The impact of parity on major depression treatment quality in the federal employees' health benefits program after parity implementation

Background: Since the 1990s, parity laws have been implemented to reduce inequities in mental health coverage compared with that for general medical conditions. It is unclear if parity under managed care is associated with improvements in mental health treatment quality. Major depressive disorder (MDD) is a prevalent but often undetected and undertreated and thus could potentially benefit from parity implementation. Objective: The objective of this study was to examine the association between parity implementation and changes in MDD treatment quality in the Federal Employees' Health Benefits (FEHB) Program. Methods: We conducted retrospective analyses of insurance claims data. Logistic regression models estimated quality changes for MDD-diagnosed enrollees from pre- to postparity. Subjects: Subjects included MDD-diagnosed FEHB insured enrollees, aged 18-64, across multiple states and 6 FEHB plans before (1999-2000) and after (2001-2002) parity implementation. Measures: Measures included receipt of any antidepressant or psychotherapy within a given calendar year of diagnosis; receipt of appropriate psychotherapy frequency/intensity and duration; and pharmacotherapy duration during acute-phase treatment episodes. Results: Postparity, several plans improved significantly in the likelihood of receiving antidepressant medication. In the acute-phase episodes, the greatest improvement was seen in the likelihood of follow up >= 4 months. Few or no other changes were observed in the acute-phase treatment intensity or duration quality measures. Conclusions: Parity under managed care was associated with modest improvements. The observed improvements were consistent with secular trends in MDD treatment. Whereas mental health parity is an important policy goal, these results highlight its limitations: improving the financing of care may not be sufficient to improve quality.