Antidepressant pharmacotherapy: economic outcomes in a health maintenance organization

Recent pharmacotherapeutic advances in the treatment of depression have included the development of selective serotonin re-uptake inhibitors (SSRIs). The present study was designed to contrast direct health service expenditures for the treatment of depression among patients enrolled in a health maintenance organization (HMO) and prescribed either the SSRI fluoxetine or one of three tricyclic antidepressants (TCAs) (amitriptyline, nortriptyline, or desipramine). Information regarding health service utilization was derived from the computer archive of a network-model HMO system serving 400,000 beneficiaries. A total of 701 HMO beneficiaries were found to satisfy the study selection criteria. Multivariate regression analysis was used to discern the incremental influence of selected demographic, clinical, financial, and provider characteristics on 1 year post-period expenditures (PPE) for health care. Analysis-of-variance procedures with Duncan's multiple-range test, or chi-square analyses, revealed no significant difference across antidepressant pharmacotherapy for age, sex, 6-month prior-period expenditures for physician visits, psychiatric visits, laboratory tests, hospitalizations, or psychiatric hospital services related to the treatment of depression, or number of prescribed therapeutic agents for disease state processes other than depression. Receipt of fluoxetine was associated with a significantly (P < or = 0.05) higher rate of initial prescribing by psychiatrists, an increase in the number of prescriptions for antidepressant pharmacotherapy obtained (30-day supplies), and a reduction in the number of monthly intervals during which time antidepressant pharmacotherapy was not procured. Receipt of fluoxetine as antidepressant pharmacotherapy was associated with a significantly (P < or = 0.05) higher mean medication possession ratio (MPR) relative to amitriptyline, nortriptyline, or desipramine. Multivariate findings for patient-level data reflecting a definitive diagnosis of depression (n = 555) indicate that receipt of a TCA resulted in a significant (P < or = 0.05) increase in the use of physician visits ($36.07), psychiatric visits ($41.38), laboratory tests ($1.71), hospitalizations ($208.77), and psychiatric hospital services ($187.27), and a significant (P < or = 0.05) reduction in expenditures for antidepressant pharmacotherapy (-$162.21), for a total increase in health service utilization of $312.99 (P < or = 0.05) 1 year post-initiation of antidepressant pharmacotherapy.(ABSTRACT TRUNCATED AT 250 WORDS)