The Department of Defense (DoD) is the largest employer in the United States, with a current active-duty enlisted military force of 1.15 million. The goal for new active-duty recruits in 2005 is approximately 169,000. The central concern in force management is ensuring that there are sufficient numbers of mentally qualified, healthy, and physically fit personnel to meet current and projected mission requirements. The ability of the Services to meet the enlisted recruiting challenge has varied over time as a function of the size of the recruiting goal, the state of the economy, and the nature of the mission. Even under the most favorable circumstances, recruiting is a difficult job.
The pool of eligible recruits is defined by a set of entrance standards that has been developed by the DoD and the Services to guide the selection of the most qualified and able personnel. When recruiting becomes difficult, as it has in 2005, questions arise concerning the validity of the standards and the consequences of changing them on the size and readiness of the force. In this context, the Committee on Youth Population and Military Recruitment: Physical, Medical, and Mental Health Standards was established to examine the health and fitness of American youth as they relate to current screening enlistment standards and to assess the validity of these standards for predicting attrition and injury in training and on the job.
The charge to the committee consists of four related tasks designed to provide the DoD with guidance on physical, medical, and mental health standards for use in selecting members of the enlisted force. The population of interest for the project, as directed by the committee’s sponsor, is
18-24-year-olds and their service during the first term of active-duty military enlistment. Individuals attending the military academies or participating in the Reserve Officers’ Training Corps (ROTC), Reserve, and National Guard units are outside the sponsor’s purview.
The committee’s findings are presented in terms of each task.
Profile of American Youth
Task 1: Develop a profile of the physical and medical condition of American youth today and in the future.
The committee examined the following health-related factors: physical fitness; body weight and composition; asthma; alcohol, drug, and cigarette use; and mental health. We selected these factors on the basis of their specification in the charge, their frequency of occurrence in the applicant population, the extent to which disqualification for the condition could be overruled or waived by one of the Services, the existence of a military and academic research base, and the extent to which changing the standard could make a difference in the eligibility of a significant number of recruits. There are many disqualifying medical conditions that were not included in the committee’s investigation because of strong clinical or scientific evidence concerning their adverse effects on combat performance. These include serious diseases, physiological abnormalities, and physical impairments such as blindness and deafness.
Physical fitness is a multidimensional construct consisting of several core components, including cardiorespiratory endurance (aerobic fitness), muscular strength, muscular endurance, flexibility, and body composition. There are only a few studies on trends over time in the cardiorespiratory health of the youth population. Nevertheless, the evidence suggests that cardiorespiratory endurance in young men has declined by approximately 10 percent since 1966, whereas there was no change for young women during the same period. The cardiorespiratory fitness levels of men and woman entering the Army in the 1980s and 1990s were found to be unchanged for men and slightly improved for women. At the present time there are no military enlistment standards for physical fitness; fitness tests are administered at the beginning of, and at different points during, basic training.
Body mass index (BMI, a ratio of body weight to body height) has historically been used by the Services as a screen for enlistment. In fact, each Service has its own criteria for determining acceptable levels of BMI and percentage of body fat. According to the Centers for Disease Prevention and Control (CDC), a BMI over 25 is considered overweight and carries health risks; a BMI over 30 is defined as obese. In the youth population, the prevalence of overweight in children and adolescents tripled between 1963 and 1999 from approximately 5 to 15 percent. The highest prevalence of overweight or risk for overweight during that period was among Mexican American boys and non-Hispanic black girls. Data from the National Health and Nutrition Examination Survey 1999-2000 showing the distribution of BMI for the general population of people ages 16 to 24 indicate that 40 percent have BMIs over 25, and more than 15 percent have BMIs of 30 and over. Thus, the currently recommended BMI enlistment standard used by DoD and most of the Services of 25 or under for young women could lead to disqualification of 40 percent of them from the pool of eligible recruits, while the currently recommended BMI standard of 27.5 percent for young men could lead to disqualification of approximately 25 percent of them from the pool.
Asthma is one of the most common chronic illnesses in the United States. The rate of those who have ever experienced an asthma episode varies between 38 and 43 per 1,000 people in the population. This same rate is evident in individuals ages 15 to 34, but the rate is higher in those under age 15. The rate for non-Hispanic blacks is slightly higher than non-Hispanic whites and Hispanics. CDC data from 1980 to the mid-1990s indicate that women were more than twice as likely as men to be hospitalized for asthma. Historically, asthma has been among the top 10 medical disqualifying conditions for which waivers are requested from the Services. The current military enlistment standard disqualifies any applicant who has experienced asthma symptoms after the 13th birthday. Using asthma as an exclusionary factor is likely to work against the enlistment of minorities and women, as these groups exhibit the highest prevalence of asthma.
Psychological adaptation to military service is critical for successful completion of a tour of duty. Stressors associated with transition from
civilian to military life include changes in living arrangements, geographic locations, peer relationships, support systems, schedules, priorities, and control over one’s life, as well as separation from family and friends, difficulties in communication with home, and loss of privacy. Soldiers on wartime missions must deal effectively with the stress and anxiety associated with potential loss of their lives and their fellow soldiers.
About 20 percent of children ages 9-17 in the United States have a diagnosable mental or addictive disorder associated with at least minimum impairment, while 11 percent have a significant functional impairment. Common disorders are anxiety, depression, disruptive behavior disorders, and substance use disorder. Estimates of the prevalence of attention deficit hyperactivity disorder range from 7 to 16 percent of youth, and the rates are two to three times higher for boys than for girls. Recent evidence demonstrates that childhood attention deficit hyperactivity disorder (ADHD) is a predictor for adolescent substance use; stimulant therapy for childhood ADHD has been shown to reduce the risk of subsequent adolescent drug and alcohol use disorders. Growing numbers of youth receive outpatient treatment or are hospitalized for mental health disorders. There has been a substantial increase in the use of psychotropic medications, particularly antidepressants and stimulants, for children and adolescents with psychiatric disorders.
Psychiatric disorders account for 6 percent of the disqualifications at the military entrance processing stations; of these, almost half apply for and receive a waiver from one of the Services. It is important to note that many with mild conditions may be discouraged from applying on the basis of questioning at the beginning of the recruiting process; the medical prescreening tool does not differentiate among minor and major psychiatric conditions, and all require the provision of some medical follow-up information. Data from the medical prescreen are not included in any database.
Current enlistment standards reflect the reality that some consumption of alcohol is commonplace among youth, despite the fact that in most states it is illegal to consume any alcoholic beverage under age 21. Occasional or “recreational” use of marijuana is also fairly common among youth, and as a result the military decided during the early 1990s that such use would not be disqualifying under its moral character standards. Supply constraints are therefore more focused on heavy or chronic use of illicit drugs or alcohol, especially when they indicate drug dependence.
Alcohol consumption in the population of high school age youth dropped significantly between 1980 and 1993, from a high of more than 70
percent to a low of about 50 percent. Since then, it has fluctuated only slightly. The percentage of youth who indicated being drunk in the past 30 days changed very little between 1991 and the present, standing at just over 30 percent in 2003. Rates of alcohol use are related to both gender and race and ethnicity, but the gender effects are much smaller. For both young men and young women, whites have the highest rates of alcohol consumption and blacks the lowest. Hispanic youth are in between but are closer to whites than blacks.
Marijuana usage also shows a steep drop between 1978 and 1992, from a maximum of 37 percent to a low of 12 percent. The rate began rising again in the early 1990s and reached a more recent maximum of just under 25 percent in 1997, and it has remained at about that level since that time. The rate of other illicit drug use has remained very close to 10 percent for the past eight years or so. Total illicit drug use among men differs very little by race; however, black women have rates that are consistently 10 points below white women. Approximately 6 percent of applicants are initially disqualified on the basis of a positive test for marijuana during the physical examination at the military entrance processing station.
Preservice smoking is of interest because of its demonstrated relationship with early attrition during the first term of military service. Trend data generally show that smoking rates declined during the 1970s, remained fairly flat during the 1980s, and began increasing during the 1990s (when marijuana use also began rising). Cigarette smoking rates reached a peak in 1997 and then began declining. By 2003, smoking rates had reached historic lows of 24 percent for any smoking and 16 percent for daily smoking. With regard to daily cigarette smoking, rates are somewhat higher for young men, but usually by just a few percentage points, while larger differences exist by race and ethnicity. White young men and women are much more likely to smoke than their black or Hispanic counterparts. Black youth have the lowest rates of smoking of all groups. There are no enlistment standards related to preservice smoking.
The Nature of Military Work
Task 2: Examine the changing nature of work generally and the new demands placed on the military in the post–cold war era.
Studies show that technology is increasing the physical demands of some jobs and decreasing the demands of others. This leads to the ques-
tion of whether it is feasible or advisable to set different physical and medical standards for different military occupational specialties (MOSs). With limited exceptions, there is little research detailing the physical requirements of individual MOSs. However, the crucial feature regarding the question of setting lower standards for some MOSs than for others is the DoD policy decision that every uniformed service member must be combat-ready. This implies a common set of requirements for combat tasks, regardless of one’s primary MOS.
Part of the charge to the committee was to review evidence on the physical requirements of military jobs, but we found no research detailing the fitness requirements of all of the common military tasks required for combat readiness. Furthermore, there is no documentation that would allow an in-depth examination of the physical demands of each MOS in each Service. The committee therefore accepted the policy that military service itself requires a minimum level of physical fitness for all uniformed Service members. As noted in Department of Defense Instruction 1308.3, “It is DoD policy that physical fitness is essential to combat readiness and is an important part of the general health and well-being for Armed Forces personnel.”
Task 3: Review the literature on the predictive validity of medical and physical selection standards for training and job performance in the military and in the civilian population.
The committee’s approach to evaluating existing standards was to assess their effects on attrition and injury during basic training and through the first term of service. Measuring job performance after training, although of considerable interest, was not possible due to the difficulty of obtaining valid and reliable measures of individual performance. Ideally, formal trade-off models, like those applied to assessing enlistment standards for education and aptitude, would be used to validate medical and physical standards. They would be particularly useful for continuous conditions, like weight and strength, for which no disqualifying level can be established clinically, as well as for dichotomous conditions, like the use/nonuse of marijuana or having/not having asthma; the presence of these conditions may reduce effectiveness but is not automatically disqualifying. Such models examine the trade-off between performance effectiveness and the proportion of potentially available recruits who have the necessary characteristics. At this time, the trade-off model-
ing approach has not been used to evaluate standards in the medical and physical domains, in part due to the inaccessibility or unavailability of the required medical data and the difficulty of linking personnel and medical files for research purposes. The committee provides a description of this approach and illustration of its use.
Military research organizations have conducted several studies on the relationship between physical and medical factors and injury and attrition for fitness, BMI, asthma, and preservice tobacco use. The committee found one useful study showing that recruits receiving mental health waivers were more likely to leave the military early compared with recruits who were qualified on all physical, medical, and mental health standards. Major contributors to the research base include the Accession Medical Standards Analysis and Research Activity, the U.S. Army Center for Health Promotion and Injury Prevention, the U.S. Army Institute for Environmental Research, the U.S. Army Research Institute for the Behavioral and Social Sciences, and the Human Resources Research Organization.
As noted earlier, there are no enlistment standards for physical fitness; however, data are available on the relationship between different levels of physical fitness, as measured in basic training, and injury and attrition. Musculoskeletal injuries resulting from basic and advanced individual training pose the single most significant medical impediment to military readiness. Military research and the committee’s own analyses show that both male and female recruits who have low levels of cardiorespiratory fitness are more likely to be injured or leave basic training and military service early (or both) than those with high levels of cardiorespiratory fitness. Women with low fitness are twice as likely as men with low fitness to be injured and to leave military service. This finding may be due in part to the biomechanical differences between men and women and the interaction of these differences with basic training regimens.
Unlike the findings for fitness, the results for BMI show that there are essentially no relationships between BMI and injury and attrition for men and only a slight relationship between BMI and attrition for women. That is, recruits who exceed the current height and weight standard and body fat standard and have received a waiver to enter military service are not
injured or do not leave early with any greater frequency than recruits who meet the enlistment standards.
Available data indicate that military personnel who have been admitted to military service with an asthma condition have lower attrition rates than those without asthma, although studies show that their health care costs are higher. Some evidence suggests those with asthma that is discovered after enlistment are more likely to drop out during basic training. Currently, asthma that is present at any level of severity precludes participation in the military. It is likely that individuals without symptoms for a prolonged period of time, or even those with mild and infrequent symptoms, could carry out their service requirements, especially if they received optimal medical therapy and self-management education. However, there are costs associated with ensuring timely access of personnel to needed medical therapies and making self-management education available.
Cigarette smoking has periodically surfaced as an issue in the U.S. military. An initial Navy study found that attrition from Navy boot camp was nearly twice as high for smokers (15 percent) than for nonsmokers (8 percent). Additional research found that recruits who required some form of enlistment waiver were approximately 1.5 times more likely than their counterparts without a waiver to have smoked before entering military service. A subsequent Air Force study found preservice smokers were approximately 1.8 times more likely to be discharged during the first year of service than were nonsmokers. A large-scale Army study found that the odds of attrition for soldiers who smoked prior to accession were 1.54 times those of nonsmokers. Finally, recruits who smoke are considerably more likely than nonsmokers to have had behavioral problems before enlistment, including high school misbehavior, criminal offenses, drug use, psychological difficulties, and trouble in dealing with authority.
RECOMMENDATIONS AND POLICY OPTIONS
Task 4: Develop policy options. Consider a full range of personnel options for ensuring that recruits are healthy and fit for military service.
The results of the committee’s work led to five broad categories of conclusions and recommendations: reducing injuries and attrition, in-
creasing the pool of eligible youth, developing databases and procedures needed to study the relationship between standards and outcomes, identifying standards that need further investigation, and identifying standards that should be retained. A complete list of conclusions and recommendations is presented in Chapter 8.
Two recommendations concern reducing injury and attrition: (1) develop a standardized fitness test for use in the recruiting process and (2) tailor the demands of basic training to the fitness levels of recruits. Recommendations aimed primarily at reducing attrition involve obtaining better information about recruits’ mental health status via the use of a brief self-report of mental symptoms at the military entrance processing station, accompanied by a brief mental status exam by a physician.
Three recommendations concern increasing the proportion of the youth population eligible for entry into military service: (1) do not use BMI as a proxy for fitness, (2) do not use a BMI standard for retention that is more stringent than a BMI standard for entry, and (3) do not require documentation or further medical reviews for self-reported mood and anxiety disorders that occur before the 13th birthday.
Five recommendations concern developing databases and administrative procedures to permit a broader and more probing inquiry into the relationship between standards and outcomes than is possible in light of data available today: (1) maintain data from the medical history form completed by recruits at the recruiting station, (2) develop a common core of physical strength and fitness measures across the Services, (3) collect data permitting the linkage between medical standards and outcomes, (4) increase the specificity of the single mental health item on the medical history prescreen administered at the military entrance processing station, and (5) collect and retain mental health data from recruitment through length of service.
Six recommendations concern substantive research studies needed prior to recommending changes in a current standard or in implementing a new one: (1) analyze the physical requirements of the set of common military tasks across military occupational specialties to obtain a clearer picture of the physical demands of these tasks, (2) study prebasic training fitness interventions to determine whether they are a viable and cost-effective route to reduced injury and attrition, (3) examine the causes of increased injury and attrition in women, (4) compare attrition rates of enlistees with and without mental health conditions existing prior to service, (5) conduct cost-benefit analysis regarding the effects of increasing the stringency of the current marijuana waiver policy, and (6) conduct further research on the relationship between smoking and attrition, with particular attention to the behavioral factors driving the observed relationship.
One recommendation concerns retaining a current standard. Due to the prevalence of asthma, the committee carefully reviewed the literature on the relationship between asthma and outcomes of interest to the Services and concluded that the current standard and waiver process are appropriate.
The committee concluded its earlier study of the role of youth attitudes toward the military and of aptitude and educational standards by noting that recruiting is a complex process, with no single route toward achieving recruiting goals. We end here with the same conclusion. We think, however, that we have been able to highlight a variety of important issues meriting attention as efforts to improve the effectiveness of the recruiting process continue.