Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Clinical Trials

Clinical Trials

Clinical trials are prospective experimental studies conducted on humans to determine the safety and efficacy of treatments, drugs, diet methods, and medical devices. Using statistics in clinical trials enables researchers to derive reasonable and accurate conclusions from the collected data, allowing them to make wise decisions in uncertain situations. In medical research, statistical methods are crucial for preventing errors and bias.
There are four phases in a clinical trial. A phase one...

Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches

Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches

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,...

Clinical Trials: Overview

Clinical Trials: Overview

Clinical development focuses on how the drug will interact with the human body and encompasses four key phases of clinical trials, each serving a specific purpose in assessing the safety and effectiveness of new drugs. These phases overlap and build upon one another. Phase I involves a small group of healthy volunteers (typically 20-80 individuals) or, in cases where significant toxicity is expected, patients with the targeted disease, such as cancer or AIDS. The volunteers are tested for...

The Placebo Effect

The Placebo Effect

The placebo effect occurs when people's expectations or beliefs influence or determine their experience in a given situation. In other words, simply expecting something to happen can actually make it happen.

Blinding

Blinding

Blinding is a commonly used method of not telling participants which treatment a subject is receiving. Blinding is a critical part of a randomized control trial or RCT. It reduces the bias that affects the results. In an RCT, blinding is used in the form of a placebo. A placebo effect occurs when untreated subjects falsely believe they have received the treatment and report improved symptoms. A placebo or a dummy treatment is administered to subjects to negate the bias caused by such an effect.

Regression Toward the Mean

Regression Toward the Mean

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...

You might also read

Related Articles

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

Sort by

Same author

Regulation of the growth-to-ripening transition in tomato fruits by energy charge involving SlATP-PRT and SlAPRT1.

Molecular horticulture·2026

Same author

Research on influencing factors and improvement paths of rational medication literacy among college students: a cross-sectional survey in Zhejiang province.

Frontiers in public health·2026

Same author

Synthesis of Confined HPW@ZIF-8 for Ambient Catalytic Oxidation of Aromatic Sulfides in Diesel.

Chemistry (Weinheim an der Bergstrasse, Germany)·2026

Same author

Restoration of intracellular osmotic pressure balance induced by protein nanoparticles: A potential target for developing Alzheimer's disease treatment strategies.

Neural regeneration research·2026

Same author

Riboflavin intake and kidney health: population evidence and mechanistic insights from NHANES and molecular docking analyses.

Renal failure·2026

Same author

Expanding the frontiers of oxidation catalysis with high-entropy material catalysts.

Chemical communications (Cambridge, England)·2026

Search research articles

Related Experiment Video

Updated: Jun 14, 2025

Measuring the Subjective Value of Risky and Ambiguous Options using Experimental Economics and Functional MRI Methods

Measuring the Subjective Value of Risky and Ambiguous Options using Experimental Economics and Functional MRI Methods

Published on: September 19, 2012

Delta Inflation, Optimism Bias, and Uncertainty in Clinical Trials.

Charles C Liu¹, Peiwen Wu², Ron Xiaolong Yu²

¹Department of Biostatistics, Gilead Sciences, 333 Lakeside Drive, Foster City, CA, 94404, USA. cliu17@gilead.com.

Therapeutic Innovation & Regulatory Science

|September 6, 2024

Summary

This summary is machine-generated.

Delta inflation, where trial effects exceed real-world outcomes, may stem from clinical equipoise, not just optimism bias. Genuine uncertainty before trials offers a new explanation for this common phenomenon.

Keywords:

Assurance Brier score Equipoise Prior-data conflict Probability of success

More Related Videos

A Clinical Trial Assessing the Safety, Efficacy, and Delivery of Olive-Oil-Based Three-Chamber Bags for Parenteral Nutrition

A Clinical Trial Assessing the Safety, Efficacy, and Delivery of Olive-Oil-Based Three-Chamber Bags for Parenteral Nutrition

Published on: September 20, 2019

Experimental Research Examining How People Can Cope with Uncertainty Through Soft Haptic Sensations

Experimental Research Examining How People Can Cope with Uncertainty Through Soft Haptic Sensations

Published on: September 16, 2015

Related Experiment Videos

Last Updated: Jun 14, 2025

Measuring the Subjective Value of Risky and Ambiguous Options using Experimental Economics and Functional MRI Methods

Measuring the Subjective Value of Risky and Ambiguous Options using Experimental Economics and Functional MRI Methods

Published on: September 19, 2012

A Clinical Trial Assessing the Safety, Efficacy, and Delivery of Olive-Oil-Based Three-Chamber Bags for Parenteral Nutrition

A Clinical Trial Assessing the Safety, Efficacy, and Delivery of Olive-Oil-Based Three-Chamber Bags for Parenteral Nutrition

Published on: September 20, 2019

Experimental Research Examining How People Can Cope with Uncertainty Through Soft Haptic Sensations

Experimental Research Examining How People Can Cope with Uncertainty Through Soft Haptic Sensations

Published on: September 16, 2015

Area of Science:

Clinical Trials
Medical Research Methodology
Biostatistics

Background:

Delta inflation, the overestimation of treatment effects in trial designs compared to observed outcomes, is a recognized issue.
This phenomenon is often attributed to investigators' optimism bias regarding new therapies.

Purpose of the Study:

To propose clinical equipoise as an alternative explanation for delta inflation.
To explore methodologies for assessing investigators' beliefs and trial uncertainty.

Main Methods:

Review of existing literature on delta inflation and optimism bias.
Discussion of alternative methodologies like Bayesian priors and forecasting analysis.
Examination of the role of explicit uncertainty expression in trial design.

Main Results:

Delta inflation may naturally arise from clinical equipoise (genuine uncertainty) rather than solely from optimism bias.
Evidence for optimism bias is mixed and depends on explicit uncertainty declaration during trial design.

Conclusions:

Clinical equipoise provides a plausible alternative to optimism bias for explaining delta inflation.
Assessing investigators' beliefs requires explicit uncertainty quantification at the trial design stage.