Cost-effectiveness of olanzapine long-acting injection in the treatment of patients with schizophrenia in the United States: a micro-simulation economic decision model.
OBJECTIVE
To compare, from the perspective of third-party payers in the United States health care system, the cost-effectiveness of olanzapine long-acting injection (LAI, depot) with alternative antipsychotic agents including risperidone-LAI, paliperidone-LAI, haloperidol-LAI, and oral olanzapine, in the treatment of patients with schizophrenia who have been non-adherent or partially adherent with oral antipsychotics.


METHODS
A 1-year micro-simulation economic decision model was developed to simulate the dynamics of usual care of patients with schizophrenia who continue, discontinue, switch, or restart their medication. The model uses a range of clinical and cost parameters including adherence levels, relapse with and without hospitalization, quality-adjusted life years (QALYs), treatment discontinuation rates by reason, treatment-emergent adverse events, suicide, health care resource utilization, and direct health care costs. Published medical literature and a clinical expert panel were used to develop baseline model assumptions.


METHODS
Key model outputs include annual total direct cost (US$) per treatment and incremental cost-effectiveness values per additional QALY gained.


RESULTS
Model results found that the olanzapine-LAI treatment strategy was more effective (greater QALYs) and less costly than risperidone-LAI, paliperidone-LAI, and haloperidol-LAI. In addition, olanzapine-LAI was both more effective and more costly, with an estimated incremental cost/QALY of $26,824 compared to oral olanzapine. The base-case and multiple sensitivity analyses found olanzapine-LAI to remain within acceptable cost-effective ranges (<$50,000) in terms of incremental cost/QALY gained.


CONCLUSIONS
This micro-simulation model finds the olanzapine-LAI treatment strategy to result in better effectiveness and to be a cost-effective alternative compared to oral olanzapine and the LAI formulations of risperidone, paliperidone, and haloperidol in the treatment of non-adherent and partially adherent patients with schizophrenia in the United States. A key limitation is the assumption how LAI therapies compare to oral counterparts due to sparse head-to-head data. Further research is needed to verify baseline assumptions.
Medical Decision Modeling Inc., Indianapolis, IN, USA.
Nicolas M
NM
Furiak
Haya
H
Ascher-Svanum
Robert W
RW
Klein
Lee J
LJ
Smolen
Anthony H
AH
Lawson
William
W
Montgomery
Robert R
RR
Conley
D000465:Algorithms; D014150:Antipsychotic Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000191:economics; D001569:Benzodiazepines / Q000008:administration & dosage* / Q000009:adverse effects / Q000191:economics*; D002626:Chemistry, Pharmaceutical; D003198:Computer Simulation; D003362:Cost-Benefit Analysis; D003661:Decision Support Techniques; D006801:Humans; D007267:Injections / Q000191:economics; D055118:Medication Adherence; D018803:Models, Economic; D000077152:Olanzapine; D012559:Schizophrenia / Q000188:drug therapy* / Q000191:economics*; D014481:United States
D014150:Antipsychotic Agents; D001569:Benzodiazepines; D000077152:Olanzapine