Comparative Effectiveness and Prognostic Factors for Outcome of Surgical and Non-surgical Management of Lumbar Spinal Stenosis in an Elderly Population: Protocol for an Observational Study

Introduction: Lumbar spinal stenosis is a common cause of low back and leg pain in elderly impacting physical activity and quality of life. Initial treatments are non-surgical options. If unsuccessful, surgery is advocated. The literature is not clear as to the outcome of surgery when compared to non-surgical treatment, and the optimal time for surgery is not explicit.

Materials and analysis: This observational study is designed to investigate the course of treatment, compare effectiveness of surgical and non-surgical treatment in patients with lumbar spinal stenosis, and identify prognostic factors for outcome in the context of current clinical practice. Prospectively registered data on treatment, outcome and patient characteristics are collected from nationwide registers on health and social issues, a clinical registry of people with chronic back pain and hospital medical records. Primary outcome is change in physical function measured by the Zurich Claudication Questionnaire. Secondary outcomes are changes in symptom severity, pain-related function, health-related quality of life, and general self-efficacy. All outcomes are measured at baseline, 6 months and 12 months follow up. Comparisons on these variables will be made between those who undergo surgery for lumbar spinal stenosis and those not receiving surgery at 12 months follow up according to different analysis populations. Prognostic factors include treatment allocation, back and leg pain intensity, comorbidity, duration of symptoms, pre-treatment function, self-rated health, income, general self-efficacy and magnetic resonance imaging graded compression of central stenosis.

Ethics and dissemination: The study has been evaluated by The Regional Committees on Health Research for Southern Denmark (S-20172000-200) and notified to the Danish Data Protection Agency (17/30636). All participants provide consent. Findings will be disseminated in peer-reviewed publications and presented at national and international conferences following the guidance from the STROBE and PROGRESS statement. Potential sources of bias will be addressed using ROBINS-I.