Medicaid prior authorization and controlled-release oxycodone.

BACKGROUND: Since its introduction in 1996, controlled-release (CR) oxycodone use has increased steadily despite its high cost. To control use and expenditures, many Medicaid programs have implemented CR oxycodone prior authorization (PA) policies. Few studies evaluate Medicaid policies or compare lenient and strict policies in multiple states.
OBJECTIVE: To estimate the impact of PA on CR oxycodone use by Medicaid beneficiaries.
DESIGN: Secondary data analysis of 50 states' aggregate Medicaid prescription dispensing records,1996-2005. PA details were systematically collected. Regression and random effects meta-analyses estimated impact of strict and lenient PA policies on CR oxycodone use and expenditures. MEASURES: Change in rate of CR oxycodone use, proportion of long-acting opiates accounted for by CR oxycodone and average long-acting opiate dose expenditure.
RESULTS: In 2004, CR oxycodone accounted for 12.4% of all opiates and 32.2% of long-acting opiates dispensed to Medicaid beneficiaries. Over the study period its use increased, on average, 109% annually, and 21 states implemented PA. PA was associated with state-specific use changes ranging from -76% to 9%. In aggregate, PA was associated with a nonsignificant decrease in CR oxycodone use, a significant 8% decrease in CR oxycodone as a proportion of long-acting opiate doses, and a small but significant change of -$0.31 in average cost per long-acting opiate dose. Strict policies were associated with greater changes.
CONCLUSIONS: PA impact varied by state and was less dramatic than previously described Medicaid PA effects, suggesting CR oxycodone is relatively refractory to PA. A refined measure of such policies is needed to identify effective prescription management strategies.