Functioning in persons with Spinal Cord Injury compared with the general population

To develop a harmonized functioning metric enabling direct comparison between persons with spinal cord injury or disease (SCI/D) and the Swiss general population, and to quantify differences in functioning across population and chronic-condition groups.

We conducted a cross-sectional comparative analysis using data from the Swiss Spinal Cord Injury Cohort Study (SwiSCI) and the Swiss Health Survey (SHS). Functioning items from the 2012, 2017, and 2022 waves of both surveys were linked to International Classification of Functioning, Disability and Health (ICF) categories to identify items measuring comparable aspects of functioning, which were then psychometrically evaluated using the Partial Credit Model. Suitable anchor items were identified based on item fit, local dependence, and differential item functioning, and used to derive a common 0-100 functioning metric. Epidemiological comparisons were restricted to the 2022 wave, the most recent wave available in both surveys, after exact matching of SHS participants to SwiSCI participants on age, sex, and language region.

The metric-development sample included 1,773 participants from each survey. The matched 2022 comparison included 1,311 SwiSCI participants and 11,836 SHS participants. Combining complete and incomplete injuries within each group, mean functioning was 53.6 (SD 8.8) among participants with paraplegia and 52.0 (SD 9.4) among those with tetraplegia, compared with 74.7 (SD 10.2) among SHS participants without a history of myocardial infarction, stroke, or cancer. Mean functioning was also higher among SHS participants with cancer, 71.6 (SD 12.0), stroke, 69.2 (SD 15.0), or myocardial infarction, 72.4 (SD 12.4), than among participants with SCI/D. Functioning decreased with age in the SHS and paraplegia groups, but no clear age association was observed in the tetraplegia group.

This study developed a harmonized functioning metric that enabled direct comparison between persons with SCI/D and the Swiss general population. Persons with SCI/D showed substantially lower functioning than Swiss general-population participants, both with and without major chronic conditions, even after demographic matching. These findings support the use of functioning as a distinct population health outcome that complements mortality and morbidity in health surveillance and health-system planning.