Software application profile: mrrobust-a tool for performing two-sample summary Mendelian randomization analyses

Motivation: In recent years, Mendelian randomization analysis using summary data from genome-wide association studies has become a popular approach for investigating causal relationships in epidemiology. The mrrobust Stata package implements several of the recently developed methods. Implementation: mrrobust is freely available as a Stata package. General features: The package includes inverse variance weighted estimation, as well as a range of median, modal and MR-Egger estimation methods. Using mrrobust, plots can be constructed visualizing each estimate either individually or simultaneously. The package also provides statistics such as I-GX(2), which are useful in assessing attenuation bias in causal estimates.