Pulmonary Pathology Diagnoses in the US Military During the Global War on Terrorism

Purpose To document and compare prevalences of pulmonary pathology diagnoses among US Service members deployed during the Global War on Terrorism and non-deployed US service members. Difficulties establishing associations between deployment-related exposures and pulmonary pathology reported among US military service members deployed during the Global War on Terrorism include retrospective estimations of exposures, documenting medical outcomes and lack of comparison groups. Methods Pulmonary diagnoses reported between 2002 and 2015 were identified from the records of the former Armed Forces Institute of Pathology and The Joint Pathology Center. Military service and deployment were confirmed by the Defense Manpower Data Center. Diagnoses were reviewed and coded due to variations in diagnostic terminology. Propensity matching and adjusted binomial modeling were applied to comparisons between the deployed and non-deployed to address possible confounding variables. Results 404 deployed and 2006 non-deployed service members were included. Demographic differences and the date of pathology report complicate unadjusted comparisons. The deployed had no significant increased prevalence of neoplastic conditions. Propensity matching identified a significant increased prevalence of organizing pneumonia in the non-deployed. An adjusted binomial model identified significant increased prevalences of small airways disease, constrictive bronchiolitis and hypersensitivity pneumonitis in the deployed. Both diagnoses were strongly associated with the date of pathology report. Small airways disease, constrictive bronchiolitis comprised 5% of deployed surgical lung biopsy diagnoses. Conclusion This is the largest study of post-deployment pulmonary pathology diagnoses to date, and contains a comparison group. It provides context for studies of pulmonary outcomes among the deployed.