Pharmacoepidemiology and Pharmacoeconomics Research Unit, Centre de Recherche, Centre Hospitalier de l'Université de Montréal, Campus Hôtel-Dieu, Montreal, Quebec, Canada.
Empirical studies of antidepressant cost-effectiveness suggest that the use of venlafaxine may be no more costly than selective serotonin reuptake inhibitors (SSRIs) in the treatment of depression. The objectives of this study were to identify patients' characteristics and factors associated with the choice of antidepressant and to assess differences in persistence, healthcare utilization and direct medical costs associated with venlafaxine and SSRIs pharmacotherapy.
We examined demographic and clinical characteristics of patients (n = 17 144) who received both a diagnosis of depression and a prescription for venlafaxine or an SSRI between 1996 and 2004 using the Quebec health administrative databases. Logistic regression models were used to identify factors independently associated with the choice of antidepressant. Persistence to treatment and overall direct medical costs during 12 months after initiation of therapy were assessed using Cox proportional hazard and GLM models, respectively.
Age, sex, provider specialty, and prior 12-month healthcare utilization significantly influenced initial antidepressant choice. Fewer venlafaxine-treated patients discontinued their initial therapy relative to SSRIs' (persistence to initial treatment: 38.4% vs. 29.4% and 24.4% vs. 15.8% at 6 and 12 months, respectively; p