Effects of a commercial insurance policy restriction on lumbar fusion in North Carolina and the implications for national adoption

Study Design. An analysis of the State Inpatient Database of North Carolina, 2005 to 2012, and the Nationwide Inpatient Sample, including all inpatient lumbar fusion admissions from nonfederal hospitals. Objective. The aim of the study was to examine the influence of a major commercial policy change that restricted lumbar fusion for certain indications and to forecast the potential impact if the policy were adopted nationally. Summary of Background Data. Few studies have examined the effects of recent changes in commercial coverage policies that restrict the use of lumbar fusion. Methods. We included adults undergoing elective lumbar fusion or re-fusion operations in North Carolina. We aggregated data into a monthly time series to report changes in the rates and volume of lumbar fusion operations for disc herniation or degeneration, spinal stenosis, spondylolisthesis, or revision fusions. Time series regression models were used to test for significant changes in the use of fusion operation following a major commercial coverage policy change initiated on January 1, 2011. Results. There was a substantial decline in the use of lumbar fusion for disc herniation or degeneration following the policy change on January 1, 2011. Overall rates of elective lumbar fusion operations in North Carolina (per 100,000 residents) increased from 103.2 in 2005 to 120.4 in 2009, before declining to 101.9 by 2012. The population rate (per 100,000 residents) of fusion among those under age 65 increased from 89.5 in 2005 to 101.2 in 2009, followed by a sharp decline to 76.8 by 2012. There was no acceleration in the already increasing rate of fusion for spinal stenosis, spondylolisthesis, or revision procedures, but there was a coincident increase in decompression without fusion. Conclusion. This 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. Nevertheless, broader adoption of the policy could significantly reduce the national rates of fusion operations and associated costs.