Clinical trial response and dropout rates with olanzapine versus risperidone

Antipsychotic type and correlates of antipsychotic treatment discontinuation in the outpatient treatment of schizophrenia

Antipsychotic medication maintenance and the factors influencing it were analyzed using data from the SOHO study, a large observational study of the outcomes of antipsychotic treatment for schizophrenia in Europe. A total of 7186 adult patients in the outpatient setting who were initiating or changing their antipsychotic medication and who were prescribed only one antipsychotic after the baseline visit were analyzed. Medication maintenance at 12 months varied with the type of antipsychotic prescribed, being highest with clozapine (79.5%) and olanzapine (77.0%), and lowest with quetiapine (51.4%) and amisulpride (58.2%). Multiple logistic regression analysis demonstrated that the type of antipsychotic prescribed at baseline was the most important predictor of medication maintenance. Alcohol dependency, taking mood stabilizers, compulsory admission or arrest in the previous 6 months, greater clinical severity, and changing antipsychotic medication due to lack of effectiveness at baseline predicted a higher frequency of medication discontinuation in the subsequent 12 months. In contrast, medication maintenance was higher among patients who were treatment naïve at baseline, socially active or who had loss of libido at baseline. The findings from this study should be interpreted conservatively because of its non-randomized observational design.

Determinants of patient adherence: a review of systematic reviews

PURPOSE

A number of potential determinants of medication non-adherence have been described so far. However, the heterogenic quality of existing publications poses the need for the use of a rigorous methodology in building a list of such determinants. The purpose of this study was a systematic review of current research on determinants of patient adherence on the basis of a recently agreed European consensus taxonomy and terminology.

METHODS

MEDLINE, EMBASE, CINAHL, Cochrane Library, IPA, and PsycINFO were systematically searched for systematic reviews published between 2000/01/01 and 2009/12/31 that provided determinants on non-adherence to medication. The searches were limited to reviews having adherence to medication prescribed by health professionals for outpatient as a major topic.

RESULTS

Fifty-one reviews were included in this review, covering 19 different disease categories. In these reviews, exclusively assessing non-adherence to chronic therapies, 771 individual factor items were identified, of which most were determinants of implementation, and only 47-determinants of persistence with medication. Factors with an unambiguous effect on adherence were further grouped into 8 clusters of socio-economic-related factors, 6 of healthcare team- and system-related factors, 6 of condition-related factors, 6 of therapy-related factors, and 14 of patient-related factors. The lack of standardized definitions and use of poor measurement methods resulted in many inconsistencies.

CONCLUSIONS

This study provides clear evidence that medication non-adherence is affected by multiple determinants. Therefore, the prediction of non-adherence of individual patients is difficult, and suitable measurement and multifaceted interventions may be the most effective answer toward unsatisfactory adherence. The limited number of publications assessing determinants of persistence with medication, and lack of those providing determinants of adherence to short-term treatment identify areas for future research.

Clinical Global Impression of Improvement (CGI-I) as a valid proxy measure for remission in schizophrenia: analyses of ziprasidone clinical study data

OBJECTIVE

To determine the degree to which a proxy measure of remission in schizophrenia correlates with the criteria identified by the Remission in Schizophrenia Working Group, and how well early treatment response to ziprasidone predicts remission.

METHODS

Data from 10 ziprasidone studies were analyzed to determine rates of remission achieved with ziprasidone using a remission definition of Clinical Global Impression of Improvement (CGI-I) of 1, and compared with rates of remission achieved using the remission working group criteria. Positive and Negative Syndrome Scale (PANSS) and Brief Psychiatric Rating Scale (BPRS) scores were then investigated as predictors of remission.

RESULTS

A CGI-I score of 1 correlated with the remission criteria developed by the remission working group. In the combined ziprasidone arms, BPRS scores at Weeks 1, 3, and 4 successfully predicted PANSS remission (p<0.01) and BPRS remission (p<0.0001) at study endpoint (44-196weeks). PANSS scores (at Weeks 1, 3, and 4) successfully predicted PANSS remission (p<0.01) at study endpoint. PANSS scores at Week 3 successfully predicted BPRS remission (p=0.02) at study endpoint. A CGI-I score of 1 or 2 at Week 1 also successfully predicted remission in schizophrenia.

CONCLUSION

The findings show a correlation between clinical and research scales (remission working group criteria) for the assessment of remission in schizophrenia. This proxy measure for the assessment of remission should be easy to apply in a clinical setting and facilitates the prediction of remission in schizophrenia.

Adherence to treatment and therapeutic strategies in schizophrenic patients: the ADHERE study

AIM

To assess the degree of compliance and adherence to treatment during the follow-up of schizophrenic outpatients after a new therapeutic strategy had been initiated.

METHODS

A multicenter, retrospective, prospective, observational study of 1,848 outpatients with schizophrenia or schizoaffective disorders (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria) was conducted. Patients were treated either with oral or injectable conventional or second generation antipsychotics, and were followed up for 3 months at mental health centers. Patient compliance with the pharmacological treatment was assessed by the use of questionnaires, scales, medication accountability, and the Medication Event Monitoring System. Patients were considered compliant if they reported a high compliance rate (> or = 80%).

RESULTS

At baseline only 29% of patients on oral medication were compliant compared with 79% of patients on injectable medication (injection counting) (OR= 9.11; 95% CI 6.02-13.77; P<.0001). At the 3 month visit, 84% of patients had changed their treatment and in these, the compliance rate of those on injectable medication was 94% versus 87% of patients taking oral medication (OR= 2.47; 95% CI 1.21-5.05; P=.022).

CONCLUSION

The use of long-acting injectable antipsychotics, which improves compliance rates and patient follow-up, should facilitate the management of Spanish patients with schizophrenia in mental health centers.

Cost-effectiveness model comparing olanzapine and other oral atypical antipsychotics in the treatment of schizophrenia in the United States

BACKGROUND

Schizophrenia is often a persistent and costly illness that requires continued treatment with antipsychotics. Differences among antipsychotics on efficacy, safety, tolerability, adherence, and cost have cost-effectiveness implications for treating schizophrenia. This study compares the cost-effectiveness of oral olanzapine, oral risperidone (at generic cost, primary comparator), quetiapine, ziprasidone, and aripiprazole in the treatment of patients with schizophrenia from the perspective of third-party payers in the U.S. health care system.

METHODS

A 1-year microsimulation economic decision model, with quarterly cycles, was developed to simulate the dynamic nature of usual care of schizophrenia patients who switch, continue, discontinue, and restart their medications. The model captures clinical and cost parameters including adherence levels, relapse with and without hospitalization, quality-adjusted life years (QALYs), treatment discontinuation by reason, treatment-emergent adverse events, suicide, health care resource utilization, and direct medical care costs. Published medical literature and a clinical expert panel were used to develop baseline model assumptions. Key model outcomes included mean annual total direct cost per treatment, cost per stable patient, and incremental cost-effectiveness values per QALY gained.

RESULTS

The results of the microsimulation model indicated that olanzapine had the lowest mean annual direct health care cost ($8,544) followed by generic risperidone ($9,080). In addition, olanzapine resulted in more QALYs than risperidone (0.733 vs. 0.719). The base case and multiple sensitivity analyses found olanzapine to be the dominant choice in terms of incremental cost-effectiveness per QALY gained.

CONCLUSION

The utilization of olanzapine is predicted in this model to result in better clinical outcomes and lower total direct health care costs compared to generic risperidone, quetiapine, ziprasidone, and aripiprazole. Olanzapine may, therefore, be a cost-effective therapeutic option for patients with schizophrenia.

Adherence and persistence to typical and atypical antipsychotics in the naturalistic treatment of patients with schizophrenia

OBJECTIVE

To compare adherence and persistence to typical versus atypical antipsychotics and between specific atypical agents in the usual care of schizophrenia and to examine the association between adherence and persistence.

METHOD

Data were drawn from a 3-year prospective, nonrandomized, noninterventional study of schizophrenia conducted during 1997-2003. Initiators on haloperidol, risperidone, olanzapine, quetiapine, and clozapine with at least 1 year of follow-up were included (n = 878). Adherence (Medication Possession Ratio, MPR) and persistence (time to all-cause medication discontinuation) were assessed using medical record prescription information. Analyses employed multivariate statistics adjusted for group differences.

RESULTS

Overall, 58% of the patients were deemed adherent (MPR >80%). Adherence rates were higher: for atypical (59.4%) than typical antipsychotics (34.5%, p < 0.001), for clozapine (77%) than each comparator excluding olanzapine (p < 0.01), and for olanzapine (64%) than risperidone (57%, p = 0.027) and quetiapine (52%, p = 0.019). Differences between risperidone and quetiapine were not statistically significant. Adherence and persistence were highly correlated (r = 0.957, p < 0.001).

CONCLUSION

In the usual care of schizophrenia, medication adherence and persistence appear to be highly correlated and to significantly differ between typical and atypical antipsychotics and among atypical agents. The choice of antipsychotic may play a meaningful role in patients' adherence to and persistence with antipsychotic medications.

Risk of discontinuation of atypical antipsychotic agents in the treatment of schizophrenia

OBJECTIVES

To compare discontinuation rates of atypical antipsychotic agents in patients with schizophrenia.

METHOD

Adult Maryland Medicaid patients with schizophrenia were categorized based on initial atypical antipsychotic drug received: aripiprazole (n=446); olanzapine (n=1705); quetiapine (n=1467); risperidone (n=1580); and ziprasidone (n=700). Discontinuation was measured using refill patterns, allowing 14-day gaps between refill dates. Using olanzapine as the reference drug, the hazard of discontinuation within the first year of follow-up was compared across atypicals using Cox proportional hazard models adjusted for demographic and clinical covariates. Sensitivity analysis tested the robustness of results by using different definitions of the index date.

RESULTS

At one-year follow-up, most patients discontinued their antipsychotic medication (90.4% adjusted mean discontinuation). The hazard ratio (HR) for discontinuing therapy in patients starting treatment on aripiprazole, risperidone, or ziprasidone was not significantly different from olanzapine [HR 1.047, 0.973 and 0.990, respectively]. Quetiapine was associated with significantly higher hazard of discontinuation [HR 1.130] than olanzapine. Covariates associated with significantly lower discontinuation were being male [HR 0.899], older age [HR 0.997] and being on concurrent medication when initiating therapy [HR 0.225]; having a previous hospitalization was associated with significantly higher discontinuation hazard [HR 1.276]. Results were robust in the sensitivity analysis.

CONCLUSIONS

Discontinuation rates were high at one-year follow-up and did not differ significantly for patients on aripiprazole, olanzapine, risperidone, or ziprasidone. The higher hazard of discontinuation associated with quetiapine when compared to olanzapine is consistent with that observed in Phase I of the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE).

All-cause treatment discontinuation in schizophrenia during treatment with olanzapine relative to other antipsychotics: an integrated analysis

OBJECTIVES

Treatment continuation, as measured by time to all-cause treatment discontinuation, is a broad measure of overall treatment effectiveness. This integrated analysis compared the likelihood of discontinuation from olanzapine treatment versus other antipsychotics among patients with schizophrenia.

METHODS

Clinical trials of all sponsors were included if they met the following criteria: double-blind, randomized, comparative; duration of 12 weeks or longer; no mandatory discontinuation before 12 weeks; and schizophrenia-spectrum disorders; 20 patients or more per treatment. Weighted mean hazard ratios and 95% confidence intervals were calculated from discontinuation time. Meta-analyses were performed for the following comparators that had at least 2 studies: haloperidol (5 studies), risperidone (5 studies), ziprasidone (2 studies), clozapine (3 studies), and perphenazine (2 studies) (13 studies in total; 3 included more than 1 comparator). Only 1 eligible published study was found for fluphenazine, amisulpride, and quetiapine; therefore, meta-analyses could not be performed for these comparators.

RESULTS

Significantly (P < 0.05) greater likelihood of discontinuation relative to olanzapine treatment (hazard ratio [95% confidence interval]) was observed for haloperidol (1.4 [1.2-1.7]), risperidone (1.3 [1.1-1.6]), ziprasidone (1.6 [1.4-2.0]), and quetiapine (1.4 [1.1-1.9]), but not clozapine (1.2 [0.9-1.6]), fluphenazine (1.8 [0.8-4.3]), perphenazine (1.3 [0.7-2.1]), or amisulpride (1.1 [0.8-1.6]).

CONCLUSIONS

These data suggest that patients with schizophrenia and related disorders may continue olanzapine treatment longer than haloperidol, risperidone, ziprasidone, or quetiapine treatment.

An examination of factors affecting persistence with initial antipsychotic treatment in patients with schizophrenia

OBJECTIVES

During a schizophrenia treatment episode, persistence with the initial antipsychotic may indicate optimal pharmacotherapy and be a precursor to longer-term effectiveness and other positive outcomes. The objective of this study was to examine the ability of selected variables to predict antipsychotic persistence among patients receiving olanzapine or risperidone as initial treatment.

RESEARCH DESIGN AND METHODS

Data for this analysis, which was not defined in the original study protocol, came from a naturalistic, randomized, open-label trial comparing costs and effectiveness of first-line antipsychotic treatment options in schizophrenia. Predictor variables were as follows: (1) patients' initial antipsychotic (olanzapine [n = 222] or risperidone [n = 218]); (2) current (within 30 days) comorbid diagnosis of substance abuse; and (3) nine self-report items from the Rating of Medication Influence (ROMI) scale, including an item assessing patients' perceptions of the role of their therapeutic alliance in their adherence.

MAIN OUTCOME MEASURES

For the primary analysis, a stepwise logistic regression was used in predicting antipsychotic persistence of at least 180 days. Variables found to be significantly predictive were included in a second analysis that assessed persistence at additional thresholds (> 90 days, > 270 days, and completion of the 1-year study).

RESULTS

Four variables predicted longer antipsychotic persistence; olanzapine as initial antipsychotic (p = 0.004), absence of comorbid substance abuse (p = 0.025), and two of the ROMI items representing patients' subjective response to treatment--positive relationship with clinical staff (p = 0.048) and fulfillment of life goals (p = 0.050).

CONCLUSIONS

Within a randomized trial design, this study corroborated the influence of several factors on antipsychotic persistence in schizophrenia. Results support the importance of the initial antipsychotic treatment option, presence of a comorbid substance abuse diagnosis, and the role of patients' subjective responses. Additional research is needed to further explore these and other factors as predictors of antipsychotic persistence, and of subsequent treatment outcomes.

Differential rates of treatment discontinuation in clinical trials as a measure of treatment effectiveness for olanzapine and comparator atypical antipsychotics for schizophrenia

Antipsychotic treatment discontinuation can be used to measure overall treatment effectiveness. Our goal was to investigate differential treatment discontinuation comparing olanzapine with other atypical antipsychotics. A post hoc pooled analysis of 4 randomized, double-blind, 24- to 28-week schizophrenia clinical trials included 822 olanzapine-treated and 805 risperidone-, quetiapine-, or ziprasidone-treated patients. A checklist was used to record the reason for discontinuation. Treatment differences were assessed between olanzapine and the other 3 antipsychotics combined. Poor response/symptom worsening was the primary reason for discontinuation, regardless of medication. The rate of discontinuation due to poor response/symptom worsening significantly varied by treatment (olanzapine, 14.23%, vs. other atypical antipsychotics, 24.60%; P < 0.0001). The rate of discontinuation due to intolerability of medication did not significantly vary by treatment (olanzapine, 5.60%, vs. other atypical antipsychotics, 7.45%; P = 0.13). Consequent to the differential rates of discontinuation due to poor response/symptom worsening, the olanzapine-treated patients experienced a significantly greater likelihood of overall treatment completion (53.9% vs. 39.3%; P < 0.001) and a significantly longer duration of treatment (19.1 vs. 16.1 weeks; P < 0.0001) than other atypical-treated patients. The predominant reason for the significantly lower discontinuation rate of treatment for patients taking olanzapine compared with that of patients taking other atypical antipsychotics was the significantly higher dropout rates in other atypical antipsychotics because of poor response/symptom worsening.

Cognitive improvement in schizophrenic patients does not require a serotonergic mechanism: randomized controlled trial of olanzapine vs amisulpride

Combined serotonin-2A (5-HT(2A)) and dopamine-2 (D2) receptor blockade has been proposed as a candidate mechanism by which second-generation antipsychotics (SGAs) improve both cognition and negative symptoms in schizophrenic patients, in contrast to antipsychotics of the first generation. The SGA amisulpride, however, only binds to D2/D3 receptors, which makes it an interesting tool to test this assumption. In a randomized controlled trial, 52 schizophrenic patients were allocated to treatment with either olanzapine (10-20 mg/day) or amisulpride (400-800 mg/day). A comprehensive neuropsychological test battery and clinical ratings were used to assess participants at inclusion and after 4 and 8 weeks. Cognitive improvements of moderate size were observed, with effect sizes similar to those obtained in previous studies on the cognitive effects of SGAs. Importantly, amisulpride was not inferior to olanzapine for any cognitive domain. Combined 5-HT(2A)/D2 receptor blockade is probably not necessary for cognitive improvement by SGAs.

A comparison of olanzapine and risperidone on the risk of psychiatric hospitalization in the naturalistic treatment of patients with schizophrenia

Background

Decreasing hospital admissions is important for improving outcomes for people with schizophrenia and for reducing cost of hospitalization, the largest expenditure in treating this persistent and severe mental illness. This prospective observational study compared olanzapine and risperidone on one-year psychiatric hospitalization rate, duration, and time to hospitalization in the treatment of patients with schizophrenia in usual care.

Methods

We examined data of patients newly initiated on olanzapine (N = 159) or risperidone (N = 112) who continued on the index antipsychotic for at least one year following initiation. Patients were participants in a 3-year prospective, observational study of schizophrenia patients in the US. Outcome measures were percent of hospitalized patients, total days hospitalized per patient, and time to first hospitalization during the one-year post initiation. Analyses employed a generalized linear model with adjustments for demographic and clinical variables. A two-part model was used to confirm the findings. Time to hospitalization was measured by the Kaplan-Meier survival formula.

Results

Compared to risperidone, olanzapine-treated patients had significantly lower hospitalization rates, (24.1% vs. 14.4%, respectively, p = 0.040) and significantly fewer hospitalization days (14.5 days vs. 9.9 days, respectively, p = 0.035). The mean difference of 4.6 days translated to $2,502 in annual psychiatric hospitalization cost savings per olanzapine-treated patient, on average.

Conclusions

Consistent with prior clinical trial research, treatment-adherent schizophrenia patients who were treated in usual care with olanzapine had a lower risk of psychiatric hospitalization than risperidone-treated patients. Lower hospitalization costs appear to more than offset the higher medication acquisition cost of olanzapine.

Comparison of risperidone and olanzapine as used under "real-world" conditions in a state psychiatric hospital

As a follow-up to our previous study of clozapine, medical records of a state psychiatric hospital were reviewed for patients who were prescribed an atypical antipsychotic. From that sample, demographic and clinical data were obtained for individuals with an initial score of 35 or greater on the Brief Psychiatric Rating Scale (BPRS), and at least two additional successive monthly BPRS ratings. A total of 100 patients met the criteria. Most received either olanzapine (46%) or risperidone (36%), with few administered quetiapine (11%) or clozapine (7%). Most also received adjunctive medications, including conventional antipsychotics, anticonvulsants/mood stabilizers, antidepressants, and antiparkinsonian agents. The number of patients whose BPRS total scores decreased by 20% or more from baseline was significantly greater for those who received olanzapine than those who received risperidone. However, there was no difference between the two antipsychotics in the number of patients who maintained that degree of improvement, in the average latency to achieve that decrease (1.67 and 1.47 months, respectively), or the average length of stay (LOS; 332 and 376 days, respectively). These results indicate a modest therapeutic advantage of olanzapine compared to risperidone, and a substantial degree of polypharmacy in the use of atypical antipsychotics. This uncontrolled "real-world" evaluation supports data from controlled clinical trials, showing that either risperidone or olanzapine would be a reasonable first choice in patients with treatment-resistant schizophrenia, with the decision based on the least adverse side effect profile and economic constraints. When compared to our previous clozapine study, we confirm a slight advantage for the effectiveness of clozapine in the treatment of this refractory population.

Dropout rates with olanzapine or risperidone: a multi-centre observational study

OBJECTIVE

In patients with schizophrenia, risperidone and olanzapine are the two most commonly used atypical anti-psychotics. A recent meta-analysis based on randomized trials suggests that, in the long term, olanzapine can have a lower frequency of treatment discontinuation (or dropout) in comparison with risperidone. To better test this hypothesis, our observational study was aimed at assessing whether or not this advantage of olanzapine versus risperidone could be confirmed in a patient series examined in an observational setting.

METHODS

Our study was based on a retrospective multi-centre observational design. We collected the following information from each patient: demographic characteristics; current anti-psychotic treatment (olanzapine or risperidone, under the condition of a stable therapy over months -1 to -4); cumulative dose of the drug; previous anti-psychotic treatment (during months -5, -6, -7 and/or, when available, also before month -7); daily dose and treatment duration. Our primary analysis traced back the patient's history from the date of enrollment retrospectively up to month -7. The secondary analysis followed-up the patient's history prior to month -7, thus extending this retrospective recording as long as possible (depending on what information was actually available for individual patients).

RESULTS

The patients were enrolled from 31 institutions. In our primary analysis (months -1 to -7), a total of 144 patients were included; in this subgroup treated with olanzapine or risperidone as initial drug ( n=94), we observed 4 of 54 switches from olanzapine to risperidone and 11 of 40 switches from risperidone to olanzapine ( P=0.01). A total of 454 patients were enrolled in our secondary analysis (from month -1 up to month -73); the same comparison showed 9 of 236 switches from olanzapine to risperidone and 17 of 150 switches from risperidone to olanzapine ( P=0.004).

CONCLUSION

Our analysis confirms the results of a recent meta-analysis and shows that olanzapine might imply a lower risk of dropout than risperidone.