[Health technology assessment in public health interventions: is prevention better than cure?]

Medical activities are increasingly performed with preventive purposes, as part of community programs for secondary prevention but also as part of many clinical activities. However, there are few evaluations of preventive and health promotion activities and, in general, these evaluations only assess aspects of efficacy/effectiveness with little consideration of cost and cost-effectiveness and even less of the ethical, legal, social or organizational consequences. Given the growing interest in evaluation of these interventions from different perspectives, health technology assessment (HTA) has emerged as a multidisciplinary analysis strategy with distinct methodological approaches that may be useful to health administrations and policy-makers for decision making at different levels (micro, meso and macro). This manuscript discusses the characteristics and differential aspects related to assessment of preventive and health promotion activities. This type of evaluation poses constraints, limitations and challenges that should be considered during the process of HTA. In the case of public health there are additional challenges, because the evidence must satisfy a diverse audience, including public health professionals, clinicians, politicians, managers, economists and consumers. The challenge is even greater when evaluating complex, integrated community interventions in which local and contextual aspects are of tremendous importance. In addition, assessment of ethical issues is of the utmost importance since these issues comprise the origin of health services and the target populations are usually healthy.