Comparative cost-effectiveness of 11 oral antipsychotics for relapse prevention in schizophrenia within Singapore using effectiveness estimates from a network meta-analysis

Abstract

This study modelled the cost-effectiveness of 11 oral antipsychotics for relapse prevention among patients with remitted schizophrenia in Singapore. A network meta-analysis determined the relative efficacy and tolerability of 11 oral antipsychotics (amisulpride, aripiprazole, chlorpromazine, haloperidol, olanzapine, paliperidone, quetiapine, risperidone, sulpiride, trifluoperazine and ziprasidone). The clinical estimates were applied in a Markov model to estimate lifetime costs and quality-adjusted life-years gained. Quality-of-life data were obtained from published literature. Resource utilization and cost data were retrieved from local hospital databases. The annual direct cost of healthcare services for a patient experiencing a relapse episode was three-fold that of a patient not in relapse of schizophrenia. The most favourable pharmacological treatment for relapse prevention was olanzapine with an annual probability of relapse of 0.24 (0.13-0.38) with placebo as a reference of 0.75 (0.73-0.78). Olanzapine emerged as the dominant treatment with the highest quality-adjusted life-years gained and lowest lifetime costs. Ziprasidone, aripiprazole and paliperidone incurred higher lifetime costs compared with no treatment. Probability and cost of relapse were key drivers of cost-effectiveness in sensitivity analyses. The data can help prescribers in choosing appropriate treatment and payers in allocating resources for the clinical management of this serious psychiatric disorder.

Cost/effectiveness of aripiprazole vs. olanzapine in the long-term treatment of schizophrenia

“…In another model done in the United States, olanzapine was also the dominant cost/ effective choice in the treatment of schizophrenia, due to its higher efficiency and lower cost of treatment compared to aripiprazole [13]. Our results are in accordance with the conclusion of the study from Singapore, where olanzapine also proved to be more cost/effective antipsychotic than aripiprazole [14]. The same conclusion about the superiority of a pharmacoeconomic profile of olanzapine was reached in the study by Obradovic et al [15], the focus of which was compliance rate, rehospitalization rate for compliant and non-compliant patients, duration and frequency of hospitalization, and adverse event rate.…”

The Cost of Relapse in Schizophrenia

“…Sixteen papers reported costs of relapse over a defined period of observation (table 1). The studies originated from US (5) [10,[15][16][17][18], UK (1) [19], Germany (2) [20,21], Brazil (1) [22], Singapore (1) [23], China (2) [24,25], Australia (1) [26], and Sweden (1) [27], with the remaining two pan-European [28,29]. All were based on retrospective analysis of clinical or administrative data and used a bottom-up costing approach.…”

“…Thirteen studies allowed calculation of an excess cost of relapse from comparison of data on relapsing and non-relapsing patients [10,[15][16][17][18][19][20][23][24][25][26][27][28] and one paper reported the proportional cost increase associated with relapse without reporting the raw costs [21]. The majority of studies reported costs over one year [10,16,17,20,[22][23][24][25][26]28]; one study reported costs over 15 months [18]; three studies reported costs over 6 months [19,21,27]; one study reported costs over three months [29] and one study reported costs over one week [15]. The majority of studies reported mental health related costs [10,18,19,[21][22][23][25][26][27]29].…”

“…The majority of studies reported costs over one year [10,16,17,20,[22][23][24][25][26]28]; one study reported costs over 15 months [18]; three studies reported costs over 6 months [19,21,27]; one study reported costs over three months [29] and one study reported costs over one week [15]. The majority of studies reported mental health related costs [10,18,19,[21][22][23][25][26][27]29]. Six studies reported all cause health costs [15][16][17]20,24,25], of which three also reported schizophrenia related costs [15,16,20], one study also reported total costs [24], and one study reported all-cause, mental health related and schizophrenia related costs [25].…”

“…One study reported solely schizophrenia related costs [28]. Most studies included adults with a diagnosis of schizophrenia [10,[15][16][17][18][19][20][21][22][23][26][27][28][29]. US studies exploiting administrative data generally identified patients using International Classification of Disease (ICD)-9 codes without excluding schizophreniform and schizoaffective disorder [15][16][17]; German studies used ICD-10 codes which excluded schizophreniform and schizoaffective disorder [20,21].…”