skip to primary navigation skip to content
Loading Events

« All Events

BSU Seminar: “How to obtain valid tests and confidence intervals for treatment effects after confounder selection”

January 22, 2019 @ 2:00 pm - 3:00 pm

Free

Speaker: Dr Oliver Dukes, Ghent University

Title: “How to obtain valid tests and confidence intervals for treatment effects after confounder selection”

Abstract: The problem of how to best select variables for confounding adjustment forms one of the key challenges in the evaluation of exposure or treatment effects in observational studies. Routine practice is often based on stepwise selection procedures that use hypothesis testing, change-in-estimate assessments or the lasso, which have all been criticised for not giving sufficient priority to the selection of confounders. This has prompted vigorous recent activity in developing procedures that prioritise the selection of confounders, while preventing the selection of so-called instrumental variables that are associated with exposure but not outcome (after adjustment for the exposure). A major drawback of all these procedures is that there is no finite sample size at which they are guaranteed to deliver treatment effect estimators and associated confidence intervals with adequate performance. This is the result of the estimator jumping back and forth between different selected models, and standard confidence intervals ignoring the resulting model selection uncertainty.

In this talk, I will develop insight into this by evaluating the finite-sample distribution of the exposure effect estimator in linear regression, under a number of the aforementioned confounder selection procedures. I will then propose a simple and generic solution in the context of generalised linear models, which overcomes this concern (under weaker conditions than competing proposals).

Details

Date:
January 22, 2019
Time:
2:00 pm - 3:00 pm
Cost:
Free
Event Category:

Organiser

MRC Biostatistics Unit
Phone:
01223 768263
Email:
alison.quenault@mrc-bsu.cam.ac.uk

Venue

Large Seminar Room, IPH
Institute of Public Health, Forvie Site
Cambridge, CB2 0SR United Kingdom
+ Google Map
Website:
www.iph.cam.ac.uk