Oakland – A new California Workers’ Compensation Institute (CWCI) study finds that non-steroidal anti-inflammatories (NSAIDs) have supplanted opioids as the most common therapeutic drug group prescribed to injured workers in California, while payment data show that both dermatological medications and anticonvulsants now rank ahead of opioids in terms of total reimbursements.  

Using data from 5.75 million prescriptions dispensed to California injured workers from 2009 to June 2018, CWCI analysts examined changes in the prescription and payment distributions among therapeutic drug groups, identified trends in the use of generics, and determined average amounts paid for drugs within each drug group over the past decade.  The results show that efforts to curb inappropriate use of opioids – tighter scrutiny via utilization review and independent medical review; restrictions by payers, medical provider networks, pharmacy benefit managers and in the Medical Treatment Utilization Schedule (MTUS) formulary; and growing awareness of opioid risks – are continuing to have an effect, as opioids fell to 18.0% of the prescriptions filled in the first half of 2018, down from 20.2% in 2017, and down from 30.5% a decade ago.  Conversely, NSAIDs, often prescribed as non-opioid alternatives to treat pain, surpassed opioids as the top drug group in California workers’ compensation in 2016, and since then, their share of the prescriptions has continued to grow, climbing to a record 31.7% of the drugs dispensed to injured workers in the first half of 2018.  Anticonvulsants’ share of the prescriptions also has increased, more than doubling from 4.1% in 2009 to 9.7% in the first half of 2018, likely due to their growing use as a non-opioid alternative to treat neuropathic pain.  The 2018 data show anticonvulsants were the third most prescribed drug group, moving ahead of muscle relaxants, which under the MTUS formulary that took effect on January 1, 2018, are not exempt from utilization review, with the exception of limited special fill or perioperative allowances that restrict the quantity of the drug that can be dispensed.   

Aside from the changing mix of drugs used to treat injured workers, CWCI’s study also found shifts in the distribution of prescription payments.  A decade ago, dermatological products accounted for 10.1% of the total drug spend in California workers’ compensation, and were the fourth most costly drug group behind opioids, NSAIDs, and ulcer drugs.  In the first half of 2018, however, that proportion was up to 17.6%, making dermatologicals the top drug group in terms of total payments.  Until a few years ago, growth in dermatological payments was largely driven by high-cost “custom” pharmacy compounded drugs, but with legislative changes that took effect in 2012 (AB 378), high-profile indictments involving compounded drug kickbacks, and more public awareness, custom compounds have become less prevalent, though the study notes two other factors now underlie the continued growth in dermatologlical payments:  

• the increased prevalence of high-cost, mass-produced private label topicals containing one or more active ingredients (e.g., capsaicin, lidocaine, menthol, or methyl salicylate) commonly found in over-the-counter topical analgesics, which are marketed to physicians for in-office or mail order dispensing; and

• increased payments for topicals containing a prescription NSAID (e.g., diclofenac) which are available in a number of formulations and strengths, some of which are exempt from utilization review under the formulary.

In addition to the increasing share of the workers’ compensation prescription dollars going toward dermatologicals, the study also found that anticonvulsants’ share of the drug spend tripled from 4.8% in 2009 to 15.2% in the first half of 2018, so anticonvulsants now rank ahead of opioids as the second most costly drug group.  The data show that most of the growth in anticonvulsant’s share of the payments occurred over the past four years, coinciding with the decline in opioid use, suggesting the use of certain anticonvulsants in place of opioids.  Notably, anticonvulsant prescriptions used in California workers’ comp are heavily concentrated in just two drugs, one of which is only available as a brand drug, and that drug accounted for nearly three quarters of the anticonvulsant dollars paid in the first half of 2018.      

CWCI has published its study in a Research Update report, “California Workers’ Comp Prescription Drug Utilization and Payment Distributions, 2009-2018: Part 1.”  The free report can be downloaded from the Research section at www.cwci.org.