Studies of long-term physical and psychosocial functional outcomes of military service members with combat injuries in the conflicts in Afghanistan (Operation Enduring Freedom, OEF) and Iraq (Operation Iraqi Freedom, OIF) are relatively few and have not specifically compared outcomes among those with burn vs non-burn injuries. The San Antonio Military Medical Center (SAMMC) is the sole referral site for all significantly burned military personnel, and provides trauma care to military service members from the Great Plains Regional Command of 17 states (approximately equal to the combined areas of VISNs 15 through 19 and 23). SAMMC also provides burn care to civilians in South Texas.
We aimed to assess long-term functional outcomes among OEF/OIF service members with non-burn trauma or burn trauma, and civilians with burns. We hypothesized that those with combat burns, compared to those with non-burn combat trauma, would have worse long-term functional outcomes. We also expected that those with either type of combat injury would have significant mental and physical impairment even when well enough for discharge from SAMMC.
VA- and DoD-funded prospective cohort studies collected patient surveys with validated instruments, chart abstraction, and administrative data in collaboration. We enrolled combat non-burn patients into the VA-funded study at discharge with follow-ups at 1, 2, 3, and 4 years. Combat and civilian burn patients were enrolled in the DoD-funded study at discharge with follow-ups at 6, 12, and 18 months, and then were invited to join the VA-funded study for follow-ups at 2, 3, and 4 years. Inclusion criteria were service members with burn or non-burn combat injuries while serving in OEF/OIF, medically evacuated to SAMMC and hospitalized for less than 72 hours, or civilians with burn injuries hospitalized at SAMMC for less than 72 hours. Planned primary outcomes were Activities/Instrumental Activities of Daily Living (ADL/IADL), work status, and community integration. We used the first question of the SF-36 (SF1) to assess self-reported general health status, the Center for Epidemiological Studies-Depression (CES-D) scale to assess depressive symptoms, the PTSD Checklist-Military (PCL-M) to assess post-traumatic stress disorder (PTSD) symptoms, and the Satisfaction with Life Scale (SWLS) to assess subjective well-being. Multivariable linear regression with boot-strapped standard errors was used to assess the cross-sectional association at discharge between the continuous primary outcome variables and burn versus non-burn injury after adjustment for length of stay (LOS), Injury Severity Score (ISS), traumatic brain injury (TBI) and type of amputation. Multivariable ordinal logistic regression was used to assess the cross-sectional association between the SF1 and burn versus non-burn injury after adjustment for LOS, ISS, TBI, and type of amputation. Bootstrap estimation was used for the multivariable linear regression models to produce a more robust and reproducible estimate.
Across the 3 cohorts of eligible subjects, 77 with military burn injuries, 82 with civilian burn injuries, and 81 with non-burn combat injuries were enrolled. Of the two burn cohorts, 22 military burn patients and 4 civilian burn patients enrolled for longer follow-up out to 4 years. Attrition was high, as all three populations were transient. Follow-up data were obtained at 1, 2, 3, and 4 years after discharge for 40, 33, 25, and 21 patients of the non-burn trauma military patients and 64, 12, 4, 14 military burn patients, respectively.
Among all military service members, 97% were male; non-burn patients were more likely to be non-Hispanic white (78% vs. 69%) and have some college (66% vs 44%) than burn patients, and to have served in Afghanistan than Iraq. The median LOS was similar for burn and non-burn patients, but those for burn patients were more likely to exceed 60 days (26% vs. 3%) than non-burn patients, Fisher exact p < 0.001. There was no significant difference in ISS between burn and non-burn patients. While there was no difference in the overall number of amputations, the non-burn patients were more likely to have lower extremity amputations (12% vs. 3%), but burn patients were more likely to have hand or finger amputations (10% vs 0%). Non-burn patients had higher prevalence of TBI at discharge than did burn patients (30% vs 17%), but this difference was not statistically significant.
Although more burn patients met PCL-M cut-off criteria scores of at least 44 for PSTD (22% vs 16%; p=0.390) and CES-D cut-off criteria of at least 16 for depression (68% vs. 62%) than non-burn patients, the differences were not significant. Nevertheless, prevalences of positive PTSD screens and especially symptoms indicative of clinical depression were quite high. There were also no significant differences in self-reported general health status between burn and non-burn patients.
We used multivariable linear or logistic analyses to test cross-sectional associations between injury characteristics and status at discharge. There was no association between injury type or other covariates and PCL-M, CES-D or SWLS scores at discharge. Non-burn injuries (adjusted mean difference 2.12, 95% CI 0.99 - 3.26, P<0.001) and increased LOS (adjusted mean difference 0.03, 95% CI 0.01 - 0.05, p=0.014) were significantly associated with worse ADL scores (R2 = 0.30). Non-burn injuries (adjusted mean difference 3.1, 95% CI 1.59 - 4.63, p<0.001), finger amputations (adjusted mean difference 7.6, 95% CI 2.73 - 12.53, p=0.003), and LOS (adjusted mean difference 0.04, 95% CI 0.01 - 0.07, p=0.01) were associated with significantly worse IADL function at discharge (R2=0.35).
This study provides one of the few comparisons of functional outcomes among military service members with burn and non-burn combat injuries done in collaboration between VA and DoD, using similar measures and variables among the cohorts. More than 60% of all participants had symptoms of clinical depression, and approximately 20% screened positive for PTSD at discharge. Contrary to our hypotheses about worse functional outcomes among combat burn patients compared to combat nonburn, we found the opposite. Non-burn injuries, after adjusted analyses, were associated with worse ADL and IADL function at the time of hospital discharge. These findings have immediate implications for managing depression, PTSD, and rehabilitation after hospital discharge and after transitioning to VA care.
- Lawrence VA. Long-term outcomes in burned OEF/OIF veterans. Strategies, insights, lessons learned, and possibilities for improving collaboration (invited speaker). VA/DoD Collaborations Interest Group. Presented at: VA HSR&D National Meeting; 2009 Feb 11; Baltimore, MD.