Longitudinal Methodology Series II – ‘Mediation analysis for life course epidemiology’ – Professor Bianca De Stavola, Professor of Biostatistics and Director of the London School of Hygiene and Tropical Medicine Centre for Statistical Methodology
In diverse fields of empirical research attempts are made to decompose the effect of an exposure on an outcome into its effects via a number of different pathways. Path analysis has a long tradition in dealing with enquiries of this sort, but more recent contributions in the causal inference literature have led to greater understanding of the statistical estimands for these pathway-specific effects, the assumptions under which they can be identified, and statistical methods for doing so.
However the majority of causal inference contributions has focused on settings with no intermediate confounders (i.e. confounders of the mediator-outcome relationship on the causal pathway from the exposure) and considers only partitioning the total effect of an exposure into the components that involve or do not involve a single mediator. These restrictions are very limiting in mediation studies applied to life course epidemiology, where intermediate confounding is the norm, and enquiries involve multiple mediators.
During this talk Professor Stavola discussed an example taken from a life course study of eating disorders in girls.