Longitudinal validation of a modified Edmonton symptom assessment system (ESAS) in haemodialysis patients

Background. Health-related quality of life (HRQL) is an important outcome in the treatment of end-stage renal disease (ESRD) and appears to be highly associated with patient self-report of symptom burden. This study examines the longitudinal validity of the modified Edmonton symptom assessment system (ESAS) to determine the impact of change in symptom burden on the change in HRQL of haemodialysis (HD) patients. Methods. 261 haemodialysis patients completed the Kidney Disease Quality of Life-Short Form (KDQOL-SF) and the ESAS at baseline and at 6 months. Results. The change in overall symptom distress score was strongly correlated with the change in KDQOL-SF subscales symptom/problem list (R = -0.73, P < 0.01), effects of kidney disease (R = -0.53, P < 0.01), and burden of kidney disease (R = -0.46, P < 0.01) as well as overall physical health composite (R = -0.58, P < 0.01) and overall mental health composite (R = -0.68, P < 0.01). The change in symptom burden, as described by the ESAS, accounted for 46% of the change in the mental HRQL and 34% of the change in the physical HRQL. There was no correlation between baseline demographics, comorbidity or changes in biochemical markers with changes in either the ESAS or HRQL scores. Conclusion. The modified ESAS is a simple, valid tool for the longitudinal assessment of physical and psychological symptom burden in ESRD and is responsive to change in HD patients. The use of this symptom assessment scale and improved management of patient symptoms would be expected to positively impact HD patients' HRQL.