The top 10% of doctors who prescribe Schedule II opioids for injured workers in California account for nearly 80% of all workers’ compensation prescriptions for these drugs, 87% of the morphine equivalents, and 88% of the associated payments according to a new California Workers’ Compensation Institute (CWCI) study. The study also found that nearly half of all Schedule II opioid prescriptions in California workers’ compensation are for minor back injury claims, even though the American College of Occupational and Environmental Medicine says the use of these drugs is “typically not useful in the sub-acute and chronic phases.”

Schedule II opioids are major narcotics such as oxycodone, fentanyl, morphine and methadone, which have limited FDA-approved medical uses and carry a high potential for addiction and abuse. Prior CWCI research showed that the use of these drugs in California workers’ compensation has skyrocketed in recent years, especially in back sprain and strain claims where they have increasingly been used to treat chronic, non-malignant pain. Such widespread use has raised concerns about whether Schedule II opioids are being prescribed appropriately, the long-term health effects on injured workers, and the growing cost of these medications, which rose from 3.8% of workers’ compensation prescription drug costs in 2005 to 23.6% in 2009.

In its new study, the authors examine the prescribing patterns of the doctors who write these prescriptions for injured workers, using data from a sample of 233,276 Schedule II opioid prescriptions dispensed to 16,890 injured workers in California between January 2005 and December 2009. The prescription data included the physician’s name and Drug Enforcement Agency number, so the researchers were able to identify the 9,174 physicians in the study sample who prescribed these drugs (42% of the claims involved more than one prescribing physician), and to calculate the average number of prescriptions, the average number of morphine equivalents (dosage levels) and the associated payments – both on a per claim and on a per physician basis. Claim and physician distributions were then developed based on the volume of opioids prescribed, which showed highly skewed results, with the top 10% of the physicians who prescribe these drugs, and the 10% of the claims with the highest volume of these prescriptions, accounting for the vast majority of the prescriptions, morphine equivalents and Schedule II opioid payments.

CWCI has published its study in a Research Update report, Prescribing Patterns of Schedule II Opioids in California Workers’ Compensation. The full report, including data tables, is available for free in the Research section of the California Workers’ Compensation Institute website, http://www.cwci.org/research.html.