The impact of quality of life on the survival of elderly patients with end-stage renal disease: a prospective multicenter cohort study in Korea

Background Quality of life (QOL) is associated with mortality in dialysis patients. However, the impact of QOL index or score on elderly patients undergoing maintenance dialysis is unclear. We analyzed the relationship between QOL domains and survival in elderly end-stage renal disease (ESRD) patients on dialysis. Methods We included 492 incident ESRD patients aged >= 65 years from a Korean nationwide prospective cohort study who were assessed for QOL with a follow-up duration of 67.3 +/- 34.6 months after dialysis initiation. Their QOL was evaluated using the Kidney Disease Quality of Life (KDQOL) instrument, and the effect of each QOL domain on mortality was analyzed. Multivariable Cox regression analysis was performed to identify independent risk factors for death after adjusting for confounding factors. Results Low physical component summary (PCS) and Short Form-36 score were significantly associated with low survival rate (P < .001 and P = .017, respectively), whereas the mental component summary and ESRD-targeted item scores were not correlated with survival rate. Multivariable Cox regression analysis confirmed that only a high PCS score was associated with better survival (hazard ratio 0.71; 95% confidence interval 0.52-0.97; P = .031). Linear regression analysis revealed that age, sex, modified Charlson comorbidity index, albumin and intact parathyroid hormone were associated with PCS. Among the PCS items, only the physical functioning score was significantly associated with mortality (P = .017). Conclusion PCS was an independent risk factor for death in elderly ESRD patients. A higher physical functioning score was associated with a better outcome, suggesting the importance of physical condition in elderly dialysis patients. {Graphical Abstract}