Enfoques modernos del sesgo y la causalidad en la investigación epidemiológica

Abstract

The concepts of causation and bias are crucial to modern biomedical research, ranging from the analysis of hundreds of exposure factors to megatrials, in order to assess the impact of interventions. As consumers of these research products, we are amazed that a statement made today is put into question tomorrow, discarded afterwards, and eventually retaken in the future from different perspectives or under different assumptions. Although the methodological bias is not the only culprit, it plays an important role as determinant of this reality. This paper intended to clarify the concept of bias, which is relevant, among other possible meanings, to contemporary biomedical research, and its association with the technical meaning of confounding. Other objectives were to present the current vision on the practical meaning of cause in epidemiological causal inference, and to critically review two modern analytical tools to deal with bias and causation such as propensity scores and instrumental variables.