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Assessing cost-effectiveness of drug interventions for schizophrenia

journal contribution
posted on 01.01.2005, 00:00 authored by Annette Magnus, V Carr, Cathy Mihalopoulos, Rob CarterRob Carter, T Vos
Objective: To assess from a health sector perspective the incremental cost-effectiveness of eight drug treatment scenarios for established schizophrenia.

Method: Using a standardized methodology, costs and outcomes are modelled over the lifetime of prevalent cases of schizophrenia in Australia in 2000. A two-stage approach to assessment of health benefit is used. The first stage involves a quantitative analysis based on disability-adjusted life years (DALYs) averted, using best available evidence. The robustness of results is tested using probabilistic uncertainty analysis. The second stage involves application of 'second filter' criteria (equity, strength of evidence, feasibility and acceptability) to allow broader concepts of benefit to be considered.

Results: Replacing oral typicals with risperidone or olanzapine has an incremental costeffectiveness ratio (ICER) of A$48 000 and A$92 000/DALY respectively. Switching from low-dose typicals to risperidone has an ICER of A$80 000. Giving risperidone to people experiencing side-effects on typicals is more cost-effective at A$20 000. Giving clozapine to people taking typicals, with the worst course of the disorder and either little or clear deterioration, is cost-effective at A$42 000 or A$23 000/DALY respectively. The least costeffective intervention is to replace risperidone with olanzapine at A$160 000/DALY.

Conclusions: Based on an A$50 000/DALY threshold, low-dose typical neuroleptics are indicated as the treatment of choice for established schizophrenia, with risperidone being reserved for those experiencing moderate to severe side-effects on typicals. The more expensive olanzapine should only be prescribed when risperidone is not clinically indicated. The high cost of risperidone and olanzapine relative to modest health gains underlie this conclusion. Earlier introduction of clozapine however, would be cost-effective. This work is limited by weaknesses in trials (lack of long-term efficacy data, quality of life and consumer satisfaction evidence) and the translation of effect size into a DALY change. Some stakeholders, including SANE Australia, argue the modest health gains reported in the literature do not adequately reflect perceptions by patients, clinicians and carers, of improved quality of life with these atypicals.

History

Journal

Australian & New Zealand Journal of Psychiatry

Volume

39

Issue

1-2

Pagination

44 - 54

Publisher

Wiley Interscience

Location

Malden, Mass.

ISSN

0004-8674

eISSN

1440-1614

Language

eng

Publication classification

C1.1 Refereed article in a scholarly journal

Copyright notice

2006 The Authors; Journal compilation and The Royal Australian and New Zealand College of Psychiatrists