Objectives: Advanced age is associated with shorter survival on dialysis. The aim of the present study was to compare the adherence with KDOQI guideline targets and the association between mortality and satisfying the guidelines targets between hemodialysis patients aged 65 years and over and those younger than 65 years.
Methods: Data were collected using a questionnaire sent to all 46 HD centers in Serbia with totally 3868 HD patients. The 24 centers responded and sent the data on all patients aged 18 years or older that were on regular HD for more than 3 months (2153 patients, 1320 males, aged 18-90 years). Data are presented in two groups: a group of patients younger than 65 years (1438, 66.8 %) and a group of patients aged 65 years and over (715, 33.2 %). The percentage of patients whose values failed to meet the targets recommended by KDOQI Clinical Practice Guidelines was calculated for dialysis dose (spKt/V), hemoglobin, serum phosphorus, serum calcium and plasma iPTH (150-300 pg/mL). Patients were followed from enrollment until their death, kidney transplantation, departure from the center or the end of the study.
Results: Elderly patients were more likely to have hypertension, significantly lower systolic and diastolic blood pressure and smaller dialysis vintage than younger patients. They were less frequently treated with high-flux membranes and hemodiafiltration and they had significantly lower number of dialysis hours per week and significantly lower interdialytic weight gain. They used ESA and phosphate binders less frequently than younger patients (p < 0.001 and p = 0.002). Older patients had similar Kt/V as younger ones but they had significantly more frequent Hb level outside the target range than younger patients. During the year follow-up period, by using a Cox proportional hazards model it has been confirmed that age, dialysis vintage, weekly dialysis time and target values for Kt/V were significant independent predictors of time to death for younger patients and gender, dialysis vintage and iPTH were independent predictor of time to death for older patients.
Conclusion: Despite less favorable dialysis prescription, older patients had similar Kt/V and less frequent deviations from the target values proposed by KDOQI for serum phosphorus and iPTH but more frequent deviation for Hb value as compared with younger patients. Risk factors for mortality differ between older and younger patients; out of five KDOQI targets, only Kt/V proved to be a significant risk factor for mortality for younger and iPTH for older patients.