Impact of baseline health-related quality of life scores on survival of incident patients on peritoneal dialysis: a cohort study

Introduction: In an attempt to decrease mortality in patients with end-stage renal disease, an increase in the lifetime of these patients without much focus on health-related quality of life (HRQOL) was pursued for a long period of time. However, lately, an improvement in the quality of this extended lifetime has focused on both the physical as well as the social and emotional aspects, as these parameters may be associated with clinical outcomes in end-stage renal disease patients. Aim: To evaluate the impact of self-determined HRQOL at admission on survival of incident peritoneal dialysis (PD) patients. Patients and Methods: A total of 1,624 incident Brazilian PD patients participating in a multicenter prospective cohort study (BRAZPD) were evaluated. HRQOL was assessed using the SF-36, divided into mental and physical components. Cox proportional regression analysis was used to determine the influence of HRQOL (mental and physical components) on mortality. Multivariate Cox proportional hazards analyses were used to adjust gradually for more potential explanatory variables: first for demographic variables, followed by additional adjustment for socioeconomic, clinical and laboratory variables. The significance level in all analyses was set at p < 0.05. All analyses were carried out with SPSS 17.0. Results: Incident PD patients presented with low HRQOL scores on admission to therapy. Even after correction for sociodemographic variables, comorbidities, PD modality and laboratory parameters, HRQOL (both the mental and the physical components) remained a predictor [HR: 0.97 (CI: 0.95-0.98); HR: 0.97 (CI: 0.96-0.99), respectively] of survival. Conclusion: On admission to therapy, patients presenting with low HRQOL scores for both the mental and the physical components were associated with a higher mortality. These results suggest that early and timely intervention measures to improve the QOL of these patients are important.