Back to Top Skip to main content Skip to sub-navigation

Incidence, Timing, and Seasonal Patterns of Heat Illnesses During U.S. Army Basic Combat Training, 2014–2018

U.S. Marines participate in morning physical training during a field exercise at Marine Corps Base Camp Pendleton, California. (Photo Courtesy: U.S. Marine Corps) Marines participate in morning physical training during a field exercise at Marine Corps Base Camp Pendleton, California. (U.S. Marine Corps photo)

Recommended Content:

Medical Surveillance Monthly Report

ABSTRACT

Risk factors for heat illnesses (HIs) among new soldiers include exercise intensity, environmental conditions at the time of exercise, a high body mass index, and conducting initial entry training during hot and humid weather when recruits are not yet acclimated to physical exertion in heat. This study used data from the Defense Health Agency’s–Weather-Related Injury Repository to calculate rates and to describe the incidence, timing, and geographic distribution of HIs among soldiers during U.S. Army basic combat training (BCT). From 2014 through 2018, HI events occurred in 1,210 trainees during BCT, resulting in an overall rate of 3.6 per 10,000 BCT person-weeks (p-wks) (95% CI: 3.4–3.8). HI rates (cases per 10,000 BCT p-wks) varied among the 4 Army BCT sites: Fort Benning, GA (6.8); Fort Jackson, SC (4.4); Fort Sill, OK (1.8); and Fort Leonard Wood, MO (1.7). Although the highest rates ofHIs occurred at Fort Benning, recruits in all geographic areas were at risk. The highest rates of HI occurred during the peak training months of June through September, and over half of all HI cases affected soldiers during the first 3 weeks of BCT. Prevention of HI among BCT soldiers requires relevant training of both recruits and cadre as well as the implementation of effective preventive measures.

WHAT ARE THE NEW FINDINGS?    

During 2014–2018 BCT classes, the greatest number of HIs occurred in week 2. The highest overall rate of HI was at Fort Benning (6.8 cases per 10,000 p-wks), followed by Fort Jackson (4.5 per 10,000 p-wks), Fort Sill (1.8 per 10,000 p-wks), and Fort Leonard Wood (1.7 per 10,000 p-wks).

WHAT IS THE IMPACT ON READINESS AND FORCE HEALTH PROTECTION?

Service members experience the highest rates of HIs during the first phase of BCT. Entry month should be considered as a modifiable factor to reduce HI rates during training. The findings of this analysis may inform Commanders at each training location about the time of year that targeted mitigation strategies could be most effective.

BACKGROUND

U.S. military training activities in hot and humid environments pose competing demands from a public health perspective because of the military’s obligation to perform realistic training to develop operational capability and readiness while also needing to protect service members against heat-related illness. For example, a recent study examining the risk and timing of heat illness (HI) in the U.S. active duty (AD) Army population demonstrated that the peak incidence of HI occurs during the first 2 months of duty.1 This period is when soldiers are engaged in initial entry training (IET). IET encompasses a variety of courses, each with unique exposures that may affect the risk of HI.

IET consists of 2 phases: basic combat training (BCT) and advanced individual training (AIT). BCT, which lasts 10 weeks, is followed by AIT, which varies from 5 to over 20 weeks, depending on military occupational specialty.2 In one station unit training (OSUT), BCT and AIT take place at the same installation. The 10-week BCT course is conducted at 4 locations: Fort Benning, GA; Fort Jackson, SC; Fort Leonard Wood, MO; and Fort Sill, OK. Figure 1 provides a summary timeline view of the IET process. This study only includes the 10-week period of BCT (i.e., recruits participating in BCT as a part of OSUT were excluded).

No recently published studies have reported HI rates during BCT. The current study assessed the incidence, timing, and geographic distribution of HI during BCT. Information about the timing and geographic location of HI in this population could inform efforts to reduce the burden of HI during the conduct of training essential to the development of individual skills needed for operational capability and readiness of the U.S. Army.

METHODS

Study design

The current study employed a retrospective cohort design using data from the Defense Health Agency’s (DHA)–Weather-Related Injury Repository (WRIR). The WRIR utilizes many available data sources with the goal of being the most complete record system possible for weather-related injuries in Army soldiers. The WRIR enables researchers to review prior years’ data and provides contextual perspective to emerging trends. The WRIR includes 6 main data sources: hospital admissions (from the Standard Inpatient Data Record [SIDR] and from TRICARE Encounter Data–Institutional [TED-I]), in-theater medical records (from the Theater Medical Data Store [TMDS]), reportable medical events (RMEs), and outpatient encounters (from the Comprehensive Ambulatory/Professional Encounter Record [CAPER] and from TRICARE Encounter Data–Non-Institutional [TED-NI]). The WRIR began collecting data in 2014, so it includes International Classification of Diseases (ICD) codes from both the 9th and 10th revisions.

Study population

All U.S. Army enlisted soldiers who began BCT for the first time at any of the 4 BCT sites from January 2014 through December 2018 were included in the analysis. In order to better compare variables of interest in the training population, recruits conducting BCT as part of OSUT were excluded from the analysis. BCT rosters from 2014–2018 were downloaded from the Army Training Requirements and Resources System (ATRRS). Each BCT site has a unique school code, which was used to pull the data from ATRRS.

Outcome

The outcome of interest was the occurrence of any HI. For this analysis, the identification of a case of HI was based on the Armed Forces Health Surveillance Branch (AFHSB) surveillance case definition and included heat exhaustion (HE) and heat stroke (HS).3 The AFHSB case definition defines a case of HI as 1 hospitalization or outpatient medical encounter with selected diagnoses of HI (Table 1) in the primary or secondary diagnostic position or 1 record of an RME of HI reported to the Disease Reporting System internet.4

The incidence date was the date of the first hospitalization, outpatient encounter, or RME associated with an HI. For individuals with more than 1 type of HI medical encounter during BCT, HS is prioritized over HE. Outcome data extracted from the WRIR were matched to ATRRS BCT roster data by social security number. Cases were included in the analysis only if the first encounter date fell between a recruit’s first and last day of class in BCT.

Basic combat training exposure time and seasonality

Army BCT is conducted throughout the year and includes the following 3 phases:

Red phase (phase 1; weeks 1–3): The red phase consists of an environment where recruits must demonstrate that they possess the foundation for physical fitness, resiliency, and a level of adaptability to military life. Strenuous outdoor activities with an overlapping risk of heat exposure include 2.5- and 5-mile foot marches.

White phase (phase 2; weeks 4–6): The white phase is centered on the development of basic combat skills, with special emphasis on weapons qualification and physical readiness training. Strenuous outdoor activities with an overlapping risk of heat exposure include a 7.5-mile foot march, land navigation exercises, and time spent at rifle ranges.

Blue phase (phase 3; weeks 7–10): The blue phase includes a 10-mile foot march and concentrates on tactical training, increased soldier responsibilities, and demonstration of teamwork and self-discipline. Recruits are evaluated in basic soldiering skills and prepared for AIT. The blue phase culminates in a field training exercise and the demonstration of proficiency in warrior tasks and battle drills.

Recruit exposure time was measured using a time-to-event approach (measured in weeks). For each recruit, exposure time began at the BCT class starting date and continued until censored because of an outcome event (an HI), attrition from BCT, or the end of the BCT class, whichever occurred first. Censoring due to attrition was identified by the graduation status variable from ATRRS.

Because BCT classes begin throughout the calendar year, each BCT class experiences unique month-to-month variation in weather-related exposures due to interannual seasonal variation. In order to control for the effect of this variation, data were analyzed by BCT phase and grouped by the month in which recruits started BCT. A recruit was considered to have entered BCT in a given month if their class start date fell within the first 20 days of the month. Recruits whose BCT started on or after the 21st day of a given month were considered to have entered training in the following month.

Statistical analysis

Descriptive analyses included chisquare tests for differences in the outcome frequency distributions by BCT entry-month and site. For BCT site and phase-specific rates, the frequency distribution of outcomes was reported by entry-month and site. Site- and phase-specific incidence rates of HI were calculated as the number of HI cases per 10,000 person-weeks (p-wks) with associated 95% confidence interval (CIs). Rate ratios (RRs) were computed by BCT site and entry-month using Fort Leonard Wood as the reference group because of its northernmost location. Because of low case counts at Fort Leonard Wood during the fall and winter months, RRs are reported for spring and summer months only. P values less than .05 were considered statistically significant. Exact RR estimates, 95% CIs, and mid-p values were calculated using OpenEpi v3.01.5

RESULTS

A total of 352,739 recruits entered BCT for the first time during 2014–2018 and were included in the current study (Table 2). Although total annual recruit arrivals varied from year-to-year, the distribution of recruit arrivals by month remained consistent, with an average low of approximately 4,500 recruit arrivals in January to an average high of 9,000 recruit arrivals in June (data not shown). As a result of high school graduation, there is a predictable surge of new and younger recruits entering BCT during the summer months (Figure 2). The BCT population was observed for a total of 3,362,271 p-wks. The mean observed time per recruit was 9.5 weeks (median,9.7; standard deviation, 0.95; range, 0–10 weeks) (data not shown). A total of 9,159 HIs were reported in the WRIR during the study period among all AD Army service members, of which 13.2% (n=1,210) occurred during BCT. The proportion of recruits without any HI who successfully graduated BCT was 90.0% (n=316,205/351,529) compared to 66.9% (n=809/1,210) of those who were diagnosed with an HI (data not shown). During the 5-year surveillance period, July had the highest total number (n=327) and proportion (27.0%) of HI cases (Figure 3).

The demographic characteristics of all recruits and those affected by an HI are shown in Table 2. The rates of HI events were significantly higher among several demographic groups (Table 3). The HI rate was higher among women than men (RR: 2.3) and higher among non-Hispanic black recruits than those in all other race/ethnicity groups. Recruits aged 20 years or older were less likely than those aged 17–19 years to be affected by an HI. Soldiers in the National Guard had slightly increased rates (RR: 1.1) compared to soldiers in the AD component.

Basic combat training location

Incident HIs were disproportionately distributed among the individual BCT sites, with the highest rate at Fort Benning (6.8 per 10,000 p-wks), followed by Fort Jackson (4.5 per 10,000 p-wks), Fort Sill (1.8 per 10,000 p-wks), and Fort Leonard Wood (1.7 per 10,000 p-wks) (Table 4). Further, recruits who received BCT at Fort Benning had 4.1 (95% CI: 3.2–5.2) times the rate of HI events compared to recruits who received BCT at Fort Leonard Wood. The rate of HI events among Fort Jackson recruits was 2.7 times the rate among Fort Leonard Wood recruits. After controlling for the entry month of BCT, recruits at both Fort Benning and Fort Jackson experienced HI rates that were between 1.9 and 10.3 times the rates among recruits at Fort Leonard Wood for the months of May–August (Table 5). For example, among recruits who started in August, those at Fort Benning experienced 5.9 (95% CI: 3.4–11.2) times the rate of HI events compared to recruits at Fort Leonard Wood.

Basic combat training phase

Of the 1,210 total HIs that occurred during BCT, 686 (56.8%) occurred during phase 1 of training, 277 (22.9%) occurred during phase 2, and 247 (20.4%) occurred during phase 3 (data not shown). The greatest number of incident HI cases occurred in the second week of training (Figure 4), when 23.0% of all HI events occurred (data not shown). In unadjusted analyses, phase 1 of BCT had the highest HI rates at all BCT sites, with 6.5 cases per 10,000 p-wks, followed by phases 2 and 3 with 2.0 and 1.8 cases per 10,000 p-wks, respectively (data not shown). Entering BCT after May was associated with a substantial increase in phase 1 rates and a small reduction in phase 3 rates (Figure 5). After controlling for location, phase, and entry-month, rates varied widely (Table 6). The highest phase 1 rate was 27.1 HIs per 10,000 p-wks for recruits who entered BCT in June at Fort Benning. At Fort Leonard Wood, the highest phase 1 rates were also seen among recruits who entered BCT in June (10.8 per 10,000 p-wks). On the other hand, phase 1 rates at Fort Sill peaked at 9.7 per 10,000 p-wks for those who entered in August, and phase 1 rates at Fort Jackson peaked at 17.7 per 10,000 p-wks for those who entered in July (Table 6).

EDITORIAL COMMENT

This study examined the timing of HI events among recruits during BCT by month of entry into training and phase of training at each of the 4 BCT locations. HI events occurred at all BCT locations and during all phases of BCT. However, variability in the rates, measured in numbers of HI events per 10,000 p-wks, was seen across BCT sites, BCT entry-month, and BCT training phase. When location was examined, the southernmost locations (Fort Benning and Fort Jackson) had the highest rates of HI events, and rates were significantly higher when compared to the northernmost BCT site (Fort Leonard Wood). This is consistent with the results of a study of active component service members between 2013 and 2017, where Fort Benning and Fort Jackson were among the top 5 Army locations with the highest numbers of HI events.6

Despite being located in the southeastern U.S., Fort Benning and Fort Jackson had significantly different HI rates. The quantifiable factors examined in this study did not fully explain this difference. The recruits at these 2 BCT sites experience similar weather environments and training schedules; however, there are many individual risk factors for HI that could not be controlled for in this study. For example, other studies have found that physical fitness, body composition, sex, individual motivation, medication, and prior illness are associated with an increased risk of HI.1,6–8 While differences in the overall HI injury risk by BCT location have been reported in the past, future investigations into the causes of these differences may benefit from inclusion of environmental and/or local climatological data, factors related to the delivery of training, and care-seeking behavior.9,10 Another factor that is difficult to control for between BCT sites is diagnostic consistency among medical providers and access to medical care. For example, Fort Benning has an emergency department on the installation; Fort Jackson does not. This may result in considerable and systemic variations in HI diagnosis.

If a recruit entered BCT between Mayand November, rates of HIs were highest during phase 1. In the later BCT training phases, HI rates were highest among recruits who entered training in May. Each phase is approximately 3 weeks long, so for a recruit entering BCT in May, the later phases of BCT would coincide with the peak summer months of July and August. It is possible that these recruits have adapted to the physical intensity of BCT, but have not been fully acclimatized to hot and humid conditions.

At the time of this report, this was the only study that examined the rate of HI during Army BCT controlling for BCT entry-month and training phase. However, the studies that have been conducted tend to support the results of the current analysis. For example, a study of Army enlisted soldiers found that the highest rates of mild and severe HI occurred within the first 2 months of service; however, this study did not specifically examine the time the enlistees spent in BCT.1 Moreover, a study of Marine Corps recruits found that the highest number of HI cases occurred during the first 2 weeks of a 12-week recruit training, with a second peak of HI events towards the end of training in weeks 8 and 9,8 supporting the current report’s finding of higher rates of HI during the first few weeks of BCT (phase 1). However, unlike the current study, the Marine study did not consider how seasonal variations in temperature affected the number of HI events.

HI events occurred during each month of the year, but as expected, the majority of HI events at BCT occurred during the summer months (June–August). This is a common finding across the HI literature describing military populations.1,11,12 Approximately 70,000 recruits entered BCT per calendar year from 2014–2018. The surge of new and younger recruits entering BCT during the hottest months leads to a larger number of recruits completing phase 1 of their training during the period when they are most at risk for an HI.

The findings of this analysis should be interpreted in light of several important limitations. The first potential limitation is the use of U.S. Army administrative data that is not collected or maintained for research purposes to identify the first-time BCT recruits. Despite potential data quality issues with pertinent variables of interest (e.g., training dates) previous research suggests that data sources like the ones used to identify this cohort of likely first-time BCT recruits are valid and consistent with other estimates of the BCT population.13 The second potential limitation is that while the ICD-9/ICD-10 coding was largely used to define outcomes, a single ICD code may not represent a true or final diagnosis. Moreover, diagnosis coding can be subject to clinician- or site-specific bias and ultimately lead to a potential source of misclassification bias. In order to reduce this bias, the current analysis included only medical records with a code of interest in the first 2 diagnostic code positions. Third, recruits in OSUT, AIT, or basic officer leadership courses were excluded from this analysis. Although roughly 70% of all new trainees receive BCT as part of their overall IET, the results of this analysis do not represent the complete burden of HI for all service members as evidenced by the fact that the 1,210 HI cases in this study accounted for only 13% (n=1,210/9,159) of all HI cases in Army service members (active component, National Guard, Reserve) during the study period. Fourth, this study did not incorporate climate data (e.g., temperature, humidity, or wind speed) into the analysis. The goal of this study was to identify the differences in HI rates by the timing of BCT entry and BCT phase. The use of climate data in a future analysis could account for short-term (e.g., daily) and long-term (e.g., interannual) variability in local climate and build upon the findings in the current study. Despite these limitations, use of the comprehensive DHA–WRIR data combined with U.S. Army administrative data allowed for a novel level of granularity and insight into the timing and incidence of HI during BCT.

The results of the current study indicate that Fort Benning had the highest rates of HI events, particularly among recruits entering phase 1 training in the summer months (June–August). The rates of HI were lower in the later phases of BCT; however, HI rates increased during BCT phases 2 and 3 among recruits who entered BCT in the spring months (April and May). The identification of periods during the calendar year and within the 10-week training period when rates of HI events are higher could facilitate the targeted implementation of interventions or prevention strategies to mitigate the risk of HI during BCT. Examination of such results by BCT location could inform each site about the time of year when targeted mitigation strategies could be most effective.

Author affiliations: Armed Forces Health Surveillance Branch, Silver Spring, MD (Mr. Barnes, Dr. Ambrose, Ms. Kebisek, Ms. McCabe, Dr. Forrest, and Mr. Steelman); United States Army Public Health Center Clinical Public Health and Epidemiology Directorate, Disease Epidemiology Division (Dr. Maule, Ms. Scatliffe, and LTC Superior).

Disclaimer: The contents, views, or opinions expressed in this publication are those of the author(s) and do not necessarily reflect the official policy or position of the Defense Health Agency, the Department of Defense (DoD), or the Department of the Army.

 

REFERENCES

1. Nelson DA, Deuster PA, O’Connor FG, Kurina LM. Timing and predictors of mild and severe heat illness among new military enlistees. Med Sci Sport Exer. 2018;50(8):1603–1612.

2. Headquarters, Department of the Army, Training and Doctrine Command. TRADOC Regulation 350-6. Enlisted Initial Entry Training Policies and Administration. Washington, DC: Department of the Army; 2018. https://adminpubs.tradoc.army.mil/regulations/TR350-6withChange1.pdf. Accessed 08 March 2019.

3. Armed Forces Health Surveillance Branch. Surveillance Case Definition. Heat Illness. March 2018. https://www.health.mil/Reference-Center/Publications/2017/03/01/Heat-Injuries. Accessed 8 March 2019.

4. Armed Forces Health Surveillance Branch. Armed Forces Reportable Medical Events: Guidelines and Case Definitions. https://health.mil/Reference-Center/Publications/2017/07/17/Armed-Forces-Reportable-Medical-Events-Guidelines. Accessed 08 March 2019.

5. Sullivan KM, Dean A, Soe MM. OpenEpi: a web-based epidemiologic and statistical calculator for public health. Public Health Rep. 2009;124(3):471–474.

6. Armed Forces Health Surveillance Branch. Update: Heat illness, active component, U.S. Armed Forces, 2017. MSMR. 2018;25(4):6–10.

7. Gardner JW, Kark JA, Karnei K, et al. Risk factors predicting exertional heat illness in male Marine Corps recruits. Med Sci Sport Exer. 1996;28(8):939–944.

8. Wallace RF, Kriebel D, Punnett L, et al. Risk factors for recruit exertional heat illness by gender and training period. Aviat Space Environ Med. 2006;77(4):415–421.

9. Swedler DI, Knapik JJ, Williams KW, Grier TL, Jones BH. Risk factors for medical discharge from United States Army Basic Combat Training. Mil Med. 2011;176(10):1104–1110.

10. Grier TL, Knapik JJ, Canada S, Canham-Chervak M, Jones BH. Risk factors associated with self-reported training-related injury before arrival at the U.S. Army Ordnance School. Public Health. 2011;124(7):417–423.

11. Kark, JA, Burr PQ, Wenger CB, Gastaldo E, Gardner JW. Exertional heat illness in Marine Corps recruit training. Aviat Space Environ Med. 1996;67(4):354–360.

12. Stacey MJ, Brett S, Woods D, Jackson S, Ross D. Case ascertainment of illness in the British Army: evidence of under-reporting from analysis of Medical and Command notifications, 2009–2013. J R Army Med Corps. 2016;162(2):428–433.

13. Sulsky SL, Karlsson LH, Bulzacchelli MT, et al. Methodological challenges of using U.S. Army administrative data to identify a cohort of basic combat trainees and descriptive analysis of trends in characteristics that are potential risk factors for training-related injury. Mil Med. 2014;179(12):1487–1496.

 

Global view of the U.S. Army initial entry training process

Cumulative numbers and mean ages, by entry month of basic combat training, U.S. Army recruits, 2014-2018

Basic combat training heat illnesses, by month and location, U.S. Army recruits, 2014–2018

Daily heat illness case counts, by week and phase of basic combat training, U.S. Army recruits, 2014–2018

Heat illness rate, by basic combat training phase and entry month, U.S. Army recruits, 2014–2018

ICD-9/ICD-10 codes used in the heat illness case definition

Demographic characteristics of basic combat training population (n=352,739) with results of chi-square tests comparing those with and without a heat illness, U.S. Army recruits, 2014–2018

Heat illness rates and rate ratios, by demographic and military characteristics, U.S. Army recruits, 2014–2018

Heat illness rates and rate ratios, by basic combat training location, U.S. Army recruits, 2014–2018

Heat illness rates and rate ratios, by basic combat training location, U.S. Army recruits, 2014–2018

Heat illness rates by location, phase, and entry month, U.S. Army recruits, 2014–2018

You also may be interested in...

Outbreak of Influenza and Rhinovirus co-circulation among unvaccinated recruits, U.S. Coast Guard Training Center Cape May, NJ, 24 July – 21 August 2016

Infographic
2/5/2018
On 29 July 2016, the U.S. Coast Guard Training Center Cape May (TCCM), NJ, identified an increase in febrile respiratory illness (FRI) among recruits who were unvaccinated against seasonal influenza as a result of the annual vaccine’s expiration. This report characterizes the outbreak and containment measures implemented at TCCM during the outbreak period. In 2016, respiratory infections affected more than 250,000 U.S. service members and comprised approximately 22% of medical encounters among military recruit populations – who are highly susceptible to respiratory infections. Seasonal influenza and rhinovirus are two of the leading respiratory pathogens. During the Surveillance Period: 115 recruits reported respiratory infection symptoms. Pie chart 1 shows the following data: •	41 (35.7%) suspected cases •	74 (64.3%) confirmed cases Among confirmed cases, lab specimens tested positive for: •	Influenza A 34 (45.9%) •	Rhinovirus 28 (37.8%) •	Influenza A and rhinovirus co-infection 11 (14.9%) •	Rhinovirus and adenovirus co-infection 1 (1.4%) Data above depicted in pie chart 2. •	24 July – 6 August, Influenza predominated •	7 August – 20 August, Rhinovirus predominated Although the outbreak significantly affected operations at TCCM, a timely and comprehensive response resulted in containment of the outbreak within 5 weeks. Key Factor for Outbreak Control •	Rapid detection through FRI sentinel surveillance •	Quick decision-making •	Streamlined response by using a single chain of command •	Rapid implementation of both nonpharmaceutical and pharmaceutical interventions Access the full report in the January 2018 MSMR (Vol. 25, No. 1). Go to: www.Health.mil/MSMR

This report characterizes the outbreak and containment measures implemented at the U.S. Coast Guard Training Center Cape May (TCCM), New Jersey, during a July 24 – August 21, 2016 outbreak period.

Recommended Content:

Health Readiness | Medical Surveillance Monthly Report | Integrated Biosurveillance | Influenza Summary and Reports

Department of Defense Global, Laboratory-based Influenza Surveillance Program’s Influenza vaccine effectiveness estimates and surveillance trends, 2016 – 2017 Influenza Season

Infographic
2/5/2018
Each year, the Department of Defense (DoD) Global, Laboratory-based Influenza Surveillance Program performs surveillance for influenza among service members of the DoD and their dependent family members. In addition to routine surveillance, vaccine effectiveness (VE) studies are performed and results are shared with the Food and Drug Administration, Centers for Disease Control and Prevention, and the World Health Organization for vaccine evaluation. This report documents the annual surveillance trends for the 2016 – 2017 influenza season and the end-of-season VE results. The analysis was performed by the U.S. Air Force School of Aerospace Medicine Epidemiology Laboratory, and the DoD Influenza Surveillance Program staff at Wright-Patterson Air Force Base, OH. FINDINGS: A total of 5,555 specimens were tested from 84 locations: •	2,486 (44.7%) negative •	1,382 (24.9%) influenza A •	1,093 (19.7%) other respiratory pathogens •	443 (8.0%) influenza B •	151 (2.7%) co-infections The predominant influenza strain was A (H3N2), representing 73.8% of all circulating influenza. Pie chart displays this information. Graph showing the numbers and percentages of respiratory specimens positive for influenza viruses, and numbers of influenza viruses identified, by type, by surveillance week, Department of Defense healthcare beneficiaries, 2016 – 2017 influenza season displays. The vaccine effectiveness (VE) for this season was slightly lower than for the 2015 – 2016 season, which had a 63% (95% confidence interval: 53% - 71%) adjusted VE. The adjusted VE for the 2016 – 2017 season was 48% protective against all types of influenza.  Access the full report in the January 2018 MSMR (Vol. 25, No. 1). Go to: www.Health.mil/MSMR

This infographic documents the annual surveillance trends for the 2016 – 2017 influenza season and the end-of-season vaccine effectiveness.

Recommended Content:

Health Readiness | Influenza Summary and Reports | Medical Surveillance Monthly Report | Vaccine-Preventable Diseases | Force Health Protection

2018 #ColdReadiness Twitter chat recap: Preventing cold weather injuries for service members and their families

Fact Sheet
2/5/2018

To help protect U.S. armed forces, the Armed Forces Health Surveillance Branch (AFHSB) hosted a live #ColdReadiness Twitter chat on Wednesday, January 24th, 12-1:30 pm EST to discuss what service members and their families need to know about winter safety and preventing cold weather injuries as the temperatures drop. This fact sheet documents highlights from the Twitter chat.

Recommended Content:

Medical Surveillance Monthly Report | Winter Safety | Medical and Dental Preventive Care Fitness | Health Readiness

Seizures among Active Component service members, U.S. Armed Forces, 2007 – 2016

Infographic
1/25/2018
This retrospective study estimated the rates of seizures diagnosed among deployed and non-deployed service members to identify factors associated with seizures and determine if seizure rates differed in deployment settings. It also attempted to evaluate the associations between seizures, traumatic brain injury (TBI), and post-traumatic stress disorder (PTSD) by assessing correlations between the incidence rates of seizures and prior diagnoses of TBI and PTSD. Seizures have been defined as paroxysmal neurologic episodes caused by abnormal neuronal activity in the brain. Approximately one in 10 individuals will experience a seizure in their lifetime. Line graph 1: Annual crude incidence rates of seizures among non-deployed service members, active component, U.S. Armed Forces data •	A total of 16,257 seizure events of all types were identified among non-deployed service members during the 10-year surveillance period. •	The overall incidence rate was 12.9 seizures per 10,000 person-years (p-yrs.) •	There was a decrease in the rate of seizures diagnosed in the active component of the military during the 10-year period. Rates reached their lowest point in 2015 – 9.0 seizures per 10,000 p-yrs. •	Annual rates were markedly higher among service members with recent PTSD and TBI diagnoses, and among those with prior seizure diagnoses. Line graph 2: Annual crude incidence rates of seizures by traumatic brain injury (TBI) and recent post-traumatic stress disorder (PTSD) diagnosis among non-deployed active component service members, U.S. Armed Forces •	For service members who had received both TBI and PTSD diagnoses, seizure rates among the deployed and the non-deployed were two and three times the rates among those with only one of those diagnoses, respectively. •	Rates of seizures tended to be higher among service members who were: in the Army or Marine Corps, Female, African American, Younger than age 30, Veterans of no more than one previous deployment, and in the occupations of combat arms, armor, or healthcare Line graph 3: Annual crude incidence rates of seizures diagnosed among service members deployed to Operation Enduring Freedom, Operation Iraqi Freedom, or Operation New Dawn, U.S. Armed Forces, 2008 – 2016  •	A total of 814 cases of seizures were identified during deployment to operations in Iraq and Afghanistan during the 9-year surveillance period (2008 – 2016). •	For deployed service members, the overall incidence rate was 9.1 seizures per 10,000 p-yrs. •	Having either a TBI or recent PTSD diagnosis alone was associated with a 3-to 4-fold increase in the rate of seizures. •	Only 19 cases of seizures were diagnosed among deployed individuals with a recent PTSD diagnosis during the 9-year surveillance period. •	Overall incidence rates among deployed service members were highest for those in the Army, females, those younger than age 25, junior enlisted, and in healthcare occupations. Access the full report in the December 2017 MSMR (Vol. 24, No. 12). Go to www.Health.mil/MSMR

This infographic documents a retrospective study which estimated the rates of seizures diagnosed among deployed and non-deployed service members to identify factors associated with seizures and determine if seizure rates differed in deployment settings. The study also evaluated the associations between seizures, traumatic brain injury (TBI), and post-traumatic stress disorder (PTSD) by assessing correlations between the incidence rates of seizures and prior diagnoses of TBI and PTSD.

Recommended Content:

Health Readiness | Posttraumatic Stress Disorder | Armed Forces Health Surveillance Division | Medical Surveillance Monthly Report

Insomnia and motor vehicle accident-related injuries, Active Component, U.S. Armed Forces, 2007 – 2016

Infographic
1/25/2018
Insomnia is the most common sleep disorder in adults and its incidence in the U.S. Armed Forces is increasing. A potential consequence of inadequate sleep is increased risk of motor vehicle accidents (MVAs). MVAs are the leading cause of peacetime deaths and a major cause of non-fatal injuries in the U.S. military members. To examine the relationship between insomnia and motor vehicle accident-related injuries (MVAs) in the U.S. military, this retrospective cohort study compared 2007 – 2016 incidence rates of MVA-related injuries between service members with diagnosed insomnia and service members without a diagnosis of insomnia. After adjustment for multiple covariates, during 2007 – 2016, active component service members with insomnia had more than double the rate of MVA-related injuries, compared to service members without insomnia. Findings:  •	Line graph shows the annual rates of motor vehicle accident-related injuries, active component service members with and without diagnoses of insomnia, U.S. Armed Forces, 2007 – 2016  •	Annual rates of MVA-related injuries were highest in the insomnia cohort in 2007 and 2008, and lowest in 2016 •	There were 5,587 cases of MVA-related injuries in the two cohorts during the surveillance period. •	Pie chart displays the following data: 1,738 (31.1%) in the unexposed cohort and 3,849 (68.9%) in the insomnia cohort The highest overall crude rates of MVA-related injuries were seen in service members who were: •	Less than 25 years old •	Junior enlisted rank/grade •	Armor/transport occupation •	 •	With a history of mental health diagnosis •	With a history of alcohol-related disorders Access the full report in the December 2017 (Vol. 24, No. 12). Go to www.Health.mil/MSMR Image displays a motor vehicle accident.

To examine the relationship between insomnia and motor vehicle accident-related injuries (MVAs) in the U.S. military, this retrospective cohort study compared 2007 – 2016 incidence rates of MVA-related injuries between service members with diagnosed insomnia and service members without a diagnosis of insomnia.

Recommended Content:

Armed Forces Health Surveillance Division | Health Readiness | Medical Surveillance Monthly Report

Exertional heat injuries pose annual threat to U.S. service members

Article
7/20/2017
Two U.S. service members perform duties in warm weather where they may be exposed to extreme heat conditions and a higher risk of heat illness.

Exertional heat injuries pose annual threat to U.S. service members, according to a study published in Defense Health Agency’s Armed Forces Health Surveillance Branch (AFHSB) peer-reviewed journal, the Medical Surveillance Monthly Report.

Recommended Content:

Armed Forces Health Surveillance Division | Medical Surveillance Monthly Report | Summer Safety

Heat Illnesses by Location, Active Component, U.S. Armed Forces, 2012-2016 Fact Sheet

Fact Sheet
3/30/2017

This fact sheet provides details on heat illnesses by location during a five-year surveillance period from 2012 through 2016. 11,967 heat-related illnesses were diagnosed at more than 250 military installations and geographic locations worldwide. Three Army Installations accounted for close to one-third of all heat illnesses during the period.

Recommended Content:

Armed Forces Health Surveillance Division | Medical Surveillance Monthly Report

Demographic and Military Traits of Service Members Diagnosed as Traumatic Brain Injury Cases

Fact Sheet
3/30/2017

This fact sheet provides details on the demographic and military traits of service members diagnosed as traumatic brain injury (TBI) cases during a 16-year surveillance period from 2001 through 2016, a total of 276,858 active component service members received first-time diagnoses of TBI - a structural alteration of the brain or physiological disruption of brain function caused by an external force.

Recommended Content:

Armed Forces Health Surveillance Division | Medical Surveillance Monthly Report

Rhabdomyolysis by Location, Active Component, U.S. Armed Forces, 2012-2016 Fact Sheet

Fact Sheet
3/30/2017

This fact sheet provides details on Rhabdomyolysis by location for active component, U.S. Armed Forces during a five-year surveillance period from 2012 through 2016. The medical treatment facilities at nine installations diagnosed at least 50 cases each and, together approximately half (49.9%) of all diagnosed cases.

Recommended Content:

Armed Forces Health Surveillance Division | Medical Surveillance Monthly Report

2016 marks first year of zero combat amputations since the start of the Afghan, Iraq wars

Article
3/28/2017
An analysis by the Medical Surveillance Monthly Report recently reported 2016 marks the first year without combat amputations since the wars in Afghanistan and Iraq began. U.S. Armed Forces are at risk for traumatic amputations of limbs during combat deployments and other work hazards. (DoD photo)

An analysis by the Medical Surveillance Monthly Report (MSMR) recently reported 2016 marks the first year of zero combat amputations since the wars in Afghanistan and Iraq began.

Recommended Content:

Medical Surveillance Monthly Report | Epidemiology and Analysis
<< < ... 11 12 13 14 > >> 
Showing results 196 - 205 Page 14 of 14

DHA Address: 7700 Arlington Boulevard | Suite 5101 | Falls Church, VA | 22042-5101

Some documents are presented in Portable Document Format (PDF). A PDF reader is required for viewing. Download a PDF Reader or learn more about PDFs.