Considerations of the non-inferior clinical researches on the anti-vascular endothelial growth factor therapy for fundus diseases

Abstract

In evidence-based medicine, randomized controlled clinical trials are considered as the gold standard to evaluate the curative effect of the anti-vascular endothelial growth factor drugs on fundus diseases. The non-inferiority design is widely used due to the existence of the "ceiling effect" if vision improvement is used as the primary outcome. It is critical to make several issues clear before non-inferiority studies are performed. For example, patients can benefit from the new therapy other than efficacy; the determination of the non-inferiority margin should be based on the comprehensive consideration of clinical and statistical meanings; the traditional significance test method is not suitable for non-inferiority tests; the superiority test could be further performed if the non-inferiority conclusion has been reached. This article aims to elaborate these hot issues and to provide guidance for clinical researchers to carry out research designs and interpret findings objectively and scientifically. (Chin J Ophthalmol, 2020, 56: 895-898).