Stability of reported trauma over extended intervals: Initial evaluation of an exposure screening protocol.

The reliability and validity of reported exposure to significant trauma is critical to research evaluating outcomes following serious and distressing life events. The current study examined the reliability of reported exposure to disaster, fire, transportation accidents, physical assault, and sexual assault across 5-(N = 251), 12-(N = 223), and 24-month (N = 109) intervals in undergraduates completing a screening measure of probable trauma (N = 3,045). Concordance with later responses to an alternate checklist and events assessed via clinical interview was examined in a subset of participants (N = 274). Five-month reliabilities ranged from good to fair (kappa = .40-.71) and were similar to 1-2 week retest estimates in the extant literature. Reliabilities for fire, accidents, and sexual assault remained stable over 12- and 24-month intervals. Coefficients for disaster and physical assault decreased over time. Agreement with the alternate checklist was fair to excellent in those completing the follow-up assessment (kappa = .51-.87). Concordance with interview-based trauma was acceptable for accidents (kappa = .52) and sexual violence (kappa = .82) but poor for disaster, fire, and physical assault (kappa = .34-.38). Specificity, negative predictive power, and negative likelihood ratios suggest checklists may hold utility in ruling out previous trauma. Sensitivities indicate that screening instruments may broadly capture individuals experiencing traumatic life events although positive predictive power was limited except in the prediction of traffic accidents and sexual assault. Variability across domains suggests that the properties of checklist measures could be better conceptualized at the level of individual exposure events.