Cost-effectiveness of quetiapine with lithium or divalproex for maintenance treatment of bipolar I disorder.
BACKGROUND
Bipolar I disorder is a recurrent illness that affects 1% of the US population and constitutes a large economic burden. Few studies have investigated the cost-effectiveness of maintenance treatment options. The objective of this analysis was to assess the cost-effectiveness of quetiapine (QTP) in combination with lithium (Li) or divalproex (DVP) compared with that of Li or DVP alone for maintenance treatment of bipolar disorder.


METHODS
The cost-effectiveness of maintenance treatment with QTP in combination with Li or DVP was compared with placebo (PBO) in combination with Li or DVP from a US direct costs perspective using a Markov model. The model simulated a cohort of 1,000 stabilized patients with bipolar I disorder and estimated the quarterly risk in three health states: euthymia, mania, and depression. Efficacy data were derived from two randomized, double-blind, placebo-controlled trials comparing QTP + Li/DVP with PBO + Li/DVP for up to 2 years. Resource data were obtained from published literature. Direct costs included drug costs, hospitalizations, and physician visits. Outcomes and costs were discounted at 3% and the price reference year was 2007. Endpoints included the number of acute mood episodes, hospitalizations due to an acute mood event, and costs per quality-adjusted life-years. A probabilistic sensitivity analysis (PSA) was conducted to evaluate uncertainty.


RESULTS
In the base-case analysis, QTP + Li/DVP dominated PBO + Li/DVP. The PSA showed these results to be robust. In addition, treatment with QTP + Li/DVP was associated with reductions in acute manic episodes (46%), acute depressive episodes (41%), and related hospitalizations (44%) compared with PBO + Li/DVP.


CONCLUSIONS
These analyses, based on two randomized clinical trials, suggest that QTP + Li/DVP is a cost-effective maintenance treatment option for patients with bipolar I disorder compared with Li or DVP alone.
Woodward
Tatia Chay
TC
United Biosource Corporation, Bethesda, MD, USA.
Tafesse
Eskinder
E
Quon
Peter
P
Kim
Jennifer
J
Lazarus
Arthur
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D000927:Anticonvulsants / Q000191:economics / Q000627:therapeutic use; D014150:Antipsychotic Agents / Q000191:economics / Q000627:therapeutic use; D001714:Bipolar Disorder / Q000188:drug therapy* / Q000191:economics*; D003362:Cost-Benefit Analysis; D003987:Dibenzothiazepines / Q000191:economics* / Q000627:therapeutic use; D004359:Drug Therapy, Combination / Q000191:economics; D005260:Female; D006801:Humans; D018020:Lithium Compounds / Q000191:economics* / Q000627:therapeutic use; D008297:Male; D008390:Markov Chains; D008875:Middle Aged; D000069348:Quetiapine Fumarate; D012720:Severity of Illness Index; D014635:Valproic Acid / Q000191:economics* / Q000627:therapeutic use; D055815:Young Adult
D000927:Anticonvulsants; D014150:Antipsychotic Agents; D003987:Dibenzothiazepines; D018020:Lithium Compounds; D000069348:Quetiapine Fumarate; D014635:Valproic Acid