Different statistical techniques dealing with confounding in observational research: measuring the effect of breast-conserving therapy and mastectomy on survival.
Marissa C Van MaarenSaskia le CessieLuc J A StrobbeCatharina G M Groothuis-OudshoornPhilip M P PoortmansSabine SieslingPublished in: Journal of cancer research and clinical oncology (2019)
Unmeasured confounding is very difficult to eliminate in observational research. We cannot conclude that BCT or mastectomy has a causal relationship with 10-year DMFS. It is crucial to critically evaluate all model's assumptions, and to be careful in drawing firm conclusions.