STARS: Strategies to Assist Navy Recruits' Success

MILITARY MEDICINE, 172, 9:942, September 2007

CAPT Reg Arthur Williams, NC, USNR (Ret.); Bonnie M. Hagerty, PhD, RN; Adin-Christian Andrei, PhD; Steven M. Yousha, PsyD, LCSW; Richard A. Hirth, PhD.; CAPT Kenneth S. Hoyle, NC USN (Ret.)

The purpose of the Strategies to Assist Navy Recruits' Success (STARS) project, a prospective cluster-randomized intervention trial, was to determine the effects of the BOOT Camp Survival Training for Navy Recruits-A Prescription (BOOT STRAP) mental health intervention on divisions of Navy recruits. A total of 1,199 recruits participated in the study. The intervention was provided weekly during basic training to an entire division. The percentage of recruits separated from the Navy who did not receive the intervention was almost twice as large as compared to the recruits who did receive intervention (10.33% vs. 5.17%; p < 0.05) during surge training. The intervention group recruits developed significantly higher group cohesion, higher scores on problem-solving coping strategies, and higher perceived social support, while reporting lower scores on anger expression coping strategies than the control group recruits. Potential cost savings per year on recruit training were estimated to be $18.6 million. Training facilitators and conducting the group intervention would cost an estimated $1.5 million per year. Building on previous research, the results of this study have the potential to decrease attrition, improve recruit performance levels, and provide a cost-effective method of enhancing recruit retention.

Introduction

This study was part of a larger research program to investigate depression and stress in Navy recruits undergoing 9 weeks of basic training at Great Lakes Naval Recruit Training Command. The first study (Factors Associated with Depression in Navy Recruits) examined predisposing and concomitant factors related to depression in Navy recruits during basic training.1 Building on those results in a second study, we examined the effects of a cognitive /behavioral intervention (called BOOT Camp Survival Training for Navy Recruits- A Prescription (BOOT STRAP))2 on stress, depression, interpersonal factors, and recruit performance outcomes for those recruits deemed "at-risk" (AR) for developing depression during training. Using the BOOT STRAP intervention, recruits learned and practiced strategies for coping, managing emotional responses and thought distortions, interacting with others, and managing stress to help them cope with stress during basic training.

In our earlier study on the effects of the BOOT STRAP intervention,2 we found that recruits not receiving the intervention were more often separated (sent home) from the Navy. By learning to reframe negative thinking, manage emotional reactions and stress, and improve their sense of belonging and camaraderie with their peers, recruits were able to maintain or improve daily functioning and complete basic training. Highly illustrative of the BOOT STRAP intervention impact was the fact that 86% of the AR intervention group, as opposed to only 74% of the AR nonintervention group, and 84% of the not-AR (NAR) comparison group completed the study and successfully graduated from basic training.2

In the current study, the Strategies to Assist Navy Recruits' Success (STARS) project, we explored further the impact of the BOOT STRAP intervention on Navy recruits by examining the effects of the intervention on entire divisions of recruits. Our specific aims were to: (1) further refine the BOOT STRAP intervention based on our previous research; (2) compare the proportion of recruits who successfully completed basic training in divisions that received the intervention to the proportion in divisions that received no intervention; (3) examine the cost-effectiveness associated with BOOT STRAP for attrition and retention of recruits in basic training; (4) examine the effects of the BOOT STRAP intervention on interpersonal factors, depressive symptoms, coping and group cohesion during recruit training; and (5) among recruits who successfully completed basic training, compare Navy retention of those recruits receiving the intervention with those recruits not receiving the intervention by following them 2 years after completion of basic training.

Methods

The STARS project used a prospective cluster-randomized intervention trial design. Eight division pairs were randomly selected and then, in a subrandomization process, assigned to either the intervention or the nonintervention (control) groups. The intervention was administered to entire divisions. We powered the study based on historical data from the BOOT STRAP study, expecting that -25% of recruits in each division were AR for depression. In the nonintervention group, we assumed a 74% basic training completion rate among those AR for depression. Among those NAR, we assumed 84% basic training completion, and we expected about an 82% basic training overall completion rate. Our power analysis computations and simulations indicated that, assuming equal group sizes, a total number of 1,016 (508 in each of the two groups) was needed to detect a difference of 5.6% (from 82% in the nonintervention group to 87.6% in the intervention group) with 80% power, with a 5% type I error. Computations were carried assuming a one-sided alternative and independent response from individual recruits within each division. Due to the nature of the intervention, however, we expected to observe mild correlations among same division recruits and, furthermore, among responses from those recruits who were in the same intervention small groups formed during the weekly interventions sessions. To account for the fact that our sample size estimates were conservative due to correlation issues described above, an increase of 10% in the estimated sample size was allowed, leading to an estimated sample size of 1,120 recruits (560 in each group).

The study sample consisted of 1, 199 Navy recruits who underwent a 9-week period Of basic fraining at Great Lakes Naval Recruit Training Command. They were grouped in 16 divisions (8 pairs of intervention-control divisions) that were randomly selected and assigned for this study over a 28-month accrual period. Recruit demographics and background characteristics are presented in Table I. Males comprised 75.5% and females represented 24.5% of the sample. The mean age in the intervention divisions was 19.91 years (SD = 2.91 years), not significantly different from the control divisions' mean age of 19.62 years (SD = 2.48 years). There were no statisticaUy significant associations between the intervention and control groups in demographic and background characteristics, as well as there being no significant difference from the historical active duty Navy saUors in race/ethnic background (χ^ sup 2^ = 1.9, df= 5,p = 0.86).

Measures

Beck Depression Inventory, Second Edition (BDI-II)

This 21 -item self-report measure assesses severity of affective, cognitive, motivational, vegetative, and psychomotor aspects of depression in adults and adolescents.3 Internal consistency has been reported as 0.92 to 0.93. Test-retest correlation, based on a sample of depressed outpatients, was 0.93 (p

Perceived Stress Scaie (PSS)

This 14-item measure uses a 5-point Likert-type scale to examine the degree to which situations in one's life are appraised as stressful over the past month. The PSS shows adequate reliability (0.85 coefficient a) and research supports concurrent and predictive validity and internal and test-retest reliabüity.4 In the current study, the adjusted coefficient α was 0.83 at baseline and 0.80 at study week 9.

Interpersonal Relationship Inventory

The Interpersonal Relationship Inventory is a 39-item Likerttype measure comprised of three separately scored subscales: social support (perceived avaüabüity or enactment of helping behaviors by persons with whom one is engaged in relationships), reciprocity (perceived avalablity or exchange of help), and conflict in interpersonal relationships (perceived discord and stress in relationships).5 Internal consistency reliabüity of the three subscales has been reported to range from 0.83 to 0.925 as well as 0.93. 6 In the current study, the adjusted Cronbach's a coefficients for the subscales ranged from 0.90 to 0.83 at baseline and 0.91 to 0.86 at week 9.

Sense of Belonging Inventory-Psychological (SOBI-P)

Sense of belonging is the experience of meaningful personal involvement in a system or environment.7 The SOBI-P consists of a scale that measures the psychological experience (18 items) of sense of belonging. The SOBI-P has good reliability with an a coefficient of 0.93.6·8 Test-retest reliability over an 8-week period was 0.84. Content and construct validity (factor analysis, contrasted groups, and correlations with measures of similar constructs) have also been demonstrated.8 The adjusted Cronbach's a coefficient was 0.93 at baseline and 0.95 at study week 9.

Coping Styles Questionnaire (CSQ)

This 52-item scale captures respondents' usual coping styles, defining a problem dealt with recently, including its outcome and state of resolution, and items devoted to exploring how the respondent approached and dealt with the stated problem. The subscales of the CSQ consist of problem-solving, negative cognition, anger expression, and distraction coping styles. Factor analysis supported construct validity9 of the CSQ and correlation patterns between the CSQ and the Coping Inventory for Stressful Situations are consistent with how the coping styles are theoreticaliy defined.9"11 In this project, the adjusted Cronbach's a coefficient for the subscales ranged from 0.84 to 0.70 at baseline and 0.88 to 0.68 at week 9.

Perceived Cohesion Scale (PCS)

Perceived cohesion, a 6-item scale, is defined as "an individual's sense of belonging to a particular group and his or her feelings of morale associated with membership in the group."12 The cohesion model was testing under confirmatory factor analysis, yielding a statistically strong model fit, with strong correlations and goodness-of-fit indicators.12·13 In the current study, the adjusted coefficient a was 0.92 at baseline and 0.94 at study week 9.

BOOT STRAP Weekly Report (WR)

The self-report BOOT STRAP WR was used to record a recruit's perceived average degrees of emotional reactivity and stress level over the past week on separate 0 to 100 scales, as well as the degree of helpfulness of the BOOT STRAP strategies. The WR also has questions focusing on the recruits' activities over the past week, and people with whom they may have communicated.

Procedure

The study was approved by the Institutional Review Board Health, University of Michigan (Ann Arbor, Michigan) and the Clinical Investigation Institutional Review Board at the National Naval Medical Center (Bethesda, Maryland); the study was reviewed by the Uniformed Services Health Sciences University for compliance of protection of human subjects.

The cognitive-behavioral approach of the BOOT STRAP intervention focused on stress and emotionality, problem solving, stress management, changing thinking associated with depressive symptoms, sense of belonging, and team buüding within the division. It could be administered in a minimal amount of time given fraining time constraints. A pair of co-occurring divisions of Navy recruits was randomly selected from a total of approximately 100 divisions in active fraining during the study accrual period of 28 months and was studied over the entire 9 weeks of basic fraining. The selection process aliowed for confrolirng the confounding variable of different start and end dates of fraining. One division received the intervention, whüe the other served as the control. Each division in each pair was composed of either ali men or approximately half men and half women (mixed). It was assumed that, within each pair, recruits' experience in both divisions were essentialiy the same since they trained together, but were housed in different quarters within the barracks. The two divisions were allowed little communication during training.

Upon agreeing to participate in the study, the intervention and control groups completed the battery of questionnaires. During the first week of fraining and data coliection, each intervention division was divided into five groups of -15 members each. Each group was assigned a group facüitator who was trained in the intervention process by the investigators and the project site director. The control divisions completed the same battery of questionnaires and worked in groups for Navy knowledge assignments, which served as the sham intervention.

Each subgroup facüitator used the Facilitator's Guide, which detailed how to conduct the BOOT STRAP intervention. These facilitators included both officers and civilians with professional mental health experience. Facilitators answered questions, assisted recruits in discussing what strategies worked for them, problems that could be addressed by the specific strategies, and coached on use of the strategies. The recruits were trained not only to apply the skills to themselves, but also to coach each other, which helped foster teamwork.

Each week both the intervention and the control groups recorded their stress level and emotional reactivity to the stress, but only recruits in the intervention group plotted their stress and emotional reactivity in the BOOT STRAP Manual provided to them, and kept track of the strategies they used to reduce their emotional reaction to the stress. The control groups recorded their stress levels and emotional reaction, but they were not plotted and they completed the required questionnaires as the intervention groups.

The project site director circulated among the groups to maintain consistency of application. Postsession debriefings provided feedback to facilitators in an effort to ensure consistency of the intervention protocol and also to track events affecting the division, as well as any obstacles tiiat might interfere with the learning and application of the intervention strategies. The researchers made regular onsite reviews of the groups to ensure consistency. Data were examined to determine whether any facilitated intervention group was significantly different tiian other intervention groups in the number of recruits separated. No differences were found.

Statistical Analyses

The proportions of recruits completing basic training in the intervention and control divisions were compared using χ^ sup 2^ tests for association. Among those who have completed basic training, we compared Navy retention proportions at 2-year postbasic fraining completion using χ^ sup 2^ tests for association. Recruits with a week 1 BDI-II score of at least 18 and a PSS score of at least 30 were classified as being AR for depression and stress. Using the paired t test, we compared week 1 and week 9 BDI-II and PSS scores separately for AR and NAR recruits, in each study arm. We used linear regression models with baseline adjustments to compare week 9 scores in the two study groups for perceived cohesion, social support, anger expression coping styles, and conflict in relationships. Weekly assessed stress scores and emotional reactivity to stress scores were compared in the two study arms using linear mixed models allowing for random intercepts and random study week effects.

Results

The number of recruits starting basic fraining increases during the summer months. During this period, referred to as "surge-time," recruit enrollment rises; thus making basic training completion more competitive. Higher stress levels in a highly competitive environment lead to an increased likelihood of failing to complete basic fraining. During surge time, 94.83% of the 232 intervention division recruits completed basic fraining as compared to 89.67% of the 242 control division recruits, which was statistically significant as revealed by a χ^ sup 2^ test for association [χ^ sup 2^ = 4.38, df = 1, p = 0.036). The percentage of recruits separated from intervention divisions was almost twice as small compared to that in the control divisions (5.17% vs. 10.33%). During surge time, the percentage of intervention recruits separated for psychiatric reasons was 1.2%, more than four times lower than the 5.2% observed in the control recruits. Overall, inclusion of both surge and non-surge-time recruits in the analysis showed a 5.3% separation percentage of intervention divisions, lower than the corresponding 7.8% percentage in the control divisions. However, this is somewhat weaker evidence since during non-surge time, the intervention and control divisions did not present significantly different separation percentages (χ^ sup 2^ = 2.98, p = 0.084).

Those recruits who successfully completed basic framing were followed to determine the Navy retention rates 2 years after basic fraining completion. This follow-up indicated that there was a 1% difference between the intervention and the control divisions, with the intervention recruits being slightly more likely to still be in the Navy (87.5%) than the control recruits (86.5%). This difference was not statistically significant (χ^ sup 2^ = 0.28, N = 1,120, p = 0.60). The 2-year postbasic training Navy retention rates are given in Table II.

We also compared the 2-year Navy retention rates in the two study groups for those recruits classified at being AR for depression at week 1 who had completed basic training. Of the 102 intervention group recruits, 100 (or 98.04%) were still in the Navy at the 2-year time point, compared to 150 (96.77%) of 155 intervention group recruits. This difference was not statistically significant.

Figure 1 illustrates the significant differences between the AR recruits as compared to the NAR recruits [p

Of the total number of 1 , 199 study participants, eight pairs of divisions or 583 were in intervention divisions, while 616 were in control divisions. Of the recruits that refused study participation, 25 were in intervention divisions and 5 were in control divisions.

Of central interest was the intervention impact on study variables, such as perceived cohesion, social support, anger expression coping strategies, and conflict. Four separate linear regression models having each of these variables as outcomes, and adjusting for gender, age, and the corresponding baseline value of interest, are shown in Table III. As such, although both study groups present an increase in perceived cohesion at week 9, as compared to week 1, the increase in the intervention divisions was significantly higher than in the control divisions. The intervention recruits perceived more social support than the control recruits. In addition, the intervention group used less anger expression coping strategies and reported less conflict in relationships.

Mean weekly levels of stress and emotionality scores are shown in Figures 3 and 4. The intervention recruits reported significantly lower self-assessed stress levels (p = 0.02) and significantly lower self-assessed emotional reaction to stress (p = 0.01). In addition, stress level scores were analyzed using linear mixed models with fixed effects for division type, age, gender, baseline stress levels, BDI-II, PSS, SOBP, and Social Support scores and an interaction term between division type and study week number. This model also allows for recruit random intercept and study week slope (time random effect). Detailed model fitting results are shown in Table IV and they point toward a similar behavior in the two study groups, with decreasing stress levels as the basic framing progresses. No significant differences were detected between the two groups at week 9, although the mean score was estimated to be -1.5 points lower (SE = 2.05, t value = 0.77, df= 792, p = 0.44) in the intervention group compared to the control group.

Cost Analysis

To help understand the economic impact of the study intervention and the potential full implementation of the BOOT STRAP program for all Navy recruits, we conducted an analysis of the cost per avoided separation and the net cost to the Navy. The assumptions underlying this cost analysis are summarized in Table V.

We used the BOOT STRAP cost and effectiveness estimates from the study to project the economic consequences of offering the program to all recruits trained during a year. The 1-year materials cost to deliver the BOOT STRAP intervention- estimated as $8.75 per group for the BOOT STRAP Manual and Facilitator's Guide- would translate into $19,705 for the year for full implementation. Assuming that the typical facilitator was at the rank of lieutenant, the estimated 2,252 total groups resulted in a cost of $1,418,790 ($630 per group). The cost to train these 125 facilitators to conduct the BOOT STRAP intervention would be $45,160. In addition, one full-time project manager is assumed at a cost of $60,238. This would create a total cost of full implementation of $1,543,893. Using the more conservative estimate of preventable separation of recruits of 2.5%, the total costs per prevented separation would be $1,567 assuming hiring only one project manager to supervise the 125 facilitators. If a second project manager were required to operate the program at the proposed scale, the total costs per prevented separation would only increase to $1,628. Thus, under full implementation, fixed costs could be spread much more effectively, potentially reducing cost per prevented separation to under $2,000.

Returns on investment are associated with replacing the separated recruits and bringing another recruit to Great Lakes and training. Costs to bring a recruit to Great Lakes vary from year to year based on the number of total recruits. Using a midpoint estimate of $1 1,000, the total recruitment and training costs to replace a separated recruit would be $18,928. Therefore, the potential cost savings to the Navy for full implementation was estimated as $10,835,000 using just the costs of bringing a recruit to the gate of Great Lakes. The cost savings is estimated as $18,644,080 using the costs of bringing the recruits to the gate and the costs associated with the 9 weeks of basic training.

Discussion

Completion of recruit training was the major outcome addressed in this study. During the surge periods of recruit training (summer months), there were significantly larger percentages of recruits from the intervention division, compared with the control divisions, who successfully completed training. Although comparison of intervention and control divisions over a complete 2-year period of data collection did not indicate significant differences in percentage of separation, there was 3.4% lower separation in the intervention divisions. This percentage represents 1,120 recruits who remained in the Navy, decreasing costs of separation. Characteristics of the surge period of recruit training may have influenced the results.

One concern was that recruits who may succeed with support from the BOOT STRAP intervention may fail later during the first tour of duty. There was no evidence in the data that this occurred. In fact, there was a nonsignificant 1% difference in favor of the intervention recruits in terms of the likelihood of recruits who completed basic training being retained in the Navy for 2 years.

Although separation rates were not significantly different between the two groups overall, tiiere were significant changes in those variables that support recruits and promote their success. It is plausible that improvements in group cohesion, social support, and use of coping strategies could be associated with indicators of success such as academic test scores and quality of physical performance. This is an area for future research.

Group cohesion is a central goal of recruit fraining. This characteristic is vital for performing tasks that require teamwork for mission success. Likewise, the perception of social support provides a solid and supportive backdrop for dealing with stressors, including recruit framing. Upon completion of recruit fraining, the intervention divisions had significantly higher rates of group cohesion and perceived social support scores. These results suggest that the BOOT STRAP intervention is useful for promoting teamwork for ali recruits, not just those AR for separation.2

At the conclusion of the 9 weeks of fraining, the intervention divisions reported lower feelings of being stressed, as well as decreased emotional reactivity to stressors. Although not statistically significant, these changes certainly have a positive practical importance. Feelings of mud stress are considered helpful to deal with a situation through activation of neuroendocrine and autonomic nervous systems. Moderate or high stress, however, interferes with an individual's cognitive abilities to respond and problem solve through taxing situations and affects behavioral responses. High levels of stress can interfere with judgment and prevent an immediate, thoughtful response and subsequent activation of necessary and appropriate behaviors to deal with the situation. Thus, an intervention that decreases stress and emotional responses may improve the sailor's ability to function in difficult situations.

The intervention divisions demonstrated significant improvement in how the recruits coped with stress. The intervention recruits scored significantly higher in problem-solving coping and significantly lower in use of anger expression. Lower angercoping scores in the intervention divisions might improve interpersonal relationships, diminish conflict, and promote an environment in which helpful coping strategies can be used. In a previous study with Navy recruits,2 higher conflict was related to separation from the Navy; conflict is antithetical to recruit training goals.

Similar to our previous intervention study,2 there were significant differences in BDI scores and PSS scores between the AR intervention group recruits and the control group recruits as compared to the NAR recruits in the intervention and control groups. Likewise, scores decreased significantly during the duration of fraining, yet the intervention and control groups were not significantly different at the end of fraining. The success of completing basic fraining appears to reduce depressive and stress symptoms comparing week 1 with week 9. It is clear that success in performance and connections made during fraining can have important impact on personal struggles. The BOOT STRAP intervention appears to be associated with improvement on factors that can influence success. Cost analysis of data from this study indicates that the intervention could save the Navy money by retaining recruits, even after costs of implementation.

One limitation of the study is the possibility that the study was underpowered with the number of clusters (divisions) we could include in the study due to the limit of funding and time for the study. It is possible that if additional divisions could have been included, some of the nonsignificant findings may move to significant differences between the intervention and control groups.

Given the success of the BOOT STRAP intervention with Navy recruits, it now needs to be tested with other populations to examine generalizability and effectiveness, in addition to other branches of the military. It may be particularly helpful for adolescents and college students who are dealing with stressors such as leaving home, academic achievement, and financial concerns. Its unique approach, using a simple booklet and coaching, makes this intervention an attractive option for promoting better functioning for dealing with stress in a cost-effective way.

Acknowledgments

We extend appreciation to the Great Lakes Naval Recruit Command, Navy Training Center, Naval Hospital, Great Lakes, the numerous Navy sailors who participated in our studies, and the School of Nursing, University of Michigan for their support of this research project. In addition, we thank Ms. Sara Peth for her assistance in preparation of this article.

The Department of Defense, TriService Nursing Research Program sponsored this research (TSNRP NO 1-002 MDA 905-01- 1 -TSNOl) at the Uniformed Services University of the Health Sciences.

References

1. Williams RA, Hagerty BM, Yousha SM, Hoyle KS, Oe H: Factors associated with depression in Navy recruits. J Clin Psychol 2002; 58: 323-37.

2. Williams RA, Hagerty BM, Yousha S, Horrocks J, Hoyle K, Liu D: Psychosocial effects of the Boot Strap intervention in Navy recruits. Milit Med 2004; 169: 814-20.

3. Beck AT, Steer RA, Brown GK: BDI-II Manual. San Antonio, TX, The Psychological Corporation, 1996.

4. Cohen S. Kamarck T, Menneistein R A global measure of perceived stress. J Health Soc Behav 1983; 24: 385-96.

5. Tilden VP, Nelson C, May BA: The Interpersonal Relationships (IPR) Inventory: development and psychometric characteristics. Nurs Res 1990; 39: 337-43.

6. Hagerty BMK, Williams RA. Coyne JC, Early MR Sense of belonging and indicators of psychological and social functioning. Arch PsychIatr Nurs 1996; 10: 235-44.

7. Hagerty BMK, Lynch-Sauer J, Patusky K, Bouwsema M, Collier P: Sense of belonging: a vital mental health concept. Arch Psychiatr Nurs 1992; 6: 172-7.

8. Hagerty BMK, Patusky KL: Developing a measure of sense of belonging. Nurs Res 1995; 44: 9-13.

9. Williams RA: Psychometrics of the Coping Styles Questionnaire(CS9).Ann Arbor, MI, University of Michigan, 1997.

10. Endler NS, Parker MA: CISS: Coping Inventory for Stressful Situations Manual, North Tonawanda, NY, Multi-Health Systems, 1990.

11. Endler NS, Parker MA: Multidimensional assessment of coping: a critical evaluation. J Pers Soc Psychol 1990; 58: 844-54.

12. Bollen KA, Hoyle RH: Perceived cohesion: a conceptual and empirical examination. Soc Forces 1990; 69: 479-504.

13. Cohen NJ, Coyne JC, Duvall JD: Parents' sense of "entitlement" in adoptive and nonadoptive families. Fam Process 1996; 35: 441-56.

Guarantor: CAPT Reg Arthur Williams, NC USNR (Ret.)

Contributors: CAPT Reg Arthur Williams, NC USNR (Ret.)*; Bonnie M. Hagerty, PhD RN[dagger]; Adin-Cristian Andrei, PhD[double dagger]; Steven M. Yousha, PsyD LCSW§; Richard A. Hirth, PhD¶; CAPT Kenneth S. Hoyle, MC USN (Ret.)||

* Professor, School of Nursing and Psychiatry, Medical School, University of Michigan, 400 North Ingalls, Room 4352, Ann Arbor, MI 48109.

[dagger] Associate Professor, School of Nursing, University of Michigan, 400 North Ingalls, Room 4350, Ann Arbor, MI 48109.

[double dagger] Assistant Professor, Department of Biostatistics and Medical Informatics, University of Wisconsin-Madison, K6/428 CSC 600 Highland Avenue, Madison, WI 53792-4675.

§ Project Site Director, University of Michigan, 7832 Karlov Avenue, Skokie, IL 60076.

¶ Associate Professor, School of Public Health, University of Michigan, Health Management and Policy, M3156 SPH II, Ann Arbor, MI 48109.

|| 24395 Hilton Place, Gaithersburg, MD 20882-3524.

The information or content and conclusions in this article do not necessarily represent the official position or policy of, nor should any official endorsement be inferred by, the TriService Nursing Research Program, the Uniformed Services University of the Health Sciences, the Department of Defense, Department of the Navy, or the U.S. government.

This manuscript was received for review in December 2005. The revised manuscript was accepted for publication in May 2007.

Copyright Association of Military Surgeons of the United States Sep 2007