The parametric g-formula for time-to-event data: intuition and a worked example.

ABSTRACT:

Background

The parametric g-formula can be used to estimate the effect of a policy, intervention, or treatment. Unlike standard regression approaches, the parametric g-formula can be used to adjust for time-varying confounders that are affected by prior exposures. To date, there are few published examples in which the method has been applied.

Methods

We provide a simple introduction to the parametric g-formula and illustrate its application in an analysis of a small cohort study of bone marrow transplant patients in which the effect of treatment on mortality is subject to time-varying confounding.

Results

Standard regression adjustment yields a biased estimate of the effect of treatment on mortality relative to the estimate obtained by the g-formula.

Conclusions

SUBMITTER: Keil AP 

PROVIDER: S-EPMC4310506 | biostudies-literature | 2014 Nov

REPOSITORIES: biostudies-literature