Results 31 to 40 of about 23,652,556 (316)

Survivor bias in Mendelian randomization analysis

Biostatistics, 2017
Mendelian randomization studies employ genotypes as experimental handles to infer the effect of genetically modified exposures (e.g. vitamin D exposure) on disease outcomes (e.g. mortality). The statistical analysis of these studies makes use of the standard instrumental variables framework.
Vansteelandt, Stijn, Dukes, Oliver, Martinussen, Torben   +2 more
openaire   +3 more sources

Homocysteine and small vessel stroke: A mendelian randomization analysis [PDF]

Annals of Neurology, 2019
ObjectiveTrials of B vitamin therapy to lower blood total homocysteine (tHcy) levels for prevention of stroke are inconclusive. Secondary analyses of trial data and epidemiological studies suggest that tHcy levels may be particularly associated with small vessel stroke (SVS).
Larsson, Susanna C., Traylor, Matthew, Markus, Hugh S.   +2 more
openaire   +3 more sources

Can we apply the Mendelian randomization methodology without considering epigenetic effects?

Emerging Themes in Epidemiology, 2009
Introduction Instrumental variable (IV) methods have been used in econometrics for several decades now, but have only recently been introduced into the epidemiologic research frameworks.
Karmaus Wilfried, Zhang Hongmei, Ogbuanu Ikechukwu U   +2 more
doaj   +1 more source

Causal effects of physical activity on the risk of overall ovarian cancer: A Mendelian randomization study

Digital Health, 2023
Objective Inconsistent results were reported on the association of physical activity with ovarian cancer. However, given the limitations of confounders and inverse causation, the validity of the association remained unclear. Therefore, we conducted a two-
Jing Wang, Huanling Zhao, Jiahao Zhu, Minmin Jiang   +3 more
doaj   +1 more source

Relationship between NAFLD and coronary artery disease: A Mendelian randomization study

Hepatology, EarlyView., 2022
Abstract Background and Aims There is an ongoing debate on whether NAFLD is an active contributor or an innocent bystander in the pathogenesis of coronary artery disease (CAD). The aim of the present study was to assess the causal relationship between NAFLD and CAD.
Zhewen Ren, Pomme I. H. G. Simons, Anke Wesselius, Coen D. A. Stehouwer, Martijn C. G. J. Brouwers   +4 more
wiley   +1 more source

Statistical methods for Mendelian randomization in genome-wide association studies: A review

Computational and Structural Biotechnology Journal, 2022
Genome-wide association studies have yielded thousands of associations for many common diseases and disease-related complex traits. The identified associations made it possible to identify the causal risk factors underlying diseases and investigate the ...
Frederick J. Boehm, Xiang Zhou
doaj   +1 more source

Clustered environments and randomized genes: a fundamental distinction between conventional and genetic epidemiology. [PDF]

, 2007
BACKGROUND: In conventional epidemiology confounding of the exposure of interest with lifestyle or socioeconomic factors, and reverse causation whereby disease status influences exposure rather than vice versa, may invalidate causal interpretations of ...
Timpson, NJ, Timpson, Nic, Harbord, RM, Day, Ian, Timpson Nic, Lawlor, D, Smith George Davey, Smith, George Davey, Lawlor, Debbie A, Ebrahim, S, Harbord, Roger, Day Ian, Debbie A Lawlor, Nic Timpson, George Davey Smith, Ian Day, Shah Ebrahim, Roger Harbord, Lawlor Debbie A, Day, INM, Davey Smith, G, Ebrahim, Shah, Harbord Roger, Ebrahim Shah   +23 more
core   +1 more source

The basic principles underlying Mendelian randomization.

, 2021
Fig 1A is the three assumptions for Mendelian randomization analysis. Fig 1B is the basic principles of bi-directional Mendelian randomization. SNP is the single nucleotide polymorphism and IV is the instrumental variable.
Zhenxing Tu (11576846), Hongquan Chen (4056973), Zhiguang Liu (174159), Jie Ding (73711)   +3 more
core   +1 more source

Overview of Mendelian Randomization Analysis

Journal of Rheumatic Diseases, 2020
The inference of causality from observational evidence may be problematic, as observational studies frequently include confounding factors or reverse causation for the identification of associations between exposure and outcome. Thus, in observational studies, the association between a risk factor and a disease of interest may not be causal.
openaire   +2 more sources

Study on the causal relationship between educational attainment and delirium: A two-sample Mendelian randomization study

Heliyon
This study aimed to investigate whether there is a causal relationship between educational attainment and delirium at the genetic level using the Mendelian randomization method, and provide new evidence for studies in this field.
Xianjie Wan, Hui Yu, Mingyi Yang, Weikun Hou, Jiale Xie, Ke Xu, Yujie Ma, Rui Ma, Fan Wang, Peng Xu   +9 more
doaj   +1 more source