Course of antidepressant treatment with tricyclic versus selective serotonin reuptake inhibitor agents: a comparison in managed care and fee-for-service environments.
We compared course of treatment with tricyclic antidepressant drugs (TCADs) and selective serotonin reuptake inhibitors (SSRIs) to assess interactive effects of antidepressant type with payer type and patient characteristics. A nationwide sampling of adults (n = 4,252) from approximately equal numbers of health maintenance organization (HMO) and indemnity enrollees were prescribed no antidepressants for 9 months, and thereafter prescribed a TCAD or SSRI. Using a retrospective analysis of prescription claims, these cohorts of TCAD and SSRI utilizers were followed for 13 to 16 months after their initial antidepressant prescription. Outcome measures included (1) termination of antidepressant treatment before 1 month; and (2) failure to receive at least one therapeutic dose during treatment lasting 3 months or more. Rates of premature termination and subtherapeutic dosing were significantly higher for TCAD-treated than SSRI-treated patients, and for HMO than indemnity enrollees. The interaction of HMO enrollment and TCAD use was associated with particularly high rates. Excluding patients terminating in the first month, the proportions of TCAD and SSRI utilizers remaining in treatment over time were not significantly different. We conclude that SSRIs may provide advantages in treatment adherence and therapeutic dosing, particularly in environments with limited prescriber time. The first month of treatment may be especially critical in determining compliance.