Early indicators of high-risk opioid use include obtaining similar opioids from multiple dispensers, both pharmacy and nonpharmacy, and overlapping opioid prescriptions, according to a study released Wednesday by the Workers’ Compensation Insurance Rating Bureau of California.

The Oakland, California-based ratings bureau compared high-risk to lower-dose opioid use claims with similar distributions of age, pain type and types of major surgery, it said in a statement.

The bureau found that both accident year 2013 and accident year 2016 high-risk opioid use claims were twice more likely to get similar opioids from two pharmacies than lower-dose use claims and almost four times more likely to involve three or more pharmacies. Similar patterns were found for non-pharmacy dispensers.

Researchers also found that claims involving high-risk opioid use were about four times more likely to have multiple similar opioids prescribed concurrently, and they were six times more likely to concurrently use three or more different opioids.

Other findings included:

• Using extended-release or long-acting opioids is a risk factor; for accident year 2013 claims, high-risk opioid use claims were three times more likely to involve ER/LA opioids than lower-dose use claims: 23% vs. 7%. For accident year 2016 claims, the differential use of ER/LA opioids was even more pronounced: 26% vs. 5%.
   
•  Also a risk factor is concurrently using opioids and benzodiazepines. Among accident year 2013 claims, high-risk opioid use claims were almost five times more likely to take opioids and benzodiazepines concurrently. In accident year 2016 that figure was seven times more likely.
   
• About 2.5% of all accident year 2013 claims with any opioid prescription involved high-risk opioid use within 12 months of the date of the injury compared with 1.4% of accident year 2016 claims.
   
• High-risk opioid use claims incurred “significantly” higher medical and indemnity costs than similar lower-dose use claims, and they tended to remain open longer. For accident year 2013 claims, about 87% of high-risk use claims were open one year after the injury as compared to 65% of similar lower-dose use claims.
   
• High-risk opioid use claims were much more likely to involve permanent disability benefits than similar lower-dose claims. For example, one year after the injury, about 55% of accident year 2013 high-risk opioid use claims involved permanent disability as compared to 40% of similar lower-dose use claims.
   
• Physical therapy, acupuncture and chiropractic services — as well as nonsteroidal anti-inflammatory drugs and non-narcotics — were used significantly more on similar lower-dose use claims than on high-risk use claims.