Psychometric validation of the brief psychosomatic symptom scale (BPSS) in Chinese adolescents: Screening cutoff and associated psychosocial factors.

OBJECTIVES: The Brief Psychosomatic Symptom Scale (BPSS) has shown promising psychometric properties in adults, but its performance in adolescents remains under-examined. This study evaluated the BPSS in Chinese adolescents, estimated an empirical screening cutoff, and examined psychosocial factors associated with elevated psychosomatic symptom burden. METHODS: The BPSS was administered to 4665 school-based Chinese adolescents. Internal consistency evidence, associations with the 26-item Psychosomatic Symptoms Scale (PSSS), the Patient Health Questionnaire-15 (PHQ-15), and the Generalized Anxiety Disorder-7 (GAD-7), and construct validity via confirmatory factor analysis (CFA) were examined. Receiver operating characteristic (ROC) analysis was used to estimate a BPSS cutoff relative to a study-defined high somatic-symptom-burden criterion based on a modified PHQ-15. Multivariable logistic regression examined psychosocial correlates of BPSS-defined elevated symptom burden. RESULTS: The BPSS showed good internal consistency (Cronbach's α = 0.885) and strong positive associations with the PSSS, PHQ-15, and GAD-7 (all p < 0.001) providing convergent evidence while requiring caution because of scale derivation and symptom-content overlap. The correlated two-factor CFA showed excellent global fit (CFI = 0.998, RMSEA = 0.037), but the factor correlation was very high (r = 0.95), indicating limited empirical separation between the factors. A cutoff of ≥8 was selected in the total sample and in both male and female subsamples. Depression, poor family functioning, bullying, personal distress, and loneliness were significantly associated with elevated BPSS scores. CONCLUSION: The BPSS showed promising internal-consistency and screening performance in this school-based sample. A score of 8 may be useful as an empirical screening threshold relative to the study-defined criterion, but it should not be interpreted as a diagnostic cutoff. The psychosocial findings represent cross-sectional associations rather than causal risk factors, and further validation in independent and more diverse samples is needed.