When Screening Misleads: A Robust Mendelian Randomization Test for Reliable Causal Discovery
筛选何时误导:用于可靠因果发现的稳健孟德尔随机化检验
Mendelian Randomization (MR) has been widely used as a standard approach for identifying causal effects in biomedical research. When the true exposure and outcome variables are unknown among many potential candidates, a common but problematic practice is to first screen for associations and then evaluate causal effects only among exposure-outcome pairs that show significant correlations. We demonstrate that the classical MR ratio estimator suffers from severe type I error…