Atypical antipsychotics generally have milder side-effects than conventional antipsychotics, but also differ among themselves in this respect. This study aimed to compare the impact of different side-effect profiles of individual atypical antipsychotics on non-compliance, relapse and cost in schizophrenia. A state-transition model was built using literature data supplemented by expert opinion. The model found that quetiapine and ziprasidone were similar in estimated non-compliance and relapse rates. Olanzapine and risperidone had higher estimated non-compliance and relapse rates, and incremental, 1-year, per-patient direct costs, using US-based cost data, of ~$530 (95% confidence interval [CI] ~$275, $800), and ~$485 (95% CI ~$235, $800), respectively, compared with quetiapine. Incremental costs attributable to different side-effect profiles were highly significant. This study shows that differing side-effect profiles of the newer antipsychotic agents are likely to lead to different compliance rates, and consequent variation in relapse rates. The cost implications of these heterogenous clinical outcomes are substantial.
WeidenPOlfsonM: Cost of relapse in schizophrenia. Schizophr Bull1995; 21: 419–429.
2.
LindstromEBingeforsK: Patient compliance with drug therapy in schizophrenia. Pharmacoeconomics2000; 18: 105–124.
3.
FleischhackerWWMeiseUGuntherVKurzM: Compliance with antipsychotic drug treatment: influence of side effects. Acta Psychiatr Scand1994; 89 (Suppl 382): 11–15.
4.
HummerMFleischhackerW: Compliance and outcome in patients treated with antipsychotics. CNS Drugs1996; 5 (Suppl 1): 13–20.
5.
KampmanOLehtinenK: Compliance in psychoses. Acta Psychiatr Scand1999; 100: 167–175.
AllisonDBMentoreJLHeoMChandlerLPCappelleriJCInfanteMC: Antipsychotic-induced weight gain: a comprehensive research synthesis. Am J Psychiatry1999; 156: 1686–1696.
8.
BarnesTMcPhillipsM: Novel antipsychotics, extrapyramidal side effects and tardive dyskinesia. Int Clin Psychopharmacol1998; 13 (Suppl 3): S49–S57.
9.
AwadAVorugantiL: Quality of life and new antipsychotics in schizophrenia. Are patients better off?Int J Soc Psychiatry1999; 45: 268–275.
LeeET (ed): Statistical Methods for Survival Data Analysis.Belmont, CA: Lifetime Learning Publications, 1980; pp162–167.
12.
JonesARakIRaniwallaJPhungDMelvinK: Weight changes in patients treated with ‘Seroquel’ (quetiapine). Schizophr Res2000; 41: 206.
13.
BrecherMRakIWMelvinKJonesAM: The long-term effect of quetiapine (Seroquel™) monotherapy on weight in patients with schizophrenia. Int J Psychiatr Clin2000; 4: 287–291.
14.
BagnallALewisRLeitnerM: Ziprasidone for schizophrenia and severe mental illness (Cochrane Review, most recently amended August 2000). In: The Cochrane Library, issue 4. Oxford: Update Software, 2000. Available at: http://www.update-software.com/cochrane/default.htm (last accessed 5 January 2001).
15.
DugganLFentonMDardennesRMEl-DosokyAIndranS: Olanzapine for schizophrenia (Cochrane Review, most recently amended October 1999). In: The Cochrane Library, issue 4. Oxford: Update Software, 2000. Available at: http://www.update-software.com/cochrane/default.htm (last accessed 5 January 2001).
16.
GilbodySMBagnallAMDugganLTuunainenA: Risperidone versus other atypical antipsychotic medication for schizophrenia (Cochrane Review, most recently amended May 2000). In: The Cochrane Library, issue 4. Oxford: Update Software, 2000. Available at: http://www.update-software.com/cochrane/default.htm (last accessed 5 January 2001).
17.
KennedyESongFHunterRClarkeAGilbodyS: Risperidone versus conventional antipsychotic medication for schizophrenia (Cochrane Review, most recently amended August 1998). In: The Cochrane Library, issue 4. Oxford: Update Software, 2000. Available at: http://www.update-software.com/cochrane/default.htm (last accessed 5 January 2001).
18.
SrisurapanoutMDisayavanishCTaimkaewK: Quetiapine for schizophrenia (Cochrane Review, most recently amended May 2000). In: The Cochrane Library, issue 4. Oxford: Update Software, 2000. Available at: http://www.update-software.com/cochrane/default.htm (last accessed 5 January 2001).
19.
RaoMGrossGStrebelB: Circadian rhythm of tryptophan, serotonin, melatonin and pituitary hormones in schizophrenia. Biol Psychiatry1994; 35: 151–163.
20.
KleinbergDLDavisJMde CosterRVan BaelenBBrecherM: Prolactin levels and adverse events in patients treated with risperidone. J Clin Psychopharmacol1999; 19: 57–61.
GehanESiddiquiM: Simple regression methods for survival time studies. J Am Stat Assoc1973; 68: 848–856.
23.
GilbertPLHarrisMJMcAdamsLAJesteDV: Antipsychotic withdrawal in schizophrenic patients: a review of the literature. Arch Gen Psychiatry1995; 52: 173–188.
24.
VigueraACBaldessariniRJHegartyJDvan KammenDPTohenM: Clinical risk following abrupt and gradual withdrawal of maintenance antipsychotic treatment. Arch Gen Psychiatry1997; 54: 49–55.
25.
TranPVDellvaMATollefsonGDWentleyALBeasleyCM: Oral olanzapine versus oral haloperidol in the maintenance treatment of schizophrenia and related psychoses. Br J Psychiatry1998; 172: 499–505.
26.
TollefsonGDAndersenSWTranPV: The course of depressive symptoms in predicting relapse in schizophrenia. Biol Psychiatry1999; 46: 365–373.
27.
MooneyCDuvalR (eds): Bootstrapping: a Nonparametric Approach to Statistical Inference.Newbury Park, California: Sage Publications, 1993.
28.
GlazerWEreshefskyL: A pharmacoeconomic model of outpatient antipsychotic therapy in ‘revolving door’ schizophrenic patients. J Clin Psychiatry1996; 57: 337–345.
29.
RosenheckRLeslieDSernyakM: From clinical trials to real-world practice: use of atypical antipsychotic medication nationally in the Department of Veterans Affairs. Med Care2001; 39: 302–308.
30.
AlmondSO'DonnellO: Cost analysis of the treatment of schizophrenia in the UK. Pharmacoeconomics2000; 17: 383–389.
31.
EvansC: The use of consensus methods and expert panels in pharmacoeconomic studies: practical applications and methodological shortcomings. Pharmacoeconomics1997; 12: 121–129.
