Item Response Theory Analysis of the PCL-5 in Measuring Sexual Violence-Related PTSD Symptoms Among Bisexual+ Women

Women with multi-gender attractions (i.e. bisexual+ women) experience alarmingly high rates of sexual violence (SV), which puts women at risk for posttraumatic stress disorder (PTSD). Bisexual+ women experience higher rates of PTSD compared to heterosexual and lesbian/gay people. The PTSD Checklist for DSM-5 (PCL-5) is a widely used self-report measure of PTSD symptoms. We conducted an item response theory (IRT) analysis to evaluate the item difficulty and discrimination of PCL-5 items in assessing PTSD symptoms related to adult SV among young bisexual+ women. We combined two samples of women: sample 1 participants were recruited via MTurk (N = 267; Mage = 25.9, range 18-35; 82.4% White) and sample 2 participants recruited via online ads (N = 133; Mage = 22.0, range 18-25, 85.0% White). Item difficulty and discrimination was evaluated using IRT with a graded response model. At clinically significant levels of PTSD, the most discriminating items were: flashbacks, nightmares, reckless behavior, inability to experience positive emotions, and intrusive memories, whereas the least discriminating items were: internal avoidance, hypervigilance, difficulty with sleep, external avoidance, and exaggerated startle response. The most difficult items were: reckless behavior, flashbacks, traumatic amnesia, nightmares, and irritability, whereas the least difficult items were: internal avoidance, cued emotional distress, external avoidance, hypervigilance, and strong negative emotions. Results suggest that symptoms related to flashbacks, nightmares, and reckless behavior are important for assessing clinically significant SV-related PTSD symptoms among young bisexual+ women, whereas symptoms related to internal and external avoidance and hypervigilance may be relatively less informative.