Inception cohort of the Swiss Spinal Cord Injury Cohort Study (SwiSCI): Design, participant characteristics, response rates and non-response.

Abstract

ObjectivesTo provide a methodological reference paper for the inception cohort of the Swiss Spinal Cord Injury Cohort Study (SwiSCI), by detailing its methodological features and reporting on participant characteristics, response rates and non-response bias.DesignProspective cohort study starting in 2013 in all 4 specialized rehabilitation centres in Switzerland.SubjectsIncluded are 655 newly diagnosed first rehabilitation patients aged ≥16 years with traumatic or non-traumatic spinal cord injury (TSCI, NTSCI).MethodsDescriptive statistics were used to depict participant characteristics and to compare characteristics of responders and non-responders. Logistic regressions were conducted to estimate non-response bias.RESULTSThe sample consisted of 69% males, with mean age 53.5 years, 57.9% TSCI, 60.7% paraplegia and 78.8% incomplete SCI. Males and younger persons more often sustained TSCI and more severe SCI, resulting in longer duration of rehabilitation. Complete lesions were more prevalent in TSCI compared to NTSCI. The response rate was 47.5% and study participation was less likely in females, older persons, persons with lower functional independence and those with NTSCI.ConclusionSwiSCI inception cohort data enable the estimation of epidemiological figures of SCI in Switzerland, and prognostic and trajectory modelling of outcomes after SCI to guide policy, service provision and clinical practice.LAY ABSTRACTThe inception cohort of the Swiss Spinal Cord Injury Cohort Study (SwiSCI) is a prospective study including newly diagnosed first rehabilitation patients aged over 16 years with traumatic or non-traumatic spinal cord injury (SCI) who received first rehabilitation in a specialized center in Switzerland. This paper describes the methods and the design of the SwiSCI inception cohort and reports on participant characteristics, response rates and differences between respondents and non-respondents. The response rate was 47.5% and 655 patients participated in the study. Of participants, 69.0% were male, mean age was 53.5 years, 57.9% had traumatic SCI, 60.7% paraplegia and 78.8% incomplete SCI. Male subjects and younger persons more often sustained traumatic SCI and more severe SCI, resulting in longer duration of rehabilitation. Complete lesions were more prevalent in traumatic SCI compared with non-traumatic SCI. Females, older persons, persons with lower functional independence and those with non-traumatic SCI were less likely to participate in the study.