Statistical Analysis for Surgical Trials

In this chapter, we review the concepts required to successfully analyze the main hypothesis for a surgical randomized controlled trial. Three hypothesis frameworks are considered for the main hypothesis for the trial: superiority, noninferiority, and equivalence. Data harmonization, checking, and processing are described as well as data visualization techniques for both continuous and categorical variables, all of which should occur prior to formal analysis. The most common statistical assumptions are reviewed as well as options for analyses if these assumptions are not met. The difference between statistical significance and clinical significance is also discussed. This chapter concludes with a section on statistical pitfalls and best practices for surgical trials. Throughout this chapter, we have worked to make these statistical concepts accessible while also providing additional resources for those who require, or are interested in, a deeper conceptual understanding.