Prior authorization for biologic disease-modifying antirheumatic drugs: a description of US Medicaid programs

To evaluate state Medicaid prior authorization programs for biologic disease-modifying antirheumatic drugs (DMARDs).

We obtained biologic DMARD prior authorization policy information from state Medicaid programs. Using aggregate Medicaid drug spending data, we calculated the proportion of DMARD prescriptions and spending attributed to adalimumab and etanercept in 1999 and 2005 and compared the changes in these proportions in states with and without prior authorization policies. Infliximab and other infused DMARDs were not included because of substantial missing data.

Thirty-two states required prior authorization for > or = 1 biologic DMARD, with wide variation in the specific agents covered and the criteria required for a drug to be authorized. There were 18 states with prior authorization requirements for adalimumab or etanercept. States that implemented prior authorization for these agents initially had lower use of the targeted medications, but use increased over time to a level similar to that in states that did not have prior authorization requirements.

States vary widely in their implementation of prior authorization policies to limit use of biologic DMARDs. Although it appears that these policies may have a short-term effect on the use of targeted medications, this effect does not appear to be sustained. The clinical impact and appropriateness of such policies is not clear from our data and should be studied further.