Medical resource use and cost of venlafaxine or tricyclic antidepressant therapy - Following selective serotonin reuptake inhibitor therapy for depression

Objective: An analysis of administrative and claims data was performed to c ompare the resource use and costs to a managed-care organisation of venlafa xine, a serotonin and norepinephrine reuptake inhibitor (SNRI), versus tric yclic antidepressant (TCA) therapy. after switching from a selective seroto nin reuptake inhibitor (SSRI). Design: One-year costs and frequencies of all medical services, and of serv ices coded for depression, were compared between patients who received venl afaxine and TCA therapy as second-line therapy using bivariate and multivar iate statistical analyses. Setting: Data were obtained from 9 individual health plans with more than 1 .1 million covered lives affiliated with a national managed-care organisati on. Patients and participants: Health plan members were included if they had a diagnosis of depression between July 1993 and February 1997. They also had to have at least 2 months of prescriptions for SSRI therapy followed by at least 2 months of venlafaxine or TCA therapy, and continuous enrolment in t he plan from at least 6 months prior to 12 months following initiation of v enlafaxine or TCA therapy. 188 patients who received venlafaxine and 172 pa tients who received TCAs met the inclusion criteria. Main outcome measures and results: Patients who received TCAs were slightly but significantly older (43 vs 40 years) than venlafaxine recipients and, during 6 months prior to initiating therapy, had significantly higher mean costs coded for depression ($US451 vs $US311) and costs not coded for depre ssion ($US4500 vs $US2090). Psychiatrists prescribed a significantly higher proportion of venlafaxine than TCA prescriptions (46.3 vs 25.0%). Prior to adjusting for confounding characteristics, during 12 months following init iation of therapy, mean depression-coded costs were significantly higher fo r venlafaxine than TCA recipients ($US1948 vs $US1396) and mean costs not c oded for depression were significantly lower ($US4595 vs $US6677). Overall costs were not significantly different ($US6543 for venlafaxine vs $US8073 for TCA). Significant cost differences were observed with primary care phys icians as initial prescribers of second-line therapy but not with pychiatri sts. However, costs between the 2 groups were similar after adjusting for c onfounding variables, including prior 6-month costs and initial prescriber of second-line therapy. Conclusions: Payer costs are similar among patients receiving venlafaxine a nd TCA therapy following SSRI therapy. Higher costs of venlafaxine pharmaco therapy relative to TCA therapy may be offset by lower costs of other medic al services. Differences in prescribing patterns and costs between primary care physicians and psychiatrists warrant further investigation.