Increased Volume of Surgery for Lumbar Spinal Stenosis and Changes in Surgical Methods and Outcomes: A Nationwide Cohort Study with a 5-Year Follow-Up

World Neurosurg. 2018 Nov:119:e313-e322. doi: 10.1016/j.wneu.2018.07.139. Epub 2018 Jul 24.

Abstract

Objective: Examining spine surgery patterns over time is crucial to provide insights into variations and changes in clinical decision making. Changes in the number of surgeries, surgical methods, reoperation rates, and cost-effectiveness were analyzed for all patients who underwent surgery for lumbar spinal stenosis without spondylolisthesis in 2003 (2003 cohort) and 2008 (2008 cohort).

Methods: The national health insurance database was used to create the 2003 cohort (n = 10,990) and 2008 cohort (n = 27,942). The surgical methods were classified into decompression and fusion surgery. The cumulative reoperation probability between those surgeries was calculated using the Kaplan-Meier method in the 2003 cohort and 2008 cohort. Comparison of the incremental cost-effectiveness ratios showed the additional direct cost of a 1% change in the reoperation probability.

Results: The surgical volume increased 2.54-fold in the 2008 cohort. The age-adjusted number of surgeries per 1 million people increased 2.6-fold (from 154 in the 2003 cohort to 399 in the 2008 cohort) in aged patients and 1.9-fold (from 154 in the 2003 cohort to 291 in the 2008 cohort) in patients 20-59 years old in the 2008 cohort. The proportion of fusion surgeries increased from 20.3% in the 2003 cohort to 37.0% in the 2008 cohort. In total, the 5-year reoperation probabilities increased from 8.1% in the 2003 cohort to 11.2% in the 2008 cohort. Fusion decreased the reoperation probability by 1% at the cost of 1,711 U.S. dollars.

Conclusions: The increased numbers of spinal surgeries, fusion surgeries, and surgeries in older patients in a recent cohort were noteworthy. However, the increased surgical volume and fusion surgeries did not reduce the reoperation rate.

Keywords: Cost-effectiveness; Lumbar vertebrae; Operation; Reoperation; Spinal fusion; Spinal stenosis; Spine.

MeSH terms

  • Adult
  • Age Distribution
  • Aged
  • Cohort Studies
  • Cost-Benefit Analysis
  • Decompression, Surgical / economics
  • Decompression, Surgical / methods*
  • Female
  • Humans
  • Insurance, Health / statistics & numerical data
  • Male
  • Middle Aged
  • Proportional Hazards Models
  • Reoperation / methods
  • Reoperation / statistics & numerical data
  • Spinal Fusion / methods*
  • Spinal Stenosis / economics
  • Spinal Stenosis / surgery*
  • Treatment Outcome*
  • Young Adult