Cost-effectiveness of long-acting risperidone injection versus alternative atypical antipsychotic agents in patients with schizophrenia in China

Efficacy and safety of prophylactic use of benzhexol after risperidone treatment

To test the effect of prophylactic use of benzhexol in schizophrenia patients after risperidone treatment. Sixty-nine drug naïve schizophrenia patients were recruited. All patients were administered risperidone. Patients in the benzhexol group were given a benzhexol tablet of 2 mg bid daily. The controls received a placebo tablet of 2 mg bid daily. The primary outcome measured using the Extrapyramidal Symptoms Rating Scale (ESRS). The Positive and Negative Syndrome Scale (PANSS) and the Brief Psychiatric Rating Scale (BPRS) measured secondary outcome. There were significant time and group effects on the ESRS scores of the two groups. The post hoc analysis yielded significant differences at 1, 2, 4, and 8 weeks between the two groups. There was a significant time effect on the PANSS scores of the two groups. No significant group and interaction effects on the PANSS scores of the two groups. There was a significant time effect on the BPRS scores of the two groups. No serious adverse events were found in this study. Prophylactic use of benzhexol reduced extrapyramidal symptom in schizophrenia patients after risperidone treatment and did not affect the antipsychotic action of risperidone.

Mobile Texting and Lay Health Supporters to Improve Schizophrenia Care in a Resource-Poor Community in Rural China (LEAN Trial): Randomized Controlled Trial Extended Implementation

BACKGROUND

Schizophrenia is a severe and disabling condition that presents a dire health equity challenge. Our initial 6-month trial (previously reported) using mobile texting and lay health supporters, called LEAN, significantly improved medication adherence from 0.48 to 0.61 (adjusted mean 0.11, 95% CI 0.03 to 0.20, P=.007) for adults with schizophrenia living in a resource-poor village in rural China.

OBJECTIVE

We explored the effectiveness of our texting program in improving participants' medication adherence, functioning, and symptoms in an extended implementation of the intervention after its initial phase.

METHODS

In an approximated stepped-wedge wait-list design randomized controlled trial, 277 community-dwelling villagers with schizophrenia were assigned 1:1 in phase 1 into intervention and wait-list control groups. The intervention group received (1) lay health supporters (medication or care supervisors), (2) e-platform (mobile-texting reminders and education message) access, (3) a token gift for positive behavioral changes, and (4) integration with the existing government community-mental health program (the 686 Program) while the wait-listed control group initially only received the 686 Program. Subsequently (in the extended period), both groups received the LEAN intervention plus the 686 Program. The primary outcome was antipsychotic medication adherence (percentage of dosages taken over the past month assessed by unannounced home-based pill counts). The secondary outcomes were symptoms measured during visits to 686 Program psychiatrists using the Clinical Global Impression scale for schizophrenia and functioning measured by trained student assessors using the World Health Organization Disability Assessment Schedule 2.0. Other outcomes included data routinely collected in the 686 Program system (refill records, rehospitalization due to schizophrenia, death for any reason, suicide, wandering, and violent behaviors). We used intention-to-treat analysis and missing data were imputed. A generalized estimating equation model was used to assess program effects on antipsychotics medication adherence, symptoms, and functioning.

RESULTS

Antipsychotics medication adherence improved from 0.48 in the control period to 0.58 in the extended intervention period (adjusted mean difference 0.11, 95% CI 0.04 to 0.19; P=.004). We also noted an improvement in symptoms (adjusted mean difference -0.26, 95% CI -0.50 to -0.02; P=.04; Cohen d effect size 0.20) and a reduction in rehospitalization (0.37, 95% CI 0.18 to 0.76; P=.007; number-needed-to-treat 8.05, 95% CI 4.61 to 21.41). There was no improvement in functioning (adjusted mean difference 0.02, 95% CI -0.01 to 0.06; P=.18; Cohen d effect size 0.04).

CONCLUSIONS

In an extended implementation, our intervention featuring mobile texting messages and lay health workers in a resource-poor community setting was more effective than the 686 Program alone in improving medication adherence, improving symptoms, and reducing rehospitalization.

TRIAL REGISTRATION

Chinese Clinical Trial Registry; ChiCTR-ICR-15006053 https://tinyurl.com/y5hk8vng.

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

BACKGROUND

Numerous economic models have assessed the cost-effectiveness of antipsychotic medications in schizophrenia. It is important to understand what key impacts of antipsychotic medications were considered in the existing models and limitations of existing models in order to inform the development of future models.

OBJECTIVES

This systematic review aims to identify which clinical benefits, clinical harms, costs and cost savings of antipsychotic medication have been considered by existing models, to assess quality of existing models and to suggest good practice recommendations for future economic models of antipsychotic medications.

METHODS

An electronic search was performed on multiple databases (MEDLINE, EMBASE, PsycInfo, Cochrane database of systematic reviews, The NHS Economic Evaluation Database and Health Technology Assessment database) to identify economic models of schizophrenia published between 2005-2020. Two independent reviewers selected studies for inclusion. Study quality was assessed using the National Institute for Health and Care Excellence (NICE) checklist and the Cooper hierarchy. Key impacts of antipsychotic medications considered by exiting models were descriptively summarised.

RESULTS

Sixty models were included. Existing models varied greatly in key impacts of antipsychotic medication included in the model, especially in clinical outcomes used for assessing reduction in psychotic symptoms and types of adverse events considered in the model. Quality of existing models was generally low due to failure to capture the health and cost impact of adverse events of antipsychotic medications and input data not obtained from best available source. Good practices for modelling antipsychotic medications are suggested.

DISCUSSIONS

This review highlights inconsistency in key impacts considered by different models, and limitations of the existing models. Recommendations on future research are provided.

A Systematic Review of Economic Models Across the Entire Schizophrenia Pathway

BACKGROUND

Schizophrenia is associated with a high economic burden. Economic models can help to inform resource allocation decisions to maximise benefits to patients.

OBJECTIVES

This systematic review aims to assess the availability, quality and consistency of conclusions of health economic models evaluating the cost effectiveness of interventions for schizophrenia.

METHODS

An electronic search was performed on multiple databases (MEDLINE, EMBASE, PsycINFO, Cochrane database of systematic reviews, NHS Economic Evaluation Database and Health Technology Assessment database) to identify economic models of interventions for schizophrenia published between 2005 and 2020. Two independent reviewers selected studies for inclusion. Study quality was assessed using the National Institute for Health and Care Excellence (NICE) checklist and the Cooper hierarchy. Model characteristics and conclusions were descriptively summarised.

RESULTS

Seventy-three models met inclusion criteria. Seventy-eight percent of existing models assessed antipsychotics; however, due to inconsistent conclusions reported by different studies, no antipsychotic can be considered clearly cost effective compared with the others. A very limited number of models suggest that the following non-pharmacological interventions might be cost effective: psychosocial interventions, stratified tests, employment intervention and intensive intervention to improve liaison between primary and secondary care. The quality of included models is generally low due to use of a short time horizon, omission of adverse events of interventions, poor data quality and potential conflicts of interest.

CONCLUSIONS

This review highlights a lack of models for non-pharmacological interventions, and limitations of the existing models, including low quality and inconsistency in conclusions. Recommendations on future modelling approaches for schizophrenia are provided.

Cost-effectiveness of olanzapine in the first-line treatment of schizophrenia in China

OBJECTIVES

This study aimed to analyze (1) the cost-effectiveness of olanzapine orally disintegrating tablet (ODT) compared to olanzapine standard oral tablet (SOT) and (2) the cost-effectiveness of olanzapine-SOT compared to aripiprazole-SOT for patients with schizophrenia in China.

METHODS

A microsimulation model was adapted from a healthcare payers' perspective. The model ran over a 1-year time horizon, using quarterly cycles. The costs of adverse events were acquired through a clinical expert panel. The average bidding prices in China of olanzapine-ODT, olanzapine-SOT, aripiprazole-SOT, and other switch alternatives were used. Inpatient and outpatient medical costs were sourced from the Urban Employee Basic Medical Insurance database in Tianjin. Additionally, adherence, efficacy, safety, and utility data were taken from the literature. Uncertainty of parameters were assessed through one-way and probabilistic sensitivity analyses.

RESULTS

The total annual costs per patient in aripiprazole-SOT arm, olanzapine-SOT arm, and olanzapine-ODT arm are USD 2,296.05, USD 1,940.05, and USD 2,292.81, respectively. The average number of relapses per patient in 1 year in the aripiprazole-SOT arm, olanzapine-SOT arm, and olanzapine-ODT arm, are 0.734, 0.325, and 0.198, respectively. The quality-adjusted life years (QALYs) gained per patient in 1 year in the aripiprazole-SOT arm, olanzapine-SOT arm, and olanzapine-ODT arm are 0.714, 0.737, and 0.758, respectively. Consequently, (1) the incremental cost-effectiveness ratios (ICERs) of administrating olanzapine-ODT over olanzapine-SOT are USD 2,791.96 per relapse avoided and USD 16,798.39 per QALY gained; and (2) the ICERs of using olanzapine-SOT over aripiprazole-SOT are USD -870.39 per relapse avoided and USD -15,477.93 per QALY gained. All ICERs are under the willingness-to-pay threshold in China of USD 25,772.67. The sensitivity analyses confirmed the robustness of the results.

CONCLUSION

As the first-line treatment for schizophrenia in China, olanzapine-ODT is cost-effective compared to olanzapine-SOT and olanzapine-SOT is cost-effective compared to aripiprazole-SOT.

Systematic review of pharmacoeconomic models for schizophrenia

Background: Economic models are broadly used in the economic evaluation of antipsychotics in schizophrenia. Our objective was to summarize the structure of these models. Methods: Model-based economic evaluations of antipsychotics in schizophrenia were identified through Medline and Embase. General information was extracted including analysis type, model type, perspective, population, comparator, outcome, and timeframe. Model-specific structures for decision tree (DT), cohort- and patient-level Markov model (CLMM, PLMM), and discrete-event simulation (DES) models were extracted. Results: A screen of 1870 records identified 79 studies. These were mostly cost-utility analyses (n = 48) with CLMM (n = 32) or DT models (n = 29). They mostly applied payer perspective (n = 68), focused on general schizophrenia for relapse prevention (n = 73), compared pharmacotherapies as first-line (n = 71), and evaluated incremental cost per quality-adjusted life year (QALY) gained (n = 40) with a 1-year (n = 32) or 5-year (n = 26) projection. DT models progressed with the branching points of response, relapse, discontinuation, and adherence. CLMM models transitioned between disease states, whereas PLMM models transitioned between adverse event states with/without disease state. DES models moved forward with times to remission, relapse, psychiatrist visit, and death. Conclusions: A pattern of pharmacoeconomic models for schizophrenia was identified. More subtle structures and patient-level models are suggested for a future modelling exercise.

A systematic review of health economic models and utility estimation methods in schizophrenia

INTRODUCTION

There is a growing need for economic evaluations describing the disease course, as well as the costs and clinical outcomes related to the treatment of schizophrenia.

AREAS COVERED

A systematic review on studies describing health economic models in schizophrenia and a targeted literature review on utility mapping algorithms in schizophrenia were carried out. Models found in the review were collated and assessed in detail according to their type and various other attributes. Fifty-nine studies were included in the review. Modeling techniques varied from simple decision trees to complex simulation models. The models used various clinical endpoints as value drivers, 47% of the models used quality-adjusted life years, and eight percent used disability-adjusted life years to measure benefits, while others applied various clinical outcomes. Most models considered patients switching between therapies, and therapeutic adherence, compliance or persistence. The targeted literature review identified four main approaches to map PANSS scores to utility values.

EXPERT COMMENTARY

Health economic models developed for schizophrenia showed great variability, with simulation models becoming more frequently used in the last decade. Using PANSS scores as the basis of utility estimations is justifiable.

Quality of pharmacoeconomic research in China: A systematic review

BACKGROUND

The number of pharmacoeconomic publications in the literature from China has risen rapidly, but the quality of pharmacoeconomic publications from China has not been analyzed.

OBJECTIVES

This study aims to identify all recent pharmacoeconomic publications from China, to critically appraise the reporting quality, and to summarize the results.

METHODS

Four databases (PubMed, Web of Science, Medline, and EmBase) were searched for original articles published up to December 31, 2014. The Consolidated Health Economic Evaluation Reporting Standards statement including 24 items was used to assess the quality of reporting of these articles.

RESULTS

Of 1046 articles identified, 32 studies fulfilled the inclusion criteria. They were published in 23 different journals. Quality of reporting varied between studies, with an average score of 18.7 (SD = 4.33) out of 24 (range 9-23.5). There was an increasing trend of pharmacoeconomic publications and reporting quality over years from 2003 to 2014. According to the Consolidated Health Economic Evaluation Reporting Standards, the reporting quality for the items including "title," "comparators of method," and "measurement of effectiveness" are quite low, with less than 50% of studies fully satisfying these reporting standards. In contrast, reporting was good for the items including "introduction," "study perspective," "choice of health outcomes," "study parameters," "characterizing heterogeneity," and "discussion," with more than 75% of the articles satisfying these reporting criteria. The remaining items fell in between these 2 extremes, with 50% to 75% of studies satisfying these criteria.

CONCLUSION

Our study suggests the need for improvement in a number of reporting criteria. But the criteria for which reporting quality was low seem to be limitations that would be straightforward to correct in future studies.

An extended cost-effectiveness analysis of schizophrenia treatment in India under universal public finance

BACKGROUND

Schizophrenia remains a priority condition in mental health policy and service development because of its early onset, severity and consequences for affected individuals and households.

AIMS AND METHODS

This paper reports on an 'extended' cost-effectiveness analysis (ECEA) for schizophrenia treatment in India, which seeks to evaluate through a modeling approach not only the costs and health effects of intervention but also the consequences of a policy of universal public finance (UPF) on health and financial outcomes across income quintiles.

RESULTS

Using plausible values for input parameters, we conclude that health gains from UPF are concentrated among the poorest, whereas the non-health gains in the form of out-of-pocket private expenditures averted due to UPF are concentrated among the richest income quintiles. Value of insurance is the highest for the poorest quintile and declines with income.

CONCLUSIONS

Universal public finance can play a crucial role in ameliorating the adverse economic and social consequences of schizophrenia and its treatment in resource-constrained settings where health insurance coverage is generally poor. This paper shows the potential distributional and financial risk protection effects of treating schizophrenia.

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.

Clinical management and associated costs for moderate and severe Alzheimer's disease in urban China: a Delphi panel study

Background

Healthcare resource utilisation for Alzheimer’s disease (AD) in China is not well understood. This Delphi panel study aimed to describe the clinical management pathways for moderate and severe AD patients in urban China and to define the amount and cost of healthcare resources used.

Methods

A panel of 11 experts was recruited from urban China to participate in two rounds of preparatory interviews. In the first round, 9 physicians specialised in dementia gave a qualitative description of the clinical management of AD patients. In the second round, 2 hospital administrators were asked about the cost of AD management and care. Results from the interviews were discussed by the experts in a Delphi panel meeting, where consensus was reached on quantitative aspects of AD management, including the rate of healthcare resource utilisation, the respective unit costs and caregiving time.

Results

Interviewees reported that mild AD is under-recognised in China; most patients are diagnosed with moderate to severe AD. Loss of independence and agitation/aggression are the main drivers for healthcare resource utilisation and contribute to a heavier caregiver burden. It was estimated that 70 % moderate AD patients are independent/non-aggressive at the time of diagnosis, 15 % are independent/aggressive, 10 % are dependent/non-aggressive, and 5 % are dependent/aggressive. Dependent/aggressive AD patients are more likely to be hospitalised (70–90 %) than accepted in a nursing home (0–20 %), while the opposite is true for dependent/non-aggressive patients (5–35 % for hospitalisation vs. 80 % for nursing home). Independent AD patients require 1–3 hours/day of caregiver time, while dependent patients can require up to 12–15 hours/day. Experts agreed that AD complicates the management of age-related comorbidities, found in 70–80 % of all AD patients, increasing the frequency and cost of hospitalisation.

Conclusions

The Delphi panel approach was an efficient method of gathering data about the amount of healthcare resources used and associated costs for moderate and severe AD patients in urban China. The results of this study provide a useful source of information for decision makers to improve future healthcare policies and resource planning, as well as to perform economic evaluations of AD therapies.

Cost-effectiveness analysis of psychosocial intervention for early stage schizophrenia in China: a randomized, one-year study

BACKGROUND

A combination of psychosocial interventions and medications has been highly recommended as a successful treatment package for schizophrenia. Its cost-effectiveness has not been fully explored yet. The aim of the present analysis was to evaluate the cost-effectiveness of antipsychotics combined with psychosocial treatment and treatment as usual for patients with early-stage schizophrenia.

METHOD

Patients with schizophrenia (N = 1, 268) were assigned to the combination of medication and psychosocial intervention or treatment as usual for up to 12 months. Cost analysis included direct medical costs, direct nonmedical costs and indirect costs. Quality-adjusted life year (QALY) ratings were assessed with Short- Form 6D.

RESULTS

Average monthly psychosocial intervention costs for combined treatment were higher than treatment as usual (p = 0.005), but no significant differences were found in direct costs, indirect costs, and total costs between two groups (all p-values ≥ 0.556). Combined treatment was associated with significant higher QALY ratings than treatment as usual (p = 0.039). Compared with treatment as usual, combined treatment resulted in a gain of 0.031 QALY ratings at an additional cost of US$ 56.4, yielding an incremental cost-effectiveness ratio of US$ 1819.4 per QALY gained.

CONCLUSIONS

Despite some limitations, our results supported that medication combined with psychosocial treatment was more cost-effective than treatment as usual for patients with early-stage schizophrenia.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00654576.

Cost analysis of risperidone long-acting injection in the treatment of schizophrenia and schizoaffective disorders in Hong Kong: an approach using generalised estimating equations

Schizophrenia is one of the most expensive psychiatric illnesses. This study compared retrospectively health-care resources consumed 12 months before and 24 months after risperidone long-acting injection (RLAI) treatment in Hong Kong. A mirror-image analysis was conducted using data (N=191) from three public hospitals in Hong Kong from 2003 to 2007. The main outcome measure was hospitalisation cost. Other secondary outcomes such as hospitalisation episodes, outpatient visits and adverse events were also compared. A predictive model was established using linear regression based on generalised estimating equations. Analysis showed that RLAI was associated with a reduction in hospitalisation cost by HK$10,001,390 (24.7%) (HK$40,418,694 vs. HK$30,417,303; P-value <0.05). Days of hospitalisation were reduced by 1538 days (10.1%) (15,271 vs. 13,733; P-value <0.05). The predictive model estimated that the hospitalisation cost of patients using RLAI was only 11.1% (3.1-3.93%, 95% confidence interval (CI)) compared to those receiving conventional antipsychotics combined with oral risperidone. Cost of hospitalisation was significantly reduced after RLAI therapy. However, results should be considered as indicative or suggestive only, due to potential channelling bias where certain drug regimens are preferentially prescribed to patients with particular conditions. The findings from our study may be useful in health-care decision making considering treatment options for schizophrenia in resource-limited settings.

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.

Preparation, Characterization, and In Vivo Evaluation of Olanzapine Poly(D,L-lactide-co-glycolide) Microspheres

The aim of this study was to prepare injectable depot formulations of Olanzapine using four poly(D,L-lactide-co-glycolide) (PLGA) polymers of varying molecular weight and copolymer composition, and evaluate in vivo performance in rats. In vivo release profiles from the formulations were governed chiefly by polymer molecular weight and to a lesser extent, copolymer composition. Formulations A and B, manufactured using low molecular weight PLGA and administered at 10 mg/kg dose, released drug within 15 days. Formulation C, prepared from intermediate molecular weight PLGA and administered at 20 mg/kg dose, released drug in 30 days, while Formulation D, manufactured using a high molecular weight polymer and administered at 20 mg/kg dose, released drug in 45 days. A simulation of multiple dosing at 7- and 10-day intervals for Formulations A and B revealed that steady state was achieved within 7-21 days and 10-30 days, respectively. Similarly, simulations at 15-day intervals for Formulations C and D indicated that steady state levels were reached during days 15-45. Overall, steady state levels for 7-, 10-, or 15-day dosing ranged between 45 and 65 ng/mL for all the formulations, implying that Olanzapine PLGA microspheres can be tailored to treat patients with varying clinical needs.

The cost effectiveness of long-acting/extended-release antipsychotics for the treatment of schizophrenia: a systematic review of economic evaluations

BACKGROUND

Antipsychotic medication is the mainstay of treatment in schizophrenia. Long-acting medication has potential advantages over daily medication in improving compliance and thus reducing hospitalization and relapse rates. The high acquisition and administration costs of such formulations raise the need for pharmacoeconomic evaluation.

OBJECTIVE

The aim of this article is to provide a comprehensive review of the available evidence on the cost effectiveness of long-acting/extended-release antipsychotic medication and critically appraise the strength of evidence reported in the studies from a methodological viewpoint.

METHODS

Relevant studies were identified by searching five electronic databases: PsycINFO, MEDLINE, EMBASE, the NHS Economic Evaluation Database and the Health Technology Assessment database (HTA). Search terms included, but were not limited to, 'long-acting injection', 'economic evaluation', 'cost-effectiveness' and 'cost-utility'. No limits were applied for publication dates and language. Full economic evaluations on long-acting/extended-release antipsychotics were eligible for inclusion. Observational studies and clinical trials were also checked for cost-effectiveness information. Conference abstracts and poster presentations on the cost effectiveness of long-acting antipsychotics were excluded. Thirty-two percent of identified studies met the selection criteria. Pertinent abstracts were reviewed independently by two reviewers. Relevant studies underwent data extraction by one reviewer and were checked by a second, with any discrepancies being clarified during consensus meetings. Eligible studies were assessed for methodological quality using the quality checklist for economic studies recommended by the NICE guideline on interventions in the treatment and management of schizophrenia.

RESULTS

After applying the selection criteria, the final sample consisted of 28 studies. The majority of studies demonstrated that risperidone long-acting injection, relative to oral or other long-acting injectable drugs, was associated with cost savings and additional clinical benefits and was the dominant strategy in terms of cost effectiveness. However, olanzapine in either oral or long-acting injectable formulation dominated risperidone long-acting injection in a Slovenian and a US study. Furthermore, in two UK studies, the use of long-acting risperidone increased the hospitalization days and overall healthcare costs, relative to other atypical or typical long-acting antipsychotics. Finally, paliperidone extended-release was the most cost-effective treatment compared with atypical oral or typical long-acting formulations. From a methodological viewpoint, most studies employed decision analytic models, presented results using average cost-effectiveness ratios and conducted comprehensive sensitivity analyses to test the robustness of the results.

LIMITATIONS

Variations in study methodologies restrict consistent and direct comparisons across countries. The exclusion of a large body of potentially relevant conference abstracts as well as some papers being unobtainable may have increased the likelihood of misrepresenting the overall cost effectiveness of long-acting antipsychotics. Finally, the review process was restricted to qualitative assessment rather than a quantitative synthesis of results, which could provide more robust conclusions.

CONCLUSIONS

Atypical long-acting (especially risperidone)/extended-release antipsychotic medication is likely to be a cost-effective, first-line strategy for managing schizophrenia, compared with long-acting haloperidol and other oral or depot formulations, irrespective of country-specific differences. However, inconsistencies in study methodologies and in the reporting of study findings suggest caution needs to be applied in interpreting these findings.