Post-COVID-19 functional status scale: Cross-cultural adaptation and measurement properties of the Brazilian Portuguese version

BACKGROUND: The Post-COVID-19 Functional Status (PCFS) scale was created to assess the functional status of patients after hospital discharge due to COVID-19. OBJECTIVE: To perform cross-cultural adaptation of the PCFS Scale and Manual into Brazilian Portuguese and evaluate its measurement properties in patients post-COVID-19. METHODS: For the cross-cultural adaptation, independent translations and back-translations were performed. This was followed by a pre-test, with analysis of the Content Validity Index (CVI), and preparation of the final version, after evaluating the measurement properties. Spearman's correlation between the PCFS and the WHO Disability Classification Scheme (WHODAS 2.0) was used for convergent validity. Weighted Kappa (wκ) was used for test-retest and interobserver reliability for PCFS scores and Kappa (κ) for PCFS items. Internal consistency was assessed using Cronbach's alpha. Only patients with post-discharge COVID-19 were evaluated through video-conferencing platforms. RESULTS: The CVI was 0.75–0.83 for comprehension and 0.83–0.84 for the language of the self-administered questionnaire and the structured interview version. For measurement properties, 63 patients were evaluated, 68% male, 51.50 (12.60) years, 12.28 (7.62) days of hospitalization. For the convergent validity, a strong correlation was found (r = 0.73; p<0.01). The test-retest (wκ=0.54) and interobserver (wκ=0.43) reliability was moderate and the item-by-item analyzes ranged from fair to substantial (κ=0.25–0.66) and weak to substantial (κ=0.07–0.79). Internal consistency was excellent (0.85). CONCLUSION: The final PCFS in Brazilian Portuguese showed adequate content validity, reliability, internal consistency, and convergent validity for the functional assessment of patients after hospital discharge due to COVID-19.