Systematic review of the methods of health economic models assessing antipsychotic medication for schizophrenia

Cost-effectiveness analysis of physical activity interventions for people with schizophrenia or bipolar disorder: systematic review

BACKGROUND

Clinical guidelines recommend providing physical activity interventions (PAIs) to people with schizophrenia or bipolar disorder for weight management. However, the cost-effectiveness of PAIs is unknown.

AIMS

To evaluate the availability and methodological quality of economic evaluations of PAIs for people with schizophrenia or bipolar disorder.

METHOD

Four databases (MEDLINE, Embase, PsycInfo and Scopus) were searched on 5 July 2022. Based on the retrieved studies, forward and backward citation searches were conducted. Two reviewers independently selected studies for inclusion. Study quality was assessed using the Drummond checklist. Review results were presented using narrative synthesis.

RESULTS

Fourteen articles reporting nine studies were included. All included studies assessed PAIs within a multicomponent lifestyle intervention. Mixed findings were reported on the cost-effectiveness of multicomponent lifestyle intervention: three studies reported it as cost-effective; four studies reported it as not cost-effective; and two studies did not conclude whether it was cost-effective or not. Very limited evidence suggests that certain patient subgroups might be more likely to benefit from multicomponent lifestyle interventions with a PAI component: men; individuals with comorbid type 2 diabetes; and individuals who have been psychiatric hospital in-patients for ≥1 year. The quality of included studies ranged from moderate to high.

CONCLUSIONS

The current economic evidence suggests that not all modalities of multicomponent lifestyle intervention including a PAI component are cost-effective for people with schizophrenia or bipolar disorder; and not all people with schizophrenia or bipolar disorder would benefit equally from the intervention. Future research is urgently needed to identify the cost-effective modality of PAI for different patient subgroups.

Appraisals by Health Technology Assessment Agencies of Economic Evaluations Submitted as Part of Reimbursement Dossiers for Oncology Treatments: Evidence from Canada, the UK, and Australia

Publicly funded healthcare systems, including those in Canada, the United Kingdom (UK), and Australia, often use health technology assessment (HTA) to inform drug reimbursement decision-making, based on dossiers submitted by manufacturers, and HTA agencies issue publicly available reports to support funding recommendations. However, the level of information reported by HTA agencies in these reports may vary. To provide insights on this issue, we describe and assess the reporting of economic methods in recent oncology HTA recommendations from the Canadian Agency for Drugs and Technologies in Health (CADTH), National Institute for Health and Care Excellence (NICE), and Pharmaceutical Benefits Advisory Committee (PBAC). Publicly available HTA recommendations and reports for oncology drugs issued by CADTH over a 2-year period, 2019-2020, were identified and compared with the corresponding HTA documents from NICE and the PBAC. Reporting of key model characteristics and attributes, survival analysis methods, methodological criticisms, and re-assessment of the economic results were characterized using descriptive statistics. Dichotomous differences in the methodological criticisms observed between the three agencies were assessed using Cochran's Q tests and substantiated using pairwise McNemar tests. Chi-squared tests were used to assess the dichotomous differences in the reporting of methods and explore the potential relationships between categorical variables, where appropriate. HTAs published by CADTH, NICE, and the PBAC consistently reported a broad spectrum of descriptive information on the economic models submitted by manufacturers. While common economic evaluation attributes were well-reported across the three HTA agencies, significant differences in the reporting of survival analysis methods and methodological criticisms were observed. NICE consistently reported more comprehensive information, compared to either CADTH or PBAC. Despite these differences, broadly similar recommendation rates were observed between CADTH and NICE. The PBAC was found to be more restrictive. Based on our 2-year sample of oncology, the HTAs published by CADTH matched with the corresponding HTAs from NICE and PBAC; we observed important variations in the reporting of economic evidence, especially technical aspects, such as survival analysis, across the three agencies. In addition to guidelines for HTA submissions by manufacturers, the community of HTA agencies should also have common standards for reporting the results of their assessments, though the information and opinions reported may differ.

A Systematic Review of Methods and Study Quality of Economic Evaluations for the Treatment of Schizophrenia

Background: Schizophrenia is a severe and complex disease with substantial economic and social burdens. Despite multiple treatment choices, adverse events, and impaired social functions are still challenges in clinical therapy. Pharmacoeconomic evaluations could provide evidence to help decision makers improve the utilization of scarce resources. However, there remains some challenges especially in modeling due to uncertainties in progression of schizophrenia. There are limited summaries about the overall methodologies of schizophrenia economic evaluations.

Objective: The aim of this study is to review the existing economic evaluations of antipsychotics for the treatment of schizophrenia and summarize the evidence and methods applied.

Methods: An electronic literature search was performed in PubMed, Web of Science, EBSCO host, The Cochrane Library and ScienceDirect from January 2014 to December 2020. Search terms included “schizophrenia,” “schizophrenic,” “pharmacoeconomic,” “economic evaluation,” “cost-effectiveness,” and “cost-utility.” The Literature was screened and extracted by two researchers independently and assessed with the Quality of Health Economic Studies (QHES) List and Consolidated Health Economic Evaluation Reporting Standards (CHEERS) Statement.

Results: A total of 25 studies were included in the review. The regions included Europe, North America, Asia and Africa. Most of the studies chose second-generation antipsychotics as comparators and integrated treatment sequences. Time horizons varied from 1 year to lifetime. The healthcare sector was the most common perspective, accordingly, most of the evaluations considered only direct medical costs. The Markov model and decision tree model were the most common choices. Adverse events, compliance and persistence were considered important parameters. Quality-adjusted life-years were the major outcomes applied to the economic evaluations. All utilities for health states and adverse events were collected from published literature. All of the studies applied uncertainty analysis to explore the robustness of the results. The quality of the studies was generally satisfactory. However, improvements were needed in the choice of time horizons, the measurements of outcomes and the descriptions of assumptions.

Conclusions: This study highlights the methodology of economic evaluation of schizophrenia. Recommendations for modeling method and future study are provided.

Appraisal of patient-level health economic models of severe mental illness: systematic review

BACKGROUND

Healthcare decision makers require accurate long-term economic models to evaluate the cost-effectiveness of new mental health interventions.

AIMS

To assess the suitability of current patient-level economic models to estimate long-term economic outcomes in severe mental illness.

METHOD

We undertook pre-specified systematic searches in MEDLINE, Embase and PsycINFO to identify reviews and stand-alone publications of economic models of interventions for schizophrenia, bipolar disorder and major depressive disorder (PROSPERO: CRD42020158243). We screened paper titles and abstracts to identify unique patient-level economic models. We conducted a structured extraction of identified models, recording the presence of key predefined model features. Model quality and validation were appraised using the 2014 ISPOR and 2016 AdViSHE model checklists.

RESULTS

We identified 15 unique patient-level models for psychosis and major depressive disorder from 1481 non-duplicate records. Models addressed schizophrenia (n = 6), bipolar disorder (n = 2) and major depressive disorder (n = 7). The predominant model type was discrete event simulation (n = 9). Model complexity and incorporation of patient heterogeneity varied considerably, and only five models extrapolated costs and outcomes over a lifetime horizon. Key model parameters were often based on low-quality evidence, and checklist quality assessment revealed weak model verification procedures.

CONCLUSIONS

Existing patient-level economic models of interventions for severe mental illness have considerable limitations. New modelling efforts must be supplemented by the generation of good-quality, contemporary evidence suitable for model building. Combined effort across the research community is required to build and validate economic extrapolation models suitable for accurately assessing the long-term value of new interventions from short-term clinical trial data.

Long-Acting Injectable Antipsychotics in the Treatment of Schizophrenia: Practical Considerations

The positive symptoms of schizophrenia are usually treated with oral antipsychotics despite high rates of nonadherence leading to relapse and rehospitalization. Seven long-acting injectable (LAI) antipsychotics are currently approved by the U.S. Food and Drug Administration for maintenance treatment of schizophrenia. These medications reduce the risk for nonadherence and relapse, yet relatively few clinicians prescribe them. All LAI anti-psychotics are equally effective in treating the positive symptoms of schizophrenia. Dosing requirements, dosing frequencies, and what clinicians should consider in choosing a LAI antipsychotic for a specific patient are discussed. Communication strategies that help patients and families understand what they need to know about schizophrenia and its treatment to share in the decision-making process are also provided. [Journal of Psychosocial Nursing and Mental Health Services, 59(7), 7-12.].

Overview and Use of Tools for Selecting Modelling Techniques in Health Economic Studies

The availability and use of tools to guide the choice of modelling technique are not well understood. Our study aims to review existing tools and explore the use of those tools in health economic models. Two reviews and one case study were conducted. Review 1 aimed to identify tools based on expert opinion and citation searching and explore the value of the tools for health economic models. Review 2, based on citation searching, aimed to describe how those tools have been used in health economic models. Both reviews were conducted using Web of Science and Scopus. Two independent reviewers selected studies for inclusion. A case study, focused on economic evaluations of antipsychotic medication in schizophrenia, was conducted to compare the modelling techniques used by existing models with modelling techniques recommended by identified tools. Seven tools were identified, of which the revised Brennan's toolkit, was assessed to be the most appropriate for health economic models. The seven tools were cited 126 times in publications reporting health economic models. Only 17 of these (13.5%) reported that they used the tool(s) to guide the choice of modelling technique. Application of these tools suggested discrete event simulation is most appropriate for modelling antipsychotic medication in schizophrenia, but discrete event simulation was only used by 17% of existing models. There is considerable inconsistency between the modelling techniques used by existing models and modelling techniques recommended by tools. It is recommended that for future modelling studies the choice of modelling technique should be justified, this can be achieved by the application of model selection tools, such as the revised Brennan's toolkit. Future research is required to explore the barriers to using model selection tools in health economic models and to update existing tools and make them easier to use.