Chapter 11:

In this final chapter, we consider the future of Mendelian randomization within the wider context of epidemiological research. We discuss developments in data availability and methodological practice. These both enable more sophisticated Mendelian randomization analyses and widen the scope for further applications.

We conclude by discussing the role of the analyst. While several aspects of the process of Mendelian randomization can be usefully automated, whether by a high-throughput algorithm or a well-meaning human researcher trying to follow best practice, every epidemiological question is different and requires thought as to how to choose the dataset and focus the analysis plan to produce the most reliable inference. Contextual judgement is required to interpret the findings of an investigation and the extent to which evidence for a causal effect has been demonstrated, particularly when estimates from different methods or analytical approaches give conflicting answers.