Self-care in spinal cord injuries inventory (SC-SCII) and self-care self-efficacy scale in spinal cord injuries (SCSES-SCI): development and psychometric properties

Study design Validation cross-sectional study. Objectives To develop and assess the psychometric properties of two instruments based on the middle-range theory of self-care in chronic illness: the Self-Care in Spinal Cord Injuries Inventory (SC-SCII) and the Self-Care Self-Efficacy Scale in Spinal Cord Injuries (SCSES-SCI). Setting Multicenter study in five spinal units across Italy and Ireland. Methods Instrument development was based on self-care behaviours identified in the scientific literature. Behaviours were grouped into four dimensions during a consensus conference: self-care maintenance, self-care monitoring, self-care management and self-care self-efficacy. Sixty-seven items were subsequently generated based on these dimensions. A multidisciplinary group of 40 experts evaluated content validity. Dimensionality of the final items was tested by confirmatory factor analyses (CFA) with a sample of 318 participants. Internal consistency and test-retest reliability were evaluated for each dimension. Construct validity was assessed using correlations between items and scoring differences amongst participants with more severe conditions and secondary complications. Results Content validity of the SC-SCII and SCSES-SCI was satisfactory for thirty-five of the previously generated items, which were further refined. CFA showed comparative fit indexes ranging from 0.94 to 0.97 and root mean square errors of approximation from 0.03 to 0.07. Internal consistency ranged from 0.71 to 0.85, and intraclass correlation coefficients were higher than 0.70. Correlations among dimensions were moderate, and the theoretical hypotheses formulated when designing the instruments were largely confirmed. Conclusions The SC-SCII and the SCSES-SCI represent valid and reliable theoretically-grounded instruments to assess self-care in people with spinal cord injury.