US regional variations in rates, outcomes, and costs of spinal arthrodesis for lumbar spinal stenosis in working adults aged 40-65 years.

OBJECTIVE It is important to identify differences in the treatment of common diseases over time and across geographic regions. Several studies have reported increased use of arthrodesis to treat lumbar spinal stenosis (LSS). The purpose of this study was to investigate geographic variations in the treatment of LSS by US region. METHODS The authors reviewed inpatient and outpatient medical claims from 2010 to 2014 using the MarketScan Commercial Claims and Encounters database (Truven Health Analytics), which includes data on commercially insured members younger than 65 years. ICD-9 code 724.02 was used to identify patients aged >= 40 and < 65 years who underwent surgery for "spinal stenosis of the lumbar region" and for whom LSS was the only principal diagnosis. The primary outcome was the performance of spinal arthrodesis as part of the procedure. Geographic regions were based on patient residence and defined according to the US Census Bureau as the Northeast, Midwest, South, and West. RESULTS Rates of arthrodesis, as opposed to decompression alone, varied significantly by region, from 48% in the South, to 42% in the Midwest, 36% in the Northeast, and 31% in the West. After controlling for patient age, sex, and Charlson Comorbidity Index values, the differences remained significant. Compared with patients in the Northeast, those in the South (OR 1.6, 95% CI 1.50-1.75) and Midwest (OR 1.3, 95% CI 1.18-1.41) were significantly more likely to undergo spinal arthrodesis. On multivariate analysis, patients in the West were significantly less likely to have a prolonged hospital stay (> 3 days) than those in the Northeast (OR 0.84, 95% CI 0.75-0.94). Compared with the rate in the Northeast, the rates of discharge to a skilled nursing facility were lower in the South (OR 0.41, 95% CI 0.31-0.55) and West (OR 0.72, 95% CI 0.53-0.98). The 30-day readmission rate was significantly lower in the West (OR 0.81, 95% CI 0.65-0.98) than in the Northeast and similar between the other regions. Mean payments were significantly higher in the Midwest (mean difference $5503, 95% CI $4279-$6762), South (mean difference $6187, 95% CI $5041-$7332), and West (mean difference $7732, 95% CI $6384-$9080) than in the Northeast. CONCLUSIONS The use of spinal arthrodesis, as well as surgical outcomes and payments for the treatment of LSS, varies significantly by US region. This highlights the importance of developing national recommendations for the treatment of LSS.