Psychometric properties of the psychosocial screening instrument for physical trauma patients (PSIT)

Background Early detection of psychosocial problems post-injury may prevent them from becoming chronic. Currently, there is no psychosocial screening instrument that can be used in patients surviving a physical trauma or injury. Therefore, we recently developed a psychosocial screening instrument for adult physical trauma patients, the PSIT. The aim of this study was to finalize and psychometrically examine the PSIT. Methods All adult (>= 18 years) trauma patients admitted to a Dutch level I trauma center from October 2016 through September 2017 without severe cognitive disorders (n = 1448) received the PSIT, Impact of Events Scale-Revised (IES-R), Patient Health Questionnaire-9 (PHQ-9), Rosenberg Self-Esteem Scale (RSES), State-Trait Anxiety Inventory-State (STAI-S), and the World Health Organization Quality of Life-Abbreviated version (WHOQOL-Bref). After 2 weeks, a subgroup of responding participants received the PSIT a second time. The internal structure (principal components analysis, PCA; and confirmatory factor analysis, CFA), internal consistency (Cronbach's alpha, alpha), test-retest reliability (Intraclass Correlation Coefficient, ICC), construct validity (Spearman's rho correlations), diagnostic accuracy (Area Under the Curve, AUC), and potential cut-off values (sensitivity and specificity) were examined. Results A total of 364 (25.1%) patients participated, of whom 128 completed the PSIT again after 19.5 +/- 6.8 days. Test-retest reliability was good (ICC = 0.86). Based on PCA, five items were removed because of cross-loadings >= 0.3. Three subscales were identified: (1) Negative affect (7 items; alpha = 0.91; AUC = 0.92); (2) Anxiety and Post-Traumatic Stress Symptoms (4 items; alpha = 0.77; AUC = 0.88); and (3) Social and self-image (4 items; alpha = 0.79; AUC = 0.92). CFA supported this structure (comparative fit index = 0.96; root mean square error of approximation = 0.06; standardized rood mean square residual = 0.04). Four of the five a priori formulated hypotheses regarding construct validity were confirmed. The following cut-off values represent maximum sensitivity and specificity: 7 on subscale 1 (89.6% and 83.4%), 3 on subscale 2 (94.4% and 90.3%), and 4 on subscale 3 (85.7% and 90.7%). Conclusion The final PSIT has good psychometric properties in adult trauma patients.