Mendelian Randomization in Cardiovascular Research

Mendelian randomization is an epidemiological approach to making causal inferences using observational data. It makes use of the natural that occurs in generation individual’s genetic makeup a way analogous study design randomized controlled trial and uses instrumental variable analysis where variant(s) are instrument (analogous random allocation treatment group trial). As with any variable, there 3 assumptions must be made about instrument: (1) it associated (not necessarily causally) exposure (relevance condition); (2) outcome only through (exclusion restriction (3) does not share common cause (ie, no confounders outcome, independence condition). Using example type II diabetes coronary artery disease, we demonstrate how method may used investigate causality discuss potential benefits pitfalls. We conclude although studies can usually establish on their own, they usefully contribute evidence base increase our certainty effectiveness (or otherwise) interventions reduce cardiovascular disease.