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

Randomized Experiments

Randomized Experiments

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...

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, controlled...

Hazard Ratio

Hazard Ratio

The hazard ratio (HR) is a widely used measure in clinical trials to compare the risk of events, such as death or disease recurrence, between two groups over time. It reflects the ratio of hazard rates—the instantaneous risk of the event occurring—between a treatment group and a control group. This measure provides valuable insights into the relative effectiveness of a treatment by assessing how the risk of an event differs between the two groups.
For example, in a clinical trial evaluating a...

Nursing Interventions II: Selecting and Classifying the Nursing Interventions

Nursing Interventions II: Selecting and Classifying the Nursing Interventions

Creating and executing a nursing diagnosis helps nurses plan care and guide patient, family, and community interventions. They are developed based on a patient's physical evaluation and support measuring the outcomes. It is not recommended to select random interventions throughout the planning process. Instead, consider the following six essential factors when choosing interventions:

Group Design

Group Design

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 the two are due to...

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...

You might also read

Related Articles

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

Sort by

Same author

Pelvic Lymph Node Dissection in Prostate Cancer: Update from a Randomized Clinical Trial of Limited Versus Extended Dissection.

European urology·2024

Same author

Successful completion of large, low-cost randomized cancer trials at an academic cancer center.

Clinical trials (London, England)·2024

Same author

Testosterone Therapy in Men After Radical Prostatectomy for Low-Intermediate Organ-Confined Prostate Cancer.

The Journal of urology·2024

Same author

Re: Early Prostate Cancer Deaths Among Men with Higher vs Lower Genetic Risk.

European urology·2024

Same author

Transperineal vs Transrectal Prostate Biopsy-The PREVENT Randomized Clinical Trial.

JAMA oncology·2024

Same author

Clinical utility of an artificial intelligence radiomics-based tool for risk stratification of pulmonary nodules.

JNCI cancer spectrum·2024

Search research articles

Related Experiment Video

Updated: Jul 19, 2026

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

Selecting patients for randomized trials: a systematic approach based on risk group.

Andrew J Vickers¹, Barry S Kramer, Stuart G Baker

¹Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, USA. vickersa@mskcc.org

|October 7, 2006

Summary

This study introduces a statistical method to optimize risk group selection in clinical trials. The approach helps determine the best strategy for including patients, improving trial design and interpretation.

More Related Videos

Inverse Probability of Treatment Weighting (Propensity Score) using the Military Health System Data Repository and National Death Index

Inverse Probability of Treatment Weighting (Propensity Score) using the Military Health System Data Repository and National Death Index

Published on: January 8, 2020

Related Experiment Videos

Last Updated: Jul 19, 2026

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

Inverse Probability of Treatment Weighting (Propensity Score) using the Military Health System Data Repository and National Death Index

Inverse Probability of Treatment Weighting (Propensity Score) using the Military Health System Data Repository and National Death Index

Published on: January 8, 2020

Area of Science:

Clinical Trial Design
Biostatistics
Health Services Research

Background:

Randomized trials often differ in patient selection, including either the entire at-risk population or only high-risk individuals.
Choosing the appropriate risk group is crucial for effective trial design but is often based on informal methods.

Purpose of the Study:

To present a simple statistical approach for selecting optimal risk groups in randomized trials.
To provide a method adaptable for identifying the best definition of high risk among competing options.

Main Methods:

Eligibility criteria were modeled as prediction rules with defined sensitivity and specificity.
Formulas were derived to calculate intervention and event proportions for different risk group strategies.
A net benefit approach was used to compare strategies based on risk group selection.

Main Results:

The method was applied to a prostatectomy adjuvant therapy trial, demonstrating the superiority of targeting a high-risk group.
The approach facilitated the selection of an optimal high-risk definition and robust sensitivity analysis.
Results offered clear clinical interpretations aiding trial design.

Conclusions:

The selection of risk groups in randomized trials can be improved using simple statistical analyses.
This method offers a more informed and data-driven approach compared to traditional informal methods.