Body Mass Index Effect on Health Service Utilization Among Active Duty Male United States Army Soldiers
Authors: Shiozawa Brian , Madsen Cathaleen , Banaag Amanda , Patel Avni , Koehlmoos Tracey 
Published: February 2019

Abstract

Introduction
Obesity and overweight, defined as body mass index (BMI) of 30.0 and above or 25.0–29.9, respectively, are of significant concern to the military population, due to their associated comorbidities and potential for impaired readiness. In 2016, the US Army reported a prevalence of 17.3% obesity and 52.9% overweight among soldiers, despite both physical demands of the job and Department of Defense (DoD) guidelines which recommend separation from service for those unable to meet body composition standards. This study examines the health service utilization of active duty, male Army soldiers in order to determine the prevalence of obesity and overweight and to estimate the effects of these conditions on readiness.

Materials and Methods
This was a cross-sectional study utilizing fiscal year (FY) 2015 TRICARE claims and military treatment facility (MTF) encounter data obtained from the Military Health System Data Repository (MDR), for 467,732 US Army male Soldiers on active duty. We obtained basic demographic information (age, race, and rank) from the Defense Enrollment Eligibility Reporting System (DEERS). Next, we calculated BMI for this cohort by matching patients to their vital statistics of height and weight measurements. Finally, we obtained their health service utilization by querying and matching patients to their healthcare claims in 2015 by major diagnostic category.

Findings
More than half (51.2%) of subjects had overweight, 28.9% had normal weight, 19.7% had obesity, and less than 1% had underweight. Soldiers with overweight and obesity were most common among the 25–34 years age range and enlisted ranks. Normal weight and underweight soldiers had a median of 7 healthcare visits in FY 2015, compared with 8 for soldiers with overweight and 12 for those with obesity. Soldiers with obesity, but not overweight, had a disproportionately greater number of healthcare encounters for diagnostic categories including musculoskeletal; mental health; ear, nose, and throat; and endocrine system. In contrast, soldiers with obesity had disproportionately fewer healthcare encounters for multiple significant trauma and for infectious and parasitic diseases.

Conclusions
More than 70% of soldiers had overweight or obesity in FY 2015, showing the highest prevalence yet measured for these conditions. Previous reports of lower prevalence may be due to the inclusion of circumference-based body fat assessments, which have been criticized for inaccuracy. In our study, disproportionately high health service use by soldiers with obesity suggests decreased readiness, as these soldiers may experience both poorer health and lose necessary training time due to increased provider visits. Proportional usage by soldiers with overweight suggests the protective effect of regular physical activity, though these soldiers should be monitored to ensure that they do not progress to obesity. Additional research should establish the burden of cost, absenteeism, and presenteeism of obesity on the MHS, as well as developing more appropriate field tests for body fat assessment and BMI standards to better support military readiness.