Comparative Effectiveness and Prognostic Factors of Surgical and Non-surgical Management of Lumbar Spinal Stenosis

Study Overview
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Brief Summary
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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.

Official Title
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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

Conditions
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Lumbar Spinal Stenosis

Intervention / Treatment
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* Procedure: Surgery
* Other: Non-surgical management


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: >60 years. ICD-10 diagnosis of degenerative lumbar spinal stenosis registered in the nationwide patient registry between January 1st - December 31st 2017. Included in the SpineData registry. Give consent to use patient-reported data for research purposes Exclusion Criteria: -

Ages Eligible for Study
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Minimum Age: 61 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Surgery<br>Exposed | Procedure: Surgery<br>* Patients receiving surgical treatment undergo various types of posterior decompressive surgery with or without spinal fusion. The method used for decompressive surgery or fusions is determined solely by the surgeon.<br>|
| Non-surgical management<br>Non-exposed | Other: Non-surgical management<br>* Patients managing lumbar spinal stenosis non-surgically are either referred to rehabilitation primary health care center or referred back to their general practitioner for treatment. Treatment may include physiotherapy, chiropractic treatment, lifestyle changes and/or pain management. Post-surgically patients may also be referred to rehabilitation at a primary health care center.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Physical function | Change in physical function score in the Zurich Claudication Questionnaire (ZCQ) collected through a clinical registry of people with chronic back pain (SpineData). The ZCQ is a condition-specific self-reported measure of symptom severity, physical function and satisfaction with treatment in patients with lumbar spinal stenosis. The questionnaire is composed of three domains (subscales) with a Likert-type scale. The physical function subscale includes 6 items addressing walking distance and walking ability. All but one item have Likert response scales with 4 categories. The physical function subscale score is calculated from the unweighted mean of all answered items. The possible range of the score is 1 to 4. Lower scores indicate less disability. | Between baseline and 12 months follow up | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Symptom severity | Change in symptom severity score in the Zurich Claudication Questionnaire (ZCQ) collected through a clinical registry of people with chronic back pain (SpineData). The ZCQ is a condition-specific self-reported measure of symptom severity, physical function and satisfaction with treatment in patients with lumbar spinal stenosis. The questionnaire is composed of three domains (subscales) with a Likert-type scale. The symptom severity subscale includes 7 items addressing pain, numbness, weakness and balance disturbances. All but one item have Likert response scales with 5 categories. The possible range of the score is 1 to 5. Lower scores express less symptom severity. | Between baseline and 12 months follow up | 
| Pain related physical function | Change in Oswestry Disability Index collected through a clinical registry of people with chronic back pain (SpineData). The Oswestry Disability Index (ODI) is a region-specific questionnaire for assessing self-reported levels of disability for patients with spinal disorders. The questionnaire contains 10 pain related sections (items) with 6 response options (statements). Each section of six response options is scored from 0 (no pain) to 5 (most severe pain). For each section of six statements the total score is 5; if the first statement is marked, the score equals 0; if the last (6th) statement is marked, the score equals 5. If more than one box is marked in each section, the highest score is used. The section scores are summarised to a total score, ranging from 0-100. Scores are expressed as a percentage of total points. Lower scores indicate less disability. | Between baseline and 12 months follow up | 
| Health related quality of life | Change in health related quality of life measured by EQ-5D-3L collected through a clinical registry of people with chronic back pain (SpineData). The EQ-5D-3L is a generic self-reported instrument for measuring health-related quality of life consisting of a descriptive system and the EQ visual analogue scale (EQ VAS). The descriptive system comprises 5 dimensions (mobility, self-care, usual activities, pain/discomfort and anxiety/depression), each with 3 response options. These are converted into a single summary index by applying preference weights obtained from the general population with a total score ranging from -0.6 to 1, where 1 corresponds to perfect health and 0 to death. Higher scores indicate better health related quality of life, The EQ VAS is a vertical, visual analogue scale scoring patients self-rated health ranging from 0 (worst imaginable health state) to 100 (best imaginable health state). Higher scores indicate better self-perceived health. | Between baseline and 12 months follow up | 
| General self-efficacy | Change in general self-efficacy score obtained by the General Self Efficacy Scale collected through a clinical registry of people with chronic back pain (SpineData). The General Self efficacy scale is a self-reported unidimensional measure of general sense of perceived self-efficacy designed for the general adult population and used in patients with chronic pain. The questionnaire comprises of 10 items (statements) with 4 response options. Responses are scored on a 4-point Likert-scale from 1 (not true at all) to 4 (exactly true). Responses of all 10 items are summarised to yield the final composite score with a range from 10 - 40 points. Higher scores express greater perceived self-efficacy. | Between baseline and 12 months follow up |