Measuring earplug noise attenuation: A comparison of laboratory and field methods.

Hearing protection device (HPD) fit-testing is a recommended best practice for hearing conservation programs as it yields a metric of the amount of attenuation an individual achieves with an HPD. This metric, the personal attenuation rating (PAR), provides hearing health care, safety, and occupational health personnel the data needed to select the optimal hearing protection for the occupational environment in which the HPD will be worn. Although commercial-off-the-shelf equipment allows the professional to complete HPD fit tests in the field, a standard test methodology does not exist across HPD fit-test systems. The purpose of this study was to compare the amount of attenuation obtained using the "gold standard" laboratory test (i.e., real-ear attenuation at threshold [REAT]) and three commercially available HPD fit-test systems (i.e., Benson Computer Controlled Fit Test System [CCF-200] with narrowband noise stimuli, Benson CCF-200 with pure tone stimuli, and Michael and Associates FitCheck Solo). A total of 57 adults, aged 18 to 63, were enrolled in the study and tested up to seven earplugs each across all fit-test systems. Once fitted by a trained member of the research team, earplugs remained in the ear throughout testing across test systems. Results revealed a statistically significant difference in measured group noise attenuation between the laboratory and field HPD fit-test systems (p < .0001). The mean attenuation was statistically significantly different (Benson CCF-200 narrowband noise was +3.1 dB, Benson CCF-200 pure tone was +2.1 dB, and Michael and Associates FitCheck Solo was +2.5 dB) from the control laboratory method. However, the mean attenuation values across the three experimental HPD fit-test systems did not reach statistical significance and were within 1.0 dB of one another. These findings imply consistency across the evaluated HPD fit-test systems and agree with the control REAT test method. Therefore, the use of each is acceptable for obtaining individual PARs outside of a laboratory environment.

SARS-CoV-2 Infection and Death Rates Among Maintenance Dialysis Patients During Delta and Early Omicron Waves - United States, June 30, 2021-September 27, 2022.

Persons receiving maintenance dialysis are at increased risk for SARS-CoV-2 infection and its severe outcomes, including death. However, rates of SARS-CoV-2 infection and COVID-19-related deaths in this population are not well described. Since November 2020, CDC's National Healthcare Safety Network (NHSN) has collected weekly data monitoring incidence of SARS-CoV-2 infections (defined as a positive SARS-CoV-2 test result) and COVID-19-related deaths (defined as the death of a patient who had not fully recovered from a SARS-CoV-2 infection) among maintenance dialysis patients. This analysis used NHSN dialysis facility COVID-19 data reported during June 30, 2021-September 27, 2022, to describe rates of SARS-CoV-2 infection and COVID-19-related death among maintenance dialysis patients. The overall infection rate was 30.47 per 10,000 patient-weeks (39.64 among unvaccinated patients and 27.24 among patients who had completed a primary COVID-19 vaccination series). The overall death rate was 1.74 per 10,000 patient-weeks. Implementing recommended infection control measures in dialysis facilities and ensuring patients and staff members are up to date with recommended COVID-19 vaccination is critical to limiting COVID-19-associated morbidity and mortality.

Declines in Influenza Vaccination Coverage Among Health Care Personnel in Acute Care Hospitals During the COVID-19 Pandemic - United States, 2017-2023.

Health care personnel (HCP) are recommended to receive annual vaccination against influenza to reduce influenza-related morbidity and mortality. Every year, acute care hospitals report receipt of influenza vaccination among HCP to CDC's National Healthcare Safety Network (NHSN). This analysis used NHSN data to describe changes in influenza vaccination coverage among HCP in acute care hospitals before and during the COVID-19 pandemic. Influenza vaccination among HCP increased during the prepandemic period from 88.6% during 2017-18 to 90.7% during 2019-20. During the COVID-19 pandemic, the percentage of HCP vaccinated against influenza decreased to 85.9% in 2020-21 and 81.1% in 2022-23. Additional efforts are needed to implement evidence-based strategies to increase vaccination coverage among HCP and to identify factors associated with recent declines in influenza vaccination coverage.

Cost and benefit of military quarantine policies.

The initial response to COVID-19 included quarantine policies. This study aims to determine the infection containment proportions and cost of two variations of quarantine policies based on geographic travel and close contact with infected individuals within deployed US military populations. Special Operations Command Africa (SOCAF) records of individuals quarantined between March 1, 2020 and June 1, 2020 were examined. The infection containment proportion and cost in containment hours were compared between types of quarantine and between geographic areas. Geographic quarantine contained 2 cases out of 63 quarantined individuals in West Africa (3.2%) compared to 0 out of 221 in East Africa (p = 0.0486). Close contact quarantine contained 3 cases out of 31 quarantined individuals in West Africa compared to 4 out of 55 in East Africa (7.3%, p = 0.6989). Total confinement was 42,048 h for each contained infection using geographic quarantine compared to 4076 h using close contact quarantine. In the US military population deployed to Africa for COVID-19, quarantining based on geographic movement is an order of magnitude more costly in terms of time for each contained infection then quarantining based on close contact with infected individuals. There is not a statistical difference between East and West Africa. The associated costs of quarantine must be carefully weighed against the risk of disease spread.

A Six-Year Follow-Up of Bloodstream Infections in Hemodialysis Facilities in the United States, National Healthcare Safety Network, 2020.

METHODS: Outpatient hemodialysis facilities report BSI events to NHSN. Pooled mean rates with 95% CI were calculated overall and for each type of vascular access (arteriovenous (AV) fistula, AV graft, or a central venous catheter (CVC)). Standardized infection ratios were calculated as observed BSI events divided by the predicted number of events based on national aggregate data. Median facility-level standardized infection ratios and 95% confidence intervals (CIs) were stratified by state and US territory. RESULTS: During 2020, 7,183 outpatient hemodialysis facilities reported data for 5,235,234 patient months with 15,181 BSI events. Pooled mean rates per 100 person-months were 0.29 (95% CI, 0.29-0.30) overall, 0.80 (95% CI, 0.78-0.82) for CVC, 0.12 (95% CI, 0.12-0.12) for AV fistula, 0.21 (95% CI, 0.20-0.22) for AV graft, and 0.28 (95% CI, 0.19-0.40) for other access types. The national standardized infection ratio was 0.40 (95% CI, 0.39-0.41). South Dakota had a standardized infection ratio significantly higher than one (1.34; 95% CI, 1.11 - 1.62). Fifty-one of 54 states and territories had BSI standardized infection ratio significantly lower than one. CONCLUSIONS: In 2020, the median standardized infection ratio for BSI in US outpatient hemodialysis facilities was lower than predicted overall and in almost all states and territories. An elevated standardized infection ratio was identified in South Dakota.

A Review of Medical Evacuations Related to Dental Emergencies and Oral-Maxillofacial Injuries.

A literature review was performed to determine the frequency of medical evacuations (MEDEVAC) that are required for dental emergencies (DE) and oral-maxillofacial (OMF) injuries. Fourteen studies were reviewed altogether - eight which quantified evacuation of DEs or OMF injuries in military personnel (from 1982-2013) and six studies that discussed medical evacuation of DEs occurring in civilians working in offshore oil and gas rigs and wilderness expeditions (from 1976-2015). Among military personnel, DE/OMF issues were frequently among one of the top categories of medical evacuations, ranging from 2-16% of all evacuations. Among oil and gas industry workers, 5.3-14.6% of evacuations were dental-related, while one study of wilderness expeditions found that DEs ranked as the third most frequent type of injury that required evacuation. Previous studies have shown that dental and OMF problems often account for one of most frequently cited reasons for evacuation. However, due to the limited study base of DE/OMF medical evacuations, further research is needed to determine their impact on the cost of health care delivery.

Incidence of Suicidal Ideation and Suicide Attempt Based on Time in a Deployed Environment.

INTRODUCTION: Knowing when suicidal ideation (SI) or suicide attempt (SA) is most likely to occur in a deployed environment would aid in focusing prevention efforts. This study aims to determine when evacuation for SA and SI is most likely to occur based on the absolute and relative number of months in a deployed setting. MATERIALS AND METHODS: This is a case-control study of active-duty military personnel evacuated from the U.S. Central Command area of responsibility for SI or an SA between April 1, 2020, and March 30, 2021. The arrival month and expected departure month were identified for all the included evacuees. The month of evacuation and proportion of completed deployment were compared. Secondary outcomes of mental health diagnosis or need for a waiver was also examined. RESULTS: A total of 138 personnel evacuated for SI or attempted suicide during the 12-month study period were included in the analysis. Evacuations occurring during month 3 of deployment were significantly higher (P < .0001) than those during other months. The 30% and 50% completion point of deployment had statistically higher frequencies of evacuations for SI/SA (<.0001). A secondary analysis revealed that 25.4% of the individuals had a documented preexisting behavioral health condition before deployment (P < .0001). CONCLUSION: Specific points along a deployment timeline were significant predictors for being evacuated for SI and SA.

Declining Military Surgical Cases and the Impact on Military Surgical Graduate Medical Education.

BACKGROUND: Several studies have indicated a decline in the number, types, and complexity of surgical procedures within military treatment facilities (MTFs). This study aims to determine what effect, if any, these downward trends have had on the relationship between the military health system (MHS) and surgical graduate medical education. METHODS: Graduating chief resident final ACGME case logs from 4 of thirteen military general surgery programs were evaluated from 2015 to 2020. The proportion of total cases performed by residents at military institutions were compared on a year over year basis. RESULTS: The proportion of cases performed within the military hospitals declined 3.27% each year between 2015 and 2020 (P < .0001) in 4 MTFs. All individual hospitals had significant declines in case volume except one (William Beaumont Army Medical Center) which increased 6.05% with each year, but also increased the number of MTF partnerships within its program (P < .0001). CONCLUSIONS: There has been a statistically significant decline over time in the proportion of cases logged by residents within the studied military treatment facilities. Investment into military hospitals to increase case numbers, case diversity, and complexity and/or acceptance of this gradual decline with greater shifting of educational workload onto civilian hospitals is required.

US Central Command military blood utilization practices 2011 to 2020.

BACKGROUND: Military involvement in Afghanistan ended in 2021, and while low-intensity troop engagements continue globally, casualty numbers are dwindling. To understand the clinical and operational connections between blood utilization and clinical paradigm shifts in resuscitation strategies, a review of blood product utilization and the changes in the last decade was conducted within the US Central Command area of responsibility. The intent of this review was to assess patterns of blood use during the last decade of the United States' involvement in the most recent major conflicts to potentially inform future blood requirements. METHODS: Blood product and types transfused between January 1, 2011, and December 31, 2020, were acquired from the Medical Situational Awareness in Theater blood reports. All reported blood usage data in the US Central Command area of responsibility were queried. RESULTS: Packed red blood cells and fresh frozen plasma (FFP) usage showed no statistically significant change over time ( τb = 0.24, p = 0.3252; τb = -0.47, p = 0.0603). Fresh and stored whole blood (SWB) use increased overtime ( τb = 0.69, p = 0.0056; τb = 0.83, p = 0.0015). A strong inverse relationship was found between SWB and FFP usage ( r = -0.68, p = 0.0309) and liquid plasma and FFP usage ( r = -0.65, p = 0.0407) over time. CONCLUSION: Whole blood usage increased significantly over time with a preference for SWB. Component therapy is anticipated to remain a critical element of resuscitation in the event of large-scale combat operations secondary to supply chain and longer storage times. LEVEL OF EVIDENCE: Therapeutic/care management; Level III.

Timeline of Psychological and Physiological Effects Occurring During Military Deployment on a Medical Team.

BACKGROUND: The negative effects of deployment on military mental health is a topic of major interest. Predeployment and postdeployment assessments are common, but to date there has been little to no intradeployment assessment of military members. This study attempts to determine the physiological and psychiatric effects on Servicemembers over the course of deployment, to provide a baseline data set and to allow for better prediction, prevention, and intervention on these negative effects. METHODS: A retrospective analysis was performed on physiological and psychiatric data collected on a single deployed medical team between 16 January 2020 and 12 July 2020. Patient health screening questionnaires (PHQ-9) and physiological measurements were completed serially twice weekly on five active-duty military volunteers for the entirety of a scheduled 6-month deployment. RESULTS: Depression symptom development followed a linear trend (p = .0149) and severity followed a quadratic trend (p < .001) over a length of a deployment. Weight (p = .435) and pulse (p = .416) were not statistically altered. Mean arterial pressure (MAP) had a statistically significant reduction (p < .001). CONCLUSION: In this specific population, there was a linear relationship between time deployed and depression symptoms and severity. Depression symptom severity decreases toward the end of deployment but does not return to baseline before deployment's end.

Variability of Value of Trauma Centers to General Surgery Combat Casualty Care Skill Sustainment.

OBJECTIVE: Military-civilian partnerships for the maintenance of trauma readiness skills will be required to maintain skills in preparation for future combat casualty care operations. There is little data describing relative worth of potential partnerships. This study aims to demonstrate that quantitative and qualitative differences are prevalent between trauma centers. DESIGN: A combat casualty care relevant case (CCC-RC) was determined to be one that was open, urgent, and required a blood transfusion. Total number of urgent trauma cases and number of cases requiring transfusions between January 1, 2017 and January 1, 2019 were tallied at Saint Louis University Hospital (ACS Level 1), San Antonio Military Medical Center (ACS Level 1), Madigan Army Medical Center (Washington Level 2), and William Beaumont Army Medical Center (Texas Level 3). At the participating level 1 trauma centers, cases were segregated by surgeon. SETTING: Saint Louis University Hospital (SLU), San Antonio Military Medical Center (SAMMC), Madigan Army Medical Center (MAMC), and William Beaumont Army Medical Center (WBAMC). PARTICIPANTS: All general surgery/trauma cases at participating hospitals between January 1, 2017 and January 1, 2019. RESULTS: A total of 267 of 721 trauma cases performed by trauma/general surgeons at SAMMC were CCC-RCs, at SLU 213 of 342, MAMC, 5 of 13, and at WBAMC 1 of 33. While SAMMC had the most cases, SLU had the highest ratio of cases that were CCC-RC (p < 0.0001). The average number of CCC-RCs of the top 5 surgeons at each level 1 institutions were 15.7 cases/year (60.5%) at SLU and 10.3 cases/year (33.6%) at SAMMC (p < 0.0001). CONCLUSIONS: The CCC-RC definition is easily used to distinguish the value and relevancy of trauma centers to general surgeon combat casualty care readiness. The volume and proportions of relevant trauma are significantly different between trauma centers. The military trauma designated hospitals are currently inadequate to support all general surgeon readiness needs. Embedding surgeons at centers with high volumes or relevant cases is the optimum solution.

Clinical utilization of deployed military surgeons.

BACKGROUND: Combat casualty care has been shaped by the prolonged conflicts in Southwest Asia, namely Afghanistan, Iraq, and Syria. The utilization of surgeons in austere locations outside of Southwest Asia and its implication on skill retention and value have not been examined. This study hypothesizes that surgeon utilization is low in the African theater. This lack of activity is potentially damaging to surgical skill retention and patient care. METHODS: Military case logs of surgeons deployed to Africa under command of Special Operations Command Africa between January 1, 2016, and January 1, 2020, were examined. Cases were organized based on population served, general type of procedure, current procedural terminology codes, and location. RESULTS: Twenty deployment caseloads representing 74% of the deployments during the period were analyzed. In 3,294 days, 101 operations were performed, which included 45 on combat/terrorism related injuries and 19 on US personnel. East and West African deployments, combat, and noncombat zones, respectively, were compared. East Africa averaged 4.1 ± 3.8 operations per deployment, and West Africa, 7.3 ± 8.0 (p = 0.2434). In East Africa, 56.1% of total operations were related to combat/terrorism, compared with 29.6% of total operations in West Africa (p = 0.0077). West Africa had a significantly higher proportion of elective (p = 0.0002) and humanitarian cases (p = <0.0001). CONCLUSION: Surgical cases for military surgeons were uncommon in Africa. The low volumes have implications for skill retention, morale, and sustainability of military surgical end strength. Reduction in deployment lengths, deployment location adjustments, and/or skill retention strategies are required to ensure clinical peak performance and operational readiness. Failure to implement changes to current practices to optimize surgeon experience will likely decrease surgical readiness and could contribute to decreased retention of deployable military surgeons to support global operations. LEVEL OF EVIDENCE: Economic/decision, level III.

Military deployment's impact on the surgeon's practice.

BACKGROUND: As the United States withdraws from overseas conflicts, general surgeons remain deployed in support of global operations. Surgeons and surgical teams are foundational to combat casualty care; however, currently, there are few casualty producing events. Low surgical volume and acuity can have detrimental effects on surgical readiness for those frequently deployed. The surgical team cycle of deployment involves predeployment training, drawdown of clinical practice, deployment, postdeployment reintegration, and rebuilding of a patient panel. This study aims to assess these effects on typical general surgeon practices. Quantifying the overall impact of deployment may help refine and implement measures to mitigate the effects on skill retention and patient care. METHODS: Surgeon case logs of eligible surgeons deploying between January 1, 2017, and January 1, 2020, were included from participating military treatment facilities. Eligible surgeons were surgeons whose case logs were primarily at a single military treatment facility 26 weeks before and after deployment and whose deployment duration, location, and number of deployed cases were obtainable. RESULTS: Starting 26 weeks prior to deployment, analyzing in 1-week intervals toward deployment time, case count decreased by 4.8% (p < 0.0001). With each 1-week interval, postdeployment up to the 26-week mark, case count increased by 6% (p < 0.0001). Cases volumes most prominently drop 3 weeks prior to deployment and do not reach normal levels until approximately 7 weeks postdeployment. Case volumes were similar across service branches. CONCLUSION: There is a significant decrease in the number of cases performed before deployment and increase after return regardless of military branch. The perideployment surgical volume decline should be understood and mitigated appropriately; predeployment training, surgical skill retention, and measures to safely reintegrate surgeons back into their practice should be further developed and implemented. LEVEL OF EVIDENCE: Economic/Decision, Level III.

Maintaining vascular trauma proficiency for military non-vascular surgeons.

BACKGROUND: Vascular injuries in combat casualty patients are common and remain an ongoing concern. In civilian trauma centers, vascular surgeons are frequently available to treat vascular injuries. Within the military, vascular surgeons are not available at all locations where specialty expertise may be optimal. This study aims to determine if a visiting surgeon model, where a general surgeon can visit a civilian trauma center, would be practical in maintaining proficiency in vascular surgery. METHODS: All vascular trauma relevant cases done by any surgical service were identified during a 2-year period at Saint Louis University Hospital between October 1, 2016 and September 30, 2018. These included cases performed by trauma/general, thoracic, vascular, and orthopedic surgery. Predictions on the number of call days to experience an operative case were then calculated. RESULTS: A total of 316 vascular cases were performed during the time period. A surgeon on call for five 24-hour shifts would experience 2.1 urgent vascular cases with 95% certainty. To achieve five cases with 95% certainty, a surgeon would have to be on call for 34 24-hour shifts. DISCUSSION: A visiting surgeon model would be very difficult to maintain to acquire or maintain proficiency in vascular surgery. High-volume trauma centers, or centers with significant open vascular cases in addition to trauma, may have more reasonable time requirements, but would have to be evaluated using these methods. LEVEL OF EVIDENCE: Economic and value-based evaluations, level II.

Heterogeneity in Military Trauma Casualty Care.

INTRODUCTION: Military combat casualty care is at the forefront of military medical readiness, but there is little data on current proficiency of deployed personnel. A previous study identified a potential performance gap in military trauma teams. This study aims to evaluate a subsequent team to determine if heterogeneity of teams exists and to determine if this level of efficiency persists or can be improved. MATERIALS AND METHODS: Military trauma teams at the Role 3 hospital in Bagram, Afghanistan, were evaluated over the course of a single deployment between April and October 2018. Trauma teams were directly observed and performance of the ATLS primary trauma survey timed. These results were compared to previously published times from Kandahar and Bagram Role 3 sites from Oct 2016 to Apr 2017. RESULTS: Time to completion of the primary survey in 2018 was statistically faster than the times reported from the Role 3 sites from Oct 2016 to Apr 2017 (344.75 s vs. 482.8 s, p < 0.05). The greatest improvements of efficiency were in the time periods between assessing the airway and breathing, evaluating the patient's circulation, and completing of the primary survey. CONCLUSIONS: Trauma teams can vary significantly in their efficiency in evaluating trauma patients. Whether this is clinically significant is currently debatable, but it highlights a possible readiness gap for deploying military personnel and the heterogeneity of military combat casualty care.

Current challenges in military trauma readiness: Insufficient relevant surgical case volumes in military treatment facilities.

BACKGROUND: The management of battlefield trauma requires a specific skill set, which is optimized by regular trauma experience. As military casualties from the prolonged conflicts in the Middle East decrease, challenges exist to maintain battlefield trauma readiness. Military surgeons must therefore depend on the Military Health System. The purpose of the study was to evaluate the frequency of surgical cases relevant to deployed combat casualty care performed at military treatment facilities (MTFs). METHODS: Combat casualty care relevant cases (CCC-RCs) were defined as emergent, open surgical cases in which the patient required a blood transfusion. Case logs from four military treatment centers with surgical residency training programs were used. Twenty-four months of case records between January 1, 2017, and January 1, 2019, were included to determine total numbers of CCC-RCs at each institution. The results were compared with San Antonio Military Medical Center's, the Department of Defense's only American College of Surgeons-verified level 1 trauma center. RESULTS: Fifty-one trauma/general surgeons and six vascular surgeons case logs were examined. Thirty (0.3%) of 10,529 cases performed by trauma/general and vascular surgeons over the 2-year study period were considered CCC-RCs. These results were in contrast to San Antonio Military Medical Center, which had a significantly higher proportion of CCC-RCs (113 of 320 cases, 35.3%, p < 0.0001). CONCLUSION: A cross-section of MTF surgical case complexity demonstrates a lack of cases considered to be CCC-RCs. At the MTFs evaluated, surgical case surrogates for combat trauma and combat casualty care is close to zero. These data are potentially representative of other military treatment centers, which focus on beneficiary care. For readiness purposes, MTFs that care primarily for Tricare beneficiaries without a significant trauma population should not be considered meaningful sources of CCC-RCs for trauma/general and vascular surgeons. LEVEL OF EVIDENCE: Therapeutic/care management study, level V.

The Burden of Dental Emergencies, Oral-Maxillofacial, and Cranio-Maxillofacial Injuries in US Military Personnel.

INTRODUCTION: High numbers of dental emergencies (DE) in military service members (approximately 15% per annum) prompted the inclusion of Dental Readiness as one of six conditions that determine service members' Individual Medical Readiness (IMR). Additionally, even with the advances in body armor and helmet design, Cranio- and Oral-maxillofacial (CMF, OMF) injuries continue to occur in hostile environments. The objectives of this report are (1) to provide a comprehensive review of the incidence of DE and CMF/OMF injuries in US military personnel deployed in multiple environments and (2) to compare the rates of DE and CMF/OMF injuries occurring in the 20th century with the rates observed in the early 21st century. MATERIALS AND METHODS: Published and unpublished studies, as well as military reports of DE, OMF, and CMF injuries occurring in US military personnel were evaluated. Study publication dates included 1955 to 2017, with data collection periods from 1941 through 2014. RESULTS: The results of 30 investigations were reviewed. Overall, the reported annual DE rates varied widely among US military personnel between 1966 and 2012, ranging from 26 to 324 (mean 152.2) DE per 1,000 personnel per year (PPY). The average annual incidence of DE for personnel in hostile environments was 125.1 per 1,000 PPY. Thirteen studies reported rates of OMF-CMF injuries from 1941 to 2014. The overall mean OMF injury rate in Operation Enduring Freedom (OEF) was 2.8 per 1,000 PPY, while the mean rate during Operation Iraqi Freedom (OIF)/Operation New Dawn (OND) was 3.2 per 1,000 PPY. A mean of 22.3 CMF injuries per 1,000 PPY was calculated from two reports during OIF. CONCLUSIONS: The percentage of DE and OMF casualties that can be expected in hostile environments is approximately 12%. Using the most recent data since 2000, the mean DE rate was 118.2 per 1,000 PPY and the OMF rate was 3.0 per 1,000 PPY. Future research should yield information which is representative of the evolving military environment. This information should be used to enhance military-specific dental therapies and to guide protection of the craniofacial region. More importantly, quality data are necessary (1) to enable the accurate prediction of DE, CMF, and OMF casualties to insure that troop levels are sufficient for mission success and (2) to insure that all outcome variables are available to measure policy success or failure.

Objective model to facilitate designation of military-civilian partnership hospitals for sustainment of military trauma readiness.

BACKGROUND: A major dilemma of the military surgeon is the requirement for battlefield trauma expertise without regular exposure to a traumatically injured patient. To solve this problem, the military is partnering with civilian trauma centers to obtain the required trauma exposure. The main objective of this article is to quantify institutional differences and develop a predictive model for estimating the number of 24-hour trauma shifts a surgeon must be on call at civilian centers to experience urgent trauma cases. METHODS: Trauma databases from multiple institutions were queried to obtain all urgent trauma cases occurring during a 2-year period. A predictive model was used to estimate the number of urgent surgical cases in multiple specialties surgeons would experience over various numbers of 24-hour shifts and the number of 24-hour shifts required to experience a defined number of cases. RESULTS: Institution 1 had the lowest number of required 24-hour shifts to experience 10 urgent operative cases for general/trauma surgery (10 calls) and orthopedic surgery (6 calls) and the highest number of predicted cases over 12 days, 18.3 (95% CI 11 to 27), with 95% confidence. The expected trauma cases and 24-hour shifts at Institution 1 were statistically significant (p<0.0001). There were seasonal effects at all institutions except for Institution 3. DISCUSSION: There are significant variabilities in trauma center volume and therefore, the expected number of shifts and cases during a specific period of time is significantly different between trauma centers. This predictive model is objective and can therefore be used as an extrapolative tool to help and inform the military regarding placement of personnel in optimal centers for trauma currency rotations. LEVEL OF EVIDENCE: Economic and value-based evaluations, level II.

Validation of a predictive model for operative trauma experience to facilitate selection of trauma sustainment military-civilian partnerships.

BACKGROUND: Trauma readiness is a Department of Defense requirement for military healthcare providers. Surgeons must maintain readiness to optimize surgical care on the battlefield and minimize preventable death. The objective of this study was to validate a predictive model for trauma operative exposure by applying the model prospectively. METHODS: The predictive model for operative trauma exposure was prospectively applied to predict the number of emergent operative cases that would be experienced over predetermined time periods at four separate trauma sustainment military-civilian partnerships (TS-MCP). Notional courses were designed to be 2 or 4 weeks long and consisting of 5 and 12 overnight call periods, respectively. A total of 51 separate 2-week courses and 49 4-week courses were evaluated using the model. The outcome measure was the number of urgent (occurring within a day of arrival) operative trauma cases. RESULTS: Trauma/general surgery case volumes during call periods of notional courses were within the predicted range at least 98% of the time. Orthopedic volumes were more variable with a range of 82%-98% meeting expectation depending on the course length and institution. CONCLUSION: The previously defined model accurately predicted the number of urgent trauma/general surgery cases course participants would likely experience when applied prospectively to TS-MCP; however, the model was less accurate in predicting acute orthopedic trauma exposure. While it remains unknown how many cases need to be performed meet a trauma sustainment requirement, having a model with a predictive capability for case volume will facilitate metric development. This model may be useful when planning for future TS-MCP. LEVEL OF EVIDENCE: Economic and Value Based Evaluations Level II.