Validation of modified C19-YRS by Croatian Research Study

Published on the 3rd of October in the International Journal of Medicine, doi: 10.1093/qjmed/hcad224

‘Psychometric properties and observational data for COVID-19 Yorkshire Rehabilitation Scale (C19-YRSm) for Post-COVID-19 Syndrome’

The abstract of the article and summary points can be read here, but for the full article, please follow the link above.


Background: The recently developed modified COVID-19 Yorkshire Rehabilitation Scale (C19-YRSm) captures comprehensive biopsychosocial components of WHO’s International Classification of Functioning, Disability, and Health related to the Long Covid or post-COVID syndrome. The scale response categories on C19-YRSm were done post hoc on data collected from the original version of C19-YRS.

Objectives: The study aims to evaluate the C19-YRSm scale using reliability and validity measures.

Methods: This prospective, observational study includes 369 patients (clinical group) and 426 subjects of the general population (control group) and captures their post-COVID-19 symptoms. In addition, the reliability of C19-YRSm was estimated by Cronbach’s alpha coefficients of internal consistency and inter-item correlations for subscales (Symptom severity, Functional disability, and Other symptoms). Convergent validity was established using correlations between C19-YRSm and Fatigue Severity Scale (FSS). The incremental validity of C19-YRSm was measured by introducing a hierarchical regression model using the C19-YRSm Overall health subscale and FSS as criterion variables.

Results: C19-YRSm subscales have excellent internal consistencies (Cronbach’s α value .81 to .96) and acceptable inter-item correlations (r value 0.23 to 0.79). Hereafter, the convergent validity of the C19-YRSm is good due to significant correlations between C19-YRSm subscales and FSS and C19-YRSm subscales. Finally, the hierarchical regression analysis supported consistent evidence for the incremental validity of the C19-YRSm subscales.

Conclusion: C19-YRSm is a reliable and valid self-assessment scale for the assessment of post-COVID-19 syndrome.


  • Lea Kustura
  • Dubravka Bobek
  • Ana Poljičanin
  • Sanda Pavelin
  • Maja Buljubašić Šoda
  • Joško Šoda
  • Jan Aksentijević
  • Klaudia Duka Glavor
  • Nikolina Narančić Knez
  • Vanja Viali
  • Antonio Cukrov
  • Ivana Todorić Laidlaw
  • Nina Ipavec
  • Dora Vukorepa
  • Ivona Stipica
  • Karla Bakrač
  • Braco Bošković
  • Angela Mastelić
  • Nikolina Režić Mužinić
  • Anita Markotić
  • Zoran Đogaš
  • Krešimir Dolić
  • Maja Rogić Vidaković