Background: "Parity" laws remove treatment limitations for mental health and substance-abuse services covered by commercial health plans. A number of studies of parity implementations have suggested that parity does not lead to large increases in utilization or expenditures for behavioral health services. However, less is known about how parity might affect changes in patients' choice of providers for behavioral health treatment.
Research design: We compared initiation and provider choice among 46,470 Oregonians who were affected by Oregon's 2007 parity law. Oregon is the only state to have enacted a parity law that places restrictions on how plans manage behavioral health services. This approach has been adopted federally in the Paul Wellstone and Pete Domenici Mental Health Parity and Addiction Equity Act. In 1 set of analyses, we assess initiation and provider choice using a difference-in-difference approach, with a matched group of commercially insured Oregonians who were exempt from parity. In a second set of analyses, we assess the impact of distance on provider choice.
Results: Overall, parity in Oregon was associated with a slight increase (0.5% to 0.8%) in initiations with masters-level specialists, and relatively little changes for generalist physicians, psychiatrists, and psychologists. Patients are particularly sensitive to distance for nonphysician specialists.
Conclusions: Our results suggest that the Paul Wellstone and Pete Domenici Mental Health Parity and Addiction Equity Act may lead to a shift in the use of nonphysician specialists and away from generalist physicians. The extent to which these changes occur is likely to be contingent on the ease and accessibility of nonphysician specialists.