Health Related Behavior Study 2018 – Limitations, Disabilities and Physical Health Among the Reserve

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

The Department of Defense commissioned the RAND Corporation to review and conduct the 2018 HRBS survey for active and reserve military personnel. This report reviews the results for the Reserve components. This report examines physical health outcomes and functional limitations.

Some results are also compared to the Health Promotion 2020 (HP2020) goals for the US population set by the US Department of Health and Human Services. Because the military population is significantly different from the general population (for example, military personnel are more likely to be young and male than the general population), these comparisons are presented for comparative purposes only.

Chronic diseases

The burden of chronic disease in the United States is significant. Chronic diseases are the leading cause of death in the United States and account for the largest share of national health care spending. The prevalence of chronic diseases is associated with functional, physical, social and cognitive limitations, as well as a decline in quality of life.

The HRBS asked respondents if they had been told by a doctor or other health professional in the last 12 months that they had high blood pressure, high blood sugar or diabetes, high cholesterol, asthma, angina or coronary heart disease, a heart attack (also known as a myocardial infarction), back pain or a bone, joint or muscle injury or disease. Overall, 36.6% of respondents reported having at least one of these eight chronic conditions.

The most common chronic condition diagnosed was a bone, joint or muscle injury or disease, with a rate of 21.9% (CI 21.0-22.8). The second most common problem was back pain, reported by 21.6% of respondents (CI 20.7-22.5). High blood pressure was the third most common problem, reported by 9.3% of respondents (CI 8.7-9.9). HP2020 aims to reduce the proportion of adults in the US with high blood pressure to 26.9%.

High cholesterol was the fourth most common problem, reported by 6.8% of respondents (CI 6.3-7.2). HP2020 aims to reduce the proportion of adults with high cholesterol in the US to 13.5%. Of all other chronic conditions covered in the HRBS, no more than 2% of respondents reported any other chronic condition.

Symptoms (Physical)

It is estimated that 34% of the population reports at least one common physical symptom, and a third of physical symptoms have no medical explanation. The prevalence of multiple physical symptoms is associated with higher rates of depression, anxiety, substance use disorders and health service use.

Respondents to the HRBS survey completed a checklist of eight common physical symptoms: stomach or bowel problems; back pain; pain in hands, feet or joints; headache; chest pain or shortness of breath; dizziness; tiredness or lack of energy; and sleep problems. Respondents were asked how much each symptom had bothered them in the last 30 days.

Overall, 21.1% (CI 20.2-22.0) reported that one or more body pain symptoms, including headache, bothered them “very much”. The most commonly reported single symptom was sleep disturbance, with 13.7 percent (CI 12.9-14.5) reporting that this symptom was “very bothersome”.

The severity of physical symptoms was calculated by scoring each symptom for each respondent as 0 (not at all bothersome), 1 (somewhat bothersome) or 2 (very bothersome). Scores ranged from 0 to 16, with 8 or more points indicating the severity of the physical symptoms. Overall, 11.0% (CI 10.3-11.7%) of respondents had very severe physical symptoms.

Head trauma and post-concussion symptoms

Military personnel are exposed to a variety of physical injuries. Some potentially injury-related factors, such as physical training, are common in the military. Other possible factors include road traffic accidents and sports injuries. Deployments also increase the risk of certain types of injuries. These and other factors can increase the risk of brain injury in service members.

The HRBS assessed TBI with three sets of questions based on the Brief Traumatic Brain Injury Test. Respondents were classified as having a mild traumatic brain injury if they reported one or more injuries in the past 12 months and recalled losing consciousness for 20 minutes or less, feeling dizzy, being confused or seeing stars, suffering post-concussion symptoms, or losing memory of the event.

In the survey, respondents were classified as having a moderate or severe injury if they reported losing consciousness for more than 20 minutes. In the HRBS, respondents were classified as having post-concussion symptoms if they tested positive for TBI and reported at least four post-concussion symptoms in the past 30 days.

Overall, 21.2% (CI: 20.2-22.1) of HRBS respondents reported being injured in the past year. Across all units, 4.3% (CI: 3.8-4.8) of reservists had CTCM, 0.2% (CI: 0.1-0.3) had moderate or severe CTCM, and 2.7% (CI: 2.3-3.1) had post-concussion symptoms.

Health rated by yourself

In addition to physical symptoms, members were asked to rate their general health. These measures have been shown to be valid for measuring physical and emotional health and predicting overall mortality. Members were asked to rate their health as excellent, very good, good, fair or poor. 57.3% (CI 56.2-58.5) rated their health as excellent or very good.

Health-related functional disabilities

Chronic illnesses and physical limitations can affect access to health services, quality of life and the ability to carry out normal daily activities. This can lead to reduced productivity and loss of school or work days. The HRBS assessed absenteeism – days absent from work or school due to health problems – and attendance – days when they went to work or school but their ability to work was impaired due to health problems.

Respondents were asked how many days in the last 30 years their mental or physical symptoms had caused them to be absent from school or work, or to feel so unwell that they were unable to work even when they were at school or work. On average, members reported 0.53 days (CI 0.47-0.59) of absence in the past 30 days. They also reported 1.50 days (CI 1.39-1.61) in the past 30 days.

Results compared to the Active Servicemen

To compare HRBS results for active and reserve members, RAND researchers developed regression models that account for respondents' demographic characteristics. Significant differences between reservists and members of the active component are as follows

• They are less likely to have multiple medically diagnosed chronic conditions: high blood pressure, back pain, and bone, joint and muscle injuries (including arthritis).
• Less likely to have a medically diagnosed chronic illness in the past year.
• Less likely to have physical pain and intensity of physical symptoms.
• Fewer head injuries and post-concussion symptoms, – fewer head injuries and post-concussion symptoms.
• More likely to report their health as ‘excellent' or ‘very good', and
• Fewer days of absence (absenteeism) and fewer days of reduced productivity (attendance) due to health problems.

Conclusions and Suggestions for Politics

Pain is a common health problem among reservists. High levels of pain are not surprising given the physical demands of military service. However, since pain can impair physical functioning or lead to health risks associated with the use of prescription drugs such as opioids, it is a potential problem in military readiness.

DOD, the services, and the Coast Guard should continue to focus on policies and programs related to injury and pain prevention and emphasize a variety of non-pharmacological approaches to pain medications.

Methods

RAND conducted the 2018 HRBS survey of US active duty and reserve military personnel from October 2018 to March 2019. Five Reserve Component members – Air Force, Army, Marine Corps, Navy, and Coast Guard – and two National Guard members – Air National Guard and Army National Guard – participated in the Reserve Component survey.

The 2018 HRBS was a confidential online survey that allowed researchers to target reminders to non-respondents and reduce survey burden by linking responses to administrative data. A stratified random sampling method was used to select the sample by grade level, grade and gender. The overall weighted response rate to the survey was 9.4%, resulting in a final analytical sample of 16,475 responses for the Reserve.

To deal with missing data, RAND researchers used imputation, a statistical procedure that uses available data to estimate missing values. To ensure representativeness of the reserve population, responses were weighted to account for over-sampling of service members in some sections. Point estimates and 95% CIs are presented in this survey report[3].

RAND researchers controlled for differences in each outcome between major factor levels or subgroups – service area, grade, gender, race/ethnicity, and age group – using a two-step procedure based on the Rao-Scott chi-square test for overall differences between individual factor levels, and if the overall test was statistically significant, a two-sample t-test for all possible pairwise comparisons between factor levels (e.g., men and women).

Readers interested in these differences should consult the full final report of the HRBS 2018 Reserve Component. This memo is one of eight memos on the Reserve; this memo and six of the other seven memos are the various chapters of the full report, with the eighth memo providing an overview of all the results and policy implications. Eight similar reports deal with the results of the active part.

Restrictions

The response rate to the survey is considered low. While a low response rate does not automatically mean that the survey data are biased, it does increase the likelihood of bias. As with any self-report survey, social desirability bias is possible, especially for sensitive questions and topics. For some groups representing a small percentage of the total military population, survey estimates may be inaccurate and should be interpreted with caution.