Whiplash Patients' Responses on the Impact of Events Scale-R Congruent With Pain or PTSD Symptoms?

Objectives: Posttraumatic stress disorder (PTSD) symptoms are common among people with whiplash following a motor vehicle crash. The Impact of Events Scale-Revised (IES-R) screens for PTSD symptoms with psychologist referral recommended for above-threshold scores. Recent data indicate that PTSD symptoms post-whiplash may relate more to pain and disability than the crash itself. This study explored the interpretation of IES-R items by people with whiplash to establish whether responses relate to the crash or to whiplash pain and disability. Methods: Adults with whiplash scoring > 24 on the IES-R were eligible. The 3-step test-interview technique was used and responses analyzed using content analysis. A coding framework was developed, comprising 5 categories: " congruent"-responses related to the crash; " incongruent"-responses did not relate to the crash; " ambiguous"responses were both congruent and incongruent; " confusion"-participants misunderstood the item content; " not applicable"-irrelevancy of items to participants' circumstances. Results: The 15 participants (mean IES-R= 37/88) were inclined to respond congruently to specific PTSD items and incongruently to nonspecific PTSD items. Participants were more inclined to rate nonspecific PTSD items in terms of pain and disability, for example, > 60% responded incongruently to item 2: " I had trouble staying asleep"; item 4: " I felt irritable and angry"; item 15: " I had trouble falling asleep"; and item 18: " I had trouble concentrating." Discussion: Incongruent responses on nonspecific PTSD items may inadvertently inflate levels of PTSD symptoms measured with the IES-R for some whiplash patients, raising implications for the assessment and treatment of the psychological sequelae of whiplash.