Cost effectiveness of paliperidone palmitate versus risperidone long-acting injectable and olanzapine pamoate for the treatment of patients with schizophrenia in Sweden

Abstract

Objective:

To model the cost effectiveness of paliperidone palmitate (paliperidone long-acting injectable; PLAI), a new once-monthly long-acting antipsychotic therapy, compared with risperidone long-acting injectable (RLAI) and olanzapine pamoate (OLAI), in multi-episode patients (two or more relapses) with schizophrenia in Sweden.

Methods:

A Markov decision analytic model was developed to simulate the history of a cohort of multi-episode patients transitioning through different health states on a monthly basis over a 5-year time horizon from the perspective of the Swedish healthcare system. Therapeutic strategies consisted of starting treatment with RLAI (mean dose 37.5 mg every 2 weeks), PLAI (mean dose 75 mg equivalent (eq.) every month) or OLAI (150 mg every 2 weeks or 300 mg every 4 weeks). Probability of relapse, level of adherence, side-effects (extrapyramidal symptoms, tardive dyskinesia, weight gain and diabetes) and treatment discontinuation (switch) were derived from long-term observational data when feasible. Incremental cost-effectiveness outcomes, discounted at 3% annually, included cost per quality-adjusted life-year (QALY) and cost per relapse avoided (expressed in 2009 Swedish Krona SEK).

Results:

Relative to RLAI and OLAI, PLAI is economically dominant: more effective (additional QALYs, less relapses) and less costly treatment option over a 5-year time horizon. The results were robust when tested in sensitivity analysis.

Limitations:

The impact of once-monthly treatment on adherence levels is not yet known, and not all variables that could impact on real-world outcomes and costs were included in this model.

Conclusion:

PLAI was cost saving from a Swedish payer perspective compared with RLAI and OLAI in the long-term treatment of multi-episode (two or more relapses) schizophrenia patients.

• Adherence
• Atypical antipsychotic
• Cost-effectiveness analysis
• Long-acting therapy
• Relapse
• Schizophrenia

Transparency

Declaration of funding

This study was funded by Janssen Global Services, LLC, Raritan, NJ, USA, and Janssen Pharmaceutica NV, Beerse, Belgium.

Declaration of financial/other relationships

A.M. has disclosed that she is employed by Janssen Pharmaceutica NV; D.N. has disclosed that she is an employee of Janssen Global Services, LLC; H.P. has disclosed that she is employed by Janssen Cilag Oy, Helsinki, Finland; M.M. has disclosed that she is a full-time employee of OptumInsight (formerly i3 Innovus, a company that was contracted by the sponsor to conduct this study). A.McG. has disclosed that he is an employee of LSE and a paid consultant and advisor for OptumInsight. He has no other conflicts of interest to declare.

Acknowledgments

Literature searches and model programming were performed by i3 Innovus, Uxbridge, UK. Writing and editorial assistance with the manuscript was provided by ApotheCom ScopeMedical Ltd, UK, funded by Janssen Pharmaceutica NV, Beerse, Belgium.