Analyzing 850,000 claims, one large pharmacy benefits manager is reporting an 8.3% drop in prescription drugs costs in workers compensation in 2018, according to a report released Monday.

The drop — the largest in a decade — is attributed to three factors: a 4.1% increase in wholesale pricing making up the lowest drug inflation experienced in 10 years; a 7.3% decrease in drug utilization in comp; and a 5.1% decrease in “product and claim mix,” namely new clinical and intervention programs to improve drug overutilization and treatment, according to the report released by Optum Workers’ Comp and Auto No-fault Solutions.

The opioid spend also saw a record decrease of 18.8% in 2018, according to the Eden Prairie, Minnesota-based PBM. Overall, 43.3% of claims in 2018 included opioid prescriptions, down from 49.4% in 2017 and 53.7% in 2016, the report shows.

The PBM also noted increases of prescribing of opioid alternatives. Namely, the spend for anti-inflammatories increased from 14.7% in 2017 to 16.8% in 2018 and the spend for anticonvulsants increased from 10.7% to 11.1% over that same time, according to the report.

In 2018, generic utilization and generic efficiency percentage rates remain steady and high at 86.2% and 99.7%, respectively, according to the report. “Highlighting the importance of these numbers is the fact that, with every 1% increase in generic utilization there is a 3.5% decrease in spend,” the report states.