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

Abstract

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

Methods: 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.

Results: 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.

Conclusion: 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.

Figure 1

Examples of clinical criteria for prior authorization from two representative states.

Figure 2

Trends in DMARD prescriptions and spending in Medicaid from 1999 to 2005. Figure 2a shows, for each calendar quarter, the number of Medicaid-covered prescriptions for etanercept, for adalimumab, and for all other DMARDs. Figure 2b shows the same trends for total spending.

Figure 2

Trends in DMARD prescriptions and spending in Medicaid from 1999 to 2005. Figure 2a shows, for each calendar quarter, the number of Medicaid-covered prescriptions for etanercept, for adalimumab, and for all other DMARDs. Figure 2b shows the same trends for total spending.

Figure 3

Proportion of Medicaid DMARD prescriptions (figure 3a) and spending (figure 3b) accounted for by etanercept and adalimumab in 1999 and 2005, according to prior authorization policy status. In each panel of the figure, the left-most pair of bars shows data for the 31 states that did not implement prior authorization for adalimumab or etanercept. The next pair of bars shows data for the 2 states with prior authorization in place in 1999. The third pair of bars shows data for the 9 states that implemented prior authorization for adalimumab and etanercept between 2000 and 2004. The final pair of bars shows data for the 7 states that implemented prior authorization in 2005 or later.

Figure 3

Proportion of Medicaid DMARD prescriptions (figure 3a) and spending (figure 3b) accounted for by etanercept and adalimumab in 1999 and 2005, according to prior authorization policy status. In each panel of the figure, the left-most pair of bars shows data for the 31 states that did not implement prior authorization for adalimumab or etanercept. The next pair of bars shows data for the 2 states with prior authorization in place in 1999. The third pair of bars shows data for the 9 states that implemented prior authorization for adalimumab and etanercept between 2000 and 2004. The final pair of bars shows data for the 7 states that implemented prior authorization in 2005 or later.