To assess the effect of a mental health carve‐out on treatment patterns and quality of care for outpatient treatment of depression.
Outpatient and pharmaceutical claims from September 1993 through March 1997 for one large managed care organization in the Midwest that carved‐out mental health and substance abuse benefits in September 1995.
Using the treatment episode as the unit of analysis (=1,747), changes in treatment patterns associated with the change to a carve‐out were evaluated. Logistic regression was used to assess whether in the postperiod a treatment episode was more likely to be treated with (1) an antidepressant and (2) a type and intensity of treatment with proven efficacy. To strengthen confidence in a causal relationship, I search for structural breaks in treatment patterns across a wide range of dates, assuming no a priori knowledge of the timing of the impact of the carve‐out.
I find the carve‐out to be associated with an increase in the use of drug treatments. Although I find a decrease in the use of guideline‐level treatment over the entire study period, there is an increase in the number of episodes treated with guideline‐level treatment over what would be the case in the absence of the carve‐out.
The increase in the use of drug treatments suggests previous research that excluded these costs may have overestimated the savings attributable to carve‐outs. Guideline‐level care appeared to increase as a result of carve‐out implementation suggesting the use of management and specialization to reduce costs is not antithetical to quality improvement.