Comparing the cost effectiveness of risperidone and olanzapine in the treatment of schizophrenia using the net-benefit regression approach

On the Use of Markov Models in Pharmacoeconomics: Pros and Cons and Implications for Policy Makers

We present an overview of the main methodological features and the goals of pharmacoeconomic models that are classified in three major categories: regression models, decision trees, and Markov models. In particular, we focus on Markov models and define a semi-Markov model on the cost utility of a vaccine for Dengue fever discussing the key components of the model and the interpretation of its results. Next, we identify some criticalities of the decision rule arising from a possible incorrect interpretation of the model outcomes. Specifically, we focus on the difference between median and mean ICER and on handling the willingness-to-pay thresholds. We also show that the life span of the model and an incorrect hypothesis specification can lead to very different outcomes. Finally, we analyse the limit of Markov model when a large number of states is considered and focus on the implementation of tools that can bypass the lack of memory condition of Markov models. We conclude that decision makers should interpret the results of these models with extreme caution before deciding to fund any health care policy and give some recommendations about the appropriate use of these models.

Cost-effectiveness analysis of olanzapine and risperidone in schizophrenic patients in the Indian healthcare settings of Andhra Pradesh, India

Objectives

The prevalence of schizophrenia in Andhra Pradesh, India is 279, and the crude disability-adjusted life year is 177 per 100 thousand people. It is one of the major mental health problems of the state. However, there is a dearth of information regarding the pharmacoeconomics of schizophrenia treatment. The purpose of this study was to evaluate the cost and effectiveness of the two most commonly used drugs olanzapine and risperidone for schizophrenia.

Methods

A prospective observational study was carried out in a tertiary care teaching hospital (Department of psychiatry) for a period of 1 year among 124 schizophrenia patients. The data were collected in a specially designed patient data form, and the cost and effectiveness of the treatment were evaluated. Then, the ICER for olanzapine 71 and risperidone 53 users were calculated. Sensitivity analysis was run creating a model to identify uncertainties and its effect on the results.

Key findings

The mean cost per patient for olanzapine was 89.96 USD, and risperidone was 85.56 USD for 8 weeks from the start of the treatment. The incremental effects and value of the treatment score with the Positive and Negative Syndrome Scale (PANSS) for olanzapine (27.33) were greater than that of risperidone (20.38). The cost (USD) per PANSS reduction for olanzapine was 3.29 and risperidone was 4.20. The overall incremental cost-effectiveness ratio (ICER) of olanzapine compared to risperidone was 0.63 USD/PANSS.

Conclusion

The results showed that olanzapine was a cost-effective drug and an alternative to risperidone in the Indian healthcare settings. With further revision and validation, the cost-effectiveness outcome of olanzapine and risperidone can be used to inform any comprehensive healthcare financing mechanism in Indian healthcare settings.

Who Benefits Most from Collaborative Dementia Care from a Patient and Payer Perspective? A Subgroup Cost-Effectiveness Analysis

BACKGROUND

Dementia care management (DCM) aims to provide optimal treatment for people with dementia (PwD). Treatment and care needs are dependent on patients' sociodemographic and clinical characteristics and thus, economic outcomes could depend on such characteristics.

OBJECTIVE

To detect important subgroups that benefit most from DCM and for which a significant effect on cost, QALY, and the individual cost-effectiveness could be achieved.

METHODS

The analysis was based on 444 participants of the DelpHi-trial. For each subgroup, the probability of DCM being cost-effective was calculated and visualized using cost-effectiveness acceptability curves. The impact of DCM on individual costs and QALYs was assessed by using multivariate regression models with interaction terms.

RESULTS

The probability of DCM being cost-effective at a willingness-to-pay of 40,000€ /QALY was higher in females (96% versus 16% for males), in those living alone (96% versus 26% for those living not alone), in those being moderately to severely cognitively (100% versus 3% for patients without cognitive impairment) and functionally impaired (97% versus 16% for patients without functional impairment), and in PwD having a high comorbidity (96% versus 26% for patients with a low comorbidity). Multivariate analyses revealed that females (b = -10,873; SE = 4,775, p = 0.023) who received the intervention had significantly lower healthcare cost. DCM significantly improved QALY for PwD with mild and moderate cognitive (b = +0.232, SE = 0.105) and functional deficits (b = +0.200, SE = 0.095).

CONCLUSION

Patients characteristics significantly affect the cost-effectiveness. Females, patients living alone, patients with a high comorbidity, and those being moderately cognitively and functionally impaired benefit most from DCM. For those subgroups, healthcare payers could gain the highest cost savings and the highest effects on QALYs when DCM will be implemented.

Systematic Literature Review of the Methods Used to Compare Newer Second-Generation Agents for the Management of Schizophrenia: A focus on Health Technology Assessment

BACKGROUND

The challenges of comparative effectiveness to support health technology assessment (HTA) agencies are important considerations in the choices of antipsychotic medications for the treatment of schizophrenia.

OBJECTIVES

Our aim was to assess the study methods used and outcomes reported in the published literature to address the question of comparative effectiveness of newer antipsychotic agents and the adequacy and availability of evidence to support HTA agencies.

DATA SOURCE

A systematic search of the PubMed database from 1 January 2009 to 30 September 2013 was conducted to identify studies evaluating new atypical antipsychotics reporting on comparative effectiveness.

STUDY SELECTION

The systematic review comprised of studies on schizophrenia patients where at least two drugs were being compared and at least one treatment group received one of the following second-generation antipsychotics: risperidone, olanzapine, aripiprazole, paliperidone, asenapine, iloperidone, lurasidone, and quetiapine. The included studies were also required to have an efficacy, safety or economic outcome, such as Positive and Negative Syndrome Scale (PANSS) score, weight gain, resource utilization, or costs.

STUDY APPRAISAL AND SYNTHESIS METHODS

Two reviewers (BW and GK) independently applied the inclusion criteria. Disagreements between reviewers were resolved by consensus, referring to the original sources. Information on the methodology and outcomes was collected for each included study. This included study description, head-to-head drug comparison, patient population, study methodology, statistical methods, reported outcomes, study support, and journal type.

RESULTS

A total of 198 studies were identified from electronic search methods. The largest category of studies was randomized controlled trials [RCTs] (N = 73; 36.9%), which were largely directed at the regulatory endpoint. Fewer studies were undertaken for HTA-purposes cohort studies (N = 53; 26.8%), meta-analyses (N = 32; 16.2%), economic studies (N = 14; 7.1%), and cross-sectional studies (N = 13; 6.6%). Direct head-to-head comparisons preferred by HTA were dominated by the comparison involving olanzapine and risperidone, representing 149 (75.3%) and 119 (60.1%) studies, respectively. RCTs, which are the primary study type for regulatory submissions, showed a lack of bias. Studies aimed at HTA were not as well performed. Cohort studies suffered from bias in the selection of comparison groups, lack of control for confounders, and differential dropout rates. As a group, cross-sectional studies scored poorly for bias, with a primary failure to identify a representative sample. Economic studies showed highly variable bias, with bias in the representation of effectiveness data, model assumptions without validation, and lack of sensitivity analyses.

LIMITATIONS

One limitation of this systematic review is that it only included studies from 2009 to 2013, potentially excluding some earlier comparator studies, particularly those involving first-generation antipsychotics.

CONCLUSIONS

This review of comparative effectiveness studies of second-generation antipsychotic agents for schizophrenic patients revealed a wide range of study types, study methodologies, and outcomes. For traditional efficacy outcomes and select safety outcomes, there is strong evidence from many well-conducted studies; however, there are fewer studies of types preferred by HTA with limited head-to-head comparisons and a higher risk of bias in the execution of these studies.

The estimation of utility weights in cost-utility analysis for mental disorders: a systematic review

OBJECTIVE

To systematically review approaches and instruments used to derive utility weights in cost-utility analyses (CUAs) within the field of mental disorders and to identify factors that may have influenced the choice of the approach.

METHODS

We searched the databases DARE (Database of Abstracts of Reviews of Effects), NHS EED (National Health Service Economic Evaluation Database), HTA (Health Technology Assessment), and PubMed for CUAs. Studies were included if they were full economic evaluations and reported quality-adjusted life-years as the health outcome. Study characteristics and instruments used to estimate utility weights were described and a logistic regression analysis was conducted to identify factors associated with the choice of either the direct (e.g. standard gamble) or the preference-based measure (PBM) approach (e.g. EQ-5D).

RESULTS

We identified 227 CUAs with a maximum in 2009, 2010, and 2012. Most CUAs were conducted in depression, dementia, or psychosis, and came from the US or the UK, with the EQ-5D being the most frequently used instrument. The application of the direct approach was significantly associated with depression, psychosis, and model-based studies. The PBM approach was more likely to be used in recent studies, dementia, Europe, and empirical studies. Utility weights used in model-based studies were derived from only a small number of studies.

LIMITATIONS

We only searched four databases and did not evaluate the quality of the included studies.

CONCLUSIONS

Direct instruments and PBMs are used to elicit utility weights in CUAs with different frequencies regarding study type, mental disorder, and country.

Validation of an economic model of paliperidone palmitate for chronic schizophrenia

OBJECTIVE

Model validation is important, but seldom applied in chronic schizophrenia. Validation consists of verifying the model itself for face validity (i.e., structure and inputs), cross-validation with other models assessing the same issue, and comparison with real-life outcomes. The primary purpose was to cross-validate a recent pharmacoeconomic model comparing long-acting injectable (LAI) antipsychotics for treating chronic schizophrenia in Sweden. The secondary purpose was to provide external validation.

METHODS

The model of interest was a decision tree analysis with a 1-year time horizon with costs in 2011 Swedish kroner. Drugs analyzed included paliperidone palmitate (PP-LAI), olanzapine pamoate (OLZ-LAI), risperidone (RIS-LAI), haloperidol (HAL-LAI), and oral olanzapine (oral-OLZ). Embase and Medline were searched from 1990-2012 for models examining LAIs. Articles were retrieved, with data extracted for all drugs compared including: expected costs, rates of hospitalization, proportion of time not in relapse, and associated QALYs. Outcomes from the model of interest were compared with those from other articles; costs were projected to 2012 using the consumer price index.

RESULTS

Twenty-six studies were used for validation; 14 of them provided evidence for cross-validation, 13 for external validation, and four for cost. In cross-validation, cost estimates varied -1.8% (range: -12.4-20.1%), hospitalizations 5.2% (-12.1-3.1%), stable disease 2.5% (-5.6-1.5%), QALYs 9.0% (4.3% after removing outliers). All estimates of clinical outcomes were within 15%. In external validation, hospitalization rates varied by 6.3% (-0.7-11.3%). The research was limited by data availability and validity of the original results.

CONCLUSION

Other models validated the outputs of our model very well.

How Much Are We Willing to Pay to Prevent A Fall? Cost-Effectiveness of a Multifactorial Falls Prevention Program for Community-Dwelling Older Adults

Cette étude a examiné le rapport coût-efficacité d’un programme multifactoriel de prévention des chutes et a évalué le compromis entre les coûts supplémentaires d’un tel programme et une augmentation de la réduction des chutes accidentelles. Le rapport coût-efficacité a été évalué en utilisant le rapport coût-efficacité différentiel traditionnel (RCED) et cadre de régression de l’avantage net (CRAN). En utilisant du CRAN, la prise de décision a été officialisée par l’incorporation, a priori, d’une predisposition à payer (PAP). Les résultats n’ont pas fourni preuve qu’un programme multifactoriel de prévention des chutes a été rentable. L’adhésion des participants au recommandations allaient de faible (41,3%) à modéré (21,1%), à élevé (37,6%). Un défi futur sera de comprendre plus clairement la relation entre la personne âgée qui habite à une communauté avec les risques de chutes qui sont potentiellement modifiables, le respect des recommandations concernant les facteurs de risque multifactoriels, les coûts, et les effets qui en résultent de pratiques pour prévenir les chutes. Les futures évaluations économiques des interventions pour éviter les chutes restent nécessaires et devraient tenir compte du CRAN afin que les outils de régression puissent faciliter l’analyse coût-efficacité.

A review and critique of studies reporting utility values for schizophrenia-related health states

Economic evaluation of health technologies in the form of cost-utility analysis is increasingly advocated. The most common outcome measure in this type of analysis is the QALY. In order to estimate QALYs, appropriate utility values are required. The objective of this review was to identify and critique utility values for schizophrenia-related health states. A critical appraisal was performed on utility values for schizophrenia identified in the systematic literature review that informed the economic analysis of the updated edition of the National Institute for Health and Clinical Excellence (NICE) clinical guideline on schizophrenia for England and Wales. Seven studies reporting utility values for schizophrenia were identified. The studies employed a variety of methods for generating utility values. None of the reported sets of utility values for schizophrenia were generated using the EQ-5D, which is a measure widely used in cost-utility analysis and preferred by NICE. Nevertheless, the EQ-5D may be less sensitive in capturing aspects of health-related quality of life in patients with schizophrenia. A condition-specific preference-based instrument may be more appropriate than a generic measure to inform cost-utility analyses of interventions for schizophrenia.