ATM and transient ischemic attack: The subgroup meta-analysis of the incidence rate of any bleeding in ischemic stroke or TIA aspirin non-responders with ATM versus those without ATM, using a fixed effects model because of low heterogeneity, indicated an effect size of 0.09 without statistical significance (OR 1.04; 95% CI 0.49 to 2.17) (Figure 6).