Fig. 2

Forest plot for all-cause mortality. Individual and pooled risk ratios (RR) with 95 % confidence intervals (CI) for randomized controlled trials (RCTs) comparing dual anti-platelet therapy with clopidogrel and ASA to single anti-platelet therapy with ASA alone either after elective coronary artery bypass graft surgery (CABG) [15, 16, 21–23] or in patients with acute coronary syndrome (ACS) who subsequently underwent CABG [18, 19], and RCTs comparing higher to lower intensity dual anti-platelet therapy with either ticagrelor [17] or prasugrel [11] and ASA vs clopidogrel and ASA in patients with ACS who subsequently underwent CABG. The pooled RRs with 95 % CI were calculated using random-effects models both overall and for each subgroup. Weight refers to the contribution of each study to the overall pooled estimate of treatment effect. Each square and horizontal line denotes the point estimate and 95 % CI for each trial’s RR. The diamonds signify the pooled RR for all trials and each subgroup; the diamond’s centre denotes the point estimate and width denotes the 95 % CI. For CREDO, the number of all-cause deaths was estimated using the ratio of this outcome to the composite outcome for each randomized group reported in the main trial publication [20] because the ACS CABG publication [18] for this trial only provided composite outcomes