Validation of the Edmonton Symptom Assessment System: Ascites Modification

Few patient-reported outcomes are available to measure the symptoms associated with malignant-related ascites in patient care and clinical research. Although the Edmonton Symptom Assessment System: Ascites Modification (ESAS:AM) is a brief tool to measure symptoms associated with malignant-related ascites, it remains to be fully validated.The objective of the study was to validate the ESAS:AM in Japanese cancer patients.We assessed the internal consistency, test-retest reliability, concurrent validity, and construct validity in 292 Japanese adult patients with cancer. They completed Japanese versions of the ESAS:AM, M.D. Anderson Symptom Inventory, European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30, and abdominal pain/ascites subscales of the EORTC Core Quality of Life Questionnaire, 26-item pancreatic cancer module.Cronbach's alpha coefficient of the ESAS:AM was 0.89. The intraclass correlation coefficient on test-retest examination of its total score was 0.93 (P 0.001). Pearson correlation coefficients of the total score of the ESAS:AM with the total score of the M.D. Anderson Symptom Inventory and abdominal pain/ascites subscales of the EORTC Core Quality of Life Questionnaire, 26-item pancreatic cancer module ranged from 0.44 to 0.81 (P 0.001) and those with global health status/quality of life and functional subscales of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 ranged from -0.40 to -0.61 (P 0.001). The total scores of the ESAS:AM were significantly higher in 20 patients with symptomatic ascites (34 [SD, 26]) than 267 patients without symptomatic ascites (23 [SD, 19]) (P = 0.018).The ESAS:AM is a reliable and valid tool for measuring symptoms associated with malignant-related ascites and can be used in daily patient care and future epidemiological studies and clinical trials.