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

Comparing Experimental Results: Student's t-Test

Comparing Experimental Results: Student's t-Test

The t-test is a statistical method used to compare the sample mean with a population mean or compare two means from two data sets. The test statistic is calculated from the standard deviation, mean, and number of measurements in the data set at a selected confidence interval and then compared to a table of critical values at this confidence level. If the test statistic is smaller than the critical value, the null hypothesis is accepted. In this case, we state that the difference between the...

Measuring Reaction Rates

Measuring Reaction Rates

Polarimetry finds application in chemical kinetics to measure the concentration and reaction kinetics of optically active substances during a chemical reaction. Optically active substances have the capability of rotating the plane of polarization of linearly polarized light passing through them—a feature called optical rotation. Optical activity is attributed to the molecular structure of substances. Normal monochromatic light is unpolarized and possesses oscillations of the electrical field in...

You might also read

Related Articles

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

Sort by

Same author

Retrospective Assessment of Food Noise Changes After Initiation of Injectable Semaglutide for Weight Management in the USA: The INFORM Survey.

Advances in therapy·2026

Same author

Safety of Semaglutide After Dialysis Initiation: An Individual-Level Pooled Analysis.

Diabetes care·2026

Same author

Real-world cardiovascular effects of liraglutide: transportability analysis of the LEADER trial.

medRxiv : the preprint server for health sciences·2025

Same author

Hypomania-Checklist-33: risk stratification and factor structure in a mixed psychiatric adolescent sample.

International journal of bipolar disorders·2024

Same author

Glucagon-like Peptide 1 Receptor Agonists and Asthma Exacerbations: Which Patients Benefit Most?

Annals of the American Thoracic Society·2024

Same author

Association of Premorbid GLP-1RA and SGLT-2i Prescription Alone and in Combination with COVID-19 Severity.

Diabetes therapy : research, treatment and education of diabetes and related disorders·2024

Search research articles

Related Experiment Video

Updated: Jul 6, 2026

Evaluating Tests of Cognition using a Computerized Touch-Sensitive Tablet, Eye Tracking, and Functional Magnetic Resonance Imaging

Evaluating Tests of Cognition using a Computerized Touch-Sensitive Tablet, Eye Tracking, and Functional Magnetic Resonance Imaging

Published on: January 30, 2026

Repeated events and total time on test.

Kajsa Kvist¹, Per Kragh Andersen, Jules Angst

¹Department of Biostatistics, University of Copenhagen, Copenhagen, Denmark. kakv@biostat.ku.dk

Statistics in Medicine

|April 3, 2008

Summary

This summary is machine-generated.

This study introduces a new method to analyze time trends in repeated events using a proportional hazards model. It avoids assumptions about frailty distributions, offering a robust approach for recurrent event data analysis.

More Related Videos

A Behavioral Test Battery for the Repeated Assessment of Motor Skills, Mood, and Cognition in Mice

A Behavioral Test Battery for the Repeated Assessment of Motor Skills, Mood, and Cognition in Mice

Published on: March 2, 2019

Computerized Adaptive Testing System of Functional Assessment of Stroke

Computerized Adaptive Testing System of Functional Assessment of Stroke

Published on: January 7, 2019

Related Experiment Videos

Last Updated: Jul 6, 2026

Evaluating Tests of Cognition using a Computerized Touch-Sensitive Tablet, Eye Tracking, and Functional Magnetic Resonance Imaging

Evaluating Tests of Cognition using a Computerized Touch-Sensitive Tablet, Eye Tracking, and Functional Magnetic Resonance Imaging

Published on: January 30, 2026

A Behavioral Test Battery for the Repeated Assessment of Motor Skills, Mood, and Cognition in Mice

A Behavioral Test Battery for the Repeated Assessment of Motor Skills, Mood, and Cognition in Mice

Published on: March 2, 2019

Computerized Adaptive Testing System of Functional Assessment of Stroke

Computerized Adaptive Testing System of Functional Assessment of Stroke

Published on: January 7, 2019

Area of Science:

Biostatistics
Survival Analysis
Epidemiology

Background:

Recurrent event data analysis is crucial in various fields.
Existing methods often rely on strong distributional assumptions for frailty.
These assumptions can lead to biased results in regression coefficients and heterogeneity estimation.

Purpose of the Study:

To investigate monotone time trends in event intensity for recurrent event data.
To propose a robust statistical method that avoids distributional assumptions about frailty.
To provide a simple routine for testing hypotheses in recurrent event processes.

Main Methods:

Adoption of the total time on test procedure.
Utilizing a proportional hazards model with a random effect to handle within-subject dependence.
The method is illustrated with real-world data analysis.

Main Results:

The proposed method effectively analyzes time trends in recurrent event intensity.
It successfully avoids making specific distributional assumptions about frailty.
Demonstrated applicability through re-analysis of Danish registry and Swiss clinical study data.

Conclusions:

The developed method offers a flexible and robust approach for analyzing recurrent event data.
It provides a reliable tool for hypothesis testing without compromising results with unverified distributional assumptions.
The findings have implications for understanding recurrence patterns in various health studies.