Trends in Opioid Dosing Among Washington State Medicaid Patients Before and After Opioid Dosing Guideline Implementation.

Abstract

By 2007, opioid-related mortality in Washington state (WA) was 50% higher than the national average, with Medicaid patients showing nearly 6 times the mortality of commercially-insured patients. In 2007, the WA Interagency Guideline on Opioid Dosing for Chronic Non-cancer Pain was released, which recommended caution in prescribing >120mg morphine-equivalent dose per day for patients not showing clinically meaningful improvement in pain and function. We report on opioid dosing in the WA Medicaid fee-for-service population for 273,200 adults with a paid claim for an opioid prescription between April 1, 2006 and December 31, 2010. Linear regression was used to test for trends in dosing over that time period, with quarter-year as the independent variable and median daily dose as the dependent variable. Prescription opioid use among WA Medicaid adults peaked in 2009, as evidenced by the unique number of opioid users (105,232), the total number of prescriptions (556,712), and the total person-years of prescription opioid use (29,442). Median opioid dose was unchanged from 2006 to 2010 at 37.5mg morphine-equivalent dose, but doses at the 75th, 90th, 95th, and 99th percentiles declined significantly (P<.001). These results suggest that opioid treatment guidelines with dosing guidance may be able to reduce high-dose opioid use without affecting the median dose used. Some fear that opioid dosing guidelines might restrict access to opioid therapy for patients who could benefit. However, there is evidence that high-dose opioid therapy entails significant risks without demonstrated benefit. These findings indicate that high-dose opioid therapy can be reduced without altering median opioid dose in a Medicaid population.