Published: Test-retest reliability of the FitMáx©-questionnaire in a clinical and healthy population

  • Publication status: Gepubliceerd
  • Type of study: Clinimetrics
  • Journal: Springer Open - Journal of Patient-Reported Outcomes
  • Meijer, R. ORCID iD

    Schep, G. ORCID iD

    Regis, M. ORCID iD

    Papen-Botterhuis, N. ORCID iD

    Savelberg, H. ORCID iD

    Hooff van, M. ORCID iD

  • Affiliations: Eindhoven University of Technology, Maastricht University, Máxima Medical Centre
  • Population: Healthy Subjects, Oncology, Cardiac, Pulmonary
  • DOI: https://doi.org/10.1186/s41687-023-00682-9
  • PMID: 35411174
  • BibTex:
      
    @article{Meijer2024FitMax,
      author  = {Renske Meijer and Goof Schep and Marta Regis and Nicole E. Papen-Botterhuis and Hans H. C. M. Savelberg and Martijn van Hooff},
      title   = {Test–retest reliability of the FitMáx©-questionnaire in a clinical and healthy population},
      journal = {Journal of Patient-Reported Outcomes},
      volume  = {8},
      pages   = {Article number: 3},
      year    = {2024},
      doi     = {10.1186/s41687-023-00682-9},
      url     = {https://jpro.springeropen.com/articles/10.1186/s41687-023-00682-9}
    }
      
    

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.