The Brazilian version of the Edmonton Symptom Assessment System (ESAS) is a feasible, valid and reliable instrument for the measurement of symptoms in advanced cancer patients

Purposes: To develop and validate a Portuguese version of the Edmonton Symptom Assessment System (ESAS) in Brazilian patients with advanced cancer. Methods: The ESAS was translated and then back translated into Portuguese in accordance with international guidelines. The final version was approved by an Expert Committee after pilot testing on 24 advanced cancer patients. Subsequently, we evaluated the time to complete the assessment, the number of unanswered items, internal consistency, convergent validity, and known-group validity in a sample of 249 advanced cancer patients who completed the ESAS along with the European Organization for Research and Treatment of Cancer Core Quality of Life Questionnaire (EORTC QLQ-C30), Hospital Anxiety and Depression Scale (HADS), and Epworth Sleepiness Scale (ESS). A total of 90 clinically stable patients were retested after 4 to 96 hours (test-retest reliability), and 80 patients answered the ESAS after 21 (±7) days to measure scale responsiveness using an anchor-based method. Results: The ESAS was completed in a mean time of only 2.2 minutes. The internal consistency was good (Cronbach's alpha = 0.861), and the removal of single items did not change the overall alpha value. For convergent validity, Spearman's correlation coefficients between the ESAS symptom scores and the corresponding EORTC QLQ-C30 and ESS symptom scores ranged between 0.520 (95% CI = 0.424-0.605) and 0.814 (95% CI = 0.760-0.856), indicating moderate to strong correlations. Test-retest reliability values were considered adequate, with intraclass correlation coefficients ranging from 0.758 (95% CI = 0.627- 0.843) to 0.939 (95% CI = 0.905-0.960). Conclusions: ESAS is a feasible, valid and reliable multi-symptom assessment instrument for use in Brazil.