Considerations for evaluating community high blood pressure control programmes.

A major reason for building evaluation procedures into community high blood pressure control programmes is the potential to influence programme planning and operation positively. Evaluation can assist smooth, successful implementation of programme plans on a continuous basis. Evaluation can provide for staff development and training and help administrators be accountable to themselves, their staffs, and their clients. Three basis types of evaluation are relevant to hypertension control programmes: process, outcome, and impact. Process evaluation measures programme efforts by assessing, modifying, and reassessing daily operations. This type of evaluation examines the use of resources, patterns of staff interaction, processes used in planning, decision making, or organization of staff to carry out these efforts. Outcome evaluation measures programme effects and extent to which programme achieve results in the target population. This activity helps determine how well programme objectives are achieved and whether activities should be continued, expanded, or redirected. Impact evaluation provides information on the long-term effects of the hypertension control programme on the community at large, such as morbidity and mortality changes. Because of the need for large sample sizes to detect these changes, impact evaluation is not usually conducted by a single community programme. As community programmes grow in number, the competition for resources becomes greater. Legislators will demand more information about programme costs and effectiveness, which will be needed to justify expenditures and compete for additional resources.