title: [CLINICAL TRIAL DESIGN].
abstract: Clinical trials/research are conducted to examine the clinical questions of practicing physicians. It is important to design trials appropriately in advance, taking their feasibility into account. A randomized, controlled trial is the ultimate design for treatment comparisons at the final confirmatory stage. However, randomized trials do not necessarily provide all answers to clinical questions. This article summarizes fundamental points of clinical trial design and the important role of randomization and contrasts superiority and noninferiority trials. In addition, it focuses on propensity score matching, a useful method to compare two treatment arms, especially in the context where randomization is infeasible. The propensity score-matching method is increasingly used in surgical clinical research.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Morita
mesh_terms: D035843:Biomedical Research; D002986:Clinical Trials as Topic; D011446:Prospective Studies; D012107:Research Design; D012189:Retrospective Studies