Interrater Reliability of the Spanish (Colombia) Version of the Post-COVID-19 Functional Status Scale

Background. COVID-19 has been one of the most critical public health challenges of recent decades. This disease develops severely in one in five patients, and approximately 5% require admission to a critical care unit. Due to the impact of the sequelae, the Post-COVID-19 Functional Status Scale (PCFS) was developed. This study is aimed at determining the interrater reliability of the Spanish (Colombia) version of the PCFS in adult patients with post-COVID-19 infection. Methods. This is an observational study performed with patients diagnosed with COVID-19. Two evaluators repeated the test-retest of the PCFS scale with knowledge and clinical experience in the care of patients with COVID-19 and had previously applied the test. The PCFS assesses functional limitations at discharge and can be used at 4 and 8 weeks to evaluate practical consequences and determine the degree of disability these patients may have. For interrater reliability, Cronbach’s alpha was applied with its respective confidence interval and the Bland-Altman method. A 95% confidence interval (CI) was taken as the basis for the interpretation of the Intraclass Correlation Coefficient (ICC). Results. A total of 112 adult patients participated in the study, aged $51.46\pm 15.94$ years. It was evidenced that the survival, constant care, and activities of daily living questions have an ICC of one (1.000) with an ICC (1.000-1.000), demonstrating excellent reliability, while those close to one were instrumental activities, role participation, symptoms, and final score with an ICC 0.918 to 0.984 and an ICC (0.881-0.989). Thus, a homogeneous distribution of the interrater data was evident. Conclusions. Excellent interobserver reliability of the Spanish (Colombia) version of the PCFS in patients with different degrees of functional status was reported.