Geographic variation in the surgical management of lumbar spondylolisthesis: characterizing practice patterns and...

The role of arthrodesis in the surgical management of lumbar spondylolisthesis remains controversial. We hypothesized that practice patterns and outcomes for this patient population may vary widely.

This study aimed to characterize geographic variation in surgical practices and outcomes for patients with lumbar spondylolisthesis.

A retrospective analysis on a national longitudinal database between 2007 and 2014 was carried out.

We calculated arthrodesis rates, inpatient and long-term costs, and key quality indicators (eg, reoperation rates). Using linear and logistic regression models, we then calculated expected quality indicator values, adjusting for patient-level demographic factors, and compared these values with the observed values, to assess quality variation apart from differences in patient populations.

We identified a cohort of 67,077 patients (60.7% female, mean age of 59.8 years (standard deviation, 12.0) with lumbar spondylolisthesis who received either laminectomy or laminectomy with arthrodesis. The majority of patients received arthrodesis (91.8%). Actual rates of arthrodesis varied from 97.5% in South Dakota to 81.5% in Oregon. Geography remained a significant predictor of arthrodesis even after adjusting for demographic factors (p<.001). Marked geographic variation was also observed in initial costs ($32,485 in Alabama to $78,433 in Colorado), 2-year postoperative costs ($15,612 in Arkansas to $34,096 in New Jersey), length of hospital stay (2.6 days in Arkansas to 4.5 in Washington, D.C.), 30-day complication rates (9.5% in South Dakota to 22.4% in Maryland), 30-day readmission rates (2.5% in South Dakota to 13.6% in Connecticut), and reoperation rates (1.8% in Maine to 12.7% in Alabama).

There is marked geographic variation in the rates of arthrodesis in treatment of spondylolisthesis within the United States. This variation remains pronounced after accounting for patient-level demographic differences. Costs of surgery and quality outcomes also vary widely. Further study is necessary to understand the drivers of this variation.