Internal consistency and convergent validity of the International Spinal Cord Injury Quality of Life Basic Data Set at discharge from first rehabilitation

Study design This study is a cross-sectional analysis using data from the Swiss Spinal Cord Injury Cohort Study. Objectives To examine internal consistency and convergent validity of the International Spinal Cord Injury Quality of Life Basic Data Set (QoL-BDS) at discharge from first inpatient rehabilitation. Setting The study was performed at four rehabilitation centers in Switzerland. Methods Participants were Swiss residents aged over 16 years newly diagnosed with traumatic or non-traumatic spinal cord injury (SCI). Measures included the QoL-BDS, World Health Organization Quality of Life (WHOQOL) items, Hospital Anxiety and Depression Scale (HADS), and Spinal Cord Independence Measure III (SCIM). Results A total of 495 participants were included. In all, 57% had a traumatic SCI, 71.1% a motor complete SCI, and 33.3% had tetraplegia. Mean age was 53 (SD = 16.4) years and 68% were male. No floor or ceiling effects were found. Inter-correlations were strong (0.73-0.80) and Cronbach's alpha was good (0.88). QoL-BDS mean scores were 6.4 (SD = 2.2) for life satisfaction, 5.8 (SD = 2.4) for physical health, 6.9 (SD = 2.4) for psychological health, and 6.4 (SD = 2.1) for total QoL. Correlations with reference measures were strongest for QoL-BDS total and WHOQOL general quality of life (r = 0.67), QoL-BDS physical health and WHOQOL health and daily activities (r = 0.64 and 0.53), and QoL-BDS psychological health and HADS depression and anxiety (r = -0.64 and -0.69). SCIM correlated weakly with all QoL-BDS items. Conclusions The QoL-BDS revealed no floor or ceiling effects and demonstrated good internal consistency and convergent validity in individuals with SCI assessed at discharge from first rehabilitation. This study supports the clinical routine use of the QoL-BDS.