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01-01-2009 | Original Research Article

Comparing the Cost Effectiveness of Risperidone and Olanzapine in the Treatment of Schizophrenia Using the Net-Benefit Regression Approach

Authors: Annemieke De Ridder, Diana De Graeve

Published in: PharmacoEconomics | Issue 1/2009

Abstract

Objective: To estimate the cost effectiveness of olanzapine and risperidone for the treatment of schizophrenia in Belgium.

Methods: Data were retrieved from a prospective, observational, nonrandomized, follow-up survey. Clinical investigators assigned 265 patients with schizophrenia to either olanzapine (n = 136) or risperidone (n = 129). Patients were followed up for 2 years. Total healthcare costs were determined from the public payer perspective and calculated by multiplying resource use with official tariffs; effectiveness of the drugs was measured with the EQ-5D. This study uses a net-benefit regression approach to accommodate for baseline differences between treatment groups and uncertainty.

Results: Total 2-year costs were very similar for patients receiving risperidone and olanzapine (€20 915.33 and €20 569.69, respectively; p = 0.925) [year 2002 values]. The health condition of the patients receiving risperidone was better than that of patients receiving olanzapine but not significantly so (1.46 and 1.41, respectively; p = 0.191). Simple ordinary least squares (OLS) regressions indicated that, for λ = €40 000, we could not reject the null hypothesis that the drugs provide similar net monetary benefits to the patient (risperidone vs olanzapine €2046.95; p = 0.656).When we controlled for several patient characteristics, risperidone moved further away from olanzapine but the difference did not reach statistical significance (risperidone vs olanzapine €3198.07; p = 0.595). Numerous sensitivity analyses confirmed the robustness of the results.

Conclusion: Results of this study suggest that it is important to control for baseline patient characteristics when performing a cost-effectiveness analysis. No significant difference in net monetary benefit was found between risperidone and olanzapine.

Standardized costs and effects were calculated as follows: e.g. stand_cost = (cost × 365.25)/follow.

Knapp M, Chisholm D, Leese M, et al., and the EPSILON Study Group. Comparing patterns and costs of schizophrenia care in five European countries: the Epsilon study. Acta Psychiatr Scand 2002; 105 (1): 42–54PubMedCrossRef

De Hert M, Thys E, Boydens J, et al. Health care expenditure on schizophrenia patients in Belgium. Schizophr Bull 1998; 24: 519–27PubMedCrossRef

Knapp M. Costs of schizophrenia. Br J Psychiatry 1997; 171: 509–18PubMedCrossRef

Evers SM, Ament AJ. Cost of schizophrenia in the Netherlands. Schizophrenia 1995; 21 (1): 141–53CrossRef

Rouillon F, Dansette GY, Le Floch C. Therapeutic management of schizophrenic patients and its cost. Encephale 1993; 20 (3): 303–9

Rupp A, Keith SJ. The costs of schizophrenia: assessing the burden. Psychiatr Clin North Am 1993; 16: 413–23PubMed

Statistisches Bundesam. Krankheitskosten 2002 [report]. Wiesbaden, 2004

Rössler W, Salize HJ, van Os J, et al. Size of burden of schizophrenia and psychotic disorders. Eur Neuropsychopharmacol 2005; 15 (4): 399–409PubMedCrossRef

Basu A. Cost-effectiveness analysis of pharmacological treatments in schizophrenia: critical review of results and methodological issues. Schizophr Res 2004; 71 (2–3): 445–62PubMedCrossRef

10.

Hargreaves WA, Gibson PJ. Effectiveness and cost of risperidone and olanzapine for schizophrenia: a systematic review. CNS Drugs 2005; 19: 393–410PubMedCrossRef

11.

De Graeve D, Peuskens J, Gillain B, et al. A description of direct medical costs in patients with schizophrenia and initiated on haloperidol, olanzapine or risperidone. Acta Psychiatr Belg 2007; 107 (4): 31–9

12.

Peuskens J, Gillain B, De Graeve D, et al. Belgian Schizophrenia Outcome Survey: results of a 2-year naturalistic study in patients stabilised on monotherapy with olanzapine, risperidone or haloperidol. Eur Psychiatry. Epub 2008 Dec 31

13.

König H, Roick C, Angermeyer MC. Validity of the EQ-5D in assessing and valuing health status in patients with schizophrenic, schizotypal or delusional disorders. Eur Psychiatry 2007; 22 (3): 177–87PubMedCrossRef

14.

van De Willige G, Wiersma D, Nienhuis FJ, et al. Changes in quality of life in chronic psychiatric patients: a comparison between EuroQol (EQ-5D) and WHOQoL. Qual Life Res 2005; 14 (2): 441–51PubMedCrossRef

15.

Prieto L, Sacristán JA, Hormaechea JA, et al. Psychometric validation of a generic health-related quality of life measure (EQ-5D) in a sample of schizophrenic patients. Curr Med Res Opin 2004; 20 (6): 827–35PubMedCrossRef

16.

Hoch JS, Briggs AH, Willan AR. Something old, something new, something borrowed, something blue: a framework for marriage of health econometrics and cost-effectiveness analysis. Health Econ 2002; 11: 415–30PubMedCrossRef

17.

Stinnet AA, Mullahy J. Net health benefits: a new framework for the analysis of uncertainty in cost-effectiveness analysis. Med Decis Making 1998; 18: 68–80CrossRef

18.

Tambour M, Zethraeus N, Johannesson M. A note on confidence intervals in cost-effectiveness analysis. Int J Technol Assess Health Care 1998; 14 (3): 467–71PubMedCrossRef

19.

Brouwer W, Van Exel J, Van Baal P, et al. Economics and public health: engaged to be happily married! Eur J Pub Health 2006; 17 (2): 122–4CrossRef

20.

Gold MR, Siegel JE, Russell LB, et al. Cost effectiveness in health and medicine. New York: Oxford University Press, 1996

21.

Evans C, Tavakoli M, Crawford B. Use of quality adjusted life years and life years gained as benchmarks in economic evaluations: a critical appraisal. Health Care Manage Sci 2004; 7: 43–9CrossRef

22.

Salomon JA, Weinstein MC, Goldie SJ. Taking account of future technology in cost effectiveness analysis. BMJ 2004; 329: 733–6PubMedCrossRef

23.

Owens D. Interpretation of cost-effectiveness analyses. Arch Int Med 1998; 13: 716–7

24.

Taylor RS, Drummond MF, Salkeld G, et al. Inclusion of cost effectiveness in licensing requirements of new drugs: the fourth hurdle. BMJ 2004; 329 (7472): 972–5PubMedCrossRef

25.

Hirth RA, Chernew ME, Miller E, et al. Willingness to pay for a quality-adjusted life year: in search of a standard. Med Decis Making 2000; 20 (3): 332–42PubMedCrossRef

26.

Laupacis A, Feeny D, Detsky AS, et al. How attractive does a new technology have to warrant adoption and utilization: tentative guidelines for using clinical and economic evaluations. Can Med Assoc J 1992; 146: 473–81

27.

Cutler DM, McClellan M. Is technological change in medicine worth it? Health Aff 2001; 20: 11–29

28.

Hadley J, Polsky D, Mandelblatt JS, et al. An exploratory instrumental variable analysis of the outcomes of localized breast cancer treatments in a medicare population. Health Econs 2003; 12 (3): 171–86CrossRef

29.

Polsky D, Basu A. Selection bias in observational data. In: Jones A, editor. Elgar companion to health economics. Cheltenham: Edward Elgar Publishing, 2006: 565

30.

Fenwick E, Marshall DA, Levy AR, et al. Using and interpreting cost-effectiveness acceptability curves: an example using data from a trial of management strategies for atrial fibrillation. BMC Health Services Research 2006; 6: 52PubMedCrossRef

31.

Löthgren M, Zethraeus N. Definition interpretation and calculation of cost-effectiveness acceptability curves. Health Econ 2000; 9: 623–30PubMedCrossRef

32.

Edgell ET, Andersen SW, Johnstone BM, et al. Olanzapine versus risperidone: a prospective comparison of clinical and economic outcomes in schizophrenia. Pharmacoeconomics 2000; 18 (6): 567–79PubMedCrossRef

33.

Rabinowitz J, Lichtenberg P, Kaplan Z. Comparison of cost, dosage and clinical preference for risperidone and olanzapine. Schizophr Res 2000; 46: 91–6PubMedCrossRef

34.

Kasper S, Jones M, Duchesne I. Risperidone Olazapine Drug Outcomes studies in Schizophrenia (RODOS): health economic results of an international naturalistic study. Int Clin Psychopharmacol 2001; 16: 189–96PubMedCrossRef

35.

Kelly DL, Nelson MW, Love RC, et al. Comparison of discharge rates and drug costs for patients with schizophrenia treated with risperidone or olanzapine. Psychiatric Serv 2001; 52 (5): 676–8CrossRef

36.

Windmeijer F, Kontodimas S, Knapp M, et al. Methodological approach for assessing the cost-effectiveness of treatments using longitudinal observational data: the SOHO study. Int J Technol Assess Health Care 2006; 22 (4): 460–8PubMedCrossRef

Title: Comparing the Cost Effectiveness of Risperidone and Olanzapine in the Treatment of Schizophrenia Using the Net-Benefit Regression Approach
Authors: Annemieke De Ridder
Diana De Graeve
Publication date: 01-01-2009
Publisher: Springer International Publishing
Published in: PharmacoEconomics / Issue 1/2009
Print ISSN: 1170-7690
Electronic ISSN: 1179-2027
DOI: https://doi.org/10.2165/00019053-200927010-00007

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Comparing the Cost Effectiveness of Risperidone and Olanzapine in the Treatment of Schizophrenia Using the Net-Benefit Regression Approach

Abstract

Keynote webinar | Spotlight on medication adherence

Springer Medicine

Abstract

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