Reliability and validity of the Swedish version of the inventory of school attendance problems (ISAP)

School attendance problems (SAPs) are heterogenous in nature and thus warrant rigorous assessment prior to intervention. The Inventory of School Attendance Problems (ISAP) is a new instrument that supports a comprehensive assessment of SAPs. This study is the first evaluation of the Swedish version of the ISAP. A web survey comprising the ISAP, School Refusal Assessment Scale-Revised (SRAS-R), and the Strengths and Difficulties Questionnaire (SDQ) were administered to a Swedish community sample (n = 399) of secondary school students aged 12-16 years. We employed a cross-sectional design to test the factor structure of the Swedish ISAP using confirmatory factor analysis (CFA). Additionally, we evaluated internal consistency using Cronbach's alpha and omega total, and we evaluated convergent validity by comparing the ISAP with subscales from the SRAS-R and SDQ. Factor analysis yielded support for a predicted 13-factor model. Despite the Chi-square test indicating a significant misfit, the remaining fit indices suggested an adequate model fit. In this sample, there was adequate internal consistency for most scales. Correlations between ISAP factors and related constructs were generally large and positive. Overall, the findings support the reliability and validity of the Swedish ISAP, indicating its potential as a valuable tool for understanding SAPs among students in community samples. Further research is needed to explore its applicability in clinical samples.