5.16Posttraumatic Stress Disorder
5.16.1PTSD at follow up
Three data sources were used to determine whether or not a participant had PTSD in the 12 months prior to the follow up study. These were the CIDI, and the PCL-S and self-reported doctor diagnosis and treatment questions in the postal questionnaire. Figure 31 shows the percentages of participants who had current PTSD based on these three measures.
Figure 31 Percentage of participants who had PTSD based on the CIDI interview, the PCL and self-reported doctor diagnosed and treated PTSD in the past 12 months
CIDI defined 12 month PTSD at follow up
Forty-seven (7.3%) Gulf War veterans and 17 (2.8%) comparison group participants met criteria for 12 month PTSD at follow up using the CIDI. This difference between groups was statistically significant, with the risk of PTSD in Gulf War veterans estimated to be more than two times higher than the risk in the comparison group (RR 2.59, adj RR = 2.37, 95% CI 1.37 – 4.09).
PCL-defined PTSD at follow up
Using the PCL data, a slightly larger proportion of participants in both study groups (compared to CIDI-defined PTSD) met criteria for PTSD at follow up; 8.2% and 4.8% respectively; and this difference between groups just met statistical significance (RR 1.73, adj RR = 1.56, 95% CI 1.02 – 2.38). Table 53 shows that the PCL total mean score was higher on average for Gulf War veterans, as was the mean score for each of the PCL subscales.
Table 53 PCL total and subscale mean scores in male Gulf War veterans and comparison group members at follow up
Gulf War veterans / Comparison groupmean / (%) / mean / (%) / mean diff / Adj mean diff(95% CI)
PCL Total score / 28.3 / (13.6) / 24.3 / (10.5) / 4.01 / 3.62 (2.29-4.94)
Intrusion / 7.7 / (4.0) / 6.7 / (3.1) / 1.05 / 1.01 (0.62-1.40)
Hyperarousal / 9.3 / (4.7) / 7.9 / (3.6) / 1.39 / 1.21 (0.76-1.66)
Avoidance / 11.3 / (5.8) / 9.7 / (4.7) / 1.55 / 1.40 (0.82-1.98)
Self-reported doctor-diagnosed PTSD
In the postal questionnaire55Gulf War veterans (7.9%) and 18 comparison group members (2.7%)reported that a medical doctor had diagnosed them with, or treated them for, PTSD in the period since January 2001,and that they had been treated by a doctor for this condition in the past 12 months. This difference between groups represented a statistically significant, almost three-fold, increase in the Gulf War veterans (RR 2.89, adj RR = 2.94, 95% CI 1.70 – 5.08).
5.16.2Association between Gulf War-deployment characteristics and 12 month PTSD in veterans at follow up
The associations between Gulf War deployment characteristics and occurrence of 12 month PTSD at follow up in male Gulf War veterans are shown in Table 54. The results indicate that the risk of 12 month PTSD was higher in Army Gulf War veterans compared to Navy or Air Force veterans, however the total number of cases in the Army was small. Whilst 12 month PTSD appears to be more prevalent in younger Gulf War veterans, differences across age were not statistically significant either with, or without, service branch and rank included in the model. Similarly, a noticeable difference across rank category, with the lowest ranked Gulf War veterans more than twice as likely to have PTSD compared to Officers, just reached statistical significance but not after service branch and age were included in the model.
Table 54 Association between Gulf War-deployment characteristics and 12 month PTSD at follow up in male Gulf War veterans
Gulf War veterans with 12-month PTSD at follow upGulf War exposure / N / n (%) / RR / Adj RR(95% CI)
Age at deployment
< 20 / 58 / 7(12.1) / 1.00 / 1.00
20-24 / 156 / 15(9.6) / 0.79 / 0.93 (0.38-2.29)
25-34 / 336 / 18(5.4) / 0.44 / 0.69 (0.26-1.88)
>=35 / 97 / 7(7.2) / 0.60 / 0.93 (0.28-3.19)
Service branch
Navy / 552 / 39(7.1) / 1.00 / 1.00
Army / 45 / 6(13.3) / 1.88 / 2.29 (>1.00-5.24)
Air Force / 50 / 2(4.0) / 0.57 / 0.77 (0.18-3.18)
Rank category
Officer / 139 / 6(4.3) / 1.00 / 1.00
Other rank-supervisory / 330 / 21(6.4) / 1.47 / 1.66 (0.66-4.21)
Other rank - non supervisory / 177 / 20(11.3) / 2.62 / 2.54 (0.87-7.43)
5.16.3Change in prevalence, also persistence, remittance and incidence of 12 month PTSD since baseline
For male participants who completed the CIDI PTSD module at both baseline and follow up (n=637 Gulf War veterans and n=555 comparison group) Table 55 shows the change in prevalence of 12 month PTSD, from baseline to follow up, in both study groups. These results indicate that, in the decade or so since the baseline study, the risk of 12 month PTSD in Gulf War veterans has significantly increased. In contrast the risk of PTSD in the comparison group has remained relatively stable in the period since the baseline study. Additional analysis showed that there was no significant difference between the two groups (RR 1.31; 95% CI 0.56-3.04) in regard to change over time.
Table 55 Prevalence of 12 month PTSD at baseline and follow up for male participants who completed the CIDI at both time points
Gulf War veterans (N=637) / Comparison group (N=555)Baseline prevalence (%)* / Follow up prevalence (%) / RR (95% CI) / Baseline prevalence (%)* / Follow up prevalence (%) / RR (95% CI)
12 month PTSD / 24 (3.8) / 47 (7.4) / 1.96 (1.29-2.97) / 10 (1.8) / 15 (2.7) / 1.50 (0.72-3.12)
*Includes only those participants who also completed the CIDI at follow up
Table 56 shows the proportions of Gulf War veterans and comparison group participants with a diagnosis (present) or without a diagnosis (absent) of 12 month PTSD at baseline and at follow up. Relatively few of the large proportion (>94%) of Gulf War veterans and comparison group members who had no diagnosis of 12 month PTSD at baseline, then had this diagnosis at follow up. Incident cases are shown in the first row of data in Table 56 as absent at baseline and present at follow up. The percentage of incident cases in the Gulf War group (6.0%) was higher than that in the comparison group (2.4%) and this difference between groups was statistically significant. Persistent cases are shown in the second row of data in Table 56 as present at baseline and present at follow up, whilst remitted cases are present at baseline and absent at follow up. Of the 24 Gulf War veterans and ten comparison group members who had a diagnosis of 12 month major depression at baseline, 42% and 20% respectively were persistent cases who also met this criteria at follow up, whereas 58% and 80% remitted. These differences between groups in persistence and remittance were not statistically significant, but the number of cases, especially for the persistence analysis, were very small.
Table 56 Persistent and new incident cases of 12 month PTSD among male Gulf War veterans and comparison group members who completed the CIDI at baseline and follow up
12-month PTSDGulf War veterans (N=637) / Comparison group (N=555)
Follow up / Follow up
Baseline / n (%)
absent / n (%)
present / Baseline / n (%)
absent / n (%)
present
absent (n = 613) / 576 (94.0) / 37 (6.0)* / absent (n = 545) / 532 (97.6) / 13 (2.4)*
present (n = 24) / 14 (58.3)‡ / 10 (41.7)† / present (n = 10) / 8 (80.0)‡ / 2 (20.0)†
Between groups
RR / Adj RR (95% CI)
Incidence / 2.53 / 2.29 (1.24–4.24)
Remittance / 0.73 / 0.72 (0.44–1.16)
Persistence / 2.08 / 2.48 (0.76–8.08)
* Incident cases
† Persistent cases
‡Remitted cases
5.16.4Key findings
More than 20 years after the Gulf War, and based on a number of different methods of measuring PTSD, the risk of PTSD in Gulf War veterans was between 1 ½ and three times higher than the risk in the comparison group. Gulf War veterans also had more symptoms across all PTSD domains. Since the baseline study, new cases of PTSD have been more likely to occur in Gulf War veterans than in the comparison group. There was also a pattern of PTSD being more likely to persist, and less likely to remit, in Gulf War veterans relative to the comparison group, however those findings did not reach statistical significance. There was a possible association between Army service at the time of the Gulf War and PTSD at follow up.
Australian Gulf War Veterans’ Follow Up Health Study: Technical Report 2015 Page 1