Edmonton Symptom Assessment System: Psychometric validation of six-point Verbal Rating Scale in Polish hospice setting

Background: The Edmonton Symptom Assessment System (ESAS) quantifying the most common symptoms rated in the numerical rating scale (NRS) for some respondents are cumbersome or incomprehensible. The study aimed to introduce, implement and validate psychometric properties of the ESAS (revisited) six-point Verbal Rating Scale — Polish version (ESAS-r 6VRS-PL) into a Polish hospice setting. Methods: In a cross-sectional, observational prospective psychometric validation study the adult advanced cancer patients admitted to a hospice were evaluated twice for test-retest reliability. Each patient’s evaluation encompassed the ESAS-r 6VRS-PL, which was compared on the first day with the validated Polish version of the European Organisation for Research and Treatment of Cancer QLQ-C15-PAL, considered the gold standard, to accomplish its external construct validity. Results: Of the 57 patients enrolled 48 were evaluated twice and 9 (15.5%) dropped out. All respondents were able to describe their symptoms in < 15 minutes independently without any need to clarify the meaning of the questions and only occasionally with assistance in reading the questions or answers. The high intraclass correlation coefficient of ESAS Global Distress Score was noted (0.825; 95%CI 0.723–0.888). Similar items of the ESAS-r 6VRS-PL and QLQ-C15-PAL showed moderate correlations (range 0.59–0.65; p < 0.001). The internal consistency of the ESAS-r 6VRS-PL measured using Cronbach’s alpha coefficient was fairly high, reaching 0.723 (item range 0.664–0.734). Conclusion: The ESAS-r 6VRS-PL is a simple, valid, reliable and feasible test which allows to estimate the QoL in advanced cancer patients.