Research Brief

The Health Related Behaviors Survey (HRBS) is the U.S. Department of Defense (DoD)'s flagship survey for understanding the health, health-related behaviors, and well-being of service members. Fielded periodically for more than 30 years, the HRBS includes content areas — such as substance use, mental and physical health, sexual behavior, and postdeployment problems — that may affect force readiness or the ability to meet the demands of military life. The Defense Health Agency asked the RAND Corporation to revise and field the 2015 HRBS.

In this brief, we review results for recent deployment experiences and health, including the frequency and duration of deployments, levels of exposure to combat-related experiences, the prevalence of deployment-related injuries, the prevalence of deployment-related substance use, and deployment-related mental and physical health.

Frequency and Duration of Deployments

The HRBS asked currently nondeployed service members about the start, end, and type of their most-recent deployment, as well as the total time spent deployed both in the past 12 months and since joining the military. Across all services, the majority of service members reported at least one previous deployment (61.3 percent; CI: 59.8–62.8). Among personnel who had previously deployed, 49.0 percent (CI: 47.5–50.6) reported deploying at least three times, and 64.3 percent (CI: 62.5–66.1) reported that their most-recent deployment was to a combat zone (defined as deployment to an area where a service member typically receives imminent danger pay, hazardous duty pay, and/or combat zone tax exclusion benefits).

Members of the Navy were the most likely to report having previously deployed (see Figure 1). Among those who had ever deployed, members of the Coast Guard were the most likely to have deployed at least three times but the least likely to report that their most-recent deployment was to a combat zone. Members of the Army were the most likely to report that their most-recent deployment was to a combat zone.

Figure 1. Previously Deployed, Deployed at Least Three Times, and Most-Recent Deployment Was to a Combat Zone, by Service Branch
Figure 1. Previously Deployed, Deployed at Least Three Times, and Most-Recent Deployment Was to a Combat Zone, by Service Branch

a Includes only respondents who reported one or more previous combat or noncombat deployments.

Combat Experiences

Not all combat-zone deployments involve combat experiences, and not all combat experiences occur during combat-zone deployments. The HRBS therefore assessed service member reports of combat-related traumatic experiences. Altogether, the HRBS estimated that 64.9 percent (CI: 63.2–66.9) of service members who had previously deployed had any combat exposure, and 45.8 percent (CI: 44.1–47.5) had high levels of combat exposure.[3] The most common combat experiences reported by service members were receiving incoming fire from small arms, artillery, rockets, or mortars (49.8 percent; CI: 48.1–51.6); being sent outside the wire on patrols, convoys, or sorties (42.1 percent; CI: 40.4–43.7); seeing dead bodies or human remains (38.6 percent; CI: 36.8–40.3); being in a unit that suffered casualties (35.6 percent; CI: 33.9–37.3); and being in a unit that fired on the enemy (35.6 percent; CI: 33.8–37.3).

Figure 2. Deployment-Related Injury, mTBI, and Postconcussive Symptoms, by Service Branch
Figure 2. Deployment-Related Injury, mTBI, and Postconcussive Symptoms, by Service Branch

NOTE: Figure includes only respondents who reported one or more previous combat or noncombat deployments.

Deployment-Related Injury

Deployments and exposure to combat and other traumatic events place military personnel at increased risk of injury. Identifying injurious events that result in postconcussive symptoms or that can lead to concussion, mild traumatic brain injury (mTBI),[4] or moderate to severe traumatic brain injury (TBI) is critical to protecting the mental health and cognitive functioning of military personnel and to preventing future deployment-related injuries.

Among service members with at least one previous deployment, 27.7 percent (CI: 26.0–29.4) reported a deployment-related injury, 11.9 percent (CI: 10.6–13.1) reported mTBI, and 8.6 percent (CI: 7.5–9.7) reported postconcussive symptoms.

Army personnel were more likely than those of other services to report any deployment injury, mTBI, or postconcussive symptoms (Figure 2). By pay grade, senior enlisted personnel were the most likely to have suffered a deployment injury, as well as mTBI or postconcussive symptoms resulting from such an injury. Men were also more likely than women to report such experiences.

Deployment-Related Substance Use

Although the military has made progress toward reducing cigarette smoking and illicit drug use among active-duty service members, other forms of nicotine, alcohol, and prescription medication continue to be pervasive throughout the military. (For more information, see the research brief on substance use among service members.[5]) Understanding the trends in tobacco, alcohol, illicit drug, and prescription drug use during and after deployment are vital to informing policies to maintain the health and readiness of the armed forces.

To capture the relationship of self-reported substance use and deployment, we used a modified question from the National Survey on Drug Use and Health. This item measures the frequency of use of alcohol, tobacco, smokeless tobacco, cigars, prescription medications, marijuana, opium, heroin, morphine, and related medications during the most-recent deployment. When interpreting these figures, it is important to note that DoD policies regarding alcohol use vary significantly depending on the geographic location of a deployment. For example, alcohol possession and consumption have long been banned for military personnel throughout nearly all the Middle East. In addition, a 2008 report by the Army's Mental Health Assessment Team found lower alcohol use in theater than was reported in the 2015 HRBS; however, comparing these results is made difficult by several factors, such as telescoping, recall biases among HRBS respondents, and the anonymity that the online HRBS afforded respondents.

Overall, 67.6 percent (CI: 65.8–69.5) of previously deployed service members reported using any substance during their most-recent deployment. Alcohol (36.2 percent; CI: 34.3–38.0) and cigarettes (28.0 percent; CI: 26.1–29.8) were among the most frequently used substances; marijuana and opiates (0.1 percent each; CI: 0.0–0.2) were the least.

Prevalence of substance use during the most-recent deployment was generally higher among Marine Corps personnel than those of other services, although there were some exceptions by substance type (see Figure 3). While Marine Corps personnel reported higher rates of using any substance overall and all three types of tobacco, Coast Guard members reported higher prevalence of alcohol use, and Army personnel reported higher prevalence of prescription medication use. By pay grade, there was no statistically significant difference in prevalence of any substance during the most-recent deployment, and men were more likely than women to report such use.

Figure 3. Substance Use During Most-Recent Deployment, by Service Branch
Figure 3. Substance Use During Most-Recent Deployment, by Service Branch

NOTE: Figure includes only respondents who reported one or more previous combat or noncombat deployments.

Service members who reported high combat exposure were more likely to report substance use during deployment than those with lower levels of such exposure, although there were differences in type of substance use. Those reporting high levels of combat exposure were more likely to report use of smokeless tobacco, cigars, and prescription drugs during their most-recent deployment, while those with lower levels of exposure were more likely to report use of alcohol.

Furthermore, when comparing substance use during the most-recent deployment, we found no statistically significant differences between those who had ever screened positive for mTBI and those who had never screened positive for TBI (mild or otherwise) (analysis restricted to those with a deployment in the past three years). However, we did find differences in type of substance use. Specifically, those with mTBI were more likely to report having used cigarettes, smokeless tobacco, or prescription drugs during their most-recent deployment, and those without TBI were more likely to use alcohol during such a deployment.

Deployment and Mental Health

Deployment in the past three years was associated with prevalence of various mental health conditions. The percentage of recently deployed service members with probable depression, generalized anxiety disorder (GAD), or posttraumatic stress disorder (PTSD) was slightly higher than the percentage among all active-duty service members. (For more on the prevalence of these conditions among all military members and how we measured them, see the research brief on service members' mental and emotional health.[6])

Among service members deployed in the past three years, those with high levels of combat exposure were significantly more likely than others to have probable GAD, PTSD, and aggressive behavior (Figure 4). Similarly, those reporting mTBI had significantly higher prevalence of probable depression, GAD, PTSD, aggressive behavior, and impulsivity than those not reporting a TBI.

Figure 4. Substance Use During Most-Recent Deployment, by Service Branch
Figure 4. Mental Health Indicators and Social and Emotional Factors Associated with Mental Health, by Level of Combat Exposure and TBI Status

NOTE: Figure includes only respondents who reported one or more combat or noncombat deployments in the past three years.

Among those with a deployment in the past three years, service members with high levels of combat exposure were also more likely than those with lower levels to report suicide ideation since joining the military or during deployment. However, they were less likely to report a suicide attempt at any point in their lifetime. Recently deployed service members with mTBI were also more likely than those with no TBI to report suicide ideation in their lifetime, in the past 12 months, since joining the military, and during deployment. They were also more likely to report suicide attempts in their lifetime and since joining the military.

Figure 5. Physical Health, Combat Exposure, and TBI Status
Figure 5. Physical Health, Combat Exposure, and TBI Status

NOTE: Figure includes only respondents who reported one or more combat or noncombat deployments in the past three years.

Deployment and Physical Health

Physical health problems related to deployment and combat exposure have important implications for readiness. Understanding the prevalence of physical health issues across the services has the potential to inform early detection and treatment processes, improve general health, and mitigate impacts on readiness. (For more details on how the 2015 HRBS assessed these issues, see the research brief on service members' physical health and functional limitations.[7])

Among service members who deployed in the past three years, those with high combat exposure or mTBI were far more likely than those without to have a high physical symptom severity score or report being bothered a lot by at least one physical symptom (including headaches) in the past month (Figure 5). Physical symptom scores summarize respondent reports of back pain; pain in the arms, legs, or joints; chest pain or shortness of breath; and headache pain.

Conclusions and Policy Implications

Taken together, these results suggest that active-duty service members have been widely exposed to combat and associated trauma in recent years. Perhaps as a result, service members with greater exposure showed elevated rates of probable anxiety and depressive disorders, PTSD, physical health problems (such as mTBI, postconcussive symptoms, somatic symptoms, and chronic pain), and negative health behaviors (e.g., substance use) compared with their less-exposed peers. Of note, mTBI was a significant correlate of other negative health outcomes. Future iterations of the HRBS should continue to monitor these trends in order to assess associations between deployment, combat exposure, and the health and well-being of service members.

Notes

  • [1] When calculating response rates, we excluded service members whom we were unable to contact because of incorrect email or mailing addresses. The number we were unable to contact was 6,770, or 3.4 percent of the sample.
  • [2] CIs provide a range in which we expect the true population value to fall. They account for sampling variability when calculating point estimates but do not account for problems with question wording, response bias, or other methodological issues that, if present in the HRBS, might bias point estimates.
  • [3] Service members were considered to have high combat exposure if scoring in the top quartile on a checklist of 18 combat exposure events.
  • [4] A positive screen for mTBI occurred when a respondent (1) reported one or more injuries during any deployment and (2) recalled having temporally related concussion or postconcussive symptoms; feeling dazed, confused, or "seeing stars"; having any associated loss of consciousness for up to 20 minutes; or being amnestic for the injury event. A positive screen for moderate to severe TBI occurred when a respondent reported that loss of consciousness lasted longer than 20 minutes. A positive screen for postconcussive symptoms required a report of mild, moderate, or severe TBI plus multiple symptoms, such as headaches, dizziness, memory problems, ringing in the ears, irritability, or sensitivity to light.
  • [5] Sarah O. Meadows, Charles C. Engel, Rebecca L. Collins, Robin Beckman, Matthew Cefalu, Jennifer Hawes-Dawson, Molly Doyle, Amii M. Kress, Lisa Sontag-Padilla, Rajeev Ramchand, and Kayla M. Williams, 2015 Health Related Behaviors Survey: Substance Use Among U.S. Active-Duty Service Members, Santa Monica, Calif.: RAND Corporation, RB-9955/7-OSD, 2018.
  • [6] Sarah O. Meadows, Charles C. Engel, Rebecca L. Collins, Robin Beckman, Matthew Cefalu, Jennifer Hawes-Dawson, Molly Doyle, Amii M. Kress, Lisa Sontag-Padilla, Rajeev Ramchand, and Kayla M. Williams, 2015 Health Related Behaviors Survey: Mental and Emotional Health Among U.S. Active-Duty Service Members, Santa Monica, Calif.: RAND Corporation, RB-9955/3-OSD, 2018.
  • [7] Sarah O. Meadows, Charles C. Engel, Rebecca L. Collins, Robin Beckman, Matthew Cefalu, Jennifer Hawes-Dawson, Molly Doyle, Amii M. Kress, Lisa Sontag-Padilla, Rajeev Ramchand, and Kayla M. Williams, 2015 Health Related Behaviors Survey: Physical Health and Functional Limitations Among U.S. Active-Duty Service Members, Santa Monica, Calif.: RAND Corporation, RB-9955/4-OSD, 2018.

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