Cost-Utility Analysis of Depot Atypical Antipsychotics for Chronic Schizophrenia in Croatia

Cost-effectiveness analysis of monthly, 3-monthly, and 6-monthly long-acting injectable and oral paliperidone in adults with schizophrenia

BACKGROUND: Paliperidone is among the most cost-effective antipsychotics in adults with schizophrenia, and it has different formulations, including oral paliperidone extended-release (ER) and long-acting injectable (LAI) paliperidone formulations administered every month (PP1M), 3 months (PP3M), or 6 months (PP6M). However, cost-effectiveness analyses comparing different paliperidone formulations were limited. OBJECTIVE: To compare the cost-effectiveness across different paliperidone formulations. METHODS: A Markov model was developed to simulate 1,000 adults aged 40 years with stable schizophrenia transitioning among stable disease-medication adherent, stable disease-medication nonadherent, relapse with hospitalization, relapse with ambulatory care, and death states every 3 months for 5 years. Drug costs were estimated using the prices listed in the Veterans Affairs Federal Supply Schedule, and costs for treating complications were estimated from published studies. All costs were estimated from the US health care system perspective and standardized to 2022 US dollars using the Consumer Price Index Inflation Calculator. Quality-adjusted life-years (QALYs) were estimated using relapse rates from randomized clinical trials and health-related quality of life scores from observational studies. The estimated future costs and QALYs were discounted at 3%. We reported incremental net monetary benefits between alternative formulations at the $50,000 willingness-to-pay (WTP) threshold with a positive value indicating cost-effectiveness. The impact of parameter uncertainty on study outcomes was assessed using 1-way deterministic and probabilistic sensitivity analyses. RESULTS: In adults with schizophrenia stabilized with paliperidone ER, switching to LAI formulations was associated with increased QALY (PP1M = 0.05, PP3M = 0.14, PP6M = 0.15) and increased cost (PP1M = 49,433, PP3M = 26,698, PP6M = 26,147), leading to a negative incremental net monetary benefit (PP1M = -$46,804, PP3M = -$19,508, PP6M = -$18,886) compared with continuing ER. Among LAI formulations, PP6M was cost-saving with the most QALYs gained (cost = $63,277, QALY = 3.731), followed by PP3M (cost = $63,828, QALY = 3.729) and PP1M (cost = $86,563, QALY = 3.638). At the $50,000 WTP threshold, the probabilities for PP1M, PP3M, and PP6M being cost-effective compared with paliperidone ER were 0.4%, 10.2%, and 9.8%, respectively. The probability of PP6M being cost-effective was 92.6% for the PP6M-PP1M pair and 55.2% for the PP6M-PP3M pair, and 91.1% of PP3M use was cost-effective in the PP3M-PP1M pair. The results were generally robust in the sensitivity analyses, even at the $190,000 WTP threshold. CONCLUSIONS: For patients with schizophrenia stabilized with paliperidone ER, switching to LAI formulations was not cost-effective, suggesting the high drug costs for LAI may not justify the improved quality of life within 5 years. Among LAI formulations, PP6M was cost-effective over PP1M and PP3M.

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.

Systematic review of utility values used in the pharmacoeconomic evaluations for schizophrenia: implications on cost-effectiveness results

Background and Objectives: Utility elicitation studies for schizophrenia generate different utility values for the same health states. We reviewed utility values used in schizophrenia pharmacoeconomic evaluations and evaluated the impact of their selection on the incremental cost-effectiveness ratio (ICER). Methods: A systematic search was performed in Medline and Embase. Health state definitions, associated utility values, elicitation studies, and value selection processes were extracted. Sets of utility values for all schizophrenia health states were used in a cost-effectiveness model to evaluate the ICER. Results: Thirty-five cost-utility analyses (CUAs) referring to 11 utility elicitation studies were included. The most frequent health states were 'stable' (28 CUAs, 7 utility elicitation studies, 10 values, value range 0.650-0.919), 'relapse requiring hospitalisation' (18, 5, 7, 0.270-0.604), 'relapse not requiring hospitalisation' (18, 5, 10, 0.460-0.762), and 'relapse only' (10, 5, 6, 0.498-0.700). Seventeen sets of utility values were identified with difference in utility values between relapse and stable ranging from -0.358 to -0.050, resulting in ICERs ranging from -56.2% to +222.6% from average. Conclusion: The use of utility values for schizophrenia health states differs among CUAs and impacts on the ICER. More rigorous and transparent use of utility values and sensitivity analysis with different sets of utility values are suggested for future CUAs.

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.

Economic evaluation of paliperidone palmitate once monthly for treating chronic schizophrenia patients in the United Arab Emirates

OBJECTIVE

Schizophrenia is one of the most debilitating diseases in the United Arab Emirates. Oral antipsychotics (OA) are commonly used in terms of pharmacotherapy; however, these treatments can be rendered ineffective by poor patient adherence. Paliperidone palmitate once monthly (PP1M) is a long acting antipsychotic which can offer an adherence advantage when compared to oral treatments. The study objective is to estimate the cost effectiveness of PP1M in the UAE setting.

RESEARCH DESIGN AND METHODS

A 1-year validated decision-tree model was adapted to the UAE setting using published literature and expert opinion. Patients on PP1M were compared with or without oral supplementation to patients on any oral antipsychotic. Patient outcomes studied were incremental cost per quality adjusted life years gained, incremental cost per hospitalizations, relapses, and emergency room visits averted.

RESULTS

After 1 year, patients on PP1M monotherapy when compared to oral antipsychotics had better outcomes (0.840 vs 0.811 QALYs; 31 relapse days averted as well as 9 and 24 percentage points of ER and hospitalizations averted, respectively), and better healthcare savings (AED 1405). PP1M economically dominated oral antipsychotics. The results were stable across a broad range of deterministic and probabilistic sensitivity analyses. PP1M plus oral antipsychotics could not be evaluated due to the absence of clinical data that would provide insight into the clinical value of combination therapy.

CONCLUSION

PP1M is estimated to save the UAE healthcare system money, while at the same time improving patient outcomes.

Treatment continuation of four long-acting antipsychotic medications in the Netherlands and Belgium: A retrospective database study

Achieving greater continuation of treatment is a key element to improve treatment outcomes in schizophrenia patients. However, reported treatment continuation can differ markedly depending on the study design. In a retrospective setting, treatment continuation remains overall poor among patients using antipsychotics. This study aimed to document the difference in treatment continuation between four long-acting injectable antipsychotics based on the QuintilesIMS LRx databases, national, longitudinal, panel based prescription databases of retail pharmacies, in the Netherlands and Belgium. Paliperidone palmitate once monthly, risperidone microspheres, haloperidol decanoate, and olanzapine pamoate were studied. This study demonstrated significantly higher treatment continuation of paliperidone palmitate once monthly compared to risperidone microspheres (p-value<0,01) and haloperidol decanoate (p-value<0,01) in both countries, a significantly higher treatment continuation of paliperidone palmitate once monthly compared to olanzapine pamoate in the Netherlands (p-value<0,01), and a general trend towards better treatment continuation versus olanzapine pamoate in Belgium. Analysing the subgroup of patients without previous exposure to long-acting antipsychotic treatment revealed the positive impact of previous exposure on treatment continuation with a subsequent long acting treatment. Additionally, the probability of restarting the index therapy was higher among patients treated with paliperidone palmitate once monthly compared to patients treated with risperidone microspheres and haloperidol decanoate. The data source used and the methodology defined ensured for the first time a comparison of treatment continuation in a non-interventional study design for the four long-acting injectable antipsychotics studied.

Pharmacoeconomics of long-acting atypical antipsychotics for acutely relapsed chronic schizophrenia in Finland

BACKGROUND

Atypical long-acting injectable (LAI) antipsychotics are increasingly available for treating chronic schizophrenia in patients chronically non-adherent to prescribed regimens. Few economic studies have compared these products.

PURPOSE

To determine the cost-effectiveness of aripiprazole (ARI-LAI), paliperidone (PP-LAI), olanzapine (OLZ-LAI), and risperidone (RIS-LAI) in patients with chronic schizophrenia in Finland.

METHODS

A 1-year decision tree model was adapted with guidance from an expert panel. Patients started hospitalized in relapse; those who responded continued treatment, others were switched to secondary drugs, then clozapine in the event of 2nd line failure. Rates of adherence, stable disease, relapse, and hospitalization were taken from pivotal trials, and utilities from published research. Included were direct costs paid by the Finnish Ministry of Health, in 2015 euros. Outcomes included quality-adjusted life-years (QALYs), hospitalization rates, and rates of relapse not requiring hospitalization. Model robustness was assessed using a series of 1-way and multivariate sensitivity analyses.

RESULTS

Expected costs were lowest for PP-LAI at 41,148€, followed by 41,543€ for ARI-LAI, 42,067€ for RIS-LAI and 45,406€ for OLZ-LAI. Respective QALYs were 0.683, 0.671, 0.666, and 0.672. Re-hospitalization rates and non-admitted relapses were 23.6% and 3.9% for PP-LAI, 28.5% and 4.1% for ARI-LAI, 28.8% and 5.0% for RIS-LAI, 28.3% and 5.2% for OLZ-LAI. PP-LAI treatment was associated with the most days with stable disease (132.0), followed by OLZ-LAI (125.5), ARI-LAI (122.6), and RIS-LAI (114.4). Sensitive inputs between PP-LAI and ARI-LAI included rates of adherence, dropouts, and relapses plus drug prices; dropout and relapse rates for RIS-LAI; OLZ-LAI results were insensitive. In probability sensitivity analyses, PP-LAI dominated ARI-LAI in 75.8% of the 10,000 iterations, RIS-LAI in 83.1% and OLZ-LAI in 95.7%.

CONCLUSIONS

PP-LAI dominated the other atypicals. It appears to be the preferred option for treating chronic relapsing schizophrenia.