A Markov Process Analysis Comparing the Cost Effectiveness of Maintenance Therapy with Citalopram versus Standard Therapy in Major Depression

Abstract
The objective of this study was to demonstrate the cost effectiveness of long term maintenance treatment with citalopram versus standard therapy (defined as short term antidepressant treatment) in patients with major depression in Germany. We chose doxepin, amitriptyline and trimipramine as standard therapy because these drugs are the leading antidepressants in that country. A Markov process analysis was used to model health status and economic outcomes as they accrued over a 1-year follow-up period. The main outcome measures were time without depression, direct costs and indirect costs (work days lost). All costs were in 1993 Deutsche marks. The clinical data were obtained from the published literature and US clinical practice guidelines; the associated unit costs of the medical resources used were derived from official German tariff lists. The results show that, compared with standard therapy, long-term maintenance treatment with citalopram is associated with a mean increase in time without depression of 7.9% (8.2 vs 7.6 months). The total costs of maintenance treatment with citalopram were substantially lower than with standard therapy (DM7985 vs DM11,948 per patient per year. In addition, both the direct and indirect costs of maintenance treatment with citalopram (DM3764 vs DM4221 per patient, respectively) were lower than with standard therapy (DM4577 vs DM7371 per patient, respectively). In conclusion, the study demonstrates that one year's maintenance treatment with citalopram is both more effective and less costly than standard therapy in the treatment of patients with major depression.