Cost effectiveness of adjunctive quetiapine fumarate extended-release tablets with mood stabilizers in the maintenance treatment of bipolar I disorder.
BACKGROUND
Bipolar I disorder (BPD I) is a recurrent illness that affects 1% of the US population and constitutes a large economic burden. However, few studies have investigated the cost effectiveness of maintenance treatment options for BPD I.


OBJECTIVE
To determine the cost effectiveness of maintenance treatment with quetiapine fumarate extended-release (XR) tablets in combination with mood stabilizers (lithium or divalproex) in comparison with the following treatments: placebo in combination with lithium or divalproex; no maintenance treatment; lithium monotherapy; lamotrigine monotherapy; olanzapine monotherapy; and aripiprazole monotherapy.


METHODS
The analysis was conducted from the societal and payer perspectives in the US, using a Markov model. The model simulated a cohort of 1000 stabilized BPD I patients and estimated the quarterly risk in three health states: euthymia, mania and depression. Efficacy data were derived from two randomized, double-blind trials comparing quetiapine + lithium/divalproex with placebo + lithium/divalproex for up to 2 years, as well as other published literature. Resource data were extracted from published literature. Drug costs, hospitalizations and physician visits were among the direct costs. Indirect costs included absenteeism, and mortality rates included suicide. Benefits and costs were discounted at 3% and the price reference year was 2009. Endpoints included number of acute mood episodes, hospitalizations due to an acute mood event and costs per QALY. Probabilistic sensitivity analysis (PSA) was conducted to evaluate uncertainty in the model inputs.


RESULTS
Treatment with quetiapine XR + lithium/divalproex was associated with reductions in acute mania (46%), acute depression (41%) and related hospitalizations (44%) compared with placebo + lithium/divalproex, and similar reductions in events were observed relative to lithium monotherapy. In the base-case analysis from the payer perspective, the discounted incremental cost per QALY for quetiapine XR + lithium/divalproex compared with placebo + lithium/divalproex was $US22 959, and compared with lithium monotherapy was $US100 235, while all other comparators were dominated. PSA showed these results to be robust to select assumptions.


CONCLUSIONS
Quetiapine XR + lithium/divalproex may be a cost-effective maintenance treatment option for patients with BPD I.
Woodward
Tatia Chay
TC
United Biosource Corporation, Bethesda, Maryland, USA.
Tafesse
Eskinder
E
Quon
Peter
P
Lazarus
Arthur
A
D000041:Absenteeism; D018692:Antimanic Agents / Q000008:administration & dosage / Q000191:economics* / Q000627:therapeutic use*; D014150:Antipsychotic Agents / Q000008:administration & dosage / Q000191:economics / Q000627:therapeutic use; D000068180:Aripiprazole; D001569:Benzodiazepines / Q000008:administration & dosage / Q000191:economics / Q000627:therapeutic use; D001714:Bipolar Disorder / Q000188:drug therapy* / Q000191:economics* / Q000401:mortality; D003362:Cost-Benefit Analysis; D003692:Delayed-Action Preparations / Q000191:economics; D003987:Dibenzothiazepines / Q000008:administration & dosage / Q000191:economics* / Q000627:therapeutic use*; D004359:Drug Therapy, Combination / Q000191:economics; D005252:Fees, Pharmaceutical; D017048:Health Care Costs; D017722:Hospital Charges; D006801:Humans; D000077213:Lamotrigine; D018020:Lithium Compounds / Q000008:administration & dosage / Q000191:economics / Q000627:therapeutic use; D008390:Markov Chains; D018803:Models, Economic; D000077152:Olanzapine; D010879:Piperazines / Q000008:administration & dosage / Q000191:economics / Q000627:therapeutic use; D019057:Quality-Adjusted Life Years; D000069348:Quetiapine Fumarate; D015363:Quinolones / Q000008:administration & dosage / Q000191:economics / Q000627:therapeutic use; D012306:Risk; D013607:Tablets; D014227:Triazines / Q000008:administration & dosage / Q000191:economics / Q000627:therapeutic use; D014481:United States; D014635:Valproic Acid / Q000008:administration & dosage / Q000191:economics / Q000627:therapeutic use
D018692:Antimanic Agents; D014150:Antipsychotic Agents; D003692:Delayed-Action Preparations; D003987:Dibenzothiazepines; D018020:Lithium Compounds; D010879:Piperazines; D015363:Quinolones; D013607:Tablets; D014227:Triazines; D001569:Benzodiazepines; D000069348:Quetiapine Fumarate; D014635:Valproic Acid; D000068180:Aripiprazole; D000077152:Olanzapine; D000077213:Lamotrigine