ABSTRACT
BACKGROUND: The recently developed modified COVID-19 (coronavirus of 2019) 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. AIM: To evaluate the C19-YRSm scale using reliability and validity measures. DESIGN: Prospective, observational study. METHODS: The 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 0.81-0.96) and acceptable inter-item correlations (r value 0.23-0.79). 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.
