Risk factors for musculoskeletal-related occupational disability among US Army soldiers

INTRODUCTION

Minimising temporary and permanent disability associated with musculoskeletal conditions (MSK-D) is critical to the mission of the US Army. Prior research has identified potentially actionable risk factors for overall military disability and its MSK-D subset, including elevated body mass index, tobacco use and physical fitness. However, prior work does not appear to have addressed the impact of these factors on MSK-D when controlling for a full range of factors that may affect health behaviours, including aptitude scores that may serve as a proxy for health literacy. Identifying risk factors for MSK-D when providing control for all such factors may inform efforts to improve military readiness.

METHODS

We studied 494 757 enlisted Army soldiers from 2014 to 2017 using a combined medical and administrative database. Leveraging data from the Army's digital 'eProfile' system of duty restriction records, we defined MSK-D as the first restriction associated with musculoskeletal conditions and resulting in the inability to deploy or train. We used multivariable Cox proportional hazards regression to assess the associations between incident MSK-D and selected risk factors including aptitude scores, physical fitness test scores, body mass index and tobacco use.

RESULTS

Among the subjects, 281 278 (45.14%) experienced MSK-D. In the MSK-D hazards model, the highest effect size was for failing the physical fitness test (adjusted HR=1.63, 95% CI 1.58 to 1.67, p<0.001) compared with scoring ≥290 points.

CONCLUSIONS

The analysis revealed the strongest associations between physical fitness and MSK-D. Additional efforts are warranted to determine potential mechanisms for the observed associations between selected factors and MSK-D.

Rates of Lapidus Procedures in the US Military Before and After the Advent of and Advocacy for Tri-Plane Lapidus Corrective Surgery

Tri-plane corrective Lapidus surgery has been described as advantageous with respect to its anatomic basis and outcomes. Because the procedure has been broadly publicized, changes in overall Lapidus procedure rates due to increased numbers of patients opting for the tri-plane approach could have occurred. Data supporting this possibility appears lacking. We employed official personnel and health records of the total active-duty US military to conduct a retrospective cohort study of Lapidus surgery rates before and after the advent of the tri-plane corrective Lapidus procedure. Least-squares and locally-weighted scatterplot smoother regression functions were used to confirm time trends. Sociodemographic and occupational traits of Lapidus patients were compared using 2-sided t tests and chi square tests. Lapidus surgery rates among hallux valgus patients decreased during 2014 to 2016 and increased during 2017 to 2021. While multiple factors might explain these trends, they coincide with the advent of and advocacy for tri-plane Lapidus surgery. The results support the possibility that its rise influenced overall Lapidus rates in this population. As these findings represent limited evidence of such an influence, further research is required to confirm a causal link. If such a link is found, and if the ongoing research suggests that superior outcomes are associated with tri-plane Lapidus surgery, substantial implications could exist for this population. Benefits might include enhanced medical readiness due to the importance of lower extremity function during military duties. Additional research is needed to confirm the impact of the procedure and to determine whether Lapidus surgery rate patterns in civilian populations mirror these findings.

An investigation of sickle cell trait, body mass index, and fitness in relation to venous thromboembolism among African American adults

BACKGROUND

The relationships of sickle cell trait (SCT), body mass index (BMI), and physical fitness to venous thromboembolism (VTE) in young adults have received little attention.

OBJECTIVES

To test for associations among SCT, BMI, fitness, and VTE.

PATIENTS/METHODS

We conducted a retrospective cohort study of 48,316 SCT-tested, African American individuals in the US Army during 2011-14. We used Cox proportional hazards models to compute adjusted hazards of deep vein thrombosis (DVT) and pulmonary embolism (PE) associated with selected factors.

RESULTS

Incidence rates of DVT and PE were 1.09 and 0.91 cases per 1000 person-years, respectively. Adjusted hazard ratios (aHRs) for DVT for men and women with SCT were 0.9 (95% confidence interval [CI]: 0.4-2.0; P = .711) and 1.51 (CI: 0.7-3.2; P = .274), respectively. aHRs for PE for SCT+ men and women were 1.1 (CI: 0.5-2.4; P = .773) and 1.2 (CI: 0.5-3.1; P = .650), respectively. Low physical fitness was associated with DVT and PE in women (DVT aHR =3.1; CI: 1.4-6.5; P = .004; PE aHR =4.6; CI: 2.1-9.9; P < .001) and DVT in men (aHR =2.2; CI: 1.0-4.6; P = .048). Recent weight gain of 1 or more BMI points was associated with DVT in men (aHR =1.8; CI: 1.1-2.8; P = .017).

CONCLUSIONS

We found no evidence of increased VTE risk associated with SCT in this population. However, lower fitness levels and BMI increases were so associated.