A new report shows large employers spent $2.6 billion to treat opioid addiction and overdoses in 2016 – an eightfold increase since 2004. More than half went to treat employees’ children.

The analysis released today by the nonpartisan Kaiser Family Foundation finds such spending cost companies and workers about $26 per enrollee in 2016. “Average inpatient expenses for opioid-addiction treatment totaled $16,104 per year in 2016, up from $5,809 in 2004,” the report said.

Employers have been limiting health-insurance coverage of opioids because of concerns about addiction. The report finds spending on opioid prescriptions falling 27 percent from a peak in 2009.

Among other findings in the Kaiser report: Older people account for the greatest use of opioids, with “22 percent of people age 55-64 having at least one opioid prescription in 2016.”

Researchers analyzed insurance claims from employers with more than 1,000 workers. Most are self-insured, meaning they assume the financial risk.

Workers share the costs. Steve Wojcik of the National Business Group on Health said for every $5 increase, employers typically cover $4 and pass $1 to workers.