COMPARISON OF COSTS AND COST-EFFECTIVENESS OF OXCARBAZEPINE AND SODIUM VALPROATE FOR NEW/RECENT ONSET PARTIAL SEIZURES
Abstract number :
2.218
Submission category :
Year :
2002
Submission ID :
3496
Source :
www.aesnet.org
Presentation date :
12/7/2002 12:00:00 AM
Published date :
Dec 1, 2002, 06:00 AM
Authors :
Gary Bazalo, Rajesh Sachdeo, Sobin Chang, Krista Yokoyama, Joseph D[ssquote]Souza. Bazalo Consulting, Scotsdale, AZ; Neurology, Robert Wood Johnson Medical School, Piscataway, NJ; Health Economics & Outcomes Research, Novartis Pharmaceuticals Corporation,
RATIONALE: The objective of this study was to determine the comparative costs and cost effectiveness of oxcarbazepine (OXC) and sodium valproate (VPA) in the treatment of new and recent onset partial epileptic seizures.
METHODS: Low, moderate and high dose maintenance regimens were determined for each drug based upon prescription audit information captured in the prescribing physician[ssquote]s office. Unit drug costs based on wholesale acquisition costs were then used to compute a daily drug cost for each dosage level. A decision-analysis model using a Monte Carlo simulation was developed to evaluate the cost-effectiveness of OXC and VPA. The model contained the computed daily drug costs along with direct payer costs associated with initiation and maintenance of therapy, treatment of adverse events and switching from one drug to another due to poor seizure control or adverse events. The probabilities of maintaining seizure control and of experiencing adverse events were obtained from double blind clinical trials comparing OXC and VPA.
RESULTS: The average daily drug costs weighted over the three dosage levels were $4.72 ($1.49 to $7.66) for OXC and $3.17 ($2.45 to $3.87) for VPA. Total one year costs for OXC, including costs of adverse events and costs of switching drugs due to poor seizure control or adverse events were $3,511 for OXC and $5,931 for VPA. The computed number of months on initial therapy was 9.95 for OXC and 9.66 for VPA. The analysis was carried out to four years using the same probabilities for adverse events and seizure control. The four-year costs were $20,426 and $23,790 with 25.2 and 24.6 months of therapy for OXC and VPA respectively.
CONCLUSIONS: These findings suggest that OXC results in lower expected total costs compared to VPA when drug costs, evaluation and management, adverse events and costs of switching therapies are taken into account.
[Supported by: Novartis Pharmaceuticals Corporation]; (Disclosure: Salary - Novartis Pharmaceuticals Corporation, Consulting - Novartis Pharmaceuticals Corporation, Honoraria - Novartis Pharmaceuticals Corporation)