Time-course of PTSD symptoms in the Australian Defence Force: a retrospective cohort study

Waller, M., Charlson, F. J., Ireland, R. E. E., Whiteford, H. A. and Dobson, A. J. (2015) Time-course of PTSD symptoms in the Australian Defence Force: a retrospective cohort study. Epidemiology and Psychiatric Sciences, 25 4: 393-402. doi:10.1017/S2045796015000517


Author Waller, M.
Charlson, F. J.
Ireland, R. E. E.
Whiteford, H. A.
Dobson, A. J.
Title Time-course of PTSD symptoms in the Australian Defence Force: a retrospective cohort study
Journal name Epidemiology and Psychiatric Sciences   Check publisher's open access policy
ISSN 2045-7979
Publication date 2015-06-01
Year available 2015
Sub-type Article (original research)
DOI 10.1017/S2045796015000517
Open Access Status Not Open Access
Volume 25
Issue 4
Start page 393
End page 402
Total pages 10
Place of publication Rome, Italy
Publisher Cambridge University Press
Language eng
Subject 2713 Epidemiology
2739 Public Health, Environmental and Occupational Health
2738 Psychiatry and Mental health
Abstract Aims. Understanding the time-course of post-traumatic stress disorder (PTSD), and the underlying events, may help to identify those most at risk, and anticipate the number of individuals likely to be diagnosed after exposure to traumatic events. Method. Data from two health surveys were combined to create a cohort of 1119 Australian military personnel who deployed to the Middle East between 2000 and 2009. Changes in PTSD Checklist Civilian Version (PCL-C) scores and the reporting of stressful events between the two self-reported surveys were assessed. Logistic regression was used to examine the association between the number of stressful events reported and PTSD symptoms, and assess whether those who reported new stressful events between the two surveys, were also more likely to report older events. We also assessed, using linear regression, whether higher scores on the Kessler Psychological Distress Scale or the Alcohol Use Disorder Identification Test were associated with subsequent increases in the PCL-C in those who had experienced a stressful event, but who initially had few PTSD symptoms. Results. Overall, the mean PCL-C scores in the two surveys were similar, and 78% of responders stayed in the same PCL-C category. Only a small percentage moved from having few symptoms of PTSD (PCL-C < 30) in Survey 1 to meeting the criteria for PTSD (PCL-C ≥ 50) at Survey 2 (1% of all responders, 16% of those with PCL-C ≥ 50 at Survey 2). Personnel who reported more stressful lifetime events were more likely to score higher on the PCL-C. Only 51% reported the same stressful event on both surveys. People who reported events occurring between the two surveys were more likely to record events from before the first survey which they had not previously mentioned (OR 1.48, 95% CI (1.17, 1.88), p < 0.001), than those who did not. In people who initially had few PTSD symptoms, a higher level of psychological distress, was significantly associated with higher PCL-C scores a few years later. Conclusions. The reporting of stressful events varied over time indicating that while the impact of some stressors endure, others may increase or decline in importance. When screening for PTSD, it is important to consider both traumatic experiences on deployment and other stressful life events, as well as other mental health problems among military personnel, even if individuals do not exhibit symptoms of PTSD on an initial assessment.
Formatted abstract
Aims. Understanding the time-course of post-traumatic stress disorder (PTSD), and the underlying events, may help to identify those most at risk, and anticipate the number of individuals likely to be diagnosed after exposure to traumatic events.

Method. Data from two health surveys were combined to create a cohort of 1119 Australian military personnel who deployed to the Middle East between 2000 and 2009. Changes in PTSD Checklist Civilian Version (PCL-C) scores and the reporting of stressful events between the two self-reported surveys were assessed. Logistic regression was used to examine the association between the number of stressful events reported and PTSD symptoms, and assess whether those who reported new stressful events between the two surveys, were also more likely to report older events. We also assessed, using linear regression, whether higher scores on the Kessler Psychological Distress Scale or the Alcohol Use Disorder Identification Test were associated with subsequent increases in the PCL-C in those who had experienced a stressful event, but who initially had few PTSD symptoms.

Results. Overall, the mean PCL-C scores in the two surveys were similar, and 78% of responders stayed in the same PCL-C category. Only a small percentage moved from having few symptoms of PTSD (PCL-C < 30) in Survey 1 to meeting the criteria for PTSD (PCL-C ≥ 50) at Survey 2 (1% of all responders, 16% of those with PCL-C ≥ 50 at Survey 2). Personnel who reported more stressful lifetime events were more likely to score higher on the PCL-C. Only 51% reported the same stressful event on both surveys. People who reported events occurring between the two surveys were more likely to record events from before the first survey which they had not previously mentioned (OR 1.48, 95% CI (1.17, 1.88), p < 0.001), than those who did not. In people who initially had few PTSD symptoms, a higher level of psychological distress, was significantly associated with higher PCL-C scores a few years later.

Conclusions. The reporting of stressful events varied over time indicating that while the impact of some stressors endure, others may increase or decline in importance. When screening for PTSD, it is important to consider both traumatic experiences on deployment and other stressful life events, as well as other mental health problems among military personnel, even if individuals do not exhibit symptoms of PTSD on an initial assessment
Keyword Delayed onset
Military
Traumatic events
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ
Additional Notes In Press

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2016 Collection
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Created: Mon, 22 Jun 2015, 23:50:51 EST by Mr Michael Waller on behalf of School of Public Health