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In a new US study, scientists suggest that large for-profit kidney dialysis chains in the US give patients more anti-anemia drugs and aim for higher hemoglobin levels than nonprofit centres.
Giving patients too much anti-anemia drugs can put their lives at risk.
The study is published in the Journal of the American Medical Association (JAMA).
Healthy kidneys produce a hormone called erythropoietin that stimulates bone marrow to make red blood cells. People with kidney disease don't make enough erythropoietin, so fewer red blood cells are made and they get anemic. Red blood cells are important because they carry oxygen in their hemoglobin to other cells of the body.
Epoetin (marketed as Epogen and Procrit) is a manmade version of erythropoietin and is prescribed to kidney patients as part of their dialysis treatment, depending on how anemic they are and the level of hemoglobin their doctor is aiming to get them to.
In the US as well as hospital-based dialysis facilities there are independently owned profit based facilities that claim back expenses for patient treatment, including anti-anemia epoetin, from the government insurance scheme, Medicare.
Epoetin therapy is the single largest Medicare drug expenditure for dialysis-related anemia, accounting for 1.8 billion dollars of expenditure in 2004, said the study authors.
The study was conducted by scientists from the Medical Technology and Practice Patterns Institute, Bethesda, Maryland, the Veterans Affairs Boston Healthcare Systems, the Boston University School of Medicine, Boston, and the Harvard School of Public Health, also in Boston, Massachusetts.
The researchers used data from the US Renal Data System and found 159,522 adult Medicare-eligible, end-stage renal disease patients who were receiving hemodialysis at various centres during November and December 2004.
They analyzed the data using statistical regression models to examine the mean epoetin dose and dose adjustment by profit, chain, and affiliation status of the centres that patients attended.
The researchers found that:
-- Dosing of epoetin varied significantly depending on organizational status and ownership of the kidney dialysis centre.
-- The 106,116 patients who attended large for-profit dialysis centres were consistently administered the highest doses of epoetin compared with 28,199 patients who attended nonprofit centres, regardless of how anemic they were.
-- A typical hospital-based centre administered an average dose of 16,188 units per week of epoetin, while for-profit chain centres administered an average dose of 20,838 units a week.
-- On average, for-profit centres gave patients an average dose of 3,306 units a week more than non-profit dialysis centres.
-- The greatest difference in dosing practice patterns between centres was found among patients with hematocrit levels of less than 33 per cent.
-- On average, compared with nonprofit centres, for-profit centres increased epoetin doses 3-fold for patients with hematocrit levels of less than 33 per cent.
-- Among the 6 large chain facilities with a similar patient case-mix, the average dose of epoetin ranged from 17,832 units per week at chain 5 (nonprofit facilities with a mean hematocrit level of 34.6 per cent) to 24,986 units per week at chain 2 (for-profit facilities with a mean hematocrit level of 36.5 per cent).
The hematocrit level is a measure of the percentage of blood volume occupied by red blood cells. It is normally between 38 and 52 per cent for men and 37 and 47 per cent for women.
The researchers concluded that:
"Dialysis facility organizational status and ownership are associated with variation in epoetin dosing in the United States. Different epoetin dosing patterns suggest that large for-profit chain facilities used larger dose adjustments and targeted higher hematocrit levels."
The authors expressed concern that overprescription of epoetin was taking place in the for-profit centres.
In an accompanying editorial (Use of Epoetin in Chronic Renal Failure), Dr Daniel Coyne, professor of medicine at Washington University School of Medicine, in St Louis, said that the authorities disagree on what the optimal level of hemoglobin in the blood should be.
For example, the US Food and Drug Administration (FDA), recommend the maximum level of blood hemoglobin should be under 12 grams per decilitre (12 g/dl).
But, this compares with 13 g/dl, the maximum level recommended by the National Kidney Foundation, which Dr Coyne says is about to revise its guidelines. In his view, because of recent clinical trials, Dr Coyne thinks the 12 g/dl limit is safer.
Experts reacting to this study suggest that changing the way for-profit dialysis centres are reimbursed by Medicare (currently they are paid for doing dialysis and giving the anemia drugs separately) to a composite system would be a better way to do it and would remove the incentive that is tied to the drug on its own.
Administrators of for-profit dialysis centres say that the decision on which dose and guideline to follow is under the control of the patient's doctor.
The FDA has recently issued warnings for epoetin and another similar drug darbepoetin which is used to treat cancer patients with anemia.
Too much hemoglobin is dangerous because it increases the risk of heart attacks, strokes and blood clots.
"Dialysis Facility Ownership and Epoetin Dosing in Patients Receiving Hemodialysis."
Mae Thamer, Yi Zhang, James Kaufman, Dennis Cotter, Fan Dong, Miguel A. Hern¨¢n.
JAMA. 2007;297:1667-1674.
Vol. 297 No. 15, April 18, 2007
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