Related Experiment Video
Updated: Jul 6, 2025

Validation of a Psychosocial Intervention on Body Image in Older People: An Experimental Design
Published on: May 31, 2021
Test-retest reliability of the FitMáx©-questionnaire in a clinical and healthy population
Renske Meijer1,2, Goof Schep3, Marta Regis4
1Department of Sports and Exercise, Máxima Medical Centre (Máxima MC), Veldhoven, The Netherlands. renske.meijer@mmc.nl.
Purpose:
The FitMáx© was developed as a questionnaire-based instrument to estimate Cardiorespiratory Fitness (CRF) expressed as oxygen uptake at peak exercise (VO2peak). Test-retest reliability is a clinometric measurement property, which defines stability over time if multiple measurements are performed (i.e. reliability). The present study aimed to assess the test-retest reliability of the FitMáx©-questionnaire in different patient groups.
Patients And Methods:
A total of 127 cardiac, pulmonary and oncology patients and healthy subjects aged 19-84 years who completed the questionnaire twice within an average of 18 days were included for analysis. Participants were in a stable clinical situation (no acute disease or participating in a training program). To determine the test-retest reliability, the Intraclass Correlation Coefficient (ICC) and Standard Error of the Measurement (SEM) was calculated between the first (T0) and second (T1) administration of the questionnaires.
Results:
An excellent agreement was found between the FitMáx©-questionnaire scores at T0 and T1, with an ICC of 0.97 (SEM 1.91) in the total study population and an ICC ranging from 0.93 to 0.98 (SEM 1.52-2.27) in the individual patient groups.
Conclusion:
The FitMáx©-questionnaire proves to be reliable and stable over time to estimate CRF of patients and healthy subjects. Trial registration NTR (Netherlands Trial Register), NL8846. Registered 25 August 2020, https://trialsearch.who.int/Trial2.aspx?TrialID=NL8846.
More Related Videos
Related Concept Videos
Reliability and Validity
Self-Report Tests of Personality
Comparing Experimental Results: Student's t-Test
Statistical Methods to Analyze Parametric Data: Student t-Test and Goodness-of-Fit Test
The Student's t-test is a statistical test that examines if there is a statistically significant difference between the means of two groups. This test is instrumental when dealing with...
Multiple Comparison Tests
It would be easy to compare two samples using a significance alpha level of 0.05. In other words, there is only one sample pair to be compared. However, it would be difficult to identify a significantly different sample if the number...
Goodness-of-Fit Test

