Context: Depression is a leading cause of functional impairment in elderly individuals and is associated with high medical costs, but there are large gaps in quality of treatment in primary care.
Objective: To determine the incremental cost-effectiveness of the Improving Mood Promoting Access to Collaborative Treatment (IMPACT) collaborative care management program for late-life depression.
Design: Randomized controlled trial with recruitment from July 1999 to August 2001.
Setting: Eighteen primary care clinics from 8 health care organizations in 5 states.
Participants: A total of 1801 patients 60 years or older with major depression (17%), dysthymic disorder (30%), or both (53%).
Intervention: Patients were randomly assigned to the IMPACT intervention (n = 906) or to usual primary care (n = 895). Intervention patients were provided access to a depression care manager supervised by a psychiatrist and primary care physician. Depression care managers offered education, support of antidepressant medications prescribed in primary care, and problem-solving treatment in primary care (a brief psychotherapy).
Main outcome measures: Total outpatient costs, depression-free days, and quality-adjusted life-years.
Results: Relative to usual care, intervention patients experienced 107 (95% confidence interval [CI], 86 to 128) more depression-free days over 24 months. Total outpatient costs were USD $295 (95% CI, -$525 to $1115) higher during this period. The incremental outpatient cost per depression-free day was USD $2.76 (95% CI, -$4.95 to $10.47) and incremental outpatient costs per quality-adjusted life-year ranged from USD $2519 (95% CI, -$4517 to $9554) to USD $5037 (95% CI, -$9034 to $19 108). Results of a bootstrap analysis suggested a 25% probability that the IMPACT intervention was "dominant" (ie, lower costs and greater effectiveness).
Conclusions: The IMPACT intervention is a high-value investment for older adults; it is associated with high clinical benefits at a low increment in health care costs.