Evidence map›Paper›PMID 31651042›Full record

ArticleBiometrics2020

Approximation of bias and mean-squared error in two-sample Mendelian randomization analyses.

Lu Deng, Han Zhang, Lei Song, Kai Yu

Abstract read
In one paragraph

Article in Biometrics, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 10 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
10citing papers in PubMed, 1 pooled it
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

10 citing papers in PubMed, 1 synthesis or guideline pooled it.

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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

4 authors.

Lu DengDivision of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, Maryland.
Han ZhangDivision of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, Maryland.ORCID 0000-0001-7977-9616
Lei SongDivision of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, Maryland.
Kai YuDivision of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, Maryland.ORCID 0000-0002-5337-137X

Funding

Methods for Epidemiology StudiesZIACP010181 · NCI · DIVISION OF CANCER EPIDEMIOLOGY AND GENETICS · PI ALBERT, PAUL · 2009 to 2025
$34.8M
Intramural NIH HHS ZIA CP010181Intramural Program of the National Institutes of Health and the National Cancer Institute
6 · The paper itself

Abstract

Mendelian randomization (MR) is a type of instrumental variable (IV) analysis that uses genetic variants as IVs for a risk factor to study its causal effect on an outcome. Extensive investigations on the performance of IV analysis procedures, such as the one based on the two-stage least squares (2SLS) procedure, have been conducted under the one-sample scenario, where measures on IVs, the risk factor, and the outcome are assumed to be available for each study participant. Recent MR analysis usually is performed with data from two independent or partially overlapping genetic association studies (two-sample setting), with one providing information on the association between the IVs and the outcome, and the other on the association between the IVs and the risk factor. We investigate the performance of 2SLS in the two-sample-based MR when the IVs are weakly associated with the risk factor. We derive closed form formulas for the bias and mean squared error of the 2SLS estimate and verify them with numeric simulations under realistic circumstances. Using these analytic formulas, we can study the pros and cons of conducting MR analysis under one-sample and two-sample settings and assess the impact of having overlapping samples. We also propose and validate a bias-corrected estimator for the causal effect.

Indexed as

BiasBiometryBirth WeightCaffeineCausalityComputer SimulationFemaleFetal MacrosomiaGenetic VariationGenome-Wide Association StudyHumansInfant, NewbornLeast-Squares AnalysisMendelian Randomization AnalysisPregnancyPregnancy in ObesityCaffeinebiasinstrumental variablemean squared errorMendelian randomizationtwo-stage least squares estimate

Identifiers

PMID31651042
PMCPMC7182476

What OpenQuestion holds

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.