The Impact on Family Scale/FaBel: Psychometric testing of a German 18 items short form

Background The Impact on Family Scale (IOFS) is a key tool for measuring the burden on families with chronically ill or disabled children. While a validated 33-item German version, the "Familien-Belastungs-Fragebogen" (FaBel), exists, its length can reduce its practical use. To improve feasibility, a shorter, 18-item version (FaBel-18) was developed to maintain the measurement's multidimensional nature. The purpose of this study was to evaluate the psychometric properties, such as validity and reliability, of this new short-form instrument. Methodology The FaBel-18, an 18-item questionnaire using a Likert scale, was administered in a cross-sectional study to assess family burden across five dimensions: familial/social impact, financial burden, personal strains, mastery/coping, and impact on siblings. The study included 1,070 parents and guardians of children in Germany who require care. Psychometric testing involved analyzing the instrument's validity and reliability. Results The psychometric analysis demonstrated that the FaBel-18 has very good construct validity, acceptable internal consistency, and evidence of discriminant validity. However, the underlying factor structure of the short form did not perfectly align with the original 33-item German FaBel. Conclusions The FaBel-18 is a psychometrically sound instrument that offers a more feasible alternative to the longer version for assessing family burden. The findings suggest the tool is valuable for research and clinical practice, although further testing may be beneficial in specific patient populations to continue exploring its properties.