вход по аккаунту



код для вставкиСкачать
Economic Analysis of Expensive
The Case of Erythropoietin
Jennifer J. Griggs, M.D.1,2
Alvin I. Mushlin, M.D., Sc.M.1
Departments of Medicine and Community and Preventive Medicine, University of Rochester
School of Medicine and Dentistry, Rochester, New York.
Department of Hematology/Oncology, University of Rochester School of Medicine and Dentistry,
Rochester, New York.
See referenced original article on pages 2588 –96,
this issue.
Address for reprints: Jennifer J. Griggs, M.D., University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Box 704, Rochester,
NY 14642.
Received August 31, 1998; accepted September
18, 1998.
© 1998 American Cancer Society
he assumption underlying the use of economic analyses of health
care interventions is that health care resources are limited and
should be directed toward health strategies that provide the most
benefit per dollar spent. Even in the absence of an explicit budgetary
constraint, there is an implicit need to control excess spending. As
outlined in the American College of Physicians Ethics Manual (Fourth
Edition), physicians have a “responsibility to use all health-related
resources in a technically appropriate and efficient manner” as they
“consider the best interest of all patients and of each patient.”1 It is
not enough to ask whether a new drug or device is effective—we must
also ask at what cost, or “What are we getting for our health care
dollar?” The Panel on Cost-Effectiveness in Health and Medicine,
convened by the U.S. Public Health Service in 1993, views costs as
“opportunity costs,” that is, dollars spent on one health care intervention are not available for others.
In a cost-effectiveness analysis, the consequences of an intervention are expressed as “natural units,” for example, years of life saved,
procedures avoided, or improvements in quality of life. The costeffectiveness ratio is therefore expressed as cost per year of life saved,
etc. For erythropoietin used in the treatment of chemotherapy-related anemia, the natural unit might be “cost per transfusion avoided.” Cost-utility analyses (CUA) (one type of CEA) employs in the
denominator the quality-adjusted life year (QALY). QALYs are calculated by multiplying the number of years of life by a quality adjuster
(also called utility)—a number from 0 (“dead”) to 1 (often “perfect
health”), thereby combining quality of life and life expectancy. Measuring utility attempts to capture the values, or preferences, that
patients have for different health states. Little agreement exists as to
which method for elicitation of utility is the “gold standard.”2 Furthermore, the criterion used to determine whether an intervention is
cost-effective, and therefore to indicate that it should be adopted, is
Cost-benefit analysis attempts to avoid these problems by measuring both costs and consequences in monetary terms. If the results
indicate savings, the decision is fairly straightforward. For many
CANCER December 15, 1998 / Volume 83 / Number 12
years, the “human capital approach” was used as a
means of valuing benefits in monetary terms. Improved health should increase productivity, and wages
could be used as a proxy for productivity and as a way
of valuing improvements in outcome. The major limitations of this approach are as follows: 1) it assumes
that the goal of a society is to promote health in order
to maximize the gross national product, and 2) it is
biased against some groups of people, including retired workers, children, volunteers, and women who
do not work outside the home or who make less than
their male peers. Furthermore, assigning a monetary
value to a life saved or to improvements in health
makes CBA less acceptable to physicians and other
members of the medical community.
Assessment of willingness to pay for an intervention is an alternative approach to assigning a monetary value to an intervention and its expected benefits.3 Respondents are asked how much money they
would be willing to contribute to have a medical intervention made available to them or, alternatively,
how much compensation they would require to forego
such a benefit. As with the other methods, debate
exists as to whose preferences should be measured:
those people with the condition, or members of the
society at large.4 – 6 The preference for a particular
health state is generally higher when the participants
are, in fact, patients.4
Erythropoietin in the prevention or treatment of
anemia due to cancer chemotherapy is an example
of a medical technology that offers benefits to some
patients at relatively high cost. The consequences of
transfusions versus erythropoietin may be measured in terms of increase in hemoglobin—for example, the ability of 1 unit of blood or 1 month of
erythropoietin to increase the hemoglobin by 1
gram. Another approach would be to assess the
improvements in quality of life that can be achieved
with the two treatments or, alternatively, preferences for treatment with the two strategies. In this
case, the incremental benefits of erythropoietin
compared with transfusion are difficult to separate
from the benefits of treating the anemia. Patients
with both ESRD and cancer who have an increase in
hemoglobin while on erythropoietin experience a
concomitant improvement in functional status and
quality of life.7–10 It is noteworthy that, among patients with ESRD, the Canadian Erythropoietin
Study Group found no differences in the psychosocial aspects of health or in utility as measured by the
time trade-off method, one commonly used approach to measuring preferences.11 That is, despite
demonstrated improvements in exercise tolerance,
the patients’ utility based on their “health status” or
“how they feel” was no different in the transfusiontreated group compared with the erythropoietintreated group in this placebo-controlled, randomized trial. Until now, patient preferences for
receiving erythropoietin versus transfusions have
not been available, so cost-utility and cost-benefit
analyses comparing these two treatment options
have not yet been performed.
In this issue of Cancer, Ortega et al. present the
results of a willingness-to-pay approach to determine
the cost-benefit of erythropoietin in the prevention of
chemotherapy-induced anemia.12 Study subjects included both patients undergoing treatment with chemotherapy and members of the general public contacted via telephone. By including both patients and
members of the general population in their study, the
authors have addressed the cost-benefit of erythropoietin from both perspectives. Patients were asked how
much they would pay for the drug itself. To make the
question realistic to nonpatients, the payment for the
drug was represented as an increase in health insurance premiums that would make the drug available
should they require treatment in the future.
Validation of this method of assessing preferences, in this study and others, is difficult because
people rarely face the hypothetical decision being
studied. One therefore cannot assess whether or not
the responses to a questionnaire correspond to actual
choices that people would make. The use of a scale by
Ortega et al. to rate the importance of the new drug
reveals what might be a disparity. Although participants considered it important to have the drug available for the prevention of cisplatin-induced anemia,
with a mean value of 9 out of 10 for patients and 8 out
of 10 for nonpatients, their willingness to pay for the
drug did not render the drug cost-beneficial. A large
part of this may reflect participants’ lack of knowledge
regarding the actual cost of medical treatments in
As one might expect, participants’ willingness to
pay increases with individuals’ incomes, or ability to
pay. This correlation has been demonstrated in other
studies.13 Even at the highest level of willingness to
pay, however, the drug was not cost-beneficial.
An important caution in the use of health state
scenarios is that all aspects of the health state and the
technology under study must be included. In this case,
for example, the state to be avoided should be anemia
rather than merely transfusion therapy.
Practical application of this study in determining
health policy is also limited by the estimations of
transfusion needs based on the Abels study of 55 patients. Differences among patient groups will lead to
differences in the cost-benefit ratio. For a patient who
Editorial/Griggs and Mushlin
requires frequent transfusions, for example, continuous erythropoietin will be a more cost-effective treatment strategy than for a patient who requires transfusion only rarely. By varying the need for transfusion in
additional sensitivity analyses, the authors may have
revealed a subset of patients for whom erythropoietin
would be cost-beneficial.
Nonetheless, the use of the willingness-to-pay approach in evaluating the cost-benefit of prophylactic
erythropoietin gives us important information about
the value these subjects place on avoidance of transfusion. This method of valuation is understandable to
participants and explores preferences for novel and
expensive technologies. The use of an increase in insurance premiums as a model for cost makes the
technique applicable to different types of health care
systems. By enumerating clinical values in terms of
cost-benefit analyses, we can find a way to include the
preferences of our patients and future patients in negotiations with policymakers and payers.
American College of Physicians. Ethics manual. 4th edition.
Ann Intern Med 1998;128:576 –94.
Froberg DG, Kane RL. Methodology for measuring healthstate preferences. II: Scaling methods. J Clin Epidemiol 1989;
42:459 –71.
O’Brien B, Viramontes JL. Willingness to pay: a valid and
reliable measure of health state preference? Med Decis Making 1994;14:289 –97.
Boyd NF, Sutherland HJ, Heasman KZ, Tritchler DL, Cummings BJ. Whose utilities for decision analysis? Med Decis
Making 1990;10:58 – 67.
Richardson J, Nord E. The importance of perspective in the
measurement of quality-adjusted life years. Med Decis Making 1997;17:33– 41.
Llewellyn-Thomas H, Sutherland HJ, Tibshirani R, Ciampi A,
Till JE, Boyd NF. Describing health states: methodologic
issues in obtaining values for health states. Med Care 1984;
Moreno F, Aracil FJ, Perez R, Valderrabano F. Controlled
study on the improvement of quality of life in elderly hemodialysis patients after correcting end-stage renal diseaserelated anemia with erythropoietin. Am J Kidney Dis 1996;
27:548 –56.
Canadian Erythropoeitin Study Group. Association between
recombinant human erythropoietin and quality of life and
exercise capacity of patients receiving haemodialysis. BMJ
1990;300:573– 8.
Glaspy J, Bukowski R, Steinberg D, Taylor C, Tchekmedyian
S, Vadhan-Raj S. Impact of therapy with epoitin alfa on
clinical outcomes in patients with nonmyeloid malignancies
during cancer chemotherapy in community oncology practice. J Clin Oncol 1997;15:1218 –34.
Henry DH, Abels RI. Recombinant human erythropoietin in
the treatment of cancer and chemotherapy-induced anemia: results of double-blind and open-label follow-up studies. Semin Oncol 1994;21:21– 8.
McNamee P, van Doorslaer E, Segaar R. Benefits and costs
of recombinant human erythropoietin for end-stage renal
failure: a review. Benefits and costs of erythropoietin. Int J
Technol Assess Health Care 1993;9:490 –504.
Ortega A, Dranitsaris G, Puodziunas ALV. What are cancer
patients willing to pay for prophylactic epoetin alfa?: a costbenefit analysis. Cancer 1998;83:2588 –96.
Appel LJ, Steinberg EP, Powe NR, Anderson GF, Dwyer SA,
Faden RR. Risk reduction from low osmolality contrast media: what do patients think it is worth? Med Care 1990;28:
324 –37.
Без категории
Размер файла
40 Кб
Пожаловаться на содержимое документа