From Observational Studies and Adjustment to Clinical Decision. Part 1

In the context of observational studies, the definition of the strength of the association between an exposure variable and an outcome variable, event or endpoint, may be affected by the unequal distribution of covariates among those with and without the specified exposure.In this paper we will review different statistical approaches to the subject matter, from multivariate analysis to adjustment which considers the inverse probability of treatment weighting, and we will apply them to examples taken from the medical literature.