Primary Submission Category: Causal Inference and Bias/Discrimination
The implementation of target trial emulation for causal inference: a scoping review
Authors: Hanxiao Zuo, Lin Yu, Sandra Campbell, Yan Yuan,
Presenting Author: Hanxiao Zuo*
Target trial emulation (TTE) is an increasingly-used method for causal inference by emulating randomized clinical trials using observational data. Even though many TTE research projects have been conducted, the rigor of TTE implementation has not been investigated. This review mapped the implementation of TTE, including research topics, frequently used strategies, study design, and common issues for future improvement.
We searched literature in PROSPERO, OVID Medline, Wiley Cochrane Library, SCOPUS, etc. using controlled vocabulary and keywords representing the concept of “target trial emulation”. The databases were searched from the inception to January 18, 2022, and all original research that met inclusion criteria was included for screenings and information extraction.
655 papers were included for screenings, of which 96 papers were eligible for extraction. Retrieved original papers show that TTE was increasingly used from 2018, and cancer research is the top studied topic (22.9%). The main components of TTE design including time-zero, assignment procedure, and contrast strategy were not implemented well in all research. Several limitations including residual confounding, limited generalization, and lack of evaluation tools need to be improved.
Future improvements are needed for TTE implementation and evaluation to make it better to support the causal inference using observational data.