Benchmarking observational analyses before using them to address questions trials do not answer: an application to coronary thrombus aspiration

Authors
Anthony A Matthews, Issa J Dahabreh, Ole Fröbert, Bertil Lindahl, Stefan James, Maria Feychting, Tomas Jernberg, Anita Berglund, Miguel A Hernán

Abstract
To increase confidence in the use of observational analyses when addressing effectiveness questions beyond those addressed by randomized trials, one can first benchmark the observational analyses against existing trial results. We use Swedish registry data to emulate a target trial similar to the TASTE randomized trial, which found no difference in the risk of death or myocardial infarction by 1 year with or without thrombus aspiration among individuals with ST-elevation myocardial infarction. We benchmark the emulation against the trial at 1 year, then extend the emulation’s follow up to 3 years and estimate effects in subpopulations underrepresented in the trial. As in the TASTE trial, the observational analysis found no differences in risk of outcomes by 1 year between groups (risk difference 0.7 (-0.7,2.0) and -0.2 (-1.3,1.0) for death and myocardial infarction respectively), so benchmarking was considered successful. We additionally show no difference in risk of death or myocardial infarction by 3 years, or within subpopulations by 1 year. Benchmarking against an index trial before using observational analyses to answer questions beyond those the trial could address allowed us to explore whether the observational data can be trusted to deliver valid estimates of treatment effects.

Link to publication in the American Journal of Epidemiology
https://academic.oup.com/aje/advance-article/doi/10.1093/aje/kwac098/6596277?login=true