Abstract

INTRODUCTION The Long Coronavirus Disease (COVID) Symptom and Impact Tools (ST and IT) are self-administered instruments designed to monitor symptoms and the impact of long COVID. We translated and culturally adapted these tools for use in Chile. This study evaluated internal consistency and test-retest reliability for the IT, described reported symptoms with the ST, and explored changes over time. METHODS The first phase, previously published, involved translation and cultural adaptation. The second phase included 28 patients with persistent COVID-19 symptoms; 20 completed a second assessment. The IT assesses impact using six items, each scored 0-10 (total 0-60). The ST lists 53 symptoms across ten categories. Internal consistency of the IT was assessed using Cronbach's alpha and item-consistency indicators. Test-retest reliability was evaluated using the intraclass correlation coefficient (ICC, 95% CI) and a Bland-Altman analysis. ST responses were summarized with absolute and relative frequencies and confidence intervals. RESULTS The IT showed excellent internal consistency (Cronbach's alpha 0.945; 95% CI 0.906-0.971). Test-retest reliability was acceptable (ICC 0.72; 95% CI 0.43-0.88), with minimal bias in the Bland-Altman plot. General, neurological, thoracic, and ear-nose-throat symptoms were the most frequent. Participants reported a mean of 19 symptoms, with no significant differences between visits. CONCLUSIONS The adapted tools demonstrated acceptable psychometric properties and appear suitable for use in Chile. Symptom reporting was extensive, underscoring the need for larger studies to confirm these findings.