An insurance policy limit on lumbar fusion procedures helped slash costs and medically unnecessary surgeries in North Carolina, and the approach could work nationally, according to new research published in the journal Spine.

“The commercial insurance policy change had its intended effect of reducing fusion operations for indications with less evidence of effectiveness, without changing rates for other indications or resulting in an overall reduction in spine surgery,” the authors wrote. “Broader adoption of the policy could significantly reduce the national rates of fusion operations and associated costs.”

Researchers analyzed North Carolina’s inpatient database from 2005 through 2012, plus the Nationwide Inpatient Sample, including all inpatient lumbar fusion admissions from nonfederal hospitals. Specifically, the authors looked at adults undergoing elective lumbar fusion or re-fusion operations.

They found that lumbar fusion for herniated discs saw a “substantial decline” after the commercial policy change limiting lumbar fusion for some indications hit Jan. 1, 2011.

Before that point, overall rates of elective lumbar fusion operations in North Carolina had jumped 16.7% from 103.2 per 100,000 residents in 2005 to 120.4 in 2009. By 2012, the number dropped -15.4% to 101.9, -1.3% below the 2005 rate.

The numbers were even more dramatic for younger patients. Rates of elective lumber fusion operations in patients under age 65 jumped 13.1% from 89.5 per 100,000 residents in 2005 to 101.2 in 2009. After the policy limit kicked in, the number dropped -24.1% to 76.8 in 2012, -14.2% below the rate in 2005.

Significantly, the researchers didn’t track any acceleration in the rate of fusion for spinal stenosis (which was already increasing), spondylolisthesis, or revision procedures. At the same time, there was a spike in decompression without fusion.