Eur J Cardiothorac Surg. 2024 Aug 24:ezae318. doi: 10.1093/ejcts/ezae318. Online ahead of print.
ABSTRACT
Overlap weighting (OW), using weights defined as the probability of receiving the opposite treatment, is a relatively new, alternative propensity score (PS)-based weighting technique used to adjust for confounding when estimating causal treatment effects. It has preferable properties compared to inverse probability of treatment weighting (IPTW) such as exact covariate balance, safeguards against extreme weights, and emphasis on medical equipoise, where treatment decisions are most uncertain. In this article we introduce the OW methodology, compare it to IPTW, and provide some strategies for assessing weighting impact, through an applied example of hospital mortality. When the PS distributions have large separation, IPTW has been shown to produce biased and less efficient estimates of the treatment effect, making OW a preferred method in such cases.
PMID:39180471 | DOI:10.1093/ejcts/ezae318
