Psychotropic medication spending among dual enrollees has contributed to the rising popularity of prior authorization (PA) among Medicaid and Medicare Part D plans.(1
) Under PA, pre-approval is required for reimbursement of prescriptions for particular drugs or drug categories. Despite their widespread use, few studies have examined the impact of PA policies on rates of medication use and health outcomes among vulnerable Medicaid and Medicare enrollees.(3
) In a recent study of Medicaid enrollees with schizophrenia, we observed increased gaps in treatment associated with prior authorization requirements for atypical antipsychotic medications.(5
) Non-elderly disabled dual enrollees may be especially vulnerable to PA-related disruptions in therapy due to a higher reliance on psychotropic medications, high prevalence of complex co-morbidities, and lower socioeconomic status, which may inhibit their ability to navigate changes in coverage.(2
) The heightened vulnerability of dual enrollees has sparked concerns about their random assignment to Medicare Part D plans, many of which require PA for mental health drugs.(6
The purpose of the current study was to evaluate the impact of the Michigan PA for non-preferred antidepressants among non-elderly disabled dual enrollees. In March 2002, the Michigan Medicaid program began requiring prior approval for new prescriptions of non-preferred antidepressants, including commonly used selective serotonin reuptake inhibitors (SSRIs) [citalopram (Celexa), fluvoxamine (Luvox), brand fluoxetine (Prozac, Sarafem), and sertraline (Zoloft)] and venlafaxine (serotonin norepinephrine reuptake inhibitor, SNRI). Preferred agents included generic fluoxetine (newly off patent) and paroxetine (Paxil, Paxil CR).(7
Federal rules required the state to respond to clinician requests for prior authorization within 24 hours and to provide a 72-hour emergency drug supply while the request was being processed. In addition, Michigan Medicaid grandfathered or excluded from the policy patients already established on non-preferred medications. Following policy implementation, patient advocacy groups reported barriers to medication access resulting from the Michigan antidepressant PA.(7
) In late June of 2003, after clinical review of the PDL, the Medicaid Director announced the removal of prior approval for antidepressants and other mental health medications, stating that “Making more of these critical drugs available without the need for prior-authorization helps to avoid possible setbacks in care due to changes in drug treatment therapy.”(8
) To date, an external evaluation of this policy has not been published.
Based on our previous study,(5
) we hypothesized that the policy would reduce the use of non-preferred SSRI/SNRI agents among dual enrollees. However, we also hypothesized that problems in the implementation of the PA policy may have resulted in short-term disruptions in treatment, including unintended switching of antidepressants among established users, and lower rates of initiation of antidepressant treatment.
Among newly treated dual enrollees, the population targeted by the policy, we investigated the impact of the policy on patterns of medication use (i.e., switching/augmentation, discontinuation, persistence) and use of non-drug health services (i.e., hospitalization, emergency room admission). We hypothesized that the policy may result in treatment disruptions that may reflect differences in treatment effectiveness, confusion about the policy and other factors. Finally, we hypothesized that undesired changes in medication use (i.e., early discontinuation) may have resulted in adverse health events (e.g., hospitalization, emergency room use) within this vulnerable subset of Medicaid patients.