Psychometric evaluation of the Sibling Cancer Needs Instrument (SCNI): An instrument to assess the psychosocial unmet needs of young people who are siblings of cancer patients

Purpose: The current study sought to establish the psychometric properties of the revised Sibling Cancer Needs Instrument (SCNI) when completed by young people who have a brother or sister with cancer. Methods: The participants were 106 young people aged between 12 and 24 who had a living brother or sister diagnosed with any type or stage of cancer in the last 5 years. They were recruited from multiple settings. The initial step in determining the dimensional structure of the questionnaire was exploratory factor analysis and further assessment followed using Rasch analysis. Construct validity and test-retest reliability (n = 17) were also assessed. Results: The final SCNI has 45 items and seven domains: information; practical assistance; "time out" and recreation; feelings; support (friends and other young people); understanding from my family; and sibling relationship. There was a reasonable spread of responses across the scale for every item. Rasch analysis results suggested that overall, respondents used the scale consistently. Support for construct validity was provided by the correlations between psychological distress and the SCNI domains. The internal consistency was good to excellent; Cronbach's alphas ranged from 0.78 to 0.94. The test-retest reliability of the overall measure is 0.88. Conclusions: The SCNI is the first measure of psychosocial unmet needs which has been developed for young people who have a brother or sister with cancer. The sound psychometric properties allow the instrument to be used with confidence. The measure will provide a substantial clinical benefit in highlighting the unmet needs of this population to assist with the prioritisation of targeted supportive care services and evaluating the impact of interventions targeted at siblings.