Risk Factors for Bone Stress Injuries in the Military: A Systematic Review with Meta-Analysis - ICMM World Congress on Military Medicine
rhon d, Drysdale l, radcliffe c, newman p
Stress fractures are common in military personnel, with training that often leads to overload and repetitive bone stress. These injuries limit duty, affect military readiness, and can end a military career. Injury mitigation is a high priority for military leadership and health, but risk profiles for stress fractures have not been fully explored. Many studies have evaluated risk factors, but meta-analyses of risk with aggregated study data are few. The purpose of this review was to conduct a systematic review of the literature to identify risk factors for stress fracture in military populations, and through meta-analysis, calculate aggregate risk profiles.
The search assessed studies published between January 1995 and September 2023 in PUBMed and CINAHL. Any study assessing risk factors for any type of stress fracture in a military population was considered, as long as an English translation was available. We excluded studies predicting disability, return to duty, or any variable not representing a stress fracture occurrence. When raw data were unavailable, we exported risk statistics as reported (e.g. risk ratios[RR], odds ratios[OR], hazard ratios [HR], rate ratios[RR]) as point estimates with 95% confidence intervals (CI) for categorical variables and means with standard deviations or 95% CI for continuous variables. We used imputation tools in Revman to estimate RR when values were not provided. We used the Prediction model Risk Of Bias ASsessment (PROBAST) Tool to assess methodological quality. We conducted a meta-analysis on unique predictor variables. We assessed heterogeneity of predictors using I2 statistics, and when heterogeneity was moderate to high (> 25%), we used a random effects model.
Despite the abundance of literature assessing risk factors for stress fractures, the variability in the capture and reporting of risk factors made data harmonization challenging. Only 3 factors were significantly associated with risk of developing a stress fracture: decreased bone mineral density in females, increased body weight, and female sex. Standardization of collecting and reporting risk factors is necessary in the future to improve the quality of meta-analysis and collective understanding or stress fracture risk factors.