title: Age and anemia management: relationship of hemoglobin levels with mortality might differ between elderly and nonelderly hemodialysis patients.
abstract: BACKGROUND
  The elderly hemodialyzed population is growing. However, little is known about the relationship between hemoglobin level and survival according to age. We investigated the effect of age on the relationship between hemoglobin and survival within the Japan Dialysis Outcomes and Practice Patterns Study (DOPPS) cohort.
  
  
  METHODS
  We enrolled the entire Japan DOPPS phases 3 and 4 population. Patients were divided by the age of 75 years into two groups. Cox's proportional hazard model was used with hemoglobin at every 4 months treated as a time-dependent variable. The interaction of age and hemoglobin was analyzed.
  
  
  RESULTS
  We included 3341 patients in the analyses. The primary outcome occurred in 567 patients during the median follow-up of 2.64 years. Hemoglobin of entire population was 10.3 ± 1.3 g/dL. The median of epoetin dose was 3000 IU/week. Interaction was found between ages stratified by the age of 75 years and hemoglobin values (P = 0.045) with use of Cox's proportional hazard model. The nonelderly population had poorer prognosis with hemoglobin <10 g/dL, while elderly population only with hemoglobin <9 g/dL. For both hemoglobin strata <9, ≥9 and <10 g/dL, interactions between age and hemoglobin were significant. Subgroup analysis indicated that interaction between age and Hb levels was observed only in the nondiabetic nephropathy group. Several sensitivity analyses demonstrated a similar trend with the original analyses and reinforced the robustness.
  
  
  CONCLUSIONS
  The elderly population might tolerate low hemoglobin levels. Our findings open the way for further investigation of individualized anemia management.
authors.affiliation: Department of Hemodialysis and Apheresis, The University of Tokyo Hospital, Tokyo, Japan Division of Total Renal Care Medicine, The University of Tokyo Hospital, Tokyo, Japan Japanese Dialysis Outcomes and Practice Patterns Study (J-DOPPS) for Anemia Working Group, Tokyo, Japan.
authors.forename: Norio
authors.initials: N
authors.lastname: Hanafusa
authors.affiliation: Medical Affairs, Kyowa Hakko Kirin, Co. Ltd., Tokyo, Japan.
authors.forename: Takanobu
authors.initials: T
authors.lastname: Nomura
authors.affiliation: Japanese Dialysis Outcomes and Practice Patterns Study (J-DOPPS) for Anemia Working Group, Tokyo, Japan Division of Nephrology, Department of Internal Medicine, Showa University Fujigaoka Hospital, Yokohama, Japan Department of Healthcare Epidemiology, Graduate School of Medicine and Public Health, Kyoto University, Kyoto, Japan Division of Nephrology, Department of Medicine, Showa University School of Medicine, Yokohama, Japan Center for Innovative Research for Communities and Clinical Excellence, Fukushima Medical University, Fukushima, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hasegawa
authors.affiliation: Department of Hemodialysis and Apheresis, The University of Tokyo Hospital, Tokyo, Japan Japanese Dialysis Outcomes and Practice Patterns Study (J-DOPPS) for Anemia Working Group, Tokyo, Japan Division of Nephrology and Endocrinology, The University of Tokyo School of Medicine, Tokyo, Japan.
authors.forename: Masaomi
authors.initials: M
authors.lastname: Nangaku
mesh_terms: D000367:Age Factors; D000368:Aged; D000740:Anemia / Q000453:epidemiology / Q000209:etiology / Q000628:therapy*; D019468:Disease Management; D004921:Erythropoietin / Q000627:therapeutic use*; D005260:Female; D005500:Follow-Up Studies; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D007676:Kidney Failure, Chronic / Q000097:blood / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D006435:Renal Dialysis / Q000401:mortality*; D015996:Survival Rate / Q000639:trends; D013997:Time Factors
chemical_list: D006454:Hemoglobins; D004921:Erythropoietin
keywords: aged population; anemia management; individualized therapy; mortality