Mendelian Randomization: The Pitfalls of Improper Reporting and Misinterpretation in Public Health and Clinical Practices

Mendelian randomization (MR) is an approach to help infer causal relationships between modifiable risk factors and outcomes from observational data. MR has been ranked relatively highly in the hierarchy of evidence because it minimizes the impact of bias and confounding, which are common in conventional epidemiological designs. However, MR studies can be subject to improper reporting and misinterpretation. This can lead to confusion, flawed decision-making, and potentially public anxiety. The reporting and interpretation of MR findings among public health practitioners and clinicians can be problematic. There is often a lack of clear distinction between the results from observational studies and those from MR studies, particularly given the ease of obtaining genetic data for two-sample MR from platforms like MR-Base. This issue stems from differences in the methodology between each design, and the interpretation of the MR findings. This summary highlights common errors in reporting MR findings, especially when treated like results from traditional observational studies.