Context
The Edmonton Symptom Assessment System (ESAS) is a brief, widely adopted multidimensional questionnaire to evaluate patient-reported symptoms.
Objectives
To develop a Korean version of the ESAS (K-ESAS) and to perform a psychometric analysis in Korean patients with advanced cancer.
Methods
We tested the K-ESAS in two pilot studies with 15 patients each. We assessed internal consistency, test-retest reliability, and concurrent validity in 163 Korean patients, who completed the K-ESAS along with the Korean versions of the M. D. Anderson Symptom Inventory (K-MDASI) and the Hospital Anxiety and Depression Scale (K-HADS) twice. Thirty-eight patients completed the questionnaires again seven days later to assess responsiveness.
Results
K-ESAS scores had good internal consistency, with a Cronbach’s alpha coefficient of 0.88, indicating that no questions had undue influence on the score. Pearson correlation coefficients for K-ESAS symptom scores between baseline and after 2–4 hours ranged from 0.72 (95% confidence interval [CI] 0.64, 0.79) to 0.87 (95% CI 0.82, 0.90), indicating strong test-retest reliability. For concurrent validity, Pearson correlation coefficients between K-ESAS symptom scores and corresponding K-MDASI symptom scores ranged from 0.70 (95% CI 0.62, 0.77) to 0.83 (95% CI 0.77, 0.87), indicating good concurrent validity. For the K-HADS, concurrent validity was good for anxiety (r = 0.73, 95% CI 0.65, 0.79) but moderate for depression (r = 0.4, 95% CI 0.26, 0.52). For responsiveness, changes in K-ESAS scores after seven days were moderately correlated with changes in K-MDASI scores but weakly correlated with changes in K-HADS scores.
Conclusion
The K-ESAS is a valid and reliable tool for measuring multidimensional symptoms in Korean cancer patients.