A summary of the U.S. Marine Recruit Assessment Program (RAP) procedures and survey from 2003 to 2021

The Recruit Assessment Program (RAP) is a cross-sectional, baseline survey of U.S. Marine recruits administered at Marine Corps Recruit Depot, San Diego. This report presents RAP study procedures and survey content that was administered to 229,015 participants between 2003 and 2021. Self-reported data were collected on recruit demographics, physical and mental health, adverse life experiences, lifestyle and risky behaviors, and substance use. In 2013, the survey was updated to remove questions with other linkable and reliable sources and those with low completion rates and low relevance to Marine health research; the removal of these items allowed for the addition of instrument measures for major depression, post-traumatic stress disorder, anger, and resilience with no significant change to overall survey length. Average completion rates are approximately 95%. Multiple studies have shown the utility of RAP data collected thus far as a robust data repository of pre-service health and behavioral measures.

Studying the Health and Performance of Shipboard Sailors: An Evidence Map

INTRODUCTION

It is estimated that sailors who are assigned to surface ships and submarines are deployed for more than 1 year across their careers and they spend 15% to 23% of their time away from home. Research suggests that shipboard sailors experience rates of behavioral health issues similar to those with ground combat experiences. Despite the rigorous operational tempo and the unique shipboard environment experienced by these service members, little military health research has examined the health outcomes of sailors serving aboard ships. The objectives of this study were to develop an evidence map of the peer-reviewed literature to (1) identify potential threats to the health and readiness of shipboard sailors, (2) identify health and performance issues experienced by this population, and (3) identify gaps in the current peer-reviewed published literature on shipboard health and performance.

MATERIALS AND METHODS

A systematic review of the existing peer-reviewed literature pertaining to the health, experiences, and performance of shipboard service members was conducted. Comprehensive search terms were used to identify articles published between January 2000 and April 2018. Identified articles were subject to a two-level review process. Study characteristics for all articles selected for final review were extracted, and articles were categorized into 13 content areas that were selected a priori. Findings are presented in an evidence map.

RESULTS

The initial literature search yielded 8,858 unique articles, 90 of which were eligible for full review. Most articles primarily examined active duty sailors from the U.S. or other foreign militaries (88.9%). A total of 60 articles (67.8%) included information about the type of ship studied; the most frequently examined were submarines (29.5%) and aircraft carriers (27.9%). Most of the included studies used cross-sectional (63.3%) or longitudinal (24.4%) designs. Only 7.8% (n = 7) of articles described interventions. The most commonly examined focal areas included physical health issues, such as viral infections and injuries (56.7%), and health behaviors, such as substance use/misuse (40.0%). Other frequently addressed content areas were occupational stress (38.9%), interpersonal issues (32.2%), ship conditions (30.0%), and mental health (28.9%). Most articles (73.3%) addressed more than one content area. There was a high degree of variation in the measurement tools used; self-report surveys were the most common (48.9%), followed by objective physical, biological, or cognitive measures (32.2%) and medical and personnel record reviews (31.1%).

CONCLUSIONS

The evidence map identified various gaps in the research pertaining to the health and performance of shipboard sailors. These gaps included a lack of research on the risk factors for common health and performance issues experienced by sailors and on the relationship between stressors of shipboard life and sailors' health, performance, and readiness. The results of this evidence map should be used to inform the development, implementation, and evaluation of interventions to improve the shipboard environment and/or the preventive health behaviors used by sailors while underway or deployed.

A Qualitative Examination of Factors That Influence Sleep Among Shipboard Sailors

INTRODUCTION

Sleep disturbance is prevalent among service members; however, little is known about factors that compromise sleep in unique operational environments, such as naval ships. Given the importance of sleep to health and performance, it is critical to identify both causes and potential solutions to this serious issue. The objective of this qualitative study was to elucidate the barriers to sleep and the strategies service members use to improve their sleep and combat fatigue while living and working aboard ships (i.e., underway).

METHODS AND MATERIALS

Interviews were conducted with 22 active duty service members assigned to sea duty. The semi-structured interview guide assessed the experiences of service members sleeping in shipboard environments. Interview transcripts were analyzed using applied thematic content analysis by two independent coders.

RESULTS

Participants were largely male (77.8%) and enlisted (88.9%). The most common barrier to obtaining sufficient sleep was stress, followed by rotating schedules, and environmental factors (e.g., noise and light). Additionally, many participants reported prioritizing other activities over sleep when off duty. Many participants did not report using any specific strategies to improve their sleep while underway. Among those who did, most described mitigating environmental barriers (e.g., noise-cancelling headphones or sleep masks). However, some participants also acknowledged these strategies are not always feasible, either attributable to cost or because sailors must be able to respond to alarms or commands. Notably, few sailors reported using stress mitigation or relaxation strategies to help sleep. Ingesting caffeine was the only strategy sailors reported using to alert themselves while fatigued.

CONCLUSIONS

Service members reported many unique barriers to sleep in the shipboard environment, yet many did not report the use of strategies to mitigate them. Further, few used alerting techniques when fatigued. This at-risk population could benefit from targeted educational interventions on sleep-promoting behaviors, prioritization of sleep, and fatigue mitigation.

Effect of corn distillers dried grains with solubles and Eimeria acervulina infection on growth performance and the intestinal microbiota of young chicks

Chicks were used to determine whether dietary corn distillers dried grains with solubles (DDGS) may prevent or ameliorate Eimeria acervulina (EA) infection. The experiment had a completely randomized design with a factorial arrangement of 3 diets (inclusion of 0, 10, or 20% DDGS) × 2 challenge treatments: inoculation with distilled water or with 10(6) sporulated EA oocysts. Each treatment was replicated with 8 pens of 5 chicks each. Experimental diets were fed from 7 to 21 d of age. Inoculation occurred on d 10 of age, considered postinoculation (PI) d 0. Feed intake and BW were measured on PI d 0, 7, and 14. Excreta samples were collected on PI d 0, 5 to 10, 12, and 14 to detect oocysts. On PI d 14, mucosal samples were collected for the analysis of bacterial populations by denaturing gradient gel electrophoresis, using the V3 region of bacterial 16S ribosome. The EA challenge reduced (P < 0.001) ADG by 17%, ADFI by 12%, and G:F by 6% from PI d 0 to 7, and by smaller percentages from PI d 7 to 14. Diet and challenge treatments did not interact in the chick performance, so dietary DDGS did not alleviate EA infection. Oocysts in excreta were detected PI only in EA chicks and no dietary effects were found. Cecal bacterial population was changed (P < 0.05) by effect of dietary DDGS and EA infection. The cecal bacterial diversity among chicks within treatments and homogeneity among chicks within treatments were reduced by EA infection (P = 0.02 to 0.001) and increased by feeding 10% DDGS (diet quadratic, P < 0.001). In summary, feeding up to 20% DDGS to young chicks did not prevent or ameliorate EA infection. Changes in cecal microbiota of chicks fed 10% DDGS can be interpreted as beneficial for intestinal health.