Of the 52 participants who were exposed to traumatic events, 48% met DSM-IV criteria for current PTSD. There were more women (n = 31) than men (n = 21) in the sample and average age of the sample was 36.8 (9.76) years.
In descending order of frequency, the types of trauma reported were physical assault (n = 14), accident (n = 10), sexual assault (n = 9), combat (n = 5), sudden death of family member (n = 4), suicide of family member (n = 4), and life threatening illness (n = 3). More females (76.0%) developed PTSD than males (24.0%), a difference that was found to be statistically significant, chi-square = 5.37, df = 1, p = .02. Those with PTSD had a higher frequency of being unmarried than those without PTSD (56.0% vs. 29.6%) but this finding was not significant. Those without PTSD seemed better educated than those with PTSD although the difference was not statistically significant. There was also no significant difference between the two groups at the time since the traumatic event occurred. Refer to Table for complete information on demographic characteristics.
PTSD and Demographic Factors
Approximately equal numbers of participants with PTSD (88.0%) and without PTSD (88.9%) reported having experienced at least one other traumatic event during their lifetime. Although not statistically significant, those with PTSD (40.0%) were more than twice as likely as those without PTSD (18.5%) to have had a history of physical abuse as a child. Participants with and without PTSD had similar frequencies of family history of mental illness, personal history of mental illness, and being raised by someone other than their parents for at least four months prior to the age of 16 (see Table ). Having a history of sexual abuse as a child was found to be more common in those with PTSD (56.0%) than those without PTSD (22.2%), a statistically significant finding, chi-square = 6.26, df = 1, p = .02.
PTSD and Early Environmental Factors
Both those with and without PTSD had similar frequencies for receiving physical injuries as a result of their trauma, having to be hospitalized due to the event, and witnessing the death or severe injury of another person (see Table ). A significant difference was found, however, depending on whether they were the victims or the witnesses of a traumatic event – 84.0% of participants with PTSD were victims whereas 44.4% of those without PTSD were witnesses, chi-square = 8.76, df = 1, p = .004.
The results from the S-Anxiety scale revealed no significant differences between those with and without PTSD on the degree of anxiety experienced while the traumatic event was occurring: 68.40 (13.03) vs. 64.41 (12.55). Again, there was no significant difference between those with and without PTSD on the reported severity of injuries they received as a result of the trauma: 3.48 (1.56) vs. 4.00 (1.57). However, significant differences were found between participants on the extent to which they felt that their life was in danger, those with PTSD reporting a higher mean score than those without PTSD: 3.84 (1.52) vs. 2.44 (1.40), t (50) = 3.45, p = .001. Significant differences were also found on the extent to which participants felt that their traumatic event was the result of an intentional act, those with PTSD reporting a higher mean score than those without PTSD: 3.92 (1.53) vs. 2.81 (1.90), t (50) = 2.30, p = .026. There were no significant differences to the extent to which participants with or without PTSD reported obtaining professional support to deal with their traumatic event or having prior training in dealing with traumatic events (see Table for frequency counts).
PTSD and Social Support and Coping
There were no differences found between groups on attribution of responsibility for the traumatic event – those with and without PTSD were both more likely to blame others for their traumatic event as opposed to blaming themselves. Those with PTSD were more likely to use emotion-oriented coping in dealing with stressful events than those without PTSD. This finding approached significance, chi-square = 5.74, df = 1, p = .06. Significant differences were found between groups depending on whether or not someone was available to talk to about their trauma. Of those with PTSD, only 40.0% reported having someone available to talk to in contrast to 81.5% of those without PTSD, chi-square = 9.44, df = 1, p = .004. Similarly, the groups differed on the extent to which they talked about their traumatic event with others – those with PTSD, on average, spoke less about their traumatic event with others than those without PTSD: 2.32 (1.38) vs. 3.33 (1.14), t (50) = -2.90, p = .006.
A direct logistic regression analysis was performed using the five variables that significantly discriminated between the two groups as the variables that would in combination best predict the probability of having PTSD. These variables were:
• having a history of sexual abuse
• the extent to which one felt one's life was in danger
• the extent to which one felt that the traumatic event was the result of a deliberate act
• whether or not there was someone to talk to about the traumatic event.
According to the Wald criterion, gender and the extent to which participants felt their lives were in danger reliably predicted PTSD, z = 2.20, p < .05 and z = 2.04, p < .05. Females were 7.6 times more likely to have PTSD than males and a one-unit increase in the extent to which participants felt their life was in danger multiplied the odds of having PTSD 1.7 times. Using the default cut point of .5, prediction success was above chance with 72.0% of participants with PTSD correctly classified as having the disorder and 81.5% of participants without PTSD correctly classified as not having the disorder, for an overall success rate of 76.9%.
Because the prevalence rate of PTSD varies depending on the type of trauma experienced, another analysis was conducted using a cut point of .17, which is the average prevalence rate for PTSD across several studies reported in the literature. Consistent with the previous results, this analysis also found that gender and the extent to which one felt their lives were in danger reliably predicted the presence or absence of PTSD, z = 2.20, p < .05 and z = 2.04, p < .05. However, using this cut-point of .17, 96.0% of participants with PTSD were correctly classified as having the disorder and only 37.0% of participants without PTSD were correctly classified as not having the disorder, for an overall success rate of 65.4% which was lower than when the cut-point used was .5.