Introduction to Mendelian randomization
Mendelian randomization is a study that uses genetic variants as instrumental variables to test the causal effect of a (non-genetic) risk factor on a disease or health-related outcome. Since its first proposal in 2003 it has been increasingly used to determine population causal effects using observational data. It is used in a large amount of the applied research in the MRC Integrative Epidemiology Unit (IEU) and throughout Population Health at the University of Bristol Medical School. Academics working in the IEU and the University of Bristol (including those who are tutors on this course) have been at the forefront of developing methods for assessing and limiting potential biases with this approach.
This course aims to provide an introduction to the conduct, assumptions, strengths and limitations of Mendelian randomization, including the use of up-to-date methods for sensitivity analyses that explore likely violation of Mendelian randomization assumptions.
This is a introductory to intermediate level course. Students will learn about one-sample and two-sample Mendelian randomization, including their assumptions and gaining practical experience of how to apply these methods to real data. They will also learn about a range of sensitivity analyses that explore likely violation of the assumptions of Mendelian randomization. Prior experience of using Mendelian randomization is not required, but participants should have an understanding of aetiological epidemiological principles, and ideally be working on causal population health questions.
- Neil Davies (course organiser)
- Kaitlin Wade (course organiser)
- Philip Haycock
- Jack Bowden
The course tutors are epidemiologists, statisticians, bioinformaticians and molecular geneticists who have a breadth of experience in the design, conduct and analysis using Mendelian randomization methodology.
Room LG-09, Canynge Hall
Date and times
The course will take place on Tuesday 16th July 2019, from 10:00 to 17:30. Arrival and registration from 9:30 am.
Participants should bring a laptop computer. If this is not possible, please let the organisers know in advance so that alternative arrangements can be made.
The fee for attending the course is £220.
Course aims and objectives
Mendelian randomization is a study that uses genetic variants as instrumental variables (proxies) to test the causal effect of a (non-genetic) risk factor. Since its first proposal in 2003 it has been increasingly used to determine causal effects in observational epidemiology and is used in a large amount of the applied research in the MRC Integrative Epidemiology Unit and throughout the School of Social and Community Medicine at the University of Bristol.
This course aims to provide an introduction to the conduct, assumptions, strengths and limitations of Mendelian randomization.
By the end of the course students will:
- Understand the principles and assumptions of instrumental variable analyses
- Understand the properties of genetic variants that make them suitable to be used as instrumental variables
- Understand the strengths and limitations of Mendelian randomization for making causal inference in epidemiology
- Be able to complete a straight forward instrumental variable analysis and correctly interpret the results from that analysis.
- Understand that the two core parts of a Mendelian randomization analysis (the association of genetic variants with the risk factor of interest and the association of genetic variants with the outcome) can be done on separate sets of studies; so called ‘two-sample Mendelian randomization’
- Know the basics of how to undertake a two-sample Mendelian randomization study
Who the course is intended for?
The course is intended for anyone who wants to be able to read and understand Mendelian randomization papers and / or undertake Mendelian randomization analyses. It is a beginners / introductory course.
The course will not include any genetic epidemiology teaching and we will not explain how to undertake a genome wide association study. Some understanding of basic genetic terms would be useful, however, genetic epidemiology and ability to complete a genome wide association study are NOT a pre-requisite for being able to understand this course.
Students intending to take this course should already understand epidemiological principles and have knowledge and skills in statistical analysis to the level of running, and correctly interpreting results from, multivariable regression analyses. Confidence using Stata and / or R (to beginner level) is necessary.
Consider attending in conjunction with the MR-Base user workshop on Friday 19th July.
The course will last seven hours, consisting of lectures, discussion sessions and a practical. Lunch will be provided for all delegates. A provisional timetable is listed below (subject to change):
|10.00||Introduction to the course||Sarah Lewis|
|10.15||Lecture 1: Introduction to Mendelian randomization||Sarah Lewis|
|11.30||Lecture 2: Power calculations in Mendelian randomization||Neil Davies|
|13.15||Practical 1: One sample Mendelian randomization practical||Sarah Lewis, Rebecca Richmond, Michelle Taylor|
|14.30||Lecture 3: Introduction to the principles of two-sample Mendelian randomization||TBD|
|15.30||Lecture 4 and practical illustration: Two-sample Mendelian Randomization & MR-Base||Philip Haycock|
|16.30||Lecture 5: Mendelian randomization, Pleiotropy, MR-Egger and weighted means analyses||Jack Bowden|
Booking will be open until 31st May.Book online