Related Experiment Video
Updated: Mar 20, 2026

Inverse Probability of Treatment Weighting Propensity Score using the Military Health System Data Repository and National Death Index
Published on: January 8, 2020
Estimating a treatment effect: Choosing between relative and absolute measures
Maria Pia Sormani1, Paolo Bruzzi2
1Biostatistics Unit, Department of Health Sciences (DISSAL), University of Genoa, Genova, Italy.
Abstract:
The size of a treatment effect in clinical trials can be expressed in relative or absolute terms. Commonly used relative treatment effect measures are relative risks, odds ratios, and hazard ratios, while absolute estimate of treatment effect are absolute differences and numbers needed to treat. When making indirect comparisons of treatment effects, which is common in multiple sclerosis (MS), having now many drugs tested in independent trials, we can have different figures if we use relative or absolute measures, and a frequently asked question by clinicians is which approach should be used. In this report, we will try to define these measures, to give numerical examples of their calculation and specify their meaning and their context of use.
Related Concept Videos
Relative Risk
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,...
Bioavailability Study Design: Absolute Versus Relative Bioavailability
Regression Toward the Mean
Odds Ratio
Comparing the Survival Analysis of Two or More Groups

