Cost-effectiveness and cost offset of a collaborative care intervention for primary care patients with panic disorder.

A collaborative care (CC) intervention for patients with panic disorder that provided increased patient education and integrated a psychiatrist into primary care was associated with improved symptomatic and functional outcomes. This report evaluates the incremental cost-effectiveness and potential cost offset of a CC treatment program for primary care patients with panic disorder from the perspective of the payer. We randomly assigned 115 primary care patients with panic disorder to a CC intervention that included systematic patient education and approximately 2 visits with an on-site consulting psychiatrist, compared with usual primary care. Telephone assessments of clinical outcomes were performed at 3, 6, 9, and 12 months. Use of health care services and costs were assessed using administrative data from the primary care clinics and self-report data. Patients receiving CC experienced a mean of 74.2 more anxiety-free days during the 12-month intervention (95% confidence interval [CI], 15.8-122.0). The incremental mental health cost of the CC intervention was $205 (95% CI, -$135 to $501), with the additional mental health costs of the intervention explained by expenditures for antidepressant medication and outpatient mental health visits. Total outpatient cost was $325 (95% CI, -$1460 to $448) less for the CC than for the usual care group. The incremental cost-effectiveness ratio for total ambulatory cost was -$4 (95% CI, -$23 to $14) per anxiety-free day. Results of a bootstrap analysis suggested a 0.70 probability that the CC intervention was dominant (eg, lower costs and greater effectiveness). A CC intervention for patients with panic disorder was associated with significantly more anxiety-free days, no significant differences in total outpatient costs, and a distribution of the cost-effectiveness ratio based on total outpatient costs that suggests a 70% probability that the intervention was dominant, compared with usual care.