Development of a new patient-reported outcome measure assessing activities and participation in people with lumbar spinal stenosis: The Cochin Spinal Stenosis 19-item questionnaire.

BACKGROUND

Lumbar spinal stenosis (LSS) is the leading cause of spinal surgery in people over 65-years old. In people with LSS, generic self-administered questionnaires are the most commonly used PROs to assess health-related quality of life, global activity limitation, and low back pain-located activity limitation.

AIM: The aim was to develop a new patient-reported outcome measure assessing activities and participation in people with LSS.

DESIGN

Observation, prospective and qualitative study.

SETTING

For the qualitative study, were enrolled in- and outpatients with LSS from 2 French tertiary care centers (Department of PRM of Cochin Hospital and Department of Rheumatology of Limoges Hospital). For the Internet E-survey, screened the electronic medical records of the Department of PRM of Cochin Hospital.

POPULATION: From February to April 2018 were enrolled patients older than 50-years and symptomatic LSS.

METHODS

We used a 2-step approach. In a first step, we conducted a qualitative study using in-depth semi-structured interviews in 20 patients with LSS to collect meaningful concepts and to develop a provisional questionnaire. In a second step, using the provisional questionnaire, we conducted an Internet E-survey in an independent sample of 200 patients with LSS.

RESULTS

Concepts collected from patients generated a 48-item provisional questionnaire. Overall, 63/200 (31.5%) patients completed the provisional questionnaire. Item reduction resulted in a 19-item questionnaire, the Cochin Spinal Stenosis 19-item (CSS-19) questionnaire. Principal component analysis extracted 3 factors. In confirmatory analysis, factor 1 influenced all items. We found convergent validity with low back pain, LSS-specific disability and divergent validity with mental health-related quality of life. Cronbach α coefficient (95% CI) was 0.96 (0.94; 0.97). ICC was 0.90 (0.70; 0.97). Bland and Altman analysis found no systematic trend for test-retest.

CONCLUSIONS

CSS-19 is a new patient-reported outcome measure assessing activities and participation in people with LSS. Its construction prioritized patients' perspectives at all stages. Its content and construct validities are good.

CLINICAL REHABILITATION IMPACT: Instruments able to capture specific needs of people with LSS in terms of activities and participation are lacking.