The psychometric properties of the Hopkins Symptom Checklist-10: a Rasch analysis based on adolescent data from Norway.

BACKGROUND: The Hopkins Symptom Checklist (HSCL-10) is widely used for both clinical and epidemiological purposes to measure psychological distress among adolescents and adults. OBJECTIVE: The purpose of this study was to investigate the psychometric properties of the HSCL-10 among adolescents in Norway using Rasch analysis. METHODS: The study is based on cross-sectional data from the Norwegian Youth Health Surveys, conducted by the Norwegian Institute of Public Health in 2001 and 2009. The target group comprised of 15- to 16-year olds (Grade 10 students) in Hedmark County, Norway. Ten items with four response categories, intended to measure anxiety and depression, were analysed. The analysis focused on invariance, including differential item functioning (DIF) across genders and years of investigations. In addition, the categorization of the items, targeting, possible multidimensionality and response dependency, was analysed. RESULTS: The HSCL-10 shows good reliability and on the whole, the items work well. However, one item, 'Sleeping difficulties', clearly misfit and some items work differently for boys and girls and between years of investigations. There is also need for a better targeting of the scale. CONCLUSIONS: The HSCL-10 has the potential to measure the psychological distress among adolescents but there is a room for improvement. Further judgement needs to be made as to whether the misfitting item 'Sleeping difficulties' should be removed or retained.