Effect of Copayments on Use of Outpatient Mental Health Services Among Elderly Managed Care Enrollees

Recent parity legislation will require many insurers and the federal Medicare program to reduce mental health copayments, so that they are equivalent to copayments for other covered services. The effect of changes in mental health cost sharing has not been well studied, particularly among elderly populations.To examine the consequences of increasing and decreasing copayments on the use of outpatient mental health services among the elderly.Difference-in-differences (DID) design comparing the use of outpatient mental health care in Medicare plans that changed mental health copayments compared with concurrent trends in matched control plans with unchanged copayments.A total of 1,147,916 enrollees aged 65 years and older in 14 Medicare plans that increased copayments by ≥ 25%, 3 plans that decreased copayments by ≥ 25%, and 17 matched control plans with unchanged copayments.In 14 plans that increased mental health copayments from a mean of $14.43 to $21.07, the proportion of enrollees who used mental health services remained at 2.2% in the year before and year after the increase (adjusted DID, 0.1 percentage points; 95% confidence interval, 0.0-0.1). Among 3 plans that decreased copayments from a mean of $25.00 to $8.33, utilization rates were 1.2% before and after the decrease (adjusted DID, 0.1 percentage points; 95% confidence interval, -0.2 to 0.3). Stratified analyses by age, gender, race, and presence of a disability yielded similar results.Few older adults in managed care plans used outpatient mental health services. Among this population, increasing or decreasing mental health copayments had negligible effects on the likelihood of using outpatient mental health care.