Stress assessment during adolescence: Psychometric properties and measurement invariance of the Student Stress Inventory-Stress Manifestations across gender and age

The main purpose of this study was to analyze the psychometric properties and measurement invariance across gender and age of the Student Stress Inventory-Stress Manifestations (SSI-SM) scores in a large sample of adolescents. The sample was comprised by a total of 1108 students (482 were male), with a mean age of 14.61 years (SD = 1.71). The results indicated that the SSI-SM scores presented adequate psychometric properties from both classical test theory and Item Response Theory (IRT). Confirmatory factorial analysis (CFA), showed that both the bifactor model and a three-factor model (emotional, physiological, and behavioural) were adequate. Multi-group CFA showed that the three-factor model had strong measurement invariance across gender and age. Statistically significant differences in gender were found between latent means as well as raw scores of SSI-SM. Ordinal alpha was .78 for Physiological, .90 for the Emotional, and .79 for the Behavioural subscales. Using IRT, the SSI-SM provides more accuracy information at the medium level of the latent trait. SSI-SM subscales were associated with emotional and behavioural problems. These results provided new sources of validity evidence of the SSI-SM scores in adolescents from general population. The SSI-SM appears to be a useful, brief, and easy to administrate self-report instrument for the screening of stress manifestations at school and educational settings.