive strategy and employed multiple methods of evaluation to assess its effectiveness. Outcome evaluation consisted of a confidential questionnaire administered at two points in time to measure changes in health-related behaviour and knowledge. It also included the collection of data from service providers to assess changes in the uptake of cervical cancer screening. Process evaluation involved the use of focus groups with randomly selected groups of women who had participated in the health education intervention and a diary kept by the project nurse. Findings. Methodological issues identified in the evaluation of the project included the extent to which changes in health-related knowledge and behaviour could be attributed to the intervention, the sensitivity of outcome measures and challenges in developing methods of process evaluation appropriate to the target population. Conclusions. The findings highlight the complexity of designing effective evaluation strategies for health education and the need to consider these issues in the development of both process and outcome evaluation.