This study brought to our attention a methodological issue in evaluating the relationship between trauma severity and the role of predispositions that deserves mention. The issue concerns the influence of predispositions on exposure to specific trauma types. Our analysis revealed that parental psychopathology predicted increased risk of experiencing sexual assault, quite apart from enhancing the PTSD effects of sexual assault. This was not the case for accidents, disaster or unexpected death of someone close; occurrence of parental psychopathology among those who were exposed to these events but did not develop PTSD was similar to their occurrence in NESARC as a whole. An analytic approach that would compare the strength of two separate measures of associations between parental psychopathology and PTSD – one among victims of sexual assault and the other among victims of a comparison event – might conclude wrongly that the PTSD effect of parental psychopathology was weaker among victims of sexual assault. Our analytic approach – multinomial logistic regression – avoids this pitfall, as we outline under the section ‘Statistical analysis’. The approach takes into account the relative
