Developing Thai Economic Model to Study Cost-Effectiveness of Switching to Bupropion Compared to Combination with Bupropion after the Failure of an SSRI for Major Depressive Disorder
Thawatchai Leelahanaj MD, MSc*
Affiliation : *Department of Psychiatry and Neurology, Phramongkutklao Hospital, Bangkok, Thailand
Objective : To present an economic model and cost-effectiveness estimates of switching to bupropion compared to combina-
tion with bupropion after failure of an SSRI for major depressive disorder (MDD).
Material and Method: An economic model was developed to simulate the transitions of Thai outpatients with nonpsychotic
MDD who had no remission or could not tolerate the SSRI citalopram and received either sustained-release bupropion
monotherapy as switching strategy or sustained-release bupropion plus citalopram as combination strategy. Clinical data
were obtained form 2 trials of the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) study. The four event
probabilities: remission rates, rates of non-remission, discontinuation rates due to intolerance, and incidence of serious
adverse events were estimated. Direct costs included drug cost, hospitalizations, and electroconvulsive therapy (ECT). The
primary outcome considered in the model was a remission of symptoms. Outputs were measured in terms of costs per
remission and costs per quality-adjusted life-years (QALYs).
Results : In the base-case analysis, the total direct costs with a bupropion switch were 22,937 THB per remission and 29,346
THB per remission with a bupropion combination. Compared with combination option, switching to bupropion also had
lower total cost per QALY (28,672 THB vs. 36,682 THB) and had cost saving of 21.8%. The incremental cost-effectiveness
of the combination regimen compared with the switching regimen was 6,409 THB per remission gained and 8,011 THB per
QALY gained. In a sensitivity analysis, combination strategy dominated switching strategy if the value of the transitional
probability of remission changed to a value of greater than 0.547.
Conclusion : The economic model indicated that treatment of MDD patients who fail to achieve remission from an SSRI with
a switch to bupropion is a cost-effectiveness treatment option compared with a combination of SSRI with bupropion.
Keywords : Cost-effectiveness, Bupropion, Switching, Combination, Major depressive disorder
