This study examined the effects of prior authorization for second-generation anti-psychotic and anti-convulsant on utilization, discontinuations in therapy, and pharmacy costs among Maine Medicaid beneficiaries with bipolar disorder.  The study found that the prior authorization policy resulted in an 8 percent the prevalence of use of non-preferred second generation drugs but did not increase the rate of use for preferred drugs or the rate of switching.  The policy reduced total pharmacy reimbursements for bipolar disorder by $27 per patient during the eight-month policy period but the hazard rate of treatment discontinuation was higher than during the pre-policy period.  The authors conclude that the use of prior authorization in Maine may have increased patient risk without significant cost savings to the Medicaid program. 

Zhang, Y., et. al. (2009). Effects of prior authorization on medication discontinuation among Medicaid beneficiaries with bipolar disorder. Psychiatric Services, 60(4): 520-7.  DOI: 10.1176/appi.ps.60.4.520 http://psychservices.psychiatryonline.org/cgi/content/abstract/60/4/520 

Authors: Yuting Zhang, Alyce S. Adams, Dennis Ross-Degnan, Fang Zhang, Stephen B. Soumerai