The present study explores the existence of gender differences in PTSD in relation to different trauma types building on an analysis of a large set of convenience samples. Altogether, this study established that the overall size of the gender difference in PTSD is in line with findings from previous research and shows a two-fold higher risk of PTSD among women than among men. The results established that gender differences exist in the prevalence of PTSD, and that gender differences in PTSD prevalence are not a constant size but varies by trauma type. Gender differences also existed within the examined trauma types although these results were somewhat equivocal. The trauma type in the present study which showed the highest level of gender difference in PTSD was disaster and accident, whereas violence showed the lowest level of gender difference in PTSD, contradicting previous findings . The same reservation applies to the trauma type chronic disease which showed a gender difference when measured by dimensional principles but not when measured by categorical principles. Besides these ambiguities, the size of the gender difference varies across the different trauma types as seen in Table 1.
Also, the present study showed that no linear correlation existed between the prevalence of PTSD and the size of the gender differences in PTSD for the trauma types examined. Thus, a high prevalence of PTSD is not necessarily followed by a high degree of gender difference. This fact calls for considerations regarding special characteristics of the trauma types which for instance determine severity of trauma and PTSD, but it also calls for considerations regarding gender specific characteristics in men and women that influence the vulnerability or resilience to PTSD. This adds to the previously mentioned considerations by Norris et al. suggesting that trauma severity might diminish gender differences in PTSD if the severity exceeds a certain level . Thereby, a possible threshold or ceiling theory is indicated for the effect of trauma severity on gender differences in PTSD. The present study, however, does not support the ceiling theory. A higher level of gender difference exists when estimates are based on dimensional measurement principles than when they are based on categorical measurement.
The present study found that more than every fifth woman and every sixth man experiencing violence qualified for PTSD. Thus, violence is a trauma type connected with a relatively high prevalence of PTSD but at the same time no gender difference was found in the prevalence rates for violence unlike what previous studies have suggested [2, 27]. Every fifth to sixth woman experiencing non-malignant disease qualified for PTSD but here only every eleventh to twelfth man showed qualification for PTSD. The prevalence of PTSD for the trauma type non-malignant disease was 13.9% showing an increased risk of PTSD when exposed to non-malignant disease.
Limitations of the study
The present study is based on data from 18 different convenience samples, and has a total sample of 5220 participants. Thus, all participants had been exposed to a potentially traumatic situation, strengthening that the study examines how women and men react to trauma and how specific trauma types affect men and women. However, certain limitations of the study must be considered. The cross-sectional design of the study raises questions regarding the representativeness of the sample due to the potential unique characteristics of the sample e.g. in geographical and/or socio-economic factors, the risk of possible cohort differences, and the risk of including too specific and unique traumatic events. Thus, the participants in the present study have been selected by convenience, as they were the ones present under a traumatic incident, or in other ways the ones experiencing the trauma. This does not necessarily guarantee that the sample is representative. However, arguments can be made that the size of the total sample strengthens the reliability of the study. Yet, the reliability of the study could have been further improved by including control variables. The lack of control variables must be regarded as a central limitation of the study. The use of self-report questionnaires as the only method of measurement can also be considered as a central shortcoming of the study. Although good reliability and validity has been found for the HTQ , the data from self-report questionnaires in general, are met with some reservations.