Epidemiological issues in health needs assessment

This is the second in a series of six articles describing approaches to and topics for health needs assessment, and how the results can be used effectively

Series editor: John Wright

The first article in this series explained the importance of health needs assessment in the context of planning and delivering health care to populations.1 It mentioned the “epidemiological approach” to health needs assessment—the traditional public health approach of describing need in relation to specific health problems using estimates of the incidence, prevalence, and other surrogates of health impact derived from studies carried out locally or elsewhere. This approach has been be extended to the consideration, alongside these measures, of the ways in which existing services are delivered and the effectiveness and cost effectiveness of interventions intended to meet the needs thus described (fig 1).2 This is a logical extension as there is little point in estimating the burden of ill health (except for determining priorities for future research) if nothing can be done to reduce it.

Epidemiology has been defined as “the study of the distribution and determinants of health-related states or events in specific populations and the application of this study to control of health problems.”3 It tends, for the most part, to use the “medical model” of health need, viewing need in terms of the occurrence of specific diseases and health related states rather than client groups. Descriptive epidemiology (as opposed to analytical epidemiology—the investigation of the determinants of health related states or events) describes the occurrence of disease in terms of person, place, and time:

• Person—who the affected people are (in terms of their age, sex, occupation, socioeconomic group, etc);

• Place—where they are when they get diseases and in what way prevalence and incidence vary geographically (locally, regionally, nationally, or internationally);

• Time—when …