The “Healthy Soldier Effect” and experiences of deployed Australian Defence Force personnel

Abstract

People in the military are typically healthier than those in the general population. This phenomenon is known as the ‘healthy soldier effect’. However, military personnel may also experience a number of risk factors for physical and mental health problems. The contrasting health benefits and risks in a military setting highlight some of the challenges in understanding the health of defence force members. This thesis used data from a number of studies of the Australian Defence Force (ADF) to assess both the ‘healthy soldier effect’ and the health of military personnel following deployment. In Chapter 3 studies of personnel who served in the Korean and Vietnam wars were used to compare mortality rates of Australian servicemen to rates observed in the general population. The results showed the ‘healthy soldier effect’ gradually declined over time. Nevertheless, in a number of analyses the effect was still apparent after more than 30 years of follow-up. Chapter 4 assessed alcohol use in the ADF using combined data from studies of ADF personnel deployed to Bougainville and East Timor. The ADF group contained fewer abstainers, fewer high risk drinkers and more low-risk drinkers than a civilian sample. Alcohol misuse in ADF members, measured from the AUDIT scale, was associated with poorer general health, poorer social functioning and more role limitations because of physical health problems. Chapters 5 and 6 were focused on the experiences and health of those who served on operational deployments. In Chapter 5, self-reported data, collected from the studies of deployments to the Iraq and Afghanistan Wars, was used to identify which types of traumatic exposures were most clearly associated with poorer mental health. Two groups of traumatic exposures were identified: ‘experienced events’ and ‘fear of events’. Both types of exposure were significantly associated with Posttraumatic Stress Disorder (PTSD) and major depressive syndrome. While it is difficult to predict or control exposure to traumatic events during a warlike deployment, it may be possible to modify individuals’ interpretation and management of the level of threat they encounter. Although the association between stressful events on warlike deployments and subsequent mental health problems has been well established, less is known about the nature of stressful events that occur on peacekeeping deployments. In Chapter 6, self-reported data from studies of ADF personnel deployed to Bougainville and East Timor were used to compare the experiences of those deployed on a peacekeeping operation (Bougainville) with those who deployed on an operation that included warlike and non-warlike missions (East Timor). In this analysis subjective assessment of traumatic events (including fear of events) was shown to be associated with poorer mental and physical health. The analysis also identified a number of non-traumatic stressors (particularly work frustration), which were associated with poorer mental health. It may be possible for militaries to control many of the non-traumatic stressors encountered on deployment, to improve the experiences and health of those deployed. The analyses in Chapters 5 and 6 found strong associations between traumatic exposures on deployment and subsequent symptoms of PTSD. In Chapter 7, data from four cross-sectional studies were combined to create a longitudinal dataset. Using this dataset the time course of PTSD and the underlying traumatic events were assessed. Members who reported more stressful lifetime events were more likely to report symptoms of PTSD. These stressful events recorded by responders included a number of traumatic experiences on deployment, but also workplace stressors and relationship and family issues. The analysis from Chapter 7 also showed that a large proportion of stressful events became less noteworthy over time, whereas some events gained importance. This thesis focused on three key factors that may influence military health: selection effects, health behaviours, and operational deployments. As with all employers it is in the best interests of a defence force to look after the wellbeing of its staff, maintain a healthy workforce and retain skilled personnel. Each chapter of this thesis identified groups within the ADF who may be at higher risk of poorer physical and mental health. It is proposed that the decline in health in these groups may be mitigated by health policies to reduce alcohol misuse; targeted training to prepare personnel for deployments; and careful screening of defence force members which accounts for experienced traumatic events and the level of risk on deployment, and previous stressful life events. The implementation of such policies is likely to yield benefits in terms of productivity, staff retention and the health and wellbeing of military personnel.