Psychometric properties of the Somatic Symptom Scale 8 (SSS-8) in a representative sample of German adolescents.

Abstract Objective The psychometric properties of the Somatic Symptom Scale 8 (SSS-8) have been investigated in different studies. However, there is no study examining its psychometric properties on representative data of adolescents. The study at hand will present results from a large representative sample of German adolescents (13 to 18 years). Methods The following analyses draw on cross-sectional data from German ninth-grade students collected in 2015. Altogether, 10,638 individuals were surveyed with a return rate of 68.5% as part of a periodic representative survey in the German federal state of Lower Saxony. Results For the SSS-8, coefficient omega for the full sample was ω = 0.90, and ω = 0.77 and 0.79 for males and females, respectively. In addition, a convergent validity was determined with the Patient Health Questionnaire 2 (PHQ-2), Generalized Anxiety Disorder 2 (GAD-2), and the brief form of Perceived Social Support Questionnaire (FSozU-K6). Based on a confirmatory factor analysis and measurement invariance analysis (for gender and migration background), the initially determined factor structure by Gierk et al. of the SSS-8 could be confirmed. Conclusion The results support the reliability and validity of the SSS-8 for use with adolescents. The use of the SSS-8 seems to be meaningful within different frameworks, especially when, due to a lack of time or for reasons of cost, no face-to-face interviews can be conducted.