Objective: The Addiction Severity Index (ASI) includes items to assess patients' history of trauma (physical or sexual). The goal of this study was to assess the sensitivity and specificity of those questions in relation to the Trauma History Questionnaire (THQ), a more thorough measure of lifetime trauma and, in addition, to an actual posttraumatic stress disorder (PTSD) diagnosis.
Method: At the start of treatment cocaine dependent outpatients (N = 110, 65.5% male) were assessed on the ASI, the THQ and a PTSD symptom checklist as part of a multisite clinical trial.
Results: Specificity of the ASI questions was higher than sensitivity for both sexual trauma (specificity = .96, sensitivity = .46) and physical trauma (specificity = .71, sensitivity = .50), while for PTSD the sensitivity of the ASI (.91) was higher than its specificity (.43). Other findings indicated that patients were more likely to report trauma on the THQ than on the ASI (which may be due to the self-report format of the THQ); that the ASI was better at assessing sexual than assessing physical trauma; and that the higher the number of ASI trauma items endorsed, the more likely was the PTSD diagnosis. Finally, PTSD patients had greater severity than non-PTSD patients on other ASI items (e.g., psychological severity, need for treatment).
Conclusions: The ASI trauma questions show stronger utility as a screen for PTSD than for trauma. Results of the study are discussed in light of ways to modify the ASI to screen more accurately for trauma, clinical implications, and limitations of the study method.