Report: Ibu Most Heavily Used Drug in California Workers’ Comp

New data shows the types of drugs used to treat injured workers in California, and the distribution of payments for those medications, has shifted over the past decade, with opioids becoming far less prevalent and anti-inflammatory drugs accounting for an increasing share of the prescriptions and the total drug spend within the workers’ comp system.

Updated figures from the California Workers’ Compensation Institute ranks top therapeutic drug categories in workers’ comp based on the volume of prescriptions and total reimbursements.

CWCI analysts compared the distributions of drugs dispensed from 2012 through 2021 to track how the mix of prescription drugs and drug payments in the system changed over the past decade. They noted more recent trends in prescription drug utilization and reimbursement.

The results show that NSAIDs, often used as non-narcotic alternatives to treat pain, surpassed opioids to become the top workers’ comp drug group in 2016, and in 2021 these alternatives increased to a record 34.0% of the prescriptions dispensed to injured workers in California.

The distribution of prescriptions by drug ingredient showed that most of the growth in NSAIDs over the past decade has been due to the increased use of inexpensive ibuprofen, which increased from 27.0% of all anti-inflammatories in 2012 to 41.2% of the NSAIDs dispensed in 2021, according to CWCI.

Ibuprofen is now the most heavily used drug in workers’ comp, accounting for 14.1% of all prescriptions dispensed last year, ranking well ahead of another NSAID, naproxen, which ranked second, accounting for 8.3% of the prescriptions dispensed to injured workers.

Opioids’ share of workers’ comp prescriptions fell to 10.2% last year. Most of the decline in opioid use within the past decade occurred between 2012 and 2019, as opioid’s share of the prescriptions has been relatively stable over the past three years, only edging down slightly from 11.7% to 10.2%, according to CWCI.

Anticonvulsants, dermatologicals, and antidepressants rounded out the top five most prescribed drug groups in 2021. Like NSAIDs, anticonvulsants and dermatologicals are often used to treat pain, and their share of the workers’ comp prescriptions has risen over the past decade, while antidepressants’ share, which ranged between 5.2% and 6.6% from 2012 through 2019, climbed to a record 8.0% in 2021 – the second year of the pandemic, according to the data.

Musculoskeletal drugs have fallen from 10.6% of all workers’ comp prescriptions in 2016 to 6.0% of the prescriptions last year, a drop that followed the state’s implementation of a workers’ comp formulary in 2017. The formulary made most prescriptions for musculoskeletal drugs subject to utilization review, with limited exceptions where they are allowed as special fill or perioperative drugs, according to CWCI.

Based on total payments, CWCI analysts found that the top 10 therapeutic drug groups combined for 77.9% of the total drug spend in 2021, down from 80.2% in 2012, when opioids consumed 26.2% of the prescription dollars (vs. 5.8% last year) and ulcer drugs accounted for 10.3% (vs. 6.3% in 2021). With opioid payments down, NSAID’s share of the prescription dollars jumped from 13.4% in 2012 to 25.0% in 2021, dermatological drugs jumped from 12.9% to 17.2%, and anticonvulsants’ share rose from 4.9% to 8.6%, data from the institute shows.

While ibuprofen and naproxen accounted for nearly two-thirds of all NSAIDs dispensed last year, average payments for these drugs were $12 and $47 respectively, making them relatively inexpensive.However, the CWCI found that as in 2020, two low-volume, high-priced NSAIDs, fenoprofen calcium and ketoprofen, made NSAIDs the most expensive drug category. In a 2021 study, CWCI noted that under the formulary, both these drugs are exempt from prospective utilization review and because they are not listed in the national Medicaid database, neither has a Federal Upper Limit, which would serve as a price control in California workers’ comp.

Instead, the drugs are reimbursed at 85% of the average wholesale price. CWCI says the impact of this can be seen in the average payment data from 2021, as the average payment for a fenoprofen calcium prescription was $1,487 and the average payment for a ketoprofen prescription was $1,073.

That means that fenoprofen calcium, which represented 0.5% of all workers’ comp prescriptions in 2021, accounted for 9.2% of the total drug spend, by far the largest percentage of any single drug, while ketoprofen, which represented 0.2% of the prescriptions, accounted for 3.0% of the total drug spend.