Subgroups in epidemiological studies on spinal cord injury: Evaluation of international recommendations in the Swiss Spinal Cord Injury Cohort Study

OBJECTIVE: To test subgroups of a community-based sample of individuals with spinal cord injury, categorized by the application of current recommendations by the International Spinal Cord Society. DESIGN: Community survey. PARTICIPANTS: Individuals with traumatic and non-traumatic spinal cord injury residing in Switzerland. METHODS: Recommended subgroups of age, gender, years since injury, severity of injury and aetiology were tested against the following criteria: (i) distribution of participants across categories; (ii) within- and between-group variability with regard to selected outcomes of functioning and quality of life. RESULTS: Data-sets for 1,549 participants (28.5% women; mean age 52 ± 15 years) were available for analyses. There was a number of participants in every subgroup, yet numbers were relatively small in the group with the shortest time since injury (< 1 year; n = 23) and in the oldest age group (≥ 76; n = 94). A high variability in some outcomes was detected between categories. All variables were predictive for most of the endpoints investigated. CONCLUSION: Recommended categorization could well fit the present sample. A minor concern was the low numbers of participants in some subgroups