Dwell Time and Psychological Screening Outcomes Among Military Service Members With Multiple Combat Deployments.

摘要

The conflicts in Iraq and Afghanistan have been the longest sustained military operations in U.S. history. To meet operational demand, many service members have had to deploy multiple times to these combat zones. The effect of dwell time, or the period of time between deployments, has recently gained attention because some studies have found that longer dwell times are protective against combat-related psychological outcomes. The objective of this study was to examine the association between dwell time and psychological morbidity, while accounting for combat exposure. U.S. Marines with two combat deployments between 2005 and 2008 were identified from electronic deployment records. Those who had screened positive for posttraumatic stress disorder and depression, and had received a referral for mental health services were identified from the Post-Deployment Health Assessment. For the final study sample of 3512 Marines, dwell time was calculated as time between deployments, and was analyzed as a ratio over length of first deployment. After adjustment for all covariates, there was an interaction (p value = 0.01) between dwell time and combat exposure on mental health referral outcome. For personnel with maximum reported combat exposure, longer dwell times were significantly associated with a 49-92% reduced odds of mental health referral. Longer dwell times may be protective against combat-related psychological outcomes. Since multiple deployments are likely to be the norm rather than the exception in future military operations, the concept of regulating dwell time, particularly for those with greater risk of combat exposure, should continue to be explored.