ABSTRACT. Treatment of the anemia of chronic renal failure withexogenous recombinant human erythropoietin (rHuEpo) is wellestablished. The objective of this randomized clinical trialwas to evaluate an anemia management team protocol in hemodialysispatients, using subcutaneous rHuEpo and intravenous iron. Atotal of 215 patients were randomized to either usual care orthe protocol. The primary outcome was the proportion of patienthemoglobin (Hgb) values between 11.0 and 12.5 g/dl over thefinal 8 wk. The study was halted after 240 d because of an institutionalchange to intravenous rHuEpo. The proportion of Hgb values inthe target range increased from 47.4% to 62.8% overall (P =0.001); there was no difference between treatment groups. Theproportion of baseline Hgb values between 11.0 and 12.5 g/dlincreased from 44.6% in patients who had enrolled within thefirst 3 mo of study inception to 75.0% in those who startedlater (P = 0.017), suggesting a Hawthorne effect. A nonsignificantdecrease in rHuEpo dose was observed in the protocol group;subgroup analysis in patients who were enrolled for at least5 mo demonstrated a reduction in the rHuEpo dose of 2788 units/wkin the protocol group (P < 0.05), independent of intravenousiron dose. Multivariate analysis demonstrated that a highertransferrin saturation and albumin and protocol group assignmentwere associated with a lower final rHuEpo dose. This study demonstratedthat a protocolized approach to anemia management in hemodialysispatients results in comparable Hgb levels and may reduce rHuEporequirements, independent of iron use. E-mail: brimbles@mcmaster.ca
Treatment of the anemia of chronic renal failure with exogenouserythropoietin (rHuEpo) is a well-established practice thathas led to improvements in a variety of clinical parameters,including exercise tolerance (1,2), quality of life (3,4), anddecreased mortality (5). Adjunctive therapy with intravenousiron has been shown to improve responsiveness to rHuEpo (612);guidelines for its use have been updated recently (13,14). Guidelinesfor the initial dosing, monitoring, and subsequent adjustmentsfor rHuEpo have also been described (13,14).
The optimal hemoglobin (Hgb) for patients with ESRD is not clear.Data exist to suggest that normalization of Hgb may be harmfulin some patients (15); thus, many experts recommend a targetvalue between 11.0 and 12.0 g/dl (13,14). Despite this recommendedlevel, a substantial proportion of patients remain below thistarget level; this may be related to underutilization of rHuEpo,unrecognized iron deficiency, or rHuEpo resistance (13).
Initial clinical trials of rHuEpo used simple dosing algorithmsto bring Hgb values of patients up to a desired level (1618);however, maintenance dosing of rHuEpo was not well studied.A study evaluating the effects of rHuEpo on left ventriculargeometry used an algorithm in an attempt to standardize rHuEpodosing across centers; however, the details of the algorithmwere not described, and its effectiveness was not evaluated(19). A recent study demonstrated that utilization of an intravenousrHuEpo dosing algorithm in a small cohort of hemodialysis patientsled to a greater number of patients achieving target Hgb levels(20). To our knowledge, no randomized, controlled trial hasevaluated the efficacy of an anemia management team protocol.The aim of this randomized, controlled trial was to evaluateprotocolized subcutaneous rHuEpo and intravenous iron changesby an anemia management team in a representative hemodialysispopulation.
Study Population and Randomization
This study was a single-center, randomized, controlled trialin which patients were allocated either to protocolized anemiamanagement or to usual care by a primary nephrologist and nurseclinician. The planned study duration was 8 mo. Patients hadto meet the following inclusion criteria: (1) on maintenancehemodialysis at least 3 mo, (2) receiving subcutaneous rHuEpoat the time of enrollment, and (3) primary nephrologist agreeableto Hgb target. Patients were excluded for any of the following:(1) inability to provide informed consent; (2) anticipated death,transfer, or transplant within the next 8 mo; (3) allergy tointravenous iron sucrose; (4) current participation in an anemiastudy; or (5) under the care of any of the study authors. Consentingpatients were allocated, using a concealed randomization scheme(blocks of four), to protocolized anemia management or usualcare, stratified by primary nephrologist. The nephrologistsand patients participating in the study were blinded to theprotocol specifics except for the target Hgb range but wereaware of patient assignment. All study participants were onhemodialysis at St. Josephs Healthcare in Hamilton, ON,Canada. Patients received dialysis thrice weekly using eithera Fresenius (2008K) or Baxter (System 1000 or Tina) hemodialysismachine with high-flux biocompatible membranes. The study wasapproved by the hospital ethics review board. All patients ortheir substitute decision makers gave written informed consent.
Anemia Protocol
A preliminary anemia management algorithm was developed by oneof us (S.B.) in consultation with the other authors, reviewof clinical practice guidelines (13,14), and the product monograph(Eprex; Jansen-Ortho). The algorithm was then pretested in 15hemodialysis patients for 2 mo before the protocol was finalized.At the time of the study, prefilled rHuEpo syringes (1,000,2,000, 3,000, 4,000, and 10,000 units) were available at thestudy center. Patients who required 8,000 units two or threetimes per week could be prescribed this dose using aliquotsfrom a 20,000-unit multidose vial; otherwise, usage of the multidosevials was not promoted in the study center during this timeperiod. The maximum dose prescribed in the center is 30,000units weekly.
Patients who were assigned to the protocol arm could be prescribedrHuEpo and iron only by the anemia management team, consistingof a research nephrologist (S.B.) and a nurse (P.M.), usingthe designed protocol (Figure 1). The research nurse obtainedresults each week and, on the basis of the algorithm, recordedchanges for the research physician to review. In the protocolarm, rHuEpo dose changes were made every 4 wk on the basis ofthe most current Hgb valuemore frequent changes weremade only when the Hgb value or the rate of Hgb change was outsidethe preset safety parameters (shown at the top of Figure 1).As an example, a patient on 10,000 units of rHuEpo weekly withan Hgb value <11.0 g/dl, a ferritin value >100 µg/L,and a transferrin saturation (TSAT) >20% would have his orher rHuEpo dose increased by one step to 4000 units thrice weekly.
Figure 1. Anemia management algorithm. The most recent hemoglobin (Hgb) value was reviewed every 2 wk; a change was made by at the physicians discretion if any of the safety parameters were breached. Otherwise, Hgb values were assessed every 4 wk for a potential change in recombinant human erythropoietin (rHuEpo) dose or intravenous iron administration, considering the most recent transferrin saturation (TSAT) and ferritin values. When a change in rHuEpo dose was indicated, a one-step change was made, based on the dosing schedule shown.
The desired Hgb range was set at 11.0 to 12.5 g/dl by consensusamong the authors; nephrologists whose patients were participatingin the control arm of the study were asked to aim for this targetrange. Otherwise, nephrologists were asked to continue anemiamanagement in their patients as they saw fit. Updated electronicreports of Hgb, ferritin, and TSAT values were sent weekly toeach of the primary nephrologists for all patients who werereceiving dialysis at the center to ensure equal access to testresults. Hgb values were obtained before the midweek dialysissession every 2 wk, and ferritin and TSAT values were obtainedmonthly. Serum albumin levels and the urea reduction ratio wereobtained monthly and parathyroid hormone and C-reactive protein(CRP) levels were obtained every 3 mo as part of routine practice.Patients who required hospitalization primarily for medicalreasons were temporarily withdrawn from the study for safetyreasons as the protocol was designed and pretested in patientswithout intervening acute medical conditions that might leadto unpredictable changes in Hgb values. Once patients were dischargedor were considered medically stable, they then resumed participationin the study.
All patients who were in the protocol arm that were not on ironsupplementation at enrollment were started on oral ferrous gluconate600 to 900 mg daily. Intravenous iron sucrose (Venofer; LuitpoldPharmaceuticals Inc.) was prescribed when the ferritin was <100µg/L or the TSAT was <20% and the Hgb was below range.Patients received 100 mg intravenously over each of the next10 hemodialysis treatments and then every 2 wk thereafter. Whensubsequent ferritin or TSAT values remained below these values,a repeat loading of 100 mg over the next five hemodialysis sessionswas given. When the ferritin or TSAT were >800 µg/Land 50%, respectively, the intravenous iron was held until thevalues fell below these values. Intravenous iron was then restartedat 50 mg every 2 wk.
Outcomes
The primary outcome of the study was the proportion of patientswith Hgb values in target range (11.0 to 12.5 g/dl), assessedby averaging all protocol Hgb values over the final 8 wk ofthe study. The baseline proportion of Hgb values in target rangewere also obtained by averaging the Hgb values over the 8 wkimmediately preceding patient entry into the study. Secondaryoutcomes evaluated were weekly rHuEpo dose at completion ofthe study, proportion of patients below the target range, meanHgb values, and average intravenous iron dose. Univariate andmultivariate predictors of the final rHuEpo dose were also evaluated.
Sample Size and Statistical Analyses
The required sample size, adjusted for stratification by a nephrologistand assuming a 10% dropout rate, was estimated to be 215 patients.This calculation assumed a clinically important difference ofthe proportion of patients within target Hgb range of 30% betweenthe two groups and using and values of 0.05 and 0.2, respectively.Mean and SD for continuous variables were calculated for bothtreatment groups. Differences between means were analyzed usingthe t test. Differences in proportions were evaluated usingthe McNemar 2 test within patient groups (baseline/follow-up)and logistic regression between patient groups (using the baselinevalue as a covariate). Differences between final rHuEpo dosesin the treatment groups were evaluated using ANCOVA with thebaseline rHuEpo dose as a covariate (21). Multivariate correlateswith final rHuEpo dose were determined using multiple linearregression on significant (P < 0.10) univariate variables,controlling for treatment assignment. P < 0.05 was consideredstatistically significant. Data analysis was carried out usingthe SPSS v. 11.0 (SPSS Inc., Chicago, IL) software package.
Patient Characteristics
A total of 468 patients were screened and 215 patients wererandomized (45.9%) between October 2001 and March 2002 (Figure 2).The most common reason for not entering the study was thatthe patient was under the care of one of the study nephrologists(96 patients; 20.5%). Other major reasons for nonentry werepatient refusal to provide consent (53 patients; 11.3%), primarynephrologist refusal to allow patient participation (29 patients;6.2%), and participation in another erythropoietic hormone study(21 patients; 4.5%). A decision was made at the study institutionin July 2002 to switch all hemodialysis patients from subcutaneousto intravenous rHuEpo on the basis of the recommendation ofthe rHuEpo provider (Eprex, Jansen-Ortho) and the Canadian HealthProducts and Food Branch. This was based on the observed rarerisk of pure red cell aplasia associated with subcutaneous Eprex.This policy prompted early termination of the study in July2002. A total of 167 patients (77.7%) had completed at least5 mo of the study; a secondary analysis of this study populationwas also carried out for differences in the outcomes of interest.Baseline demographics and clinical information were similarin the two groups (Table 1) except for the presence of diabetesmellitus (DM) and the use of arteriovenous fistulae (AVF) (bothhigher in the control group).
Table 1. Baseline characteristics of patients enrolled in the studya
Outcomes
During the study, 43 patients dropped out prematurely. Patientdata were censored at the time of withdrawal from the study;patients who were enrolled for >5 mo before censoring wereincluded in the secondary analysis. There were 20 deaths (9.3%)during the trial (eight in control group versus 12 in protocolgroup; P = 0.36), eight transplants, and five transfers to othercenters. There was no difference in hospitalization rates ortransfusion requirements (data not shown). Ten patients werewithdrawn at the request of either the patient or the primaryphysician. The mean Hgb values for the control and protocolgroups at study completion were 11.7 (± 0.9 g/dl) and11.5 (± 1.1 g/dl), respectively; these were not significantlydifferent (P = 0.17). Final Hgb values were similar in a secondaryanalysis restricted to patients who were enrolled for >5mo (11.7 versus 11.6 g/dl, respectively; P = 0.82). The overallproportion of patients in the target Hgb range (11.0 to 12.5g/dl) increased from 47.4% at baseline to 62.8% at the completionof the study (P = 0.001); these proportions increased significantlyin both the control (49.1% to 62.0%; P = 0.05) and the protocol(45.8% to 63.6%; P = 0.02) groups; however, there was no significantdifference (P = 0.80) between the groups (Figure 3). Similarresults were seen in the secondary analysis (Figure 4).
Figure 3. Overview of Hgb target results in all patients. Proportion of patient below, within, or above the targeted range at baseline and completion are shown according to group allocation. *P = 0.001; P = 0.05; P 0.02. Comparisons are the final to baseline Hgb values within the patient groups.
Figure 4. Overview of Hgb target results in patients enrolled for >5 mo. Proportion of patients below, within, or above the targeted range at baseline and completion are shown according to group allocation. P < 0.05; *P < 0.001; P = 0.005. Comparisons are the final to baseline Hgb values within the patient groups.
A nonsignificant decrease in the proportion of patients withHgb values <11.0 g/dl from baseline to the end of the studywas observed overall (P = 0.08); this decrease achieved statisticalsignificance in the secondary analysis of patients who wereenrolled for at least 5 mo (32.9% to 21.0%; P = 0.01). Therewas no difference, however, between the two groups in the proportionof patients with Hgb values <11.0 g/dl at completion of thestudy in either analysis (Figures 3 and 4). There was a decreasein the proportion of patients above the target Hgb range frombaseline (27.1%) to completion of the study (13.1%) in the protocol(P = 0.014) but not in the control group (P = 0.86; Figure 3).This finding persisted in the secondary analysis (P = 0.04;Figure 4).
Comparison of the final rHuEpo dose between the two groups showeda nonsignificant difference between the control (12,676 units/wk)and the protocol (10,925 units/wk) groups (P = 0.16). When onlypatients who had completed 5 mo of the study were considered,a decrease in rHuEpo dose in the treatment group of 2788 units/wk(P < 0.05) was observed. Neither differences between finalTSAT and ferritin levels nor difference in iron utilization,based on the proportion of patients prescribed intravenous ironand the average weekly intravenous iron dose, were observedbetween groups (Table 2). A modestly higher rHuEpo dosing frequencywas observed in the control group when the analysis was limitedto patients who had completed at least 5 mo of the study (P= 0.03). The average adjustment in the rHuEpo dose in the twogroups was markedly different. Protocol use led to an average(directionless) adjustment in rHuEpo dose of 3138 units versus6343 units in the control patients (P < 0.001). The differencewas even more pronounced when restricted to patients who hadcompleted at least 5 mo of the study (Table 2).
Table 2. Comparison of rHuEpo dose requirements and iron indices
Univariate analysis was performed to identify potential predictorsof the final rHuEpo dose required in the study population. Anincrease in the final serum TSAT and albumin and a decreasein the final serum CRP were associated with a lower rHuEpo dosein the entire study population; however, a higher mean ureareduction ratio and assignment to the protocol group were alsoassociated with a lower rHuEpo dose when the analysis was restrictedto patients who were enrolled for >5 mo. Other baseline indicatorsnot predictive of final rHuEpo dose included serum ferritinand parathyroid hormone, gender, age, weight, access type, dialysisvintage, and presence of coronary artery disease or diabetesmellitus. Multivariate analysis identified that group assignmentand final serum TSAT and albumin were the only independent predictorsof final rHuEpo dose (Table 3). Patient assignment to the protocolwas associated with a significant decrease in the final rHuEpodose of 2388 units (P = 0.04). An increase in the TSAT valueof 1% was associated with a decrease in weekly rHuEpo requirementsof 201.8 units (P < 0.001), whereas a rise in albumin of1 g/L was associated with a decrease in the weekly rHuEpo doseof 730.8 units (P < 0.001). When the analysis was restrictedto patients who were enrolled for at least 5 mo, similar resultswere observed (Table 3). The impact of group assignment persistedeven when patients who had withdrawn from the study prematurelywere included.
This randomized, controlled trial demonstrated that there wasno improvement in the ability to achieve target Hgb values inhemodialysis patients by using the described anemia managementteam protocol. Nonetheless, there was a substantial reductionin rHuEpo dose in patients who were enrolled for >5 mo, independentof the effects of intravenous iron administration and targetedHgb.
There are several potential explanations for the protocolsinability to increase the proportion of patients who achieveda desired Hgb target. Early termination of the study may havehad an impact on the final results; it seems unlikely, however,that continuation of the study would have led to any measurabledifference in the primary outcome. A previous study (20) demonstratedthat implementation of an intravenous rHuEpo algorithm led toa measurable improvement in achieving target Hgb values afteronly 3 mo.
Subsequent revision to the protocol might lead to a greaterproportion of patients achieving the desired Hgb range; however,this is difficult to assess. The use of prefilled rHuEpo syringes(as currently funded in Ontario, Canada) led to minor restrictionsin our ability to make desired dosage adjustments; utilizationof multidose vials or the availability of additional doses inprefilled syringes may have improved the performance of thealgorithm. A more obvious explanation for the ineffectivenessof the protocol was the impressive results observed in the controlgroup. The previous nonrandomized study described (20) had demonstratedthat before implementation of an anemia management protocol,the proportion of patients who achieved target hematocrit levels(31% to 35%) was only 27% of patients, whereas the proportionof patients below target range (hematocrit <31%) was 46%.This compares with 62.0% achieving a target Hgb and only 21.3%of patients below the target in the control patients in thecurrent study, although there were minor differences in theHgb targets. Of interest was the improvement in the controlgroup during the course of the study; there was a 26.3% improvementin the proportion of patients who achieved target Hgb valuesfrom baseline. This may have been because at the time of enrollment,many of the patients Hgb levels had not yet achievedsteady state; this seemed unlikely as there was neither a differencein the proportion of patients in target Hgb range nor a differencein the mean Hgb values between the baseline values and thoseover the preceding 8 wk. Alternatively, nephrologists may havebeen previously targeting different Hgb values; hence, the improvementin the primary outcome was simply due to the nephrologistsmaking the necessary rHuEpo or iron dose adjustments to achievea new Hgb target. There is some support for this theory: patientsHgb values in the control group did tend to be higher at theend of the study compared with baseline. However, the proportionof baseline Hgb values in target range increased from 44.6%in patients who had enrolled within the first 3 mo of the studysstart date to 75.0% in those who started later (P = 0.017),suggesting that initiation of the study led to an overall improvementin anemia care in the hemodialysis unit. Such a phenomenon,known as the Hawthorne effect, has been described previously(22).
Although there was no difference in the primary outcome betweenthe two groups, a difference in the rHuEpo dose requirementsin the two groups was observed. This did not seem to be a resultof greater iron utilizationboth the average weekly irondose and the indices of iron stores (TSAT and ferritin) weresimilar in the two groups. In addition, there was no differencein the upper level of rHuEpo used (30,000 units/wk). There didseem to be a reduction in the proportion of patients with Hgbvalues >12.5 g/dl in the protocol group by the end of thestudy, which may have led to minor differences in rHuEpo usage.The major difference in the groups contributing to lower rHuEporequirements in the protocol group seemed to be the incrementalnature of rHuEpo dose changes, as demonstrated by the strikingdifference in magnitude of the average dose adjustments observedin the two groups. Supportive of this hypothesis is that therewas a strong relationship between the final rHuEpo dose andthe average rHuEpo dose adjustment in patients, even when thelatter was normalized to the patients final rHuEpo dose(data not shown).
This anemia management team protocol may be associated withsignificant cost savings. The current cost of rHuEpo at thestudy center was $0.0086 per unit (U.S.). On the basis of adose reduction of 2788 units/wk, a cost savings of $1245.98per patient would be achieved. In the study center alone, whichcurrently has >430 hemodialysis patients, an estimated savingson rHuEpo costs of >$535,000 ($835,000 Canadian funds) wouldbe realized. Such savings would easily cover the cost of oneor two additional nurse coordinators if a center chose to centralizeanemia management in the hemodialysis unit.
The final results achieved in the protocol group were comparableto those observed in a previous prospective cohort study thatused an intravenous rHuEpo algorithm (20). The previous studyshowed that utilization of an anemia protocol led to an increasein patients with Hgb values in target range from 27% to 61%while reducing the proportion of patients below the target rangefrom 46% to 18%. The respective baseline values of 47.4% intarget range and 29.8% below range in this study were significantlybetter than that observed in the previous study and in an earlierU.S. national survey (23). A more recent survey, however, hasshown that these anemia parameters have been improving in dialysispatients over time (24).
Several studies have evaluated the role of various laboratorymeasures in predicting rHuEpo responsiveness, including albumin(25,26), CRP (2527), ferritin (25,28), TSAT (25,27,28),and several dialysis adequacy indices (26,28). These studiessupport the notion that markers of inflammation such as an elevatedCRP or reduced serum albumin tend to be associated with higherrHuEpo requirements, whereas greater iron stores and increaseddialysis dose are associated with reduced rHuEpo needs. Thecurrent study found similar results with the exception thatserum ferritin was not an important predictor of final rHuEpodose. The reason for this is not clear but may be related todifferences in patient populations in the different studies.Serum ferritin is known to rise with inflammation, independentof iron stores (29). In addition, this study looked at the correlationof such markers with rHuEpo requirements rather than the utilityof these markers in predicting responsiveness to iron therapy,as has been recently described (30).
There are limitations to the present study. The study was terminatedearly and evaluated the use of subcutaneous Eprex. It is nowrecognized that subcutaneous administration of Eprex seems tobe associated with an increase in the rate of pure red cellaplasia, and Canadian prescribing information for Eprex (December2002) states, "It is recommended that in hemodialysis patients,the intravenous route of administration should be considered,where feasible." Nonetheless, it would be reasonable to assumethat a similar approach could be used for subcutaneous rHuEpoproducts not associated with this increased risk. In addition,there is no reason to believe that an algorithmic approach asdescribed in the current study could not be extended to intravenouspreparations of rHuEpo such as described previously (20). Inaddition to simplifying and standardizing the approach to anemiamanagement in the hemodialysis unit, it may reduce overall rHuEporequirements and costs.
In summary, this study demonstrated that a team-based protocolizedapproach to anemia management in a representative hemodialysispopulation could safely achieve target Hgb values in >60%of patients. This approach did not seem to offer any advantageover usual care at the study center; this seemed to be substantiallydue to an improvement in the results of control patients duringthe course of the study. Nonetheless, the results obtained inthe current study were comparable to those previously describedin a nonrandomized study and were associated with a substantialreduction in rHuEpo requirements, independent of intravenousiron use.
Acknowledgments
This trial was supported by a grant from Jansen-Ortho. K.S.B.and C.G.R. have received honoraria from Jansen-Ortho. Thesedata were presented in abstract form at the 2003 Canadian Societyof Nephrology meeting.
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Received for publication March 20, 2003.
Accepted for publication July 3, 2003.
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K. Jindal, C. T. Chan, C. Deziel, D. Hirsch, S. D. Soroka, M. Tonelli, and B. F. Culleton CHAPTER 1: Hemodialysis Adequacy in Adults
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S4 - S7.
[Full Text][PDF]
L. M Moist, N. Muirhead, L. D Wazny, K. L Gallo, A P. Heidenheim, and A. A House Erythropoietin Dose Requirements When Converting from Subcutaneous to Intravenous Administration Among Patients on Hemodialysis
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40(2):
198 - 203.
[Abstract][Full Text][PDF]