Health Related Behavior Study 2018 – Physical and Functional Limitations Within the Active Servicemen

The Health-Related Behavior Survey (HRBS) is the U.S. Department of Defense's (DoD) primary survey designed to gain insight into the health, health-related behaviors, and well-being of military personnel. The HRBS has been conducted regularly for more than 30 years and covers areas that may affect military readiness or the ability to meet the demands of military life.

The Department of Defense Office of Health and Human Services commissioned the RAND Corporation to review and conduct the 2018 HRBS survey among active and reserve service members. This summary analyzes the active component results.

This summary analyzes physical health and disability results. Some results are also compared to the Health Promotion 2020 (HP2020) goals set by the U.S. Department of Health and Human Services for the U.S. population. Because military personnel differ considerably from the general population (e.g., military personnel are more likely to be young and male than the general population), the comparisons are interesting only as benchmarks.

Chronic Disease

The burden of chronic disease in the United States is substantial. Chronic diseases are the leading cause of death in the United States and account for the largest share of U.S. healthcare spending. Chronic diseases are associated with functional, physical, social, and cognitive limitations and impaired quality of life.

The HRBS asked respondents whether a doctor or other health professional had told them in the past 12 months that they had high blood pressure, high blood sugar or diabetes, high cholesterol, asthma, angina or coronary heart disease, heart attack (including myocardial infarction), back pain, or a bone, joint, or muscle injury or disease.

Overall, 40.3% (confidence interval [CI]: 39.1-41.5) reported having at least one of these eight chronic conditions, with military personnel being the most likely to report such a diagnosis. The most common chronic condition diagnosed by a physician was a bone, joint, or muscle injury or disease, reported by 26.4% (CI: 25.3-27.4). Army members reported this condition more frequently than members of any other service.

The second most reported condition was back pain, reported by 24.6% (CI: 23.6-25.6). Arterial hypertension was the third most reported problem, reported by 9.1% (CI: 8.4-9.8). The goal of HP2020 is to reduce the proportion of adults with high blood pressure in the United States to 26.9%. High cholesterol was the fourth most common problem, reported by 4.2% of respondents (CI: 3.8-4.5).

Coast Guard respondents were more likely to report high cholesterol than members of any other unit, although high cholesterol was below the HP2020 target in all units (13.5%). Of all other chronic diseases included in the HRBS, less than 5% of respondents reported any.

Symptoms (Physical)

An estimated 34% of the population reported at least one common physical symptom, and one-third of physical symptoms were medically unexplained[1]. The presence of multiple physical symptoms is associated with higher rates of depression, anxiety, substance use disorders, and medical service use.

HRBS respondents completed a checklist of eight common physical symptoms: abdominal or bowel problems, back pain, arm, leg or joint pain, headaches, chest pain or shortness of breath, dizziness, fatigue or lack of energy, and sleep problems. Respondents were asked how much each symptom had bothered them in the past 30 days.

Overall, 29.4% (CI 28.3-30.5) reported being very bothered by one or more pain symptoms, including headaches. The most frequent symptom was sleep disturbance: 20.2% (CI: 19.2-21.3) reported being very bothered. Ground Forces, Navy, and Marine Corps respondents were more likely to report a lot of sleep disturbance than Air Force and Coast Guard respondents.

Physical symptom severity was calculated by coding each respondent's symptoms as 0 (not at all bothersome), 1 (somewhat bothersome), and 2 (very bothersome). Scores ranged from 0 to 16, with a score of 8 or more indicating high physical symptom severity.

Overall, 16.7% (CI 15.8-17.6) of respondents had high physical symptom severity. Respondents from the Army, Navy, and Marine Corps were more likely to have more severe physical symptoms than those from the Air Force or Coast Guard.

Head trauma and post-concussion symptoms

Military personnel are exposed to a wide range of physical injuries. Some factors potentially related to injury, such as physical training, are common in the military. Other possible factors include traffic accidents and sports injuries. Deployment also increases the risk of certain types of injuries. These and other factors may increase the risk of traumatic brain injury (TBI) in the military.

In the HRBS, TBI was assessed using a three-question battery based on the Brief Traumatic Brain Injury Screen. In the study, respondents were classified as having sustained a mild traumatic brain injury (mTBI) if they said they had sustained one or more trauma in the past 12 months and recalled losing consciousness for 20 minutes or less, feeling vague, confused or “seeing stars,” experiencing symptoms after a TBI, or having no recollection of the event.

It classified respondents as moderately or severely injured if they reported losing consciousness for more than 20 minutes. In the HRBS, respondents were classified as having post-stroke symptoms if they tested positive for stroke and reported at least four post-stroke symptoms.

Overall, 26.9% (CI: 25.8-28.0) of HRBS respondents reported having suffered an injury in the past year. In the ground forces and navy, injury rates were higher than in the air force, navy, and coast guard.

Across all units, 6.1% (CI: 5.4-6.7) of service members experienced a MCTV, 0.2% (CI: 0.1-0.4) experienced a moderate to severe MCTV, and 4.2% (CI: 3.6-4.7) reported post-concussion symptoms. Respondents from the Army, Marines, and Navy were more likely to report MSD or post-concussion symptoms than respondents from the Air Force or Coast Guard.

Self-Assessed Health

In addition to reporting physical symptoms, service members were asked to rate their overall physical health. These measures were found to be valid indicators of physical and emotional health and predictive of overall mortality. Members were asked to rate their health as excellent, very good, good, good, fair, or poor. Overall, 52.3% (CI 51.1-53.6) rated their health as excellent or very good.

Health-related disability

Chronic diseases and physical limitations can affect people's access to healthcare, their quality of life and their ability to perform normal daily activities. This can lead to reduced productivity and days away from school or work.

The HRBS measures absenteeism (days missed from work or school due to health problems) and attendance (days missed from work or school due to health problems). Respondents were asked how many days out of the past 30 days their mental or physical symptoms caused them to miss school or work or they felt so bad that, even if they went to school or work, their ability to work was affected.

On average, those who were absent from work reported 0.62 days (CI: 0.54-0.70) of absence from work in the past 30 days and 2.19 days (CI: 2.03-2.35). The number of days absent from duty was higher in the Ground Forces, Marines and Navy than in the Air Force and Coast Guard.

Findings and Implications for Politics

Although the majority of HRBS respondents reported their health as excellent or very good, the HRBS indicates that a significant proportion of active duty soldiers suffer from one or more physical health problems. Two in five reported at least one chronic health problem, particularly sleep disorders, bone, joint or muscle injuries, and back pain. The high incidence of pain is not surprising, given the physical demands of military service.

However, because pain can interfere with physical functioning or lead to health risks associated with the use of prescription medications, such as opioids, it is a potential concern for military readiness. Defense forces and Coast Guardsmen should continue to focus their policies and programs on injury and pain prevention, emphasizing a variety of nonpharmacologic methods of pain management.

The number of absences appears to be quite low, but the average number of absences exceeds two days per month. A reduction in productivity over several days can have a greater negative impact on performance than a single day's absence, allowing for a more complete recovery. Defense forces and Coast Guardsmen must address the underlying mental and physical causes of absenteeism, including ways to reduce the resulting loss of productivity.

Methodology

RAND conducted the 2018 HRBS survey among active duty and reserve members of the Air Force, Army, Navy, Marine Corps, Marine Corps, and Coast Guard from October 2018 through March 2019. The 2018 HRBS was a confidential online survey that allowed researchers to address reminders to nonrespondents and reduce survey burden by linking responses to administrative data.

The sample was selected using a random sampling strategy, stratified by grade, class, and gender. The overall weighted response rate was 9.6%, resulting in a final analysis sample of 17,166 responses. Missing data were treated by imputation, a statistical procedure that uses available data to estimate missing values.

To represent the working population, RAND researchers weighted responses to account for oversampling of service members in some strata. Point estimates and 95% CIs are presented in this research note.

RAND researchers controlled for differences in each outcome between key factor levels or by subgroups-grade, salary level, gender, race/ethnicity, and age group-using a two-step procedure based on the Rao-Scott chi-square test for differences between overall levels within a single factor, and if the overall test was statistically significant, then a two-sample t-test to examine any possible pairwise comparisons between factor levels (e.g., male and female).

Readers interested in these differences should refer to the HRBS 2018 active component final report. This summary is one of eight summaries of the active component; this summary and six of the other seven summaries correspond to different chapters of the full report, and the eighth summary provides an overview of all findings and policy implications. A similar set of eight summaries also covers the reserve forces findings.

Restrictions

The response rate to the survey is considered low. Although the low response rate does not automatically imply that the survey data are biased, it does increase the possibility of bias. As with any self-report, socially desirable bias is possible, especially for sensitive issues and topics. For some groups, which represent a small percentage of the total military population, survey estimates may be inaccurate and should be interpreted with caution.