EconBase
← All papers

Unbiased estimation and asymptotically valid inference in multivariable Mendelian randomization with many weak instrumental variables

Yihe Yang, Noah Lorincz-Comi, Xiaofeng Zhu

arXiv 12 Jan 2023 · Statistics — Methodology · 2 citations (OpenAlex)

arXiv:2301.05130 · PDF · DOI · OpenAlex · Extracted main text

Abstract

Mendelian randomization (MR) is an instrumental variable (IV) approach to infer causal relationships between exposures and outcomes with genome-wide association studies (GWAS) summary data. However, the multivariable inverse-variance weighting (IVW) approach, which serves as the foundation for most MR approaches, cannot yield unbiased causal effect estimates in the presence of many weak IVs. To address this problem, we proposed the MR using Bias-corrected Estimating Equation (MRBEE) that can infer unbiased causal relationships with many weak IVs and account for horizontal pleiotropy simultaneously. While the practical significance of MRBEE was demonstrated in our parallel work (Lorincz-Comi (2023)), this paper established the statistical theories of multivariable IVW and MRBEE with many weak IVs. First, we showed that the bias of the multivariable IVW estimate is caused by the error-in-variable bias, whose scale and direction are inflated and influenced by weak instrument bias and sample overlaps of exposures and outcome GWAS cohorts, respectively. Second, we investigated the asymptotic properties of multivariable IVW and MRBEE, showing that MRBEE outperforms multivariable IVW regarding unbiasedness of causal effect estimation and asymptotic validity of causal inference. Finally, we applied MRBEE to examine myopia and revealed that education and outdoor activity are causal to myopia whereas indoor activity is not.

Citation extraction

61
references
106
in-text mentions
63
distinct cited
5
self-citations
13,027
main-text words

appendix boundary found by appendix_command · 65% of the source is main text. Read the extracted text to check this.

Most heavily cited references

The works this paper leans on most, across its whole bibliography — not restricted to papers in our corpus. Ranked by composite intensity, which combines how often a work is mentioned, how many sections mention it, and how much of that falls in the main text rather than the appendix.

ReferenceIntensityMentionsSectionsMain text
1Wang, K., X. Shi, Z. Zhu, X. Hao, L. Chen, S. Cheng, R. S. Foo, and… (2022) Mendelian randomization analysis of 37 clinical factors and coronary artery disease in east asian and european populations1.00083100%
2Burgess, S., S. G. Thompson, and C. C. G. Collaboration (2011) Avoiding bias from weak instruments in mendelian randomization studies1.00053100%
3Zhao, Q., J. Wang, G. Hemani, J. Bowden, and D. S. Small (2020) Statistical inference in two-sample summary-data mendelian randomization using robust adjusted profile score0.92843100%
4Morrison, J., N. Knoblauch, J. H. Marcus, M. Stephens, and X. He (2020) Mendelian randomization accounting for correlated and uncorrelated pleiotropic effects using genome-wide summary statistics0.84333100%
5Verbanck, M., C.-Y. Chen, B. Neale, and R. Do (2018) Detection of widespread horizontal pleiotropy in causal relationships inferred from mendelian randomization between complex trai…0.84333100%
6Ye, T., J. Shao, and H. Kang (2021) Debiased inverse-variance weighted estimator in two-sample summary-data mendelian randomization0.84333100%
7Yi, G. Y (2017) Statistical analysis with measurement error or misclassification: strategy, method and application0.84333100%
8Zhu, X (2020) Mendelian randomization and pleiotropy analysis self0.84333100%
9Bowden, J., G. Davey Smith, and S. Burgess (2015) Mendelian randomization with invalid instruments: effect estimation and bias detection through egger regression0.73732100%
10Vershynin, R (2018) High-dimensional probability: An introduction with applications in data science, Volume 470.6936333%

Showing the top 10 of 63 scored citations.