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Impact of psychotic relapse definitions in assessing drug efficacy and costs: comparison of quetiapine XR, olanzapine and paliperidone ER

Knapp, Martin ORCID: 0000-0003-1427-0215, Locklear, Julie and Jarbrink, Krister (2009) Impact of psychotic relapse definitions in assessing drug efficacy and costs: comparison of quetiapine XR, olanzapine and paliperidone ER. Current Medical Research and Opinion, 25 (7). pp. 1593-1603. ISSN 0300-7995

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Identification Number: 10.1185/03007990903010623


Objective: The objective of this study was to illustrate the implications of using standardised psychotic relapse definitions by comparing published clinical trial relapse and drop-out rates for patients with schizophrenia. Methods: Relapse definitions from three published placebo-controlled clinical trials were standardised to facilitate pair-wise retrospective comparison of relapse outcomes in patients with schizophrenia receiving extended-release quetiapine fumarate (quetiapine XR), paliperidone extended release (paliperidone ER) and olanzapine. Relapse definitions were based on changes in the Positive and Negative Syndrome Scale score, Clinical Global Impression-Severity score and predefined Brief Psychiatric Rating Scale positive items. Economic implications of relapse outcomes were also calculated. A limitation of this study is that this was not a head-to-head comparison. In addition, patient-level data were lacking for the paliperidone ER and olanzapine studies. Results: When the relapse definition from the paliperidone study was applied to the quetiapine XR clinical trial data, 14 quetiapine XR patients (15%) relapsed compared with 23 (22%) in the paliperidone ER study. According to the olanzapine relapse definition, three quetiapine XR patients (3.2%) experienced a relapse compared with nine patients (4.0%) in the olanzapine study. An illustrative calculation of potential economic impact associated with these standardised relapse rates implied incremental expenditures ranging from £74.8 million to £373.9 million (£2006) for paliperidone ER versus quetiapine XR treatment and no material difference with olanzapine. Conclusion: The results show that the definition of relapse has a significant impact on relapse outcomes, and associated economic implications, and that relative drug efficacy can only be considered when results are based on standardised relapse criteria.

Item Type: Article
Official URL:
Additional Information: © 2009 Informa
Divisions: Social Policy
Personal Social Services Research Unit
Subjects: R Medicine > RM Therapeutics. Pharmacology
Date Deposited: 01 Oct 2009 15:49
Last Modified: 12 Apr 2024 16:03

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