Guarantor: Laurel L. Hourani, MPH PhD Contributors: Laurel L. Hourani, MPH PhD*; Thomas V. Williams, PhD ; Amii M. Kress, MPH

Transcription

1 MILITARY MEDICINE, 171, 9:849, 2006 Stress, Mental Health, and Job Performance among Active Duty Military Personnel: Findings from the 2002 Department of Defense Health-Related Behaviors Survey Guarantor: Laurel L. Hourani, MPH PhD Contributors: Laurel L. Hourani, MPH PhD*; Thomas V. Williams, PhD ; Amii M. Kress, MPH This study examined the extent to which high levels of occupational and family stress were associated with mental health problems and productivity loss among active duty military personnel. We analyzed data from the 2002 Department of Defense Survey of Health-Related Behaviors among Military Personnel, which provided extensive population-based information on 12,756 active duty personnel in all branches of the military worldwide. Military personnel reported higher levels of stress at work than in their family life. The personnel reporting the highest levels of occupational stress were those 25 or younger, those who were married with spouses not present, and women. Personnel with high levels of stress had significantly higher rates of mental health problems and productivity loss than those with less stress. We recommend that prevention and intervention efforts geared toward personnel reporting the highest levels of stress be given priority for resources in this population. Introduction tress is a ubiquitous occurrence among active duty military S personnel and has been associated with a variety of mental health and job performance outcomes. 1 2 Although the adverse relationships between stress and mental health, stress and job performance, and mental health and job performance are wellestablished among civilian populations, the majority of the research on the relationship between stress and mental disorder in the military has focused on the psychological effects of exposure to trauma and combat. 3 6 With military downsizing requiring an increase in duties, high levels of stress may be pervasive among all military personnel, not only those who are deployed or exposed to combat. Indeed, the demanding characteristics of the military environment are such that many stressors are inherent. 7 Unfortunately, the few studies that have examined occupational stress and mental disorder in the military 8 10 were conducted with limited samples, and the prevalence and levels of stress and its impact on the mental health and productivity of the military population as a whole are unknown. Further, little research has examined the inter-relationships among stress, mental health, job performance, and receipt of mental health treatment in the general *RTI International, 3040 Cornwallis Road, Research Triangle Park, NC Center for Healthcare Management Studies, Office of the Assistant Secretary of Defense, Health Affairs, TRICARE Management Activity, 5111 Leesburg Pike, Falls Church, VA Presented in part at the 112th Annual Convention of the American Psychological Association, July 29, 2004, Honolulu, HI. The views, opinions, and findings contained in this report are those of the authors and should not be construed as an official Department of Defense position, policy, or decision, unless so designated by other official documentation. This manuscript was received for review in June The revised manuscript was accepted for publication in January military population, despite the fact that particular stressors and the guaranteed access to mental health treatment make the military both a unique and a model population for social and epidemiological investigation. Reported physical symptomatology and emotional stress are significantly higher in active duty personnel than in civilian workers, 4,9 further emphasizing the uniqueness of this population and the limitation of generalizing from results of civilian studies. In one of the few studies that examined three of the four domains, Bray et al. 11 found that both work-related stress and symptoms of depression were associated with lower functioning on the job. Hypotheses and Specific Aims The present epidemiological study expanded on findings above to simultaneously investigate the degree to which selfreported stress is associated with other measures of mental health and job performance and their correlates with treatment receipt. We hypothesized that high levels of occupational stress were associated with a greater risk of mental health problems and productivity loss and that productivity loss was associated with an increased likelihood of perceiving the need for and receiving mental health treatment. The specific aims of this study were to: 1. assess the prevalence and sociodemographic correlates of occupational and personal/family life stress and selected mental health problems in the military, 2. assess the prevalence and sociodemographic correlates of productivity loss and utilization of mental health treatment, 3. examine the association between stress and mental health, 4. examine the association between stress and productivity loss, and 5. describe the relationships among self-reported stress, mental health, productivity loss, and treatment receipt. Methods Sample and Procedures We obtained data from the 2002 Department of Defense (DoD) Survey of Health-Related Behaviors among Military Personnel, the eighth in a series of large, population-based surveys of active duty personnel in all service branches. 12 The target population for the survey included all military personnel who were on active duty at the time of data collection (September 2002 through mid-february 2003), except for recruits, academy cadets, and persons who were absent without leave, incarcerated, or under- 849

2 850 Stress and Job Performance: DoD Survey Findings going a permanent change of station. We used a two-stage sampling design to capture a random sample of eligible active duty personnel in the nation s largest installations (1,000 or more active duty personnel) within the continental United States, outside the continental United States, and at afloat designations of the U.S. Navy. From the 240 identified installations, we selected 30. We randomly drew the person-level sample (of eligible personnel [N 29,787]) from the Defense Manpower Data Center s May 2002 files. The final sample consisted of 12,756 military personnel (3,269 Army; 3,625 Navy; 3,008 Marine Corps; and 2,854 Air Force), who completed self-administered questionnaires anonymously. We selected participants to represent men and women in all pay grades of the military. We collected data primarily from participants in group sessions at military installations, and we obtained data by mail for those not attending the sessions. The overall response rate was 56%. We weighted the data to represent all eligible active duty personnel. The majority of respondents were male (83.1%), non-hispanic Caucasian (67.3%), educated beyond high school (64.0%), age 34 or younger (75.5%), married (55.7%), and in pay grades E1 to E6 (73.9%; see Table I). We have reported additional methodological details previously. 12 Measures The survey instrument was an anonymous, 147-item, selfadministered questionnaire covering selected aspects of a number of health-related behaviors relevant to the present study, including stress experienced at work or in family life, mental health problems (including anxiety and depression symptoms), and job performance and productivity. In addition to sociodemographic variables, the survey included items on perceived need for and use of mental health treatment services. Stress The questionnaire included three variables to assess the prevalence of occupational and family stress. The first variable measured occupational stress by asking, During the past 12 months, how much stress did you experience at work or while carrying out your military duties (a lot, some, a little, none at all)? The second variable, measuring family stress, asked about stress in family life or in a relationship with your spouse, live-in partner, or the person you date seriously. The third was a summary variable, occupational or family stress, measuring whether levels of occupational or family stress were high, low, or negligible. Mental Health Problems Three variables measured mental health problems: need for further mental health evaluation, perceived need for mental health treatment, and days on which poor mental health limited usual activities. The variable assessing need for further mental health evaluation combined two variables assessing the need for further depression evaluation and the need for further anxiety evaluation. To identify personnel in need of further depression evaluation, we used an eight-item set of symptoms, including six items from the Center for Epidemiological Studies Depression Scale (CES-D) 13 and two items from the Diagnostic Interview Schedule. 14 We scored need for further depression evaluation according to a multiple logistic regression probability formula using a screening criteria cut point of This formula was based on Burnam and Wells s 15 method for attaining at least 85% sensitivity and high positive predictive values when using these eight items. To allow for some missing data, if at least two of five CES-D items or both of the Diagnostic Interview Schedule items were answered positively, we categorized the respondent as being in need of further depression evaluation. To determine the need for further evaluation for anxiety, we adapted a set of six general anxiety symptom items from the Patient Health Questionnaire. 16 If respondents reported that they had been feeling nervous, anxious, or on edge, or that they had been worrying a lot about different things (the first question in the set) for several days or more, we examined whether they reported any of the other five symptoms. If they reported experiencing two or more symptoms on more than half of the days in the past month, we classified them as needing further evaluation for anxiety. Spitzer et al. 16 found the Patient Health Questionnaire to have good agreement with diagnoses made by independent mental health professionals ( 0.65). The variable assessing need for further mental health evaluation included all respondents meeting the screening criteria above for either need for further depression evaluation or need for further anxiety evaluation. We measured perceived need for mental health treatment with an item asking, At any time in the past 12 months did you feel you needed treatment or therapy from a mental health professional (either military or civilian)? To measure the number of days on which poor mental health limited usual activities in the past month, we used an item with seven response options. A summary variable categorized respondents into those who indicated 1 or more days of limited activity in the past month and those with no limited-activity days. Receipt of Mental Health Treatment The receipt of mental health treatment variable was based on responses to a single item asking, In the past 12 months, did you receive mental health treatment or therapy from the following? We defined receipt of mental health treatment as having received (according to self- reports) counseling or therapy from a mental health professional at a military or civilian facility. Job Performance We assessed job performance with an item asking on how many workdays in the past 12 months respondents had any of the following experiences: they were late for work by 30 minutes or more, they left work early for a reason other than an errand or early holiday leave, they were hurt in an accident on the job, they worked below their normal level of performance, and they did not come to work at all because of an illness or accident. We defined productivity loss as 4 or more workdays in the past 12 months with one of the above experiences. The survey also asked respondents about job performance attributed specifically to stress: During the past 12 months, how much did stress at work interfere with your ability to perform your military job (a lot, some, a little, not at all, had no stress in the family in the past 12 months)? An identical item asked about stress in your family life.

3 Stress and Job Performance: DoD Survey Findings Analysis We used the SUDAAN Software for the Statistical Analysis of Correlated Data 17 to compute all estimates and standard errors presented in this analysis. This software package is designed specifically for the analysis of complex survey data, and it took account of the multistage design of the study when computing precision estimates as well as the effects of unequal sample weights. We conducted analyses with the final analysis weights from the study, which were corrected for person nonresponse as discussed in Bray et al. 12 We produced univariate and bivariate analyses using the SUDAAN procedures DESCRIPT and CROSSTAB, omitting item nonrespondents. Most of the items exhibited an item nonresponse rate of 5% or less; consequently, the impact of potential item nonresponse bias was minimal. One notable exception was the questions that were used to produce estimates of the need for further mental health evaluation. This composite measure yielded an item nonresponse rate of 12.1%. Because several questions produced this measure and each had a relatively low item nonresponse rate, the potential item nonresponse bias was also likely negligible. We used the t test to assess significant differences, and we suppressed estimates that could not be reported with confidence because of small sample sizes ( 30) or that had large sampling errors. Results 851 Prevalence of Occupational and Family Stress To address the first aim of the study, Table I shows the percentages of military personnel who reported the highest level of stress at work and in their family lives. Overall, personnel reported higher levels of stress at work. Almost one-third of the total DoD respondents reported a lot of stress at work, compared with less than 20% who reported a lot of stress in their family lives. The prevalence of occupational stress was significantly higher than that of family stress among all sociodemographic groups. Occupational stress was highest in personnel TABLE I PREVALENCE OF SOCIODEMOGRAPHIC CHARACTERISTICS OF TOTAL POPULATION AND HIGH-STRESS GROUPS AMONG ACTIVE DUTY PERSONNEL, 2002 Sociodemographic Characteristics Total Respondent Characteristics a Eligible Participant Population High Occupational Stress High Family Stress Gender Male 9, (0.8) 31.3 (1.5) 18.0 (0.6) Female 3, (0.8) 36.9 (1.3) 22.3 (0.8) Race/ethnicity Caucasian, non-hispanic 8, (1.3) 33.3 (1.5) 18.8 (0.7) African American, non-hispanic 2, (1.4) 28.8 (1.2) 18.5 (0.8) Hispanic (0.4) 32.2 (2.0) 18.3 (1.3) Other (0.5) 33.6 (2.4) 18.5 (1.1) Education High school or less 4, (1.7) 34.9 (1.7) 20.0 (0.7) Some college 5, (1.2) 31.7 (1.5) 19.4 (0.9) College graduate or higher 3, (1.6) 28.8 (1.4) 14.8 (0.6) Age group (years) 20 or younger 1, (1.0) 37.8 (2.6) 20.3 (1.2) , (1.2) 35.3 (1.5) 21.5 (0.7) , (0.7) 30.7 (1.6) 18.8 (1.1) 35 or older 4, (1.7) 27.0 (1.1) 14.1 (0.9) Marital status Not married 5, (1.2) 34.1 (1.4) 19.1 (0.5) Married, spouse not present (0.3) 37.4 (2.9) 31.3 (1.2) Married, spouse present 6, (1.2) 30.2 (1.4) 17.2 (0.7) Family status Unmarried, living without child 4, (1.3) 34.5 (1.6) 18.2 (0.5) Unmarried, living with child (0.3) 31.3 (2.0) 27.7 (2.4) Married, living without child 2, (0.4) 35.6 (2.0) 20.2 (1.0) Married, living with child 5, (1.1) 28.6 (1.4) 17.6 (0.7) Pay grade E1 E3 2, (1.6) 36.8 (2.1) 21.3 (1.0) E4 E6 5, (1.0) 32.5 (1.5) 20.0 (1.0) E7 E9 2, (0.8) 26.3 (1.2) 14.0 (0.7) W1 W (0.2) 27.6 (1.4) 15.2 (2.6) O1 O3 1, (0.5) 29.3 (1.9) 14.9 (1.0) O4 O (1.1) 30.2 (1.9) 12.7 (1.1) Total DoD 12, ( b ) 32.3 (1.3) 18.7 (0.5) a Column entries are numbers of respondents who completed a usable questionnaire. Other column entries are percentages, with SEs in parentheses. b Estimate rounds to zero.

4 852 Stress and Job Performance: DoD Survey Findings who were 20 or younger (37.8%) and in married personnel whose spouses were not present at their duty location (37.4%). Of all the sociodemographic categories, the prevalence of family stress was notably the highest among married personnel whose spouses were not present at their duty location (31.3%) and among unmarried personnel living with a child (27.7%). Prevalence of Mental Health Problems and Productivity Loss To address the second study aim, Table II shows that almost 28% of all respondents met screening criteria suggesting a need for further mental health evaluation (i.e., by anxiety or depression symptom cutoff scores). Because the distribution of sociodemographic characteristics for respondents needing further mental health evaluation was similar to that of those whose usual activities were limited by poor mental health and those who perceived a need for mental health treatment, they are presented for the former variable only. Prevalence rates for needing further mental health evaluation decreased with increasing age. Indeed, respondents 25 or younger had two to three times the rates of those 35 or older. Respondents 20 or younger, women, and those in the lowest pay grades had the highest percentages of needing further mental health evaluation. Married personnel whose spouses were not present at their duty location had rates similar to those of unmarried personnel. As also shown in Table II, 30% of the population reported at least one of the five productivity loss indicators for 4 or more days in the previous 12 months. The sociodemographic characteristics most highly associated with loss of productivity were being 25 or under, female, African American, and unmarried especially when living with a child or when in a junior enlisted pay grade. Utilization of Mental Health Treatment Services Of all the respondents, 12.5% received mental health treatment in the previous 12 months. Most respondents received treatment from a military mental health professional (6.1%), a military chaplain (5.4%), or a physician at a military facility (4.4%) (data not shown). Unmarried personnel living with a child TABLE II PREVALENCE OF SOCIODEMOGRAPHIC CHARACTERISTICS OF ACTIVE DUTY PERSONNEL WHO NEEDED FURTHER MENTAL HEALTH EVALUATION, REPORTED ANY PRODUCTIVITY LOSS (4 DAYS), OR RECEIVED MENTAL HEALTH TREATMENT IN PREVIOUS 12 MONTHS, 2002 Sociodemographic Characteristics Needed Further Mental Health Evaluation (Anxiety or Depression) Any Productivity Loss (4 days) Received Mental Health Treatment Gender Male 25.8 (1.1) 29.3 (1.3) 10.8 (0.4) Female 38.1 (1.2) 33.3 (1.5) 21.2 (1.1) Race/ethnicity Caucasian, non-hispanic 27.1 (1.0) 29.6 (1.4) 12.7 (0.6) African American, non-hispanic 29.9 (1.3) 32.8 (1.7) 12.1 (0.8) Hispanic 29.1 (2.5) 30.0 (1.5) 11.2 (1.2) Other 28.9 (2.1) 22.9 (1.8) 14.6 (1.6) Education High school or less 34.2 (1.2) 31.3 (1.7) 12.6 (0.6) Some college 27.9 (0.8) 30.6 (1.5) 13.6 (0.8) College graduate or higher 17.1 (1.0) 26.4 (1.2) 10.1 (0.8) Age group (years) 20 or younger 38.3 (2.0) 32.9 (2.2) 14.9 (1.2) (1.0) 35.5 (1.9) 14.0 (0.8) (1.4) 27.4 (1.3) 11.7 (0.9) 35 or older 18.2 (0.8) 24.6 (1.1) 10.4 (0.7) Marital status Not married 34.0 (1.2) 32.9 (1.6) 14.2 (0.6) Married, spouse not present 36.7 (2.1) 29.9 (2.5) 13.1 (1.6) Married, spouse present 21.9 (0.9) 27.6 (1.1) 11.0 (0.6) Family status Unmarried, living without child 33.9 (1.3) 32.5 (1.6) 13.9 (0.5) Unmarried, living with child 33.5 (2.3) 35.5 (2.2) 19.5 (1.3) Married, living without child 29.0 (1.2) 29.6 (1.6) 12.2 (0.9) Married, living with child 20.4 (1.0) 26.9 (1.0) 10.8 (0.7) Pay grade E1 E (1.3) 32.5 (2.1) 16.6 (1.0) E4 E (1.0) 30.9 (1.5) 12.7 (0.9) E7 E (0.8) 26.3 (0.9) 8.5 (0.6) W1 W (1.9) 23.4 (1.3) 9.5 (1.3) O1 O (1.2) 29.3 (2.0) 9.7 (1.7) O4 O (1.5) 22.5 (1.7) 9.1 (1.1) Total DoD 27.9 (0.9) 30.0 (1.3) 12.5 (0.5) Note: Table entries are percentages, with SEs in parentheses.

5 Stress and Job Performance: DoD Survey Findings (single parents) had the highest utilization rate of all sociodemographic groups, followed by women, those in the lowest pay grade, those 20 or younger, and those of Other race/ethnicity. Approximately 26% of respondents meeting criteria for further mental health evaluation and 43% of those who felt a need for treatment actually received care. Less than one-half (46%) of those needing further mental health evaluation perceived a need for mental health treatment (data not shown). Association between Stress and Mental Health Table III shows that the most frequently reported stress level for both work and family was a lot and that the most notable differences between work- and family-related stress were at the highest levels of stress. Among those in need of further mental health evaluation in the previous month, 60.3% reported high levels of occupational stress and 38.2% reported high levels of family stress. Respondents in need of further mental health evaluation were approximately three times as likely to report higher levels of stress associated with both work and family in the past year as those who did not need such evaluation. Approximately 19% of all respondents indicated that they had perceived a need for mental health treatment in the previous 12 months. Those who perceived the need for mental health treatment were more than twice as likely to report high stress at work and more than three times as likely to report high stress in their family life as those not perceiving a need for treatment. Table IV presents the percentage distribution of days in the previous month on which poor mental health limited respondents usual activities. Almost 16% of all respondents reported having at least 1 such day in the past month. Personnel whose usual activities had been limited by poor mental health were twice as likely to report a high level of stress at work and 2.5 times as likely to report a high level of stress in their family life as those whose activities were not limited. To further address the third aim and examine the overall impact of stress on mental health, we compared respondents reporting high levels of stress with those who had less (i.e., moderate) or no stress (Table V). Among personnel reporting a great deal of occupational or family stress in the past months, approximately 50% were in need of further mental health evaluation in the past month, 34% perceived a need for mental health treatment in the past year, almost 28% reported that poor mental health limited their usual activities in the past month, and almost 21% received mental health treatment in the past year. These percentages were more than three times those of individuals reporting less stress. The pattern held for both high occupational stress and high family stress groups separately, although respondents reporting high occupational stress were significantly more likely than those reporting high personal or family stress to have mental health problems and to have received treatment. Association between Job Performance and Stress Of the 32.3% of personnel reporting the highest level of stress at work and the 18.7% reporting the highest level of stress in the family, 28% reported that these stressors interfered a lot with the performance of their military job (data not shown). Table VI addresses the fourth study aim and shows the percentages of military personnel who experienced productivity loss at work for at least 4 days during the past year. Findings are displayed for all military personnel, personnel with no stress to moderate levels of stress, and personnel in the high-stress group (i.e., those who experienced a lot of stress at work or in personal relationships in the past 12 months). The type of productivity loss most frequently reported by all personnel was working below the normal performance level (15.9%), followed by leaving work early (14.0%). Compared with military personnel, who perceived low to moderate levels of stress, those who experienced high levels of occupational or family stress were more likely to experience productivity loss. Overall productivity loss was greater for the group that experienced more stress; the high-stress group was much more likely to report more days affected in the past 12 months in all domains of job performance. Personnel in the high-stress group were more than twice as likely as those in the moderate-to-low stress group to report 4 or more days of working below their normal performance level (24.3% vs. 10.5%), being late for work by 30 minutes or more TABLE III LEVELS OF PERCEIVED OCCUPATIONAL AND FAMILY STRESS AMONG ACTIVE DUTY PERSONNEL MEETING CRITERIA FOR NEEDING FURTHER MENTAL HEALTH EVALUATION AND AMONG THOSE WHO PERCEIVED A NEED FOR MENTAL HEALTH TREATMENT Type and Level of Stress Needed Further Mental Health Evaluation, Past 30 Days (n 3,040) Did Not Need Further Mental Health Evaluation (n 8,250) Perceived Need for Mental Health Treatment, Past 12 Months (n 2,287) Did Not Perceive Need for Mental Health Treatment (n 9,919) Occupational stress A lot 60.3 (1.6) 21.7 (1.0) 58.3 (1.6) 26.3 (1.3) 32.3 (1.3) Some 22.7 (1.1) 33.3 (0.6) 26.4 (1.0) 31.4 (0.6) 30.3 (0.6) A little 11.1 (0.9) 29.6 (0.9) 12.0 (1.2) 27.4 (0.9) 24.4 (0.8) None at all 6.0 (0.8) 15.4 (1.0) 3.3 (0.4) 14.9 (1.0) 13.0 (0.8) Family stress A lot 38.2 (0.8) 11.4 (0.5) 42.8 (1.1) 13.1 (0.4) 18.7 (0.5) Some 26.6 (0.7) 23.9 (0.5) 28.0 (1.0) 24.1 (0.4) 24.9 (0.4) A little 20.2 (0.8) 37.7 (1.0) 18.9 (1.0) 36.1 (0.9) 32.5 (0.8) None at all 15.0 (0.9) 27.0 (0.9) 10.3 (0.6) 26.7 (1.0) 23.9 (0.8) Total 27.9 (0.9) 72.1 (0.9) 18.7 (0.6) 81.3 (0.6) Note: Table entries are column percentages, with SEs in parentheses. Total DoD

6 854 Stress and Job Performance: DoD Survey Findings TABLE IV LEVELS OF PERCEIVED STRESS AT WORK AND IN FAMILY LIFE IN THE PAST 12 MONTHS, BY DAYS OF LIMITED ACTIVITY DUE TO POOR MENTAL HEALTH Type and Level of Stress None (n 10,516) 1 3 Days (n 1,208) Days Usual Activities Limited by Poor Mental Health 4 10 Days (n 319) 11 or More Days (n 355) 1 or More Days (n 1,882) Stress at work A lot 27.4 (1.3) 50.4 (2.0) 65.3 (4.1) 76.5 (3.2) 58.4 (1.5) Some 31.0 (0.5) 30.6 (1.7) 24.2 (4.3) 17.1 (2.6) 26.6 (1.2) A little 26.6 (0.8) 16.2 (1.5) 8.6 (1.3) 5.4 (1.3) 12.6 (1.1) None at all 14.9 (0.9) 2.9 (0.7) 2.0 (1.0) 1.0 (0.8) 2.3 (0.4) Stress in family A lot 14.8 (0.5) 33.6 (1.5) 42.2 (2.5) 55.3 (2.3) 39.7 (1.2) Some 24.6 (0.5) 28.4 (1.5) 27.5 (2.7) 20.0 (2.0) 26.5 (0.9) A little 34.6 (1.0) 25.3 (1.2) 17.7 (2.1) 13.3 (1.7) 21.4 (0.6) None at all 26.1 (1.0) 12.7 (1.1) 12.6 (2.9) 11.4 (2.2) 12.4 (0.7) Total DoD 84.2 (0.5) 9.7 (0.4) 2.8 (0.2) 3.3 (0.2) 15.8 (0.5) Note: Table entries are column percentages, with SEs in parentheses. TABLE V OCCUPATIONAL AND FAMILY STRESS LEVELS OF ACTIVE DUTY PERSONNEL WITH MENTAL HEALTH PROBLEMS AND RECEIPT OF MENTAL HEALTH TREATMENT Occupational Stress Family Stress Occupational or Family Stress Mental Health Problem/Treatment High Moderate to None High Moderate to None High Moderate to None Total Need mental health evaluation 56.4 a (1.4) 21.2 (0.8) 51.8 a (0.8) 16.4 (0.6) 49.9 a (0.9) 13.4 (0.5) 27.9 (0.9) Do not need mental health evaluation 43.6 a (1.4) 78.8 (0.8) 48.2 a (0.8) 83.6 (0.6) 50.1 a (0.9) 86.6 (0.5) 72.1 (0.9) Perceived need for treatment 42.8 a (1.2) 13.1 (0.5) 33.6 a (1.2) 11.5 (0.5) 34.0 a (1.0) 8.7 (0.4) 18.7 (0.6) No perceived need for treatment 57.2 a (1.2) 86.9 (0.5) 66.4 a (1.2) 88.5 (0.5) 66.0 a (1.0) 91.3 (0.4) 81.3 (0.6) Activities limited by poor mental health 33.5 a (1.0) 11.7 (0.5) 28.5 a (1.0) 9.7 (0.4) 27.7 a (0.8) 8.0 (0.4) 15.8 (0.5) Activities not limited 66.5 a (1.0) 88.3 (0.5) 71.5 a (1.0) 90.3 (0.4) 72.3 a (0.8) 92.0 (0.4) 84.2 (0.5) Received treatment 27.5 a (1.2) 9.1 (0.4) 19.9 a (1.1) 9.0 (0.4) 20.7 a (1.1) 7.2 (0.4) 12.5 (0.5) Did not receive treatment 72.5 a (1.2) 90.9 (0.4) 80.1 a (1.1) 91.0 (0.4) 79.3 a (1.1) 92.8 (0.4) 87.5 (0.5) Note: Table entries are column percentages (with SEs in parentheses). a t test between high- and moderate to no-stress groups significant at p (11.9% vs. 5.6%), not coming in to work because of illness or injury (8.1% vs. 3.8%), and being hurt in an accident on the job (2.6% vs. 0.8%). Stress, Mental Health, and Job Performance Table VI also addresses the fifth study aim and presents the types of productivity loss reported by those needing further mental health evaluation, those who perceived a need for mental health treatment in the past year, those whose usual activities were limited by poor mental health for at least 1 day in the past month, and those who received mental health treatment in the past year. As shown, personnel with any of the mental health problems measured, including those who received mental health treatment, were much more likely than the total military population to have experienced productivity loss on all of the job performance variables. Among personnel with any of the mental health problem variables, those with high levels of occupational or family stress were more likely than those reporting less stress to have been late for work or to have worked below their normal performance level. Among those who met criteria for needing further mental health evaluation or who perceived a need for mental health treatment, those in the high-stress group were also more likely to have not come to work because of illness or injury 4 days or more in the past year than those with less stress. The highest rate of productivity loss (39.8% working below normal performance level) was found among those whose usual activities had been limited by poor mental health and who reported high occupational or family stress. The greatest percentage of personnel not coming to work because of illness or injury was found among those who received mental health services, especially those in the high-stress group (16.5%). Discussion This study has provided support for the hypotheses that high levels of stress reported by active duty military personnel are associated with mental health problems, productivity loss, and receipt of mental health treatment. These findings are consistent with an extensive body of research that shows a strong relationship between high levels of stress and impaired occupational functioning, including increased absenteeism, lower levels of productivity, and more interpersonal problems. 7,12,18,19 They also support findings from civilian literature showing that less occupational stress is predictive of positive mental health and job performance and of decreased sickness absence rates. 20,21

7 Stress and Job Performance: DoD Survey Findings 855 TABLE VI RATES OF PRODUCTIVITY LOSS AFFECTING 4 OR MORE DAYS, BY STRESS LEVEL AMONG ALL PERSONNEL AND THOSE WITH MENTAL HEALTH PROBLEMS OR TREATMENT Group/Problem All Personnel Moderate, Low, or No Stress High Level of Stress All personnel Late for work by 30 minutes or more 8.1 (0.6) 5.6 a (0.4) 11.9 (1.1) Left work early 14.0 (0.6) 11.5 a (0.5) 17.9 (0.9) Hurt in an on-the-job accident 1.5 (0.2) 0.8 a (0.1) 2.6 (0.4) Worked below normal performance level 15.9 (0.8) 10.5 a (0.6) 24.3 (1.2) Did not come into work because of illness or injury 5.4 (0.3) 3.8 a (0.3) 8.1 (0.4) Need for mental health evaluation (past month) Late for work by 30 minutes or more 12.5 (1.4) 9.2 a (1.4) 13.8 (1.5) Left work early 19.2 (1.2) 16.2 a (1.5) 20.6 (1.3) Hurt in an on-the-job accident 4.0 (0.8) 3.0 a (0.9) 4.4 (0.9) Worked below normal performance level 26.9 (1.8) 17.4 a (1.8) 30.9 (2.1) Did not come into work because of illness or injury 9.6 (0.8) 7.0 a (1.2) 10.6 (1.0) Perceived need for mental health treatment (past 12 months) Late for work by 30 minutes or more 13.8 (1.5) 10.4 a (0.9) 15.1 (2.0) Left work early 21.4 (1.0) 19.2 (2.2) 22.3 (1.3) Hurt in an on-the-job accident 3.9 (0.7) 2.3 (0.7) 4.5 (1.0) Worked below normal performance level 30.5 (1.9) 22.6 a (1.8) 33.8 (2.3) Did not come into work because of illness or injury 11.4 (0.9) 9.1 (1.9) 12.3 (1.2) Usual activities limited by poor mental health ( 1 day in the past 30 days) Late for work by 30 minutes or more 16.7 (1.3) 12.3 a (1.1) 18.7 (2.1) Left work early 23.1 (1.1) 20.7 (2.9) 24.1 (1.3) Hurt in an on-the-job accident 4.8 (0.7) 3.9 (0.7) 5.2 (1.2) Worked below normal performance level 36.5 (1.6) 29.3 a (2.2) 39.8 (2.2) Did not come into work because of illness or injury 11.6 (1.0) 10.3 (1.2) 12.2 (1.5) Received mental health treatment (past 12 months) Late for work by 30 minutes or more 13.1 (1.7) 7.6 a (1.1) 16.0 (2.6) Left work early 21.9 (1.2) 18.0 a (2.1) 24.1 (1.5) Hurt in an on-the-job accident 3.8 (0.8) 3.0 (0.6) 4.3 (1.1) Worked below normal performance level 27.1 (2.6) 16.2 a (2.0) 32.9 (2.9) Did not come into work because of illness or injury 13.7 (1.2) 8.5 a (1.6) 16.5 (1.4) a t test between stress groups significant at p This study has also shown that the youngest and lowestranking personnel have higher levels of stress, more mental health problems, and more productivity loss than older or higher-ranking personnel. Such findings point to the need for the development of coping strategies and stress management techniques early in a service member s military career. A preventive approach was effective in a study of Navy recruits in which a cognitive-behavioral intervention improved functioning and training performance and reduced attrition among recruits with high levels of perceived stress and depression. 22 The findings of strong associations between high levels of occupational and family stress and being either a married service member whose spouse was not present or an unmarried parent suggest a need for further surveillance, education and prevention activities, and policy adjustments (e.g., limiting separations from families for personnel in these high-risk groups). As these groups are also among those who were likely to have worked below normal performance levels and who sought mental health treatment, they constitute an important target population for mitigating psychological morbidity and improving retention of military personnel who experience mental health problems. Indeed, we suggest that because about half of the personnel reporting high levels of occupational or family stress met criteria for needing further mental health evaluation, prevention and intervention efforts geared to personnel reporting the highest levels of stress would be more cost effective than mental health treatment and should be given a high priority for resources in this population. The finding that more than one-quarter of the military population (27.9%) met screening criteria suggesting a need for further mental health evaluation is consistent with findings from a previous population-based health assessment in which 27.4% met criteria for depression using a similar screening instrument (CES-D). 23 In a related study of Navy and Marine Corps personnel, similar psychiatric screening instruments had a positive predictive value of 47% (i.e., personnel meeting criteria on the screening instruments also met clinical diagnostic criteria for a psychiatric disorder in the past year). 24 Extrapolating from these studies, we estimate that approximately 13% of military personnel may satisfy clinical criteria for major depression or anxiety disorder. This may be an underestimate given that the present data were collected before the combat operations in Afghanistan and Iraq (e.g., using a broad definition of mental disorder, Hoge et al. 25 estimated that % of four combat infantry units met screening criteria for depression or anxiety after deployment to Iraq). It should also be noted that we identified respondents who screened positive for depression or anxiety symptoms as need-

8 856 Stress and Job Performance: DoD Survey Findings ing further mental health evaluation to determine whether their symptoms were of clinical significance. That is, the need for further mental health evaluation did not necessarily translate to the need for mental health services; rather, in the present study, it indicated the need for Diagnostic Statistical Manual-IV-based assessments, possibly involving mental health services. Further research into this issue is especially important given the high proportion of personnel who screened positive for the need for further mental health evaluation but who did not feel they needed counseling or therapy. As a first step, it is strongly recommended that a population-based, epidemiological, clinical assessment of mental disorder (similar to what is being done on a national level in the National Comorbidity Survey using the Composite International Diagnostic Interview) be undertaken to more accurately reflect clinically significant disorder and the estimated need for mental health services in the total force. Future iterations of this survey will incorporate measures to facilitate comparisons with national mental health prevalence rates. Limitations Although this study has important advantages notably, its population-based, representative sample of the military and its ability to examine a large number of related variables simultaneously several limitations should be noted when interpreting these findings. Survey results are subject to the potential bias of self-reports, although the questionnaires were anonymous and collected by civilian teams to encourage honest reporting. Other potential limitations include memory errors and low response rates. Keeping the reference period of questionnaire items to the past month when possible and statistically adjusting for potential nonresponse bias helped mitigate these limitations. In addition, although modeled unidirectionally, it cannot be concluded that higher levels of stress are causing mental health problems or reduced performance. It is possible that lower productivity (e.g., frequently working below normal performance level or being hurt on the job more often than others) or the experience of mental health symptoms causes individuals to report higher levels of stress. Regardless of the direction of the relationship, however, it is clear that stress, mental health, and job performance are related in this population. This study shows that service personnel who are experiencing high levels of stress at work, in their personal/family life, or in both of these domains are at increased risk for adverse psychological conditions, which, in turn, could compromise military readiness. Acknowledgments We gratefully acknowledge the assistance of Michael Witt and Luhua Zhao with statistical analysis and of Carol Offen and Cassandra Carter with editing and document preparation, respectively. Data analysis and article preparation were funded by Grant DAMD from the DoD. References 1. Bray RM, Fairbank JA, Marsden ME: Stress and substance use among military women and men. Am J Drug Alcohol Abuse 1999; 25: Hoge CW, Lesikar SE, Guevara R, et al: Mental disorders among U.S. military personnel in the 1990s: association with high levels of health care utilization and early military attrition. 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