Objective: Observational data can be used to attempt to emulate a target trial of statin use and estimate analogues of intention-to-treat and per protocol effects on dementia risk.
Methods: Using data from a prospective cohort study in the Netherlands, we conceptualized a sequence of “trials” in which eligible individuals ages 55–80 years were classified as statin initiators or noninitiators for every consecutive month between 1993 and 2007 and were followed until diagnosis of dementia, death, loss to follow-up, or the end of follow-up.