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Using multiple genetic variants as instrumental variables for modifiable risk factors
Open accessAbstract
Mendelian randomisation analyses use genetic variants as instrumental variables (IVs) to estimate causal effects of modifiable risk factors on disease outcomes. Genetic variants typically explain a small proportion of the variability in risk factors; hence Mendelian randomisation analyses can require large sample sizes. However, an increasing number of genetic variants have been found to be robustly associated with disease-related outcomes in genome-wide association studies. Use of multiple instruments can improve the precision of IV estimates, and also permit examination of underlying IV assumptions. We discuss the use of multiple genetic variants in Mendelian randomisation analyses with continuous outcome variables where all relationships are assumed to be linear. We describe possible violations of IV assumptions, and how multiple instrument analyses can be used to identify them. We present an example using four adiposity-associated genetic variants as IVs for the causal effect of fat mass on bone density, using data on 5509 children enrolled in the ALSPAC birth cohort study. We also use simulation studies to examine the effect of different sets of IVs on precision and bias. When each instrument independently explains variability in the risk factor, use of multiple instruments increases the precision of IV estimates. However, inclusion of weak instruments could increase finite sample bias. Missing data on multiple genetic variants can diminish the available sample size, compared with single instrument analyses. In simulations with additive genotype-risk factor effects, IV estimates using a weighted allele score had similar properties to estimates using multiple instruments. Under the correct conditions, multiple instrument analyses are a promising approach for Mendelian randomisation studies. Further research is required into multiple imputation methods to address missing data issues in IV estimation.
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“All three of these SNPs have previously been shown to be strong instruments for MR analysis as measured by F-statistics > 10 [8,18]”
From Associations of genetically determined iron status across the phenome: A mendelian randomization study (2019) · cites this paper as [18]
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“Interpretation of results from MR studies relies on four conditions.12,24”
From Mendelian randomization (2022) · cites this paper as [24]
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“Crossover” in Depressive Symptoms Among Older Couples: Are Previous Findings Artifactual?
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“Such “Mendelian randomization” studies are increasingly common in etiological epidemiology (Didelez, Meng, & Sheehan, 2010; Lawlor et al., 2008; Palmer et al., 2012; Vansteelandt, Bowden, Babanezhad, & Goetghebeur, 2011).”
BackgroundZhao, Z., Cao, Q., Zhu, M., Wang, C., & Lu, X. (2023) · Scientific Reports · doi:10.1038/s41598-023-34200-0 · Cited by 5
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MethodQi, B., Yang, Z., Huang, N., Zheng, W., & Gui, C. (2023) · Journal of Cardiovascular Development and Disease · doi:10.3390/jcdd10100420 · Cited by 5
“In order to investigate the relationship between particular IVs and exposures, we also used a web tool to generate the F statistic [22].”
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“R), where “MAF” is the minor allele frequency of SNPs used as IVs, “n” is the sample size, and “k” is the number of IVs employed (Palmer et al., 2012).”
BackgroundLiu, D., Mei, Y., Ji, N., Zhang, B., & Feng, X. (2024) · International Urology and Nephrology · doi:10.1007/s11255-024-04020-w · Cited by 5
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Ye, C., Wang, T., Wang, H., Lian, G., & Xie, L. (2024) · Frontiers in Psychiatry · doi:10.3389/fpsyt.2024.1377705 · Cited by 5
“We calculated the R 2 and F statistics using the following formula: R 2 = where MAF is the minor allele frequency, b is the effect value of the genetic variant in the exposure, N is the sample size of the exposure GWAS, and K is the number of genetic instruments employed (22).”
MethodLiu, Z., Fu, Q., Yu, Q., Ma, X., & Yang, R. (2024) · Frontiers in Endocrinology · doi:10.3389/fendo.2024.1418835 · Cited by 5
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“Due to the sparse pool of IVs, we adjusted the significance threshold to 5e-5 to maintain a minimum of 10 SNPs, thereby preventing inaccuracies due to a scarcity of significant genetic variants [26].”
Hu, C., Vasileiou, E. S., Salter, A. R., Marrie, R. A., Kowalec, K., & Fitzgerald, K. C. (2024) · Multiple Sclerosis and Related Disorders · doi:10.1016/j.msard.2024.105866 · Cited by 5
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Genetic endowments, parental resources and adult health: Evidence from the Young Finns Study
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“Second, it reduces the risk that any individual SNP will bias the estimates via an alternative biological pathway (Palmer et al., 2012).”
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Cao, L., Liu, D., Karhunen, V., Ren, Y., Ye, D., Gao, J., Gill, D., & Wang, M. (2023) · Journal of Stroke and Cerebrovascular Diseases · doi:10.1016/j.jstrokecerebrovasdis.2023.107050 · Cited by 5
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Causal Effects of COVID-19 on the Risk of Thrombosis: A Two-Sample Mendel Randomization Study
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“10 8 ) and an F-statistic greater than 10, 23 which satis fi es the fi rst assumption, whose violation might introduce the so-called “ weak instruments bias.”
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“In general, F-statistics 10 were considered weak IVs and discarded 21,22 .”
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“as instrument, we calculated the F statistic [13], and to avoid bias due to use of weak instruments, we included in the MR analyses only SNPs with an F statistic equal to or greater than 10 [14].”
MethodRichmond, R. C., Smith, G. D., Ness, A., den Hoed, M., McMahon, G., & Timpson, N. J. (2015) · Apple Academic Press eBooks · doi:10.1201/b18225-9 · Cited by 8
The brief resilience scale: a genome-wide association study in the UK Biobank
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Causal Associations between Sleep Apnea and Dementia: A Two-Sample Mendelian Randomization Study
Zhao, L., Xia, L., Xu, Y., & Zhang, Y. (2025) · Archives of Medical Science · doi:10.5114/aoms/214094 · Cited by 4
“R 2 ) for each IV, was used to assess the instrumental strength, where R 2 is the proportion of phenotypic variance explained by each genetic variant in the exposure, and N is the sample size [24].”
He, Y., Han, C. Q., Li, C., Yin, X., Wang, J., Gu, L., Yan, R., Liu, B.-H., Zhou, X., & He, W. (2024) · Frontiers in Microbiology · doi:10.3389/fmicb.2024.1384095 · Cited by 4
Ding, W., Chen, L., Xia, J., Dong, G., Song, B., Pei, B., & Li, X. (2024) · Medicine · doi:10.1097/md.0000000000037735 · Cited by 4
“…IVs; the linkage disequilibrium threshold was set as R 2 < 0.01 and distance was set as kb = 10000 kb to avoid linkage disequilibrium; F-statistics [22] of each IV was calculated by F = R 2 × (N − 2)/(1 − R 2 ), where R 2 represents the genetic variant explanation of the exposure variance and N…”
MethodInfluentialZhao, D., Wu, S., Wang, Y., Zheng, H., & Zhu, M. (2024) · Archives of Dermatological Research · doi:10.1007/s00403-024-02978-2 · Cited by 4
Su, N., Li, J., Xia, Y., Huang, C., & Chen, L. (2024) · Frontiers in Endocrinology · doi:10.3389/fendo.2024.1393847 · Cited by 6
Wang, H., Dai, Y., Tai, Y., Zhou, Z., Zhou, X., Li, B., & Liang, Y. (2024) · Parkinsonism & Related Disorders · doi:10.1016/j.parkreldis.2024.107080 · Cited by 5
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Yi, J., Wu, S., & He, H. (2024) · Frontiers in Immunology · doi:10.3389/fimmu.2024.1448724 · Cited by 4
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Shen, T., Fan, J., Zheng, Y., Luo, Y., & Liu, P. (2024) · Molecular Neurobiology · doi:10.1007/s12035-024-04556-z · Cited by 5
“The formulas for the F statistic and R 2 value were as follows [11, 12].”
Chen, B., Wang, C., & Li, W. (2024) · Frontiers in Immunology · doi:10.3389/fimmu.2024.1459465 · Cited by 5
Yang, F., & Wen, J. (2024) · Hereditas · doi:10.1186/s41065-024-00352-w · Cited by 4
“R 2 represents the proportion of variance explained by the exposed SNP tools, k represents the number of tools, and N represents the exposed sample size [31, 32].”
Zhang, J., Wang, M., Wang, D., Deng, L., & Yao, P. (2025) · Hereditas · doi:10.1186/s41065-024-00358-4 · Cited by 4
Zhang, Y., Ma, X., Wu, F., Sun, Y., Mou, H., Liu, X., & Zhang, W. (2025) · Scientific Reports · doi:10.1038/s41598-025-92216-0 · Cited by 4
“In addition, to prevent the influence of weak IVs on the included IVs, we also computed the F-statistic (F = beta^2/se^2) 34,35 .”
Zhang, N., & Dong, X. (2025) · Journal of Affective Disorders · doi:10.1016/j.jad.2025.02.091 · Cited by 4
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Unraveling the Link Between Obesity and Keratoconus Risk Based on Genetic Evidence
Huang, Y., Zhuang, J., Liu, C. X., Liu, S., Ren, H., Zhang, Q., Yan, L., Qiu, J. F., Yu, N., Yu, K., et al. (2025) · Translational Vision Science & Technology · doi:10.1167/tvst.14.5.20 · Cited by 4
“16 Notably, SNPs with an F -statistic greater than 10 were regarded as robust instruments.”
Wu, Z., Yao, T., Han, Z., Wang, Z., Liu, B., Lu, M., Zheng, J., & Shen, N. (2025) · Food Science & Nutrition · doi:10.1002/fsn3.70422 · Cited by 5
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“The strength of the association between SNP and the exposure is evaluated using the F statistic.(27) If F statistic is >10, no weak instrumental variable is present.”
MethodMediators linking obesity to childhood asthma
Chen, Y.-C., Huang, Y.-T., Pan, W., & Lee, Y. (2022) · Pediatric Allergy and Immunology · doi:10.1111/pai.13859 · Cited by 3
Inflammatory bowel disease and risk of coronary heart disease
Qiu, X., Hou, C., Yang, Z., Wang, Q., & Li, L. (2022) · Wiener klinische Wochenschrift · doi:10.1007/s00508-022-02095-y · Cited by 4
“Instrumental SNPs with F statistic below 10 would be excluded from the study [21].”
BackgroundGenetic association and causal inference between lung function and venous thromboembolism
Zhang, Q., Zhang, X., Zhang, J., Jiang, M., Zhang, Y., Zheng, D., Wu, L., Wang, W., Wang, B., & Wang, Y. (2023) · Respiratory Research · doi:10.1186/s12931-023-02335-3 · Cited by 4
“N means the number of individuals of the GWAS-exposure [43].”
BackgroundYuan, Y., Tan, W., Huang, Y., Huang, H., Li, Y., Gou, Y., Zeng, S., & Hu, Z. (2023) · World Journal of Urology · doi:10.1007/s00345-023-04465-1 · Cited by 4
“where k is the number of genetic variants [16].”
BackgroundChen, B., Diallo, M. T., Ma, Y., & Wang, D. (2023) · Journal of Cancer Research and Clinical Oncology · doi:10.1007/s00432-023-05140-z · Cited by 4
“The F statistic is calculated from the accepted and reliable formula (Palmer et al. 2012): The R 2 is calculated by formula (Liu et al. 2022): Additionally, we used harmonization of the SNP effect of exposure and outcome to remove either a palindromic SNP with intermediate allele frequencies or a…”
MethodLi, J., Lu, Y., & Zhao, X. (2023) · Medicine · doi:10.1097/md.0000000000036639 · Cited by 4
“[19,20] Finally, we will replace the unavailable SNPs in the result summary with the proxy SNPs (R 2 > 0.8) from gov]).”
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“To meet assumption 1, we adopted the genome-wide significance threshold (p 5 × 10 (cid:0) 8 ) and F-statistics ≥ 10 to include the strong IVs, as weak IVs can introduce bias into MR results [23].”
MethodLiang, R., Zhong, W., Ze, S., Qiao, Y., & Yuan, L. (2024) · Medicine · doi:10.1097/md.0000000000037710 · Cited by 4
“[11,12] A threshold of F < 10 was used to define a weak IV, considered as a weak association between SNPs and exposure.”
MethodCao, M., & Cui, B. (2024) · Cardiovascular Diabetology · doi:10.1186/s12933-024-02222-1 · Cited by 5
“We estimated the variance of each protein explained by its IVs by calculating the R 2 [23] and the strength of each IV by the F-statistic [24].”
MethodMa, X., Zhang, Y., Wu, F., Liu, X., & Zhang, W. (2024) · Diabetology & Metabolic Syndrome · doi:10.1186/s13098-024-01331-x · Cited by 4
“Furthermore, we computed the F-value (F = beta^2/se^2) [16] to verify that the included independent variables are not affected by feeble IVs [17].”
MethodAssociations between dietary habits and bipolar disorder: a diet-wide mendelian randomization study
Li, J., Hu, R., Luo, H., Guo, Y., Zhang, Z., Luo, Q., & Xia, P. (2024) · Frontiers in Psychiatry · doi:10.3389/fpsyt.2024.1388316 · Cited by 6
Bi, X., Wang, Y., Lin, Y., Wang, M., & Li, X. (2024) · Metabolites · doi:10.3390/metabo14060294 · Cited by 4
“The F-statistic 10 indicates the presence of weak instrumental bias [27].”
BackgroundMethodLi, J., Huang, S.-T., Feng, F., Wang, L., Chen, T., Li, M., & Liu, L. (2024) · Frontiers in Pharmacology · doi:10.3389/fphar.2024.1389354 · Cited by 4
Shi, Y.-B., Dong, H., Chang, W.-K., Zhao, Y. P., Jin, H., Li, J.-K., & Yan, S. (2024) · Frontiers in Microbiology · doi:10.3389/fmicb.2024.1396699 · Cited by 4
Zhi-gang, Y., & Handong, W. (2024) · Frontiers in Genetics · doi:10.3389/fgene.2024.1424119 · Cited by 4
Artificial sweetener and respiratory system cancer: A Mendelian randomization analysis
Zhang, J., Fan, R., Mao, C., Zhou, X., Zhang, Q., Li, S., & Zhuang, Z. (2024) · Clinical Nutrition ESPEN · doi:10.1016/j.clnesp.2024.06.008 · Cited by 5
Lv, L., Long, Z., Tan, X., Qin, L., Yan, W., Zhang, H., Ren, F., & Wang, C. (2024) · Frontiers in Aging Neuroscience · doi:10.3389/fnagi.2024.1423773 · Cited by 4
Li, J., Wang, W., Liu, F., Qiu, L., Ren, Y., Li, M., Li, W., Gao, F., & Zhang, J. (2024) · Frontiers in Genetics · doi:10.3389/fgene.2024.1356696 · Cited by 5
Genetic prediction of asthma increases multiple sepsis risks: A Mendelian randomization study
Luo, J., Liu, P., & Luo, Y. (2024) · World Allergy Organization Journal · doi:10.1016/j.waojou.2024.100937 · Cited by 4
“18 Here, R2 represents the proportion of exposure variance explained by the selected IVs, n is the sample size, and k is the number of IVs.”
BackgroundHospital-Treated Infectious Diseases, Infection Burden, and Risk of Lung Cancer
Zheng, J., Huang, J., Yang, Q., Zhou, R., Huang, Y., Wu, X., & Tang, S. (2024) · CHEST Journal · doi:10.1016/j.chest.2024.06.3811 · Cited by 4
Causal relationship between air pollution and infections: a two-sample Mendelian randomization study
Yang, S., Tong, T., Wang, H., Li, Z., Wang, M., & Ni, K. (2024) · Frontiers in Public Health · doi:10.3389/fpubh.2024.1409640 · Cited by 4
Zhang, Q., Shen, C., Zhang, L., & Wang, M. (2024) · Journal of Cardiovascular Development and Disease · doi:10.3390/jcdd11080247 · Cited by 4
“To avoid weak instrument bias, the strength of each IV was assessed by the F-statistic using the formula F = (R 2 × (N − 2))/(1 − R 2 ), where R 2 referred to the variance explained by the SNP and N was the sample size of exposure data [23].”
MethodSun, Y., Wan, B., Liu, X., Dong, J., Yin, S., & Wu, Y. (2024) · Frontiers in Oncology · doi:10.3389/fonc.2024.1422009 · Cited by 4
Deng, T., & Liu, X. (2024) · Frontiers in Endocrinology · doi:10.3389/fendo.2024.1424070 · Cited by 4
Zhao, X., & Ding, N. (2024) · Scientific Reports · doi:10.1038/s41598-024-77788-7 · Cited by 4
“Furthermore, research indicates that SUA levels are associated with the risk of various cancers—including colorectal, pancreatic, and gallbladder cancers—in a gender-specific manner 47,50 .”
BackgroundPan, R., Liu, J., Xiao, M., Sun, C., Zhu, J., Wan, L., & Xue, B. (2024) · Frontiers in Endocrinology · doi:10.3389/fendo.2024.1443330 · Cited by 4
“R 2 ), where R 2 represents the proportion of variance in the trait illuminated by the SNP, and N denotes the sample size of GWAS involving SNPs with the trait (23).”
Wang, S. M., Zhang, M. F., Pan, Q. H., Yu, T., Lei, R. L., & Li, Q. (2024) · World Journal of Oncology · doi:10.14740/wjon1960 · Cited by 4
Liu, H., Zhang, H., Yin, Z., & Hou, M. (2025) · Epigenetics & Chromatin · doi:10.1186/s13072-025-00567-9 · Cited by 4
A Bayesian approach to Mendelian randomisation with dependent instruments
Shapland, C. Y., Thompson, J. R., & Sheehan, N. A. (2018) · Statistics in Medicine · doi:10.1002/sim.8029 · Cited by 4
“The assumptions of Mendelian randomisation ought to be validated by biological knowledge [8, 54] and in a Bayesian approach this same knowledge could be incorporated into the priors.”
BackgroundPehkonen, J., Viinikainen, J., Böckerman, P., Pitkänen, N., Lehtimäki, T. J., & Raitakari, O. T. (2019) · SSM - Population Health · doi:10.1016/j.ssmph.2019.100379 · Cited by 4
Non-Causal Effects of Asthma on COVID-19 Susceptibility and Severity
Qiu, L., Yin, K.-J., Pan, G., Ni, J., & Wang, B. (2022) · Frontiers in Genetics · doi:10.3389/fgene.2021.762697 · Cited by 4
“Meanwhile, in order to quantitatively verify instrument strength, F-statistics for each instrumental variables individually and cumulatively were calculated via the formula F-statistic R(2) × (SampleSize-2)/(1R(2)) (Palmer et al., 2012).”
MethodZou, X., Wang, L., Zeng, Y., & Zhang, L. (2023) · Journal of Human Genetics · doi:10.1038/s10038-023-01154-0 · Cited by 4
“In addition, we detected the differences between the various instrumental variables to reduce differences between groups by Cochran’s Q statistics [25].”
MethodSun, K., Li, M., Wu, Y., Wu, Y., Zeng, Y., Zhou, S., Peng, L., & Shen, B. (2023) · Orthopaedic Surgery · doi:10.1111/os.13947 · Cited by 5
Chen, K., Gao, P., Fang, X., Tang, K., Ouyang, P., Li, Z., Li, L., & Deng, Z. (2023) · Animal Models and Experimental Medicine · doi:10.1002/ame2.12373 · Cited by 4
“27 In this study, the F sta - tistics of all IVs that were ultimately included were greater than 10.”
He, B., Quan, L.-P., Li, C., Yan, W., Zhang, Z., Zhou, L., Wei, Q., Li, Z., Mo, J., Zhang, Z., et al. (2024) · Heliyon · doi:10.1016/j.heliyon.2024.e25572 · Cited by 4
“The F-test statistic ], N: sample size; K: number of IVs) was used to assess whether these selected SNPs were affected by weak instrumental variables (F > 10) [32].”
MethodZhang, X., Cai, Y., Jiang, Y., Du, W., An, W., Fu, Q.-Q., & Chen, Y. (2024) · Frontiers in Molecular Biosciences · doi:10.3389/fmolb.2024.1368669 · Cited by 4
Wang, X., Mao, R., Wang, M., Zhu, L., & Jin, L. (2024) · Scientific Reports · doi:10.1038/s41598-024-59726-9 · Cited by 5
“The following equation was used: by each IV; N is the number of samples in GWAS;and K represents the number of SNPs for analysis) 17 .”
MethodWang, W., Xiao, W., Song, Z., Zhuang, Z., Huang, N., Zhao, Y., & Huang, T. (2024) · The Journal of Clinical Endocrinology & Metabolism · doi:10.1210/clinem/dgae455 · Cited by 4
Wang, S., Wang, J., Niu, Z., Zhang, K., Yang, T., Hou, S., & Lin, N. (2024) · Frontiers in Neurology · doi:10.3389/fneur.2024.1405086 · Cited by 4
Li, L., Yang, W., Huang, L., Feng, X., Cheng, H., Ge, X., Zan, G., Tan, Y., Xiao, L., Liu, C., et al. (2021) · iScience · doi:10.1016/j.isci.2021.103191 · Cited by 4
Palmer, T., Ramsahai, R. R., Lawlor, D. A., Sheehan, N. A., & Didelez, V. (2012) · American Journal of Epidemiology · doi:10.1093/aje/kws250 · Cited by 4
Self-citationNi, J., Wang, P., Yin, K.-J., Huang, J.-X., Tian, T., Cen, H., Sui, C., Xu, Z., & Pan, H. (2022) · SSRN Electronic Journal · doi:10.2139/ssrn.4045943 · Cited by 4
Clayton, G., Soares, A. G., Goulding, N., Borges, M. C., Holmes, M. V., Smith, G. D., Tilling, K. M., Lawlor, D. A., & Carter, A. R. (2022) · medRxiv · doi:10.1101/2022.03.03.22271836 · Cited by 4
Neuroticism and posttraumatic stress disorder: A Mendelian randomization analysis
You, Z., Chen, S., & Tang, J. (2024) · Brain and Behavior · doi:10.1002/brb3.70041 · Cited by 4
“Subsequently, the F statistic was calculated to evaluate the strength of the instruments with F > 10 avoiding weak IV bias (Sanderson & Windmeijer, 2016), utilizing the formula ( F = beta 2 /se 2 ) for exposures (Palmer et al., 2012), of which beta is the effect size of single SNP.”
MethodZhang, R.-Y., Li, J.-Y., Liu, Y.-N., Zhang, Z.-X., Zhao, J., & Li, F.-J. (2024) · Frontiers in Endocrinology · doi:10.3389/fendo.2024.1408053 · Cited by 3
“The instrument strength was estimated using the F-statistic: F k , where N represents the sample size and k is the number of instrumental variables (37).”
Causal roles of dietary structure and types on prostate cancer risk: A mendelian randomization study
Li, C., Jing, Z., Guo, Q., Zheng, Z., Zhao, X., Yuan, W., Xi, Y., & Wang, J. (2024) · BMC Cancer · doi:10.1186/s12885-024-13252-z · Cited by 3
“In addition, the P of the SNP and the outcome cannot be less than 1 × 10–5 to ensure that the SNP is not directly related to the outcome [17].”
Zhang, J., Wang, B., Du, P., Song, H., Yang, L., & Zhou, Y. J. (2025) · Medicine · doi:10.1097/md.0000000000041536 · Cited by 4
“F -value is calculated by the formula Here, R 2 is the proportion of variance explained by all SNPs, N is the total sample size, and k is the number of SNPs. [17]”
Chen, Y., Sun, S., Gao, N., Bai, Z., Yu, W., Zhao, B. Q., Yun, Y., Sun, X., Lin, P., Li, W., et al. (2025) · Neurobiology of Disease · doi:10.1016/j.nbd.2025.106933 · Cited by 3
“We selected genetic variants with a genome-wide significant p -value ( p 5 × 10 8 ) and F-statistic greater than 10 (Palmer et al., 2011), which satisfies the first assumption, whose violation might introduce so-called “ weak instrument bias ” (Burgess and Thompson, 2011).”
Sun, Y., & Liu, Y. (2025) · International Journal of Molecular Sciences · doi:10.3390/ijms26104615 · Cited by 4
“This approach is based on three core assumptions: (i) the genetic instruments are strongly linked with the exposure, (ii) these instruments are free from confounding factors, and (iii) they affect CVD outcomes solely through physical activity, without involving other pathways [26–28].”
Wang, H., Xie, F., Wang, M., Ji, J., Song, Y., Dai, Y., Wang, L., Zheng, K., & Cao, L. (2025) · International Journal of Molecular Sciences · doi:10.3390/ijms26136201 · Cited by 3
“…gene region to eliminate pleiotropy; (iii) linkage disequilibrium (LD) clumping (r 2 < 0.001) was used to ensure the independence of genetic associations and remove horizontal pleiotropy [49]; (iv) the instrument strength (F-statistic) must be greater than 10 to ensure strong correlation [57].”
Influential
Metadata
- Authors
- Palmer, T. M., Lawlor, D. A., Harbord, R. M., Sheehan, N. A., Tobias, J. H., Timpson, N. J., Smith, G. D., & Sterne, J. A.
- Affiliations
- University of Bristol (GB)
- University of Leicester (GB)
- School of Clinical Sciences, University of Bristol, Bristol, UK
- Corresponding author
- Palmer, Tom M
- ORCID
- Venue
- Statistical Methods in Medical Research
- Publisher
- SAGE Publications
- Published
- 2011-01-07
- Volume
- 21
- Issue
- 3
- Pages
- 223-242
- ISSN
- 0962-2802 (ISSN-L)
- 1477-0334
- PMC
- PMC3917707
- OpenAlex
- W2151096860
- Cited by
- 1,289
- References
- 76
- Citations by year
- 2026: 92 · 2025: 240 · 2024: 394 · 2023: 164 · 2022: 83 · 2021: 67 · 2020: 44 · 2019: 33 · 2018: 22 · 2017: 20 · 2016: 27 · 2015: 44 · 2014: 20 · 2013: 19 · 2012: 14
- FWCI
- 11.61
- Type
- journal article
- Language
- en
- Open access
- green
- www.ncbi.nlm.nih.gov
- Locations
- Statistical Methods in Medical Research (publishedVersion)
- Europe PMC (PubMed Central) (publishedVersion, cc-by)
- PubMed Central (publishedVersion, cc-by)
- PubMed (publishedVersion)
- Adelaide Research & Scholarship (AR&S) (University of Adelaide) (submittedVersion)
- Lancaster EPrints (Lancaster University) (submittedVersion)
- Figshare (submittedVersion, cc-by)
- Leicester Research Archive (University of Leicester) (submittedVersion, cc-by)
- Bristol Research (University of Bristol) (submittedVersion, cc-by)
- Funders
- Wellcome Trust (G0600705, 092731)
- University of Bristol (G0600705)
- Medical Research Council (G0600705)
- Economic and Social Research Council (ES/E00234X/1)
- Topics
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Genetics › Genetic Associations and Epidemiology
- Physical Sciences › Mathematics › Statistics and Probability › Advanced Causal Inference Techniques
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Genetics › Genetics and Physical Performance
- Keywords
- Mendelian randomization, modifiable risk factors, weak instruments, finite-sample bias, fat mass, bone mineral density, children, causal effect estimation, continuous outcomes
- MeSH terms
- Female, Genotype, Humans, Male, Risk Factors, Genetic Variation, Mendelian Randomization Analysis
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