Thirteen randomized, controlled trials on the effect of aspirin for primary prevention of CVD vs control were included in this meta-analysis to examine the benefit-risk ratio of aspirin for primary prevention of CVD with a special focus on subgroups. Researchers found that aspirin use did not decrease all-cause or cardiovascular mortality, and offers an inadequate benefit-risk ratio for CVD primary prevention. Moreover, the greatest risk reduction of major adverse cardiovascular events across subgroups was noted in non-smokers, individuals treated with statins, and males.