Related Experiment Video
Updated: Apr 14, 2026
08:36
Author Spotlight: Evaluating the Adjuvant Efficacy and Safety of Angong Niuhuang Pill in Viral Encephalitis Treatment
Published on: April 19, 2024
1.4K
Is the relationship among outcome variables shown in randomized trials?
David L Schriger1, Richelle J Cooper2, Ana Lopez-O'Sullivan3
1Department of Emergency Medicine, University of California, 924 Westwood Blvd, Suite 300, Los Angeles, CA, 90024, USA. schriger@ucla.edu.
Trials
|April 18, 2015
Summary
Reports of randomized controlled trials (RCTs) rarely show how different outcomes relate at the patient level. This limits understanding of outcome associations and redundancy in clinical research.
Area of Science:
- Medical Research Methodology
- Clinical Trial Reporting
- Data Analysis in Healthcare
Background:
- Randomized controlled trials (RCTs) frequently assess multiple outcomes, including primary, secondary, and harm endpoints.
- Understanding the relationships between these outcomes is crucial for interpreting trial results and identifying associations, such as between intermediate and clinical outcomes.
Purpose of the Study:
- To evaluate the frequency with which reports of RCTs depict the relationships among outcomes at the individual patient level.
- To assess how often composite outcomes in RCTs include depictions of the relationships between their component elements.
Main Methods:
- A systematic review of RCTs published in 2011-2012 from 20 high-impact medical journals.
- Random selection of 10 RCTs per journal, totaling 200 articles.
- Data extraction on the number of outcomes, composite outcomes, and the portrayal of relationships between outcomes or composite elements.
Main Results:
- Out of 200 RCTs, 92% had multiple outcomes, but only 1% (2 studies) reported the relationships between them.
- 17% of studies reported composite outcomes, with 97% detailing component data.
- No studies presented cross-tabulations of composite outcome components.
Conclusions:
- There is a significant deficit in reporting the relationships between outcomes in RCTs.
- Mandatory data sharing or detailed appendices could enable readers to analyze outcome associations, identify redundancy, and understand outcome responsiveness.
- Current reporting practices seldom provide insights into the interrelations of outcomes within clinical trials.
More Related Videos
Related Concept Videos
01:23Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches
575
Biopharmaceutical studies constitute a vital field aiming to enhance drug delivery methods and refine therapeutic approaches, drawing upon diverse interdisciplinary knowledge. In research methodologies, the choice between controlled and non-controlled studies significantly influences the study's reliability and accuracy.
Non-controlled studies, commonly employed for initial exploration, lack a control group, rendering them susceptible to biases and external influences. In contrast,...
Non-controlled studies, commonly employed for initial exploration, lack a control group, rendering them susceptible to biases and external influences. In contrast,...
575
01:13Randomized Experiments
9.4K
The randomization process involves assigning study participants randomly to experimental or control groups based on their probability of being equally assigned. Randomization is meant to eliminate selection bias and balance known and unknown confounding factors so that the control group is similar to the treatment group as much as possible. A computer program and a random number generator can be used to assign participants to groups in a way that minimizes bias.
Simple randomization
Simple...
Simple randomization
Simple...
9.4K
01:12What is an Experiment?
19.9K
An experiment is a planned activity carried out under controlled conditions. The purpose of an experiment is to investigate the relationship between two variables. When one variable causes change in another, we call the first variable the explanatory or independent variable. The affected variable is called the response or dependent variable. In a randomized experiment, the researcher manipulates values of the explanatory variable and measures the resulting changes in the response variable. The...
19.9K
01:52Regression Toward the Mean
7.3K
Regression toward the mean (“RTM”) is a phenomenon in which extremely high or low values—for example, and individual’s blood pressure at a particular moment—appear closer to a group’s average upon remeasuring. Although this statistical peculiarity is the result of random error and chance, it has been problematic across various medical, scientific, financial and psychological applications. In particular, RTM, if not taken into account, can interfere when...
7.3K
01:21Causality in Epidemiology
2.1K
Causality or causation is a fundamental concept in epidemiology, vital for understanding the relationships between various factors and health outcomes. Despite its importance, there's no single, universally accepted definition of causality within the discipline. Drawing from a systematic review, causality in epidemiology encompasses several definitions, including production, necessary and sufficient, sufficient-component, counterfactual, and probabilistic models. Each has its strengths and...
2.1K
01:09Odds Ratio
2.4K
The odds ratio (OR) is a statistical measure used extensively in epidemiology and research to quantify the strength of association between exposure and outcome across different groups. Unlike relative risk, which compares the probabilities of an event occurring, the odds ratio compares the odds of an event occurring in the exposed group to the odds of it occurring in the unexposed group. The odds, in this context, are calculated as the probability of the event happening divided by the...
2.4K