Muestras y representatividad en vigilancia epidemiologica mediante sitios centinelas

Abstract

This article maintains that technical issues for sampling in epidemiological surveillance require a profound review of important concepts from health theory. It is particularly neccessary to emphasize living conditions and more specifically the environments or contexts in which reproductive processes of social life take place. However, both fields require access to more complete data than those produced by traditional sources. Such an approach to epidemiological surveillance requires a review of sampling types, and this implies a new look at prevailing interpretations concerning the logical basis for inferences from samples. It becomes necessary to abandon statistical samples (even stratified ones) and to promote procedures of the "sentinel site" type. This techinique, originally applied in societies with insufficient statistical systems, can be developed in such a way as to become a substantial complement to monitoring of living conditions, even in societies with good information systems. The article suggests changes in the "sentinel site" concept, adding the requirement of "qualitative representativeness" through finalistic samples based on previous typologies of spatial/demographic units.

Sentinel areas: a monitoring strategy in public health

“…In an analogy with the choice of strategic points for monitoring environmental pollution, the sentinel areas constitute hierarchical observation points represented by populational spaces where one monitors specific markers of health, economic, and social problems with the potential to generate knowledge contributing to an understanding of the epidemiological structure of the populations under surveillance in each context (Samaja, 1996). This dynamic feeds the assessment of health problems and the resulting definition of specific intervention processes for each situation.…”

“…The pertinence of this argument lies in the fact that this strategy does not aim at quantitative knowledge, but at the detection of indications of changes in the normal patterns or in the occurrence of new health problems. Changes in the epidemiological patterns should serve as "alert calls" to motivate and orient the intervention, detect impact, or even indicate the need to conduct special studies (Samaja, 1996).…”

“…The term "sentinel", when used in public health, is accompanied by various qualifiers such as health units, events, or populations, whose common axis is the gathering of information with the necessary sensitivity to monitor a certain universe of phenomena (Samaja, 1996). The term was employed for the first time by epidemiological surveillance when Rutstein et al (1976) called attention to the need to identify "sentinel events" in health, defining them as a preventable disease or incapacity or an avoidable death.…”

“…In Latin America, local experiences have been developed in this strategy for monitoring health problems by selecting and demarcating intra-urban spaces referred to as "sentinel areas" that are mutually differentiated in such a way as to represent the characteristics of a given situation or problem or even the identification of social needs particularly related to health (Samaja, 1996;UNICEF, 1992).…”

Assistência ao parto normal no Estado de Pernambuco: aspectos geográficos, socioeconômicos e profissionais, com ênfase no papel da enfermeira

“…7 Na década de 1970, a Organização Mundial da Saúde (OMS) instituiu metas para reduzir as desigualdades de acesso aos serviços básicos de saúde das populações dos países em desenvolvimento. 8,9 Entre essas metas e estratégias, figuram a extensão da cobertura dos serviços de saúde e a melhoria do ambiente, a organização e participação da comunidade com vistas a seu bem-estar, a articulação intersetorial, o desenvolvimento da pesquisa e de tecnologias apropriadas, a produção e disponibilidade de produtos e equipamentos especializados, a formação e utilização de recursos humanos, o financiamento setorial e a cooperação internacional.…”