Table 1:

The effect measures of mediation analysis

Effect	Aim of comparison	Comparison group^*	Reference group^*
Total	Difference between methods	All patients undergo CABG with the naturally occurring timing of CABG	All patients undergo PCI with the naturally occurring timing of PCI
Indirect	Difference between methods attributable to timing of CABG	All patients undergo CABG with the naturally occurring timing of CABG	All patients undergo CABG but with the naturally occurring timing of PCI
Direct	Difference between methods attributable to solely CABG	All patients undergo CABG but with the naturally occurring timing of PCI	All patients undergo PCI with the naturally occurring timing of PCI

Note: CABG = coronary artery bypass grafting, PCI = percutaneous coronary intervention.
↵* Comparison and reference groups are based on clinical and treatment data available in a dedicated, population-based registry about patients who underwent a first-time, nonurgent isolated CABG or single-session PCI procedure for multivessel or left main coronary artery disease; did not present with an acute coronary syndrome; and survived the index revascularization.