Time-to-Injury for U.S. Army Soldiers Deployed in Support of Operations in Iraq and Afghanistan

s / Annals of Epidemiology 25 (2015) 702e719 713 personyears in 2008 and 2013), while IMC outpatient visit rates trended upward (16% increase; 722.6 to 836.8 injuryoutpatient visits per 1,000personyears in 2008 and 2013) (p<0.001 for trend). Leading causes of unintentional injuryhospitalizations (69% cause-coded)were land transport accidents (20%), fall/near falls (17%), and athletics/sports (8%). Leading unintentional injuries requiring outpatient treatment (34% cause-coded) were attributed to overexertion (28%), land transport accidents (18%), and falls (17%). Conclusions: Opposing trends in IMC hospitalization and outpatient visit rates need to be explored to determine whether these findings are attributable to primarily changes in severity of injuries, shifts in treatment towards outpatient care, or other determinants. Mandatory cause coding of outpatient encounters, inclusive of IMCs, would greatly enhance military injury prevention efforts. P45. Motorcycle and Motor Vehicle (Non-Motorcycle) OccupantRelated Fatal and Nonfatal Injuries in the U.S. Army Esther Dada MPH, Michelle Canham-Chervak PhD, MPH, Bruce H. Jones MD, MPH. U.S. Army Institute of Public Health Purpose: This analysis estimates and compares exposure-based rates of motorcycle and motor vehicle (non-motorcycle) occupant-related fatal and nonfatal injuries among active duty U.S. Army Soldiers, 2003-2008. Methods: Motorcycle and motor vehicle-related fatal and nonfatal injuries resulting in hospitalizations and outpatient visits were identified from the Defense Medical Surveillance System. Exposure-based injury rates were computed by adjusting for (1) population-at-risk obtained from the Department of Defense Survey of Health Related Behaviors among Military Personnel (2003, 2005, 2008 survey years) and (2) average vehicle miles traveled for motorcycles and other motor vehicles reported in 2003-2008 Federal Highway Administration data. Results: Exposure-adjusted rates of motorcyclist fatal and nonfatal injuries were approximately 6 to 7 times the rates of motor vehicle (non-motorcycle) occupant injuries among Army Soldiers (Rate ratio [RR] 6.89 (95% Confidence Interval [CI] 5.81-8.17)) and (RR 5.68 (95% CI 5.50-5.86)), respectively), although unadjusted fatal and nonfatal injury rates were lower for motorcyclists. The exposure-adjusted hospitalization rate of motorcycle-related injuries was nearly 15 times the hospitalization rate for motor vehicle occupant injuries (RR 14.69 (95% CI 13.49-15.97)). Conclusions: This analysis suggests that motorcyclist fatal and nonfatal injuries occur at substantially higher rates than motor vehicle occupant injuries among U.S. Army Soldiers, consistent with other U.S. populations. Variations in population exposure and distance traveled by vehicle type influence rate calculations and are important when comparing rates of different modes of travel. Routine collection of data enabling calculation of these rates for the military is essential. P46. Time-to-Injury for U.S. Army Soldiers Deployed in Support of Operations in Iraq and Afghanistan Bonnie Taylor PhD, Keith Hauret MSPH, MPT, Bruce Jones MD, MPH. Army Institute of Public Health Purpose: Injuries are a public health problem in civilian and military populations. Soldier injuries during deployment create a reduction in unit readiness. The first/last 90 days of a deployment are periods when Soldiers rotate in andoutof theater. ArmySafetyProfessionals speculate that thebeginningof a deployment incurs increased mishaps, and consequently injuries, due to many possible factors including greater exposure to hazards during road movement, acclimation to the new environment/situation, circadian rhythm cycle adjustment, and operating new vehicles/equipment. This investigation examines whether Soldiers are more likely to experience injuries during the first 90 days of deployment compared to later time periods. Methods: Frequencies of time-to-injury for all deployments were determined for all injuries requiring in-theater hospitalization or out-of-theater air evacuation (US Army, Iraq and Afghanistan, October 2001-December 2013). Injury rates were calculated by deployment week. Injury cause distribution was compared (z-score) between time periods of similar length. Results: There were 2,040,794 Soldier deployments ranging from days to years. The modal length of deployment was 50 weeks. There were 60,687 injuries. Approximately 1/3 of all injuries occurred during the first 90 days of deployment; however, the injury rate in the first 90 days was lower than (p<.0001) the subsequent time period rate. Leading injury causes (battle, falls, sports, motor vehicle) were similar between time periods, but differed in distribution (p<.05). Conclusions: These empirical data do not support a greater likelihood of injury within the first 90 days of deployment. Further study should include outpatient injuries and all fatalities.