What is the treatment effect of surgery compared with nonoperative treatment in patients with lumbar spinal stenosis at 1-year follow-up?

Ulrike Held; Johann Steurer; Giuseppe Pichierri; Maria M Wertli; Mazda Farshad; Florian Brunner; Roman Guggenberger; François Porchet; Tamás F Fekete; Urs D Schmid; Isaac Gravestock; Jakob M Burgstaller

doi:10.3171/2019.1.SPINE181098

What is the treatment effect of surgery compared with nonoperative treatment in patients with lumbar spinal stenosis at 1-year follow-up?

J Neurosurg Spine. 2019 Apr 5;31(2):185-193. doi: 10.3171/2019.1.SPINE181098.

Authors

Affiliations

¹ 1Horten Centre for Patient Oriented Research and Knowledge Transfer, University of Zurich.
² 2Epidemiology, Biostatistics and Prevention Institute, Department of Biostatistics, University of Zurich.
³ 3Division of General Internal Medicine, Bern University Hospital, Bern University, Bern.
⁴ 4Spine Division, Balgrist University Hospital, Zurich.
⁵ 5Department of Physical Medicine and Rheumatology, Balgrist University Hospital, Zurich.
⁶ 6Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich.
⁷ 7Spine Unit, Department of Orthopedic Surgery and Neurosurgery, Schulthess Clinic, Zurich; and.
⁸ 8Department of Neurosurgery, Stadtspital Triemli, Zurich, Switzerland.

PMID: 30952135
DOI: 10.3171/2019.1.SPINE181098

Abstract

Objective: The aim of this study was to obtain an unbiased causal treatment estimate of the between-group difference of surgery versus nonoperative treatment with respect to outcomes on quality of life, pain, and disability in patients with degenerative lumbar spinal stenosis (DLSS) 12 months after baseline.

Methods: The authors included DLSS patients from a large prospective multicenter observational cohort study. Propensity score matching was used, including 15 demographic, clinical, and MRI variables. Linear and logistic mixed-effects regression models were applied to quantify the between-group treatment effect. Unmeasured confounding was addressed in a sensitivity analysis, assessing the robustness of the results.

Results: A total of 408 patients were included in this study, 222 patients after matching, with 111 in each treatment group. Patients with nonoperative treatment had lower quality of life at the 12-month follow-up (-6.21 points, 95% CI -9.93 to -2.49) as well as lower chances of reaching a minimal clinically important difference in Spinal Stenosis Measure (SSM) symptoms (OR 0.26, 95% CI 0.13 to 0.53) and SSM function (OR 0.26, 95% CI 0.14 to 0.49), than patients undergoing surgery. These results were very robust in case of unmeasured confounding. The surgical complication rate was low; 5 (4.5%) patients experienced a durotomy during intervention, and 5 (4.5%) patients underwent re-decompression.

Conclusions: The authors used propensity score matching to assess the difference in treatment efficacy of surgery compared with nonoperative treatment in elderly patients with DLSS. This study delivers strong evidence that surgical treatment is superior to nonoperative treatment. It helps in clinical decision-making, especially when patients suffer for a long time, sometimes over many years, hoping for a spontaneous improvement of their symptoms. In light of these new results, the number of years with disability can hopefully be reduced by providing adequate treatment at the right time for this ever-growing elderly and frail population.

Keywords: confounding; degenerative lumbar spinal stenosis; matching; propensity score; sensitivity analysis; surgery.