Measuring state and trait anxiety in Turkish adolescents: development and validation of the six-item short forms of the state–trait anxiety inventory

Abstract

Although the State–Trait Anxiety Inventory (STAI) is a well-established instrument for anxiety assessment, its length may limit feasibility in large-scale, longitudinal, and time-sensitive research settings. Existing abbreviated forms were mainly created for adults worldwide, including Türkiye. Accordingly, this study aimed to develop and psychometrically evaluate abbreviated versions of the STAI-State (STAI-S) and STAI-Trait (STAI-T) for Turkish adolescents. A two-phase psychometric validation design was implemented across two independent cohorts. Exploratory factor analysis (EFA) was initially conducted in Sample 1, comprising adolescents recruited from an outpatient child and adolescent psychiatry clinic ( n  = 420), to identify the most parsimonious item configurations. Subsequently, confirmatory factor analysis (CFA) and criterion-related validity analyses were performed in Sample 2, consisting of public high school students ( n  = 277). Measurement invariance across clinical/community status, sex, and age, comparisons with alternative factor models, and receiver operating characteristic analyses against the Generalized Anxiety Disorder-7 were examined. EFA supported a stable two-factor structure for both six-item scales, accounting for 53.7% of the total variance for the STAI-S and 57.3% for the STAI-T. Internal consistency was high for both abbreviated instruments ( α  = 0.804). CFA indicated mixed but broadly acceptable fit for the two-factor solutions (STAI-S: χ 2 /df = 3.66, CFI = 0.979, SRMR = 0.033, RMSEA = 0.098; STAI-T: χ 2 /df = 3.28, CFI = 0.987, SRMR = 0.028, RMSEA = 0.091). Standardized factor loadings ranged from 0.61 to 0.92 across models. Invariance of item thresholds and factor loadings held across clinical/community status, sex, and age in analyses treating the items as ordered-categorical. The shortened versions also showed a high correlation with the original 20-item scales and preserved their criterion-related performance. Concurrent validity was supported by correlations with the Generalized Anxiety Disorder-7 and the Satisfaction with Life Scale. The findings provide preliminary evidence supporting the reliability and structural validity of the six-item STAI-S and STAI-T in Turkish adolescents. The abbreviated forms appear suitable for research use, whereas their clinical utility requires confirmation in independent samples.