Dimensionality of posttraumatic stress symptoms: a confirmatory factor analysis of DSM-IV symptom clusters and other symptom models

Factorial invariance of posttraumatic stress disorder symptoms across three veteran samples

“…Generalizability is limited in that only veterans were assessed, many with combat-related PTSD. Results are consistent, however, with findings of studies involving civilian samples (e.g., Asmundson et al, 2000). Another limitation is that this study did not examine models with second-order or bifactor designs, as such models produce challenges to interpretation and do not readily translate to questionnaire subscales that can be used in everyday practice (cf.…”

“…As detailed by King and colleagues (2006), many studies employing a variety of symptom questionnaires and populations support a 4-factor model (King, Leskin, King, & Weathers, 1998) that includes reexperiencing, avoidance, numbing, and hyperarousal factors (Andrews, Joseph, Shevlin, & Troop, 2006;Asmundson et al, 2000;Marshall, 2004;Palmieri & Fitzgerald, 2005). The reexperiencing and hyperarousal factors are analogous to DSM-IV symptom Clusters B and D, and the numbing and avoidance factors are drawn from Cluster C. In contrast, other studies have supported a 4-factor model identified by Simms and colleagues (2002), that includes intrusions, avoidance, dysphoria, and hyperarousal (Baschnagel, O'Connor, Colder, & Hawk, 2005;Messer, Hoge, & Castro, 2007).…”

The Impact of Event Scale-Revised: Psychometric properties in a sample of motor vehicle accident survivors

“…These findings suggest that the IES-R Avoidance subscale does not fit as closely with the DSM criteria for PTSD, relative to the other two subscales. Given on-going discussion in the literature concerning the underlying factor structure of PTSD (e.g., Asmundson, et al, 2000,DuHamel, et al, 2004, it is possible that the IES-R can augment diagnostically-oriented measures, such as the CAPS and PSS-SR, in the assessment of PTSD. In particular, the IES-R Avoidance subscale may provide a more focused assessment of effortful avoidance, relative to measures that combine avoidance and numbing.…”

Evaluating symptom expression as a function of a posttraumatic stress disorder severity

“…Since we were motivated primarily by an interest in organizing and understanding symptoms on a primary dimension of PTSD and the hierarchical-multidimensional model, in which a strong common factor was identified, was at least as reasonable as a multi-dimensional only model, we did not explore the relative fit of three versus four latent factors of PTSD. However, previous studies suggest that three (Cordova, Studts, Hann, Jacobsen, & Andrykowski, 2000;Cox, Clara, & Enns, 2002;Thatcher & Krikorian, 2005) or four factor-factor models (Andrews, Joseph, Shevlin, & Troop, 2006;Asmundson et al, 2000;King, King, Fairbank, Keane, & Adams, 1998;McWilliams, Cox, & Asmundson, 2005;Palmieri & Fitzgerald, 2005;Simms, Watson, & Doebbeling, 2002) may better approximate the symptoms of PTSD. Future research should consider multidimensional IRT models and whether they better characterize the dimensionality underlying PTSD symptomology over the more parsimonious unidimensional models.…”

“…However, numerous factor analytic studies conducted across different trauma populations (e.g., male combat veterans, female sexual assault survivors, etc.) and assessment instruments [e.g., Clinically Administered PTSD Scale (Blake et al, 1995), Posttraumatic Stress Disorder Checklist (Weathers, Litz, Huska, & Keane, 1994), Mississippi PTSD Scale (Keane, Caddell, & Taylor, 1988)] have found differing solutions ranging from two (Buckley, Blanchard, & Hickling, 1998;Foa, Riggs, & Gershuny, 1995;Taylor, Kuch, Koch, Crockett, & Passey, 1998), three (Cordova, Studts, Hann, Jacobsen, & Andrykowski, 2000;Cox, Clara, & Enns, 2002;Thatcher & Krikorian, 2005), and four factors (Andrews, Joseph, Shevlin, & Troop, 2006;Asmundson et al, 2000;King, King, Fairbank, Keane, & Adams, 1998;McWilliams, Cox, & Asmundson, 2005;Palmieri & Fitzgerald, 2005;Simms, Watson, & Doebbeling, 2002). We would expect that if the DSM-IV organization of PTSD symptoms were robust, the organization of three domains would be supported across populations and different operationalizations of symptom indices.…”