Development and Validation of a Questionnaire for Assessing Activity Limitation in Patients With Lumbar Spinal Stenosis : The Cochin L3S Questionnaire.

Construction of the provisional questionnaire :

In a first step, semi-structured in-depth individual interviews were conducted from September 20, 2016 to January 4, 2017, in 20 patients fulfilling inclusion criteria to collect concepts related to LSS-specific activity limitation, participation restriction and patients' views about their condition. Thematic content was analysed using investigator triangulation. Overall, 57 items were generated by patients. 48 items were related to LSS-specific activity limitation and were used to construct the provisional 48-item Cochin L3S questionnaire (CL3S-48). Acceptability and understandability of the provisional CL3S-48 questionnaire was tested and consolidated in 10 patients with LSS.

Item reduction and validation of the questionnaire :

In a second step, 200 eligible patients according to our medical records will be informed by email of the purpose of the study, their non-opposition to the collection of data will be collected and patients will be invited to complete the following online self-administered questionnaires at baseline, 7 days and 3 months:

• Demographical and clinical characteristics at baseline
• Consolidated version of the CL3S-48 questionnaire
• Lumbar pain numeric rating scale (NRS)
• Radicular pain NRS
• Zurich Claudication Questionnaire (ZCQ) physical function subscale
• Oswestry Disability Index (ODI)
• Fukushima LSS Scale 25 (FLS-25)
• 12-Item Short Form Health Survey (SF-12)
• 1 anchoring question about patient acceptable symptom state
• 1 anchoring question about patient minimal clinically important difference at 3 months.