Reliability and validity of a Thai version of the edmonton symptom assessment scale (ESAS-Thai)

The Edmonton Symptom Assessment Scale (ESAS), created by the Edmonton Group in 1991, is an instrument assessing symptom control that is commonly used in palliative care. It asks patients to rate nine items on 11-point numeric rating scales.

The aim of this study was to translate the ESAS to Thai and validate its final version with transcultural adaptation for Thai palliative care patients. The original ESAS was translated into Thai following the process of cross-cultural adaptation of self-report measures' standard guidelines, including forward translation, synthesis of the translation, back translation, cross-cultural adaptation, and pretesting.

This cross-sectional study was first undertaken with 44 patients with advanced cancer in an inpatient setting, which led to the final version. The reliability and validity of the final version was then examined in a sample of 37 cancer patients in the outpatient department at Ramathibodi Hospital. Face validity was evaluated through patient interviews, using guide questions. The internal consistency was calculated using Cronbach's alpha.

In total, 91.8% of patients declared that the ESAS-Thai questionnaire was generally clear. It yielded a Cronbach's alpha of 0.75 in the inpatient setting. After modifying the words "appetite" and "well-being," 37 cancer patients, whose mean (standard deviation) age was 52.2 (10.8) years and who were cared for by the Departments of Medicine, Surgery, Gynecology, and Otolaryngology, self-administered the questionnaire in the outpatient department. The Cronbach's alpha in the validation sample was 0.89.

After the translation and cross-cultural adaptation, the Thai version of the ESAS achieved good levels of face validity and internal consistency. It is now available as a patient-administered instrument to evaluate symptoms among palliative care patients in Thailand.