摘要：Objectives. In this population-based cohort study, we assessed baseline risk factors for homelessness, including the role of service in the Iraq or Afghanistan conflicts, among a large cohort of recent veterans. Methods. Data for this study came from administrative records for 310 685 veterans who separated from active military duty from July 1, 2005, to September 30, 2006. We used survival analysis methods to determine incidence rates and risk factors for homelessness, based on baseline data for military factors, demographic characteristics, and diagnoses of behavioral health disorders and traumatic brain injury. Results. Service in Iraq or Afghanistan and, more specifically, posttraumatic stress disorder among veterans deployed there, were significant risk factors of modest magnitude for homelessness, and socioeconomic and behavioral health factors provided stronger indicators of risk. Gender was not a significant indicator of differential risk. Conclusions. Although service in Iraq and Afghanistan was significant, socioeconomic and behavioral health indicators show more promise in efforts to use administrative data to inform prevention efforts by identifying veterans who are at elevated risk for becoming homeless upon their return to civilian life. Soldiers have been returning from the conflicts in Iraq and Afghanistan for more than a decade, and popular support for the soldiers has manifested itself in concern for their well-being as they reenter civilian life. One focal point of this concern has been an increased vulnerability to homelessness among veterans of these conflicts, known by their military designations as Operations Enduring Freedom (OEF; i.e., Afghanistan conflict), Iraqi Freedom (OIF; i.e., Iraq conflict), and New Dawn (OND; i.e., Iraq conflict after August 2010). Media and advocacy accounts have pointed out how the increased incidence of homelessness has its roots in service-connected factors, particularly posttraumatic stress disorder (PTSD) and traumatic brain injury (TBI), in addition to the more general economic conditions they face on reentering civilian life. 1–4 The research on this topic has lagged behind the media accounts. Veterans, and especially female veterans, have been found to be at higher risk for homelessness than their nonveteran counterparts, 5 although the correlates associated with homelessness are largely the same regardless of veteran status. 6 Among veterans, behavioral health disorders, particularly substance abuse disorders and, to a lesser extent, mental health disorders, have consistently been linked with increased incidence of homelessness, and the associations between PTSD and combat experience and homelessness have been much more tenuous. 7,8 Because women have made up increasing proportions of recent veteran populations, the focus on the role of gender differences in military and veteran experiences as they have related to outcomes such as homelessness has increased. 9–11 Other factors, such as poverty and social isolation, have also been linked to homelessness among veterans and may mitigate links between behavioral health disorders and homelessness. 6,12 Two large cross-sectional studies have examined homelessness among the OEF–OIF veteran cohort (OND commenced subsequent to the service period covered in these studies). Blackstock et al. 13 identified 7431 OEF–OIF veterans as having been homeless, constituting 1.7% of the 445 319 records from the US Department of Veterans Affairs (VA) that they examined. They found no difference in gender-specific incidence of homelessness, but they did find associations between homelessness and a range of socioeconomic and demographic factors (lower educational attainment, Black race, Hispanic ethnicity, unmarried, enlisted rank, urban location) as well as disability rating and various behavioral health diagnoses, including PTSD. In the second study, Edens et al. 14 assessed homelessness, based on VA records, for 1.1 million veterans from all eras who received mental health services in 2009. Of the overall study group, 10% were identified as having experienced homelessness, whereas only 4% of the OEF–OIF veterans in this group were so identified. By contrast with Blackstock et al., Edens et al. found significant protective associations with having a service-connected disability rating and a PTSD diagnosis. Both studies were cross-sectional and thus had problems with temporal sequencing in that the assessment of homelessness occurred simultaneously with assessments of behavioral health and disability. The most extensive study to date, from the VA’s Office of Inspector General (OIG), is the only population-based cohort study to estimate the incidence of and assess potential risk factors for homelessness among OEF–OIF era veterans. 15 The study population, 310 685 veterans who separated from the military between July 1, 2005, and September 30, 2006, had no prior history of homelessness and used VA or Department of Defense (DoD) services after discharge. They were followed from the point of military separation through September 30, 2010, for any occurrence of homelessness. Their 5-year (Kaplan–Meier) homeless incidence rate was 3.7%, with the highest incidence rate found among women who were deployed in OEF–OIF (4.0%) and the lowest found among men who were not deployed there (3.2%). The report also found differential rates of homelessness on the basis of numerous bivariate relationships related to military, behavioral health, and demographic characteristics. The study did not control for differences in characteristics other than gender and OEF–OIF service (55% of the study population). We extend OIG’s descriptive study by simultaneously assessing multiple risk factors at or before separation from the military (baseline) for subsequently becoming homeless among OEF- and OIF-era veterans in this cohort. Particular foci are OEF–OIF service and gender differences, in the context of broader socioeconomic, behavioral health, and military factors at separation from the military. In identifying baseline risk factors for homelessness, this study offers a prototype for using administrative data available at military discharge to more efficiently identify and target veterans who would benefit from homeless prevention services.
