Post-traumatic stress disorder in the Australian Defence Force: estimating prevalence from defence electronic health system records.

Objective: To estimate the prevalence of post-traumatic stress disorder (PTSD) in serving members of the Australian Defence Force (ADF) in the year 2015-2016.

Methods: The electronic health records of serving members of the ADF were screened for the term PTSD over a 12-month period. A 10% sample of these records were examined alongside a randomised matched sample of records. Each record was reviewed by two psychiatrists to verify a diagnosis of PTSD from the file.

Results: The rates of documented PTSD in health records were lower than expected. 802 serving members were identified with clinically diagnosed PTSD during 2015-2016 year, and the prevalence was 0.96%. The rate was higher, 1.33%, when reserve members were excluded. The sample was predominantly of male, non-commissioned officers with the Army having the highest rate of PTSD of the three services.

Conclusions: In this review of a sample of regular and reserve ADF member's electronic health records, a lower-than-expected prevalence of documented PTSD was found. This finding was of particular interest given findings from previous research that the prevalence of PTSD was likely to be higher. Possible explanations for this finding included the role of stigma in delaying or minimising presentations due to fear of adverse impact on career, possible bias in recording of diagnosis and delayed-onset PTSD.