Cost-effectiveness of 3-month paliperidone therapy for chronic schizophrenia in the Netherlands.

BACKGROUND: A new depot formulation of paliperidone has been developed that provides effective treatment for schizophrenia for 3 months (PP3M). It has been tested in phase-3 trials, but no data on its cost-effectiveness have been published. PURPOSE: To determine the cost-effectiveness of PP3M compared with once-monthly paliperidone (PP1M), haloperidol long-acting therapy (HAL-LAT), risperidone microspheres (RIS-LAT), and oral olanzapine (oral-OLZ) for treating chronic schizophrenia in The Netherlands. METHODS: A previous 1-year decision tree was adapted, based on local inputs supplemented with data from published literature. The primary analysis used DRG costs in 2016 euros from the insurer perspective, as derived from official lists. A micro-costing analysis was also conducted. For the costing scenario, official list prices were used. Clinical outcomes included relapses (treated as outpatients, requiring hospitalization, total), and quality-adjusted life-years (QALYs). Rates and utility scores were derived from the literature. Economic outcomes were the incremental cost/QALY-gained or relapse-avoided. Model robustness was examined in scenario, 1-way, and probability sensitivity analyses. RESULTS: The expected cost was lowest with PP3M (8,781€), followed by PP1M (10,325€), HAL-LAT (11,278€), RIS-LAT (11,307€), and oral-OLZ (13,556€). PP3M had the fewest total relapses/patient (0.36, 0.94, 1.39, 1.21, and 1.70, respectively), hospitalizations (0.11, 0.46, 0.40, 0.56, and 0.57, respectively), emergency room visits (0.25, 0.48. 0.99, 0.65, and 1.14, respectively) and the most QALYs (0.847, 0.735, 0.709, 0.719, and 0.656, respectively). In both cost-effectiveness and cost-utility analyses, PP3M dominated all other drugs. Sensitivity analyses confirmed base case findings. In the costing analysis, total costs were, on average, 31.9% higher than DRGs. CONCLUSIONS: PP3M dominated all commonly used drugs. It is cost-effective for treating chronic schizophrenia in the Netherlands. Results were robust over a wide range of sensitivity analyses. For patients requiring a depot medication, such as those with adherence problems, PP3M appears to be a good alternative anti-psychotic treatment.

Modelling the treated course of schizophrenia: development of a discrete event simulation model.

In schizophrenia, modelling techniques may be needed to estimate the long-term costs and effects of new interventions. However, it seems that a simple direct link between symptoms and costs does not exist. Decisions about whether a patient will be hospitalized or admitted to a different healthcare setting are based not only on symptoms but also on social and environmental factors. This paper describes the development of a model to assess the dependencies between a broad range of parameters in the treatment of schizophrenia. In particular, the model attempts to incorporate social and environmental factors into the decision-making process for the prescription of new drugs to patients. The model was used to analyse the potential benefits of improving compliance with medication by 20% in patients in the UK. A discrete event simulation (DES) model was developed, to describe a cohort of schizophrenia patients with multiple psychotic episodes. The model takes into account the patient's sex, disease severity, potential risk of harm to self and society, and social and environmental factors. Other variables that change over time include the number of psychiatric consultations, the presence of psychotic episodes, symptoms, treatments, compliance, side-effects, the lack of ability to take care of him/herself, care setting and risk of harm. Outcomes are costs, psychotic episodes and symptoms. Univariate and multivariate sensitivity analyses were performed. Direct medical costs were considered (year of costing 2002), applying a 6.0% discount rate for costs and a 1.5% discount rate for outcome. The timeframe of the model is 5 years. When 50% of the decisions about the patient care setting are based on symptoms, a 20% increase in compliance was estimated to save 16,147 pounds and to avoid 0.55 psychotic episodes per patient over 5 years. Sensitivity analysis showed that the costs savings associated with increased compliance are robust over a range of variations in parameters. DES offers a flexible structure for modelling a disease, taking into account how a patient's history affects the course of the disease over time. This approach is particularly pertinent to schizophrenia, in which treatment decisions are complex. The model shows that better compliance increases the time between relapses, decreases the symptom score, and reduces the requirement for treatment in an intensive patient care setting, leading to cost savings. The extent of the cost savings depends on the relative importance of symptoms and of social and environmental factors in these decisions.