Design considerations in crossover trials with a single interim analysis and serial patient entry
Related Experiment Video
Updated: Oct 20, 2026

A Clinical Trial Assessing the Safety, Efficacy, and Delivery of Olive-Oil-Based Three-Chamber Bags for Parenteral Nutrition
Published on: September 20, 2019
1Department of Statistics and Actuarial Science, University of Waterloo, Ontario, Canada.
Abstract:
A two-stage sequential design is presented to facilitate a single interim analysis in crossover trials with serial patient entry. The interim analysis is based on a linear statistic that combines data from individuals observed for only one treatment period with data from those observed for both periods (Cook, R. J., 1995, Biometrics 51, 932-945). The final analysis is based on the usual test statistic used in crossover trials. The size of this procedure is controlled by partitioning the experimental type I error rate over the two analyses and deriving the appropriate critical values. We investigate the design implications of adopting this procedure over the usual analysis for crossover trials by examining the necessary sample size inflation factors to maintain power, and indicate the expected savings in terms of the number of responses required. Data from a study designed to compare two antiemetic therapies for previously untreated chemotherapy patients (Osaba, D., et al., 1986, Clinical and Investigative Medicine 9, 225-231) are used to illustrate the procedure.
More Related Videos
06:55Inverse Probability of Treatment Weighting (Propensity Score) using the Military Health System Data Repository and National Death Index
Published on: January 8, 2020
06:18Frequency and Distribution of Crossovers in Caenorhabditis elegans Meiosis by SNP Genotyping using Real-time PCR
Published on: July 11, 2025
Related Concept Videos
Clinical Trials
There are four phases in a clinical trial. A phase one...
Crossover Experiments
Crossover designs are performed even with smaller sample sizes since the samples can act as their controls. These are better than simple randomized trials since patients are exposed to all the treatments.
Clinical Trials: Overview
Bioavailability Study Design: Healthy Subjects Versus Patients
Bioequivalence Experimental Study Designs: Repeated Measures, Cross-Over, Carry-Over, and Latin Square Designs
Comparing the Survival Analysis of Two or More Groups