Health-related quality of life as predictor of mortality in end-stage renal disease patients: an observational study

BackgroundHealth-related quality of life (HRQoL) is an important component of patient-centered outcomes and a useful parameter for monitoring quality of care. We assessed HRQoL, its determinants, and associations with mortality in patients with end-stage renal disease (ESRD).MethodsShort Form-36 was used to assess HRQoL, its domain components, and physical (PCS) and mental (MCS) composite summary scores in altogether 400 (338 incident and 62 prevalent) dialysis patients with median age 64years, 37% women, 24% diabetes mellitus (DM), 49% cardiovascular disease (CVD), and median estimated glomerular filtration rate (eGFR) of 5.3 (3.0-9.4) ml/min/1.73(2). Results were analyzed separately for 338 incident patients starting on hemodialysis (HD; 68%) or peritoneal dialysis (PD; 32%), and 62 prevalent PD patients. Mortality risk was analyzed during up to 60months (median 28months).ResultsLinear multivariate regression analysis showed that in incident dialysis patients, 1-SD higher PCS associated negatively with 1-SD higher age, DM and CVD, and positively with 1-SD higher hemoglobin and sodium (adjusted r(2)=0.17). In 62 prevalent PD patients, 1-SD higher PCS was negatively associated with 1-SD higher age. MCS was not associated to any of the investigated factors. Multivariate Cox regression analysis showed that in incident dialysis patients, 1-SD increase of PCS associated with lower all-cause mortality, hazard ratio 0.65 (95% confidence interval 0.52-0.81), after adjustments for age, sex, DM, CVD, plasma albumin, C-reactive protein and eGFR whereas 1-SD lower MCS did not associate with mortality. In PD patients, neither PCS nor MCS associated with mortality.ConclusionsMCS did not associate with any of the investigated clinical factors, whereas lower PCS associated with higher age, CVD, DM, and lower hemoglobin and sodium levels. MCS was not associated with mortality, whereas lower PCS associated with increased mortality risk. These results suggest that HRQoL - in addition to its role as patient-centered outcome - matters also for hard clinical outcomes in ESRD patients. Our knowledge about factors influencing MCS in ESRD patients is limited and should motivate further studies.