Validity and Reliability of the Korean Version of the Secondary Traumatic Stress Scale for Clinical Nurses

Secondary traumatic stress (STS) is a clinically significant consequence of indirect exposure to trauma among healthcare professionals; however, a culturally validated measure for healthcare professionals has been lacking in South Korea. This study developed and evaluated the psychometric properties of a Korean version of the 17-item Secondary Traumatic Stress Scale (STSS). The instrument was translated and culturally adapted through forward–back-translation and expert content review and administered to 300 healthcare professionals indirectly exposed to work-related trauma. The sample was randomly divided into two independent subsamples (n = 150 each) for exploratory and confirmatory factor analyses (EFA and CFA, respectively). Internal consistency, structural validity, and criterion-related validity against the Impactof Event Scale–Revised (IES-R) were also examined. The Korean STSS demonstrated excellent internal consistency (Cronbach’s α = 0.95). EFA yielded a 14-item, two-factor structure—sensory-reactive and cognitive-avoidance symptoms—explaining 67.08% of the variance after removing three weakly loading items, and, in CFA, this two-factor model was the best-performing of the three models compared (one-factor, two-factor, and original three-factor), although none of the models showed fully satisfactory fit (comparative fit index = 0.91, Tucker–Lewis index = 0.89, root mean square error of approximation = 0.11). Criterion-related validity was supported by a strong correlation with the IES-R (r = 0.89, 95% CI [0.86, 0.91]), whereas evidence for discriminant validity was limited: the scale correlated weakly and negatively with perceived social support (r = −0.25) but strongly with general psychological distress (r = 0.81). The Korean STSS shows promising initial psychometric properties among Korean healthcare professionals; however, these findings need to be confirmed in larger and more diverse samples before the instrument can be recommended for routine screening.