Burden and risk factors for Achilles tendinopathy in the military population from 2006 to 2015. A retrospective cohort study

Abstract

BackgroundAnkle-foot conditions are ubiquitous in the US Military. The objective of this study was to evaluate the burden and associated factors of Achilles tendinopathy (AT).MethodsThe Defense Medical Epidemiology Database was used to identify all diagnosed AT in military personnel from 2006 to 2015. Prevalence of AT was calculated and compared by year, service branch, and military rank. Unadjusted and adjusted assessment of injury risk were calculated.ResultsOfficers incurred 37,939 episodes at a prevalence of 17.65 per 1000 (male officers: 18.20 per 1000; female officers: 14.80 per 1000). Among enlisted personnel, there were 116,122 episodes of AT that occurred in 12.22 per 1000 (male enlisted: 12.07 per 1000; female enlisted: 13.22 per 1000). All officer specialties had significantly higher risk of AT episodes compared to the ground and naval gunfire officers (PR: 1.04-1.43), with aviation demonstrating a significant protective effect (PR: 0.65). Among enlisted specialties, maritime/naval specialties had reduced risk (PR: 0.82), with all specialties (except aviation) having increased risk of AT compared to infantry (PR: 1.07-1.71). There were multiple associated factors identified, to include sex, age, rank, military occupation, and service branch.ConclusionsAT was ubiquitous in the US military, with a progressive increase in prevalence during the study epoch. There were multiple associated factors identified, to include sex, age, rank, military occupation, and service branch. These findings highlight both the need for prophylactic interventions and identification of the populations with the greatest need.

Burden and risk factors for Achilles tendon rupture in the military population from 2006 to 2015: A retrospective cohort study

“…12 Since there were excess zeros noted in the data, with many demographic categories not having any reported outcomes of interest (especially among the smaller subpopulations), assessment of convergence between the unadjusted and adjusted (hurdle) negative binomial regression models were performed. 7 In the hurdle negative binomial regression model, a logistic link is employed to remove demographic categories that contributed no episodes of ATR from the final count model. By doing so, excess zeros that contribute to skewed point estimates, standard errors, and overdispersion are parsed in the truncated regression model.…”

“…In a more recent study of care episodes for Achilles tendinopathy in the military, the prevalence was 17.65 per 1000 in officers and 12.22 per 1000 in enlisted members, with male sex, older age, senior rank, military occupation, and service branch found to be salient associated factors. 7 It is highly plausible that occupation may also be a salient factor for ATR, given that tendinopathy may be a prodromal sign of future tendon failure. Due to the changes in operational requirements, training, engagement in overseas contingency operations, and force composition that have occurred over the past 22 years, an updated assessment of burden and the associated risk factors of ATR is warranted.…”