Table 2Relationship between iron deficiency and dose of erythropoietin following website in the treatment of renal anemia of hemodialysed patients in 2002�C2005.3.3. Influence of Anemia on Hospitalization Rate in HD Patients from Kaunas Region of LithuaniaThere is no unified opinion about the influence of anemia to hospitalization rate of HD patients. Big retrospective study of dialysis patients showed that higher concentration of Hb associated with lower rate of hospitalization [10]. DOPPS study (data from 5 European countries) showed that higher Hb concentrations were associated with decreased relative risk of hospitalization: patients with Hb <100g/L were 29% more likely to be hospitalized than patients with Hb 110�C120g/L [11]. But in prospective randomized trials hospitalization rate did not differ between groups of lower and higher Hb [12].

There were no Lithuanian data about relationship between hospitalization of HD patients and anemia till our study. Relative risk of hospitalization was estimated using Cox regression evaluating time to first hospitalization. Multivariate Cox regression model revealed that relative risk for hospitalization decreased by 0.98 for every 1g/L rise of Hb (adjusted to age, sex, comorbid conditions, albumin, urea and phosphorus concentrations interdialytic weight gain, nonadherence to medications, systolic blood pressure before and dialysis, disability status). Cutoff value for Hb was <100g/L: relative hospitalization risk increased by 1.7 (95% CI 1.4�C1.95, P < 0.001) in patients with Hb <100g/L (Figure 2).

Figure 2Relation between hemoglobin level and hospitalization in Lithuanian hemodialysis patients.3.4. Association of Anemia with Mortality in HD Patients in LithuaniaAnnual data collection allows us to analyse associations between anemia and mortality in incident HD patients in Lithuania in 1998�C2005. Analysis revealed that the mean Hb value of all these patients was 101.28 �� 12.59g/L; in males it was higher than in females (102.34 �� 12.52g/L versus 100.01 �� 12.56g/L, P < 0.001) and did not differ comparing different age groups and primary renal disease groups.Multivariate Cox proportional hazards analysis revealed that anemia was an independent risk factor of death (RR=0.952, 95% CI 0.945�C0.959, P < 0.001). Relative risk of mortality was 5% lower for every 1g/L greater Hb concentration used as continuous variable and adjusted for age, sex, and primary kidney disease.

As shown in Table 3, the relationship of Hb level with mortality varied across different categories of Hb concentrations.Table 3Relative risk of death for hemoglobin categories.Patients with Hb level of 100 to 105g/L were selected as the reference group, according to national algorithm Cilengitide for the management of anemia in Lithuania from 2002 (the target Hb level in patients on chronic HD was between 100g/L and 105g/L). The Hb concentration below 100g/L was associated with a 2.5-fold increased relative risk of death.