Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Randomized Experiments01:13

Randomized Experiments

7.0K
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...
7.0K
Group Design02:01

Group Design

9.0K
The most basic experimental design involves two groups: the experimental group and the control group. The two groups are designed to be the same except for one difference— experimental manipulation. The experimental group gets the experimental manipulation—that is, the treatment or variable being tested—and the control group does not. Since experimental manipulation is the only difference between the experimental and control groups, we can be sure that any differences between...
9.0K
What is an Experiment?01:12

What is an Experiment?

11.8K
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...
11.8K
Regression Toward the Mean01:52

Regression Toward the Mean

6.3K
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...
6.3K
Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches01:23

Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches

148
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,...
148
Crossover Experiments01:16

Crossover Experiments

2.9K
Crossover experiments, also called the repeated-measurements design, is a study design in which all experimental units are exposed to all treatments in different periods. Crossover experiments are generally used in psychology, the pharmaceutical industry, agriculture, and medicine.
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.
2.9K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Bleeding Risk With Apixaban Versus Rivaroxaban: A Reference Trial Emulation Predicting the Results of COBRRA-VTE and COBRRA-AF Using US Health Care Claims.

Circulation. Population health and outcomes·2026
Same author

Systematic Evaluation of Data and Trial Fitness for Oncology Trial Emulation: Empirical Findings from the CARE Initiative.

Clinical pharmacology and therapeutics·2026
Same author

A Plasmode Simulation-Based Bias Analysis for Residual Confounding by Unmeasured Variables Leveraging Information-Rich Subsets.

Pharmacoepidemiology and drug safety·2026
Same author

Safety of IL-17A Inhibitors in Patients With Moderate to Severe Psoriasis in a US Claims Data-Based Cohort Study.

Journal of psoriasis and psoriatic arthritis·2026
Same author

Adaptive Multi-Wave Sampling for Efficient Chart Validation.

Clinical epidemiology·2026
Same author

Characterization and comparison of structured and unstructured electronic health record data mapped to MedDRA for post-marketing surveillance.

JAMIA open·2026

Related Experiment Video

Updated: Jul 21, 2025

A Psychophysics Paradigm for the Collection and Analysis of Similarity Judgments
08:12

A Psychophysics Paradigm for the Collection and Analysis of Similarity Judgments

Published on: March 1, 2022

2.6K

DESIGN DIFFERENCES EXPLAIN VARIATION IN RESULTS BETWEEN RANDOMIZED TRIALS AND THEIR NON-RANDOMIZED EMULATIONS.

Rachel Heyard1, Leonhard Held1, Sebastian Schneeweiss2

  • 1Center for Reproducible Science, Epidemiology, Biostatistics and Prevention Institute, University of Zurich, Hirschengraben 84, 8001 Zurich, Switzerland.

Medrxiv : the Preprint Server for Health Sciences
|July 28, 2023
PubMed
Summary

Differences in study design emulation explain variations between randomized controlled trials (RCTs) and real-world evidence (RWE) studies. Key factors include treatment initiation, therapy discontinuation, and delayed drug effects, impacting effect estimates.

Keywords:
Real-world evidencedesignemulation differencesheterogeneitymeta-regressionrandomized controlled trial

More Related Videos

The Innovation Arena: A Method for Comparing Innovative Problem-Solving Across Groups
14:14

The Innovation Arena: A Method for Comparing Innovative Problem-Solving Across Groups

Published on: May 13, 2022

5.9K
Determining and Controlling External Power Output During Regular Handrim Wheelchair Propulsion
08:55

Determining and Controlling External Power Output During Regular Handrim Wheelchair Propulsion

Published on: February 5, 2020

7.5K

Related Experiment Videos

Last Updated: Jul 21, 2025

A Psychophysics Paradigm for the Collection and Analysis of Similarity Judgments
08:12

A Psychophysics Paradigm for the Collection and Analysis of Similarity Judgments

Published on: March 1, 2022

2.6K
The Innovation Arena: A Method for Comparing Innovative Problem-Solving Across Groups
14:14

The Innovation Arena: A Method for Comparing Innovative Problem-Solving Across Groups

Published on: May 13, 2022

5.9K
Determining and Controlling External Power Output During Regular Handrim Wheelchair Propulsion
08:55

Determining and Controlling External Power Output During Regular Handrim Wheelchair Propulsion

Published on: February 5, 2020

7.5K

Area of Science:

  • Health research methodology
  • Comparative effectiveness research
  • Real-world evidence generation

Background:

  • Randomized controlled trials (RCTs) are the gold standard for medical treatment efficacy, but real-world evidence (RWE) studies offer complementary insights.
  • Concerns about confounding and secondary data use in RWE studies question their utility for decision-making.
  • The RCT-DUPLICATE project emulated 32 RCTs using non-randomized RWE studies to explore discrepancies.

Approach:

  • This study analyzed RCT-RWE study pairs from RCT-DUPLICATE where the effect measure was a hazard ratio.
  • Exploratory meta-regression was employed to identify factors contributing to variations in effect sizes between RCT and RWE results.
  • Explanatory variables focused on differences in study design and patient populations.

Key Points:

  • Three primary emulation differences significantly explained the variation in effect estimates between RCTs and RWE studies.
  • These differences include in-hospital treatment initiation (unobservable in claims data), discontinuation of baseline therapies at randomization (not typical in clinical practice), and delayed drug effects (missed due to short medication persistence).

Conclusions:

  • A significant portion of the variation in results between RCTs and RWE studies can be attributed to differences in how the RWE studies emulated RCT designs.
  • Addressing these emulation differences is crucial for improving the reliability and interpretability of real-world evidence.
  • This highlights the importance of careful study design when using RWE to complement RCT findings.