Related Experiment Video
Updated: Aug 11, 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
Center-weighting issues in multicenter clinical trials
1Biostatistics Department, Novartis Pharmaceuticals, East Hanover, New Jersey 07936-1080, USA.
Abstract:
For linear model analysis of data from multicenter clinical trials, results are presented to assist in comparing commonly used approaches in which individual center results are weighted either equally or according to the amount of information they provide. A measure of center size imbalance directly relating to the relative efficiencies of the two weightings is defined. It is demonstrated that when centers of different sizes are given equal weight, the method by which sample size is conventionally calculated is incorrect. Center weighting resulting from use of random-effect models is also discussed.
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
03:05Influence of Emotional Factors on the Efficacy of Acupuncture Treatment for Overweight Complicated with Hyperlipidemia: A Retrospective Cohort Study
Published on: November 21, 2025
Related Concept Videos
Clinical Trials
There are four phases in a clinical trial. A phase one...
Blinding
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, controlled...
Bioavailability Study Design: Healthy Subjects Versus Patients
Confounding in Epidemiological Studies
Bias in Epidemiological Studies