ATM and transient ischemic attack: The subgroup meta-analysis of the incidence rate of recurrent ischemic stroke in ischemic stroke or TIA aspirin non-responders with ATM versus those without ATM, using a random effects model because of high heterogeneity, indicated an effect size of 0.30 without statistical significance (OR 1.59; 95% CI 0.07 to 33.77) (Figure 5).