Introduction: Mortality rates for patients undergoing maintenance hemodialysis remain high. Published data regarding association between health-related quality of life (HRQOL) and mortality among hemodialysis patients are inconsistent. Very few data are published on the change in HRQOL over time as a predictor of mortality. The aim of this study was to assess whether HRQOL and change of it over time could be considered an independent predictor of mortality in hemodialysis patients.
Material and methods: This prospective observational study enrolled 183 patients undergoing maintenance hemodialysis. HRQOL was measured annually 2004-2008 using a generic Short Form 36 questionnaire. Physical component summary (PSC) and mental component summary (MSC) scores were calculated. The change of the patient's HRQOL over time was calculated as a difference between SF-36 scores of the first and the last HRQOL measurements.
Results: The median follow-up was 48 months (range, 1-72 months). Cutoff values for HRQOL predicting mortality for PSC score was ≥35 and for MSC score was ≥45. In the model adjusted for age, sex, dialysis months, creatinine, albumin and hemoglobin levels, mortality risk decreased by 0.96 (95% CI, 0.95-0.99) for 1-point increase in the baseline PSC score and decreased by 0.97 (95% CI, 0.95-0.98) for 1-point increase in the baseline MSC score. A 1-point decline in the PSC score (relative risk, 1.11; 95% CI, 1.008-1.221) and MSC score (relative risk, 1.07; 95% CI, 1.002-1.149) over the period of follow-up were associated with a significant additional increase in mortality.
Conclusions: Both baseline HRQOL and decline of HRQOL are independent predictors of mortality in hemodialysis patients.