Projects per year
Abstract
Background
Mendelian randomization (MR) is a form of instrumental variable analysis used to investigate causality using observational data. Another important, although less frequently applied, use of this technique is to investigate confounding due to reverse causality.
Methods
We used a form of reverse MR and data from UK Biobank in a proof-of-principle study to investigate confounding due to reverse causation. Here we focus on the association between alcohol consumption (exposure) and outcomes including educational attainment, and physical and mental health. First, we examined the observational relationship between alcohol consumption and these outcomes. Allele scores were then derived for educational attainment, and physical and mental health, and the association with alcohol consumption (as the outcome) was explored. Sample sizes ranged from 114 941–336 473 in observational analyses and 142 093–336 818 in genetic analyses.
Results
Conventional observational analyses indicated associations between alcohol consumption and a number of outcomes (e.g. neuroticism, body mass index, educational attainment). Analyses using allele scores suggested evidence of reverse causation for several of these relationships (in particular physical health and educational attainment).
Conclusion
Allele scores allow us to investigate reverse causation in observational studies. Our findings suggest that observed associations implying beneficial effects of alcohol consumption may be due to confounding by reverse causation in many cases.
Mendelian randomization (MR) is a form of instrumental variable analysis used to investigate causality using observational data. Another important, although less frequently applied, use of this technique is to investigate confounding due to reverse causality.
Methods
We used a form of reverse MR and data from UK Biobank in a proof-of-principle study to investigate confounding due to reverse causation. Here we focus on the association between alcohol consumption (exposure) and outcomes including educational attainment, and physical and mental health. First, we examined the observational relationship between alcohol consumption and these outcomes. Allele scores were then derived for educational attainment, and physical and mental health, and the association with alcohol consumption (as the outcome) was explored. Sample sizes ranged from 114 941–336 473 in observational analyses and 142 093–336 818 in genetic analyses.
Results
Conventional observational analyses indicated associations between alcohol consumption and a number of outcomes (e.g. neuroticism, body mass index, educational attainment). Analyses using allele scores suggested evidence of reverse causation for several of these relationships (in particular physical health and educational attainment).
Conclusion
Allele scores allow us to investigate reverse causation in observational studies. Our findings suggest that observed associations implying beneficial effects of alcohol consumption may be due to confounding by reverse causation in many cases.
Original language | English |
---|---|
Article number | dyac165 |
Number of pages | 9 |
Journal | International Journal of Epidemiology |
Early online date | 18 Aug 2022 |
DOIs | |
Publication status | E-pub ahead of print - 18 Aug 2022 |
Research Groups and Themes
- Bristol Population Health Science Institute
Fingerprint
Dive into the research topics of 'Using allele scores to identify confounding by reverse causation: studies of alcohol consumption as an exemplar'. Together they form a unique fingerprint.Projects
- 3 Finished
-
Rework of IEU 2 Tilling Programme
Tilling, K. M. (Principal Investigator)
1/04/18 → 31/03/23
Project: Research
-
Rework of IEU Munafo Programme
Munafo, M. R. (Principal Investigator)
1/04/18 → 31/03/23
Project: Research
-
IEU: MRC Integrative Epidemiology Unit Quinquennial renewal
Gaunt, L. F. (Principal Investigator) & Davey Smith, G. (Principal Investigator)
1/04/18 → 31/03/23
Project: Research