Related Experiment Video
Updated: Jul 5, 2025

A Clinical Trial Assessing the Safety, Efficacy, and Delivery of Olive-Oil-Based Three-Chamber Bags for Parenteral Nutrition
Published on: September 20, 2019
Samples in randomized clinical trials with interim analysis
Michelle Saaibi Meléndez1,2, Felipe Botero-Rodríguez1,2, Carlos Javier Rincón Rodríguez1,2
1Semillero de Bioestadística, Facultad de Medicina, Pontificia Universidad Javeriana, Bogotá, Colombia.
Objectives.:
This article introduces randomized clinical trials and basic concepts of statistical inference. We present methods for calculating the sample size by outcome type and the hypothesis to be tested, together with the code in the R programming language. We describe four methods for adjusting the original sample size for interim analyses. We sought to introduce these topics in a simple and concrete way, considering the mathematical expressions that support the results and their implementation in available statistical programs; therefore, bringing health students closer to statistics and the use of statistical programs, which are aspects that are rarely considered during their training.
More Related Videos
Related Concept Videos
Hazard Ratio
For example, in a clinical trial...
Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches
Non-controlled studies, commonly employed for initial exploration, lack a control group, rendering them susceptible to biases and external influences. In contrast,...
Comparing the Survival Analysis of Two or More Groups
Censoring Survival Data
Assumptions of Survival Analysis
Introduction To Survival Analysis
The primary goal of survival analysis is to estimate survival time—the time...

