Disabling Knee Injury in the United States Army: Classification of Injury for Etiologic Research

摘要

Musculoskeletal injuries, especially those associated with rigorous physical training or vigorous occupational activities, are common in the U.S. Army, and have substantial economic consequences in both direct and indirect costs. The lack of consistent, specific definitions of injuries results in misclassification bias and hinders etiologic research. This report compares 4 different classification systems (ICD-9-CM codes, percent disability, VASRD codes, and physical therapy parameters) as tools for etiologic research. Methods: A case-control study design drawn from The Total Army Injury and Health Outcomes Database (TAIHOD) is used. Bivariate and multivariate logistic regression models compare the 4 systems in their ability to accurately describe and classify disabling knee injury. Results: The VASRD and the ICD-9-CM systems were too non-specific and did not capture sufficient detail. The assessment of percentage of disability may prove useful, except that under the current coding system, it is inextricably linked to the VASRD code, and it is difficult to stratify injuries based on this measure of severity. The system that seemed most promising was the one based on physical therapy parameters. Conclusions: Selecting an appropriate classification system in epidemiologic research is important in order to accurately identify risk factors and design appropriate interventions.