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.