Evidence-based research is increasingly aimed at differentiating between no proof of difference (failed demonstration of superiority) and proof of no difference (demonstration of equivalence). The latter requires that equivalence margins are incorporated in the analysis of outcomes. We applied an analysis of equivalence to study the incremental benefit of newer-generation vs early-generation drug-eluting stents (DES) in women receiving percutaneous coronary intervention. The clinical material was derived from published data. Our equivalence testing was focused on the end-point of target-lesion revascularisation (TLR). Results were expressed as rate differences (RDs), while the equivalence margins (±2.9%) were derived from the statistical power calculations of a recent trial. Our results clearly indicated that, in women, there was an equivalent effectiveness between newer-generation and early-generation of DES.
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