Target Trial Emulation with the R Package TTE: A Tutorial and Methodological Guide
This study addresses the susceptibility of causal effect estimation in observational studies to bias by proposing a systematic framework based on target trial emulation. By rigorously specifying eligibility criteria, treatment assignment, time zero, and follow-up rules to emulate a randomized controlled trial design, the approach integrates advanced statistical methods—including inverse probability weighting, weighted discrete-time survival models, model standardization, competing risk analysis, and cluster bootstrap at the individual level—into an end-to-end R implementation. The framework supports comparative analyses of both intention-to-treat and per-protocol effects and demonstrates its validity and practicality through two synthetic case studies, successfully estimating relative risks, absolute risks, and cumulative incidence functions.