Carbon monoxide poisoning, active and reserve component service members and non-service member beneficiaries of the military health system, U.S. armed forces, july 2009–june 2019

Morbidity and mortality from carbon monoxide (CO) poisoning are important public health problems, but their full impact is difficult to estimate. The current analysis used the 2018 Council of State and Territorial Epide-miologist criteria and International Classification of Diseases (ICD) code-based data to classify CO poisoning cases by intent, source of exposure, and degree of certainty that poisoning was CO related. During July 2009–June 2019, there were 1,288 CO poisoning cases classified as confirmed/proba-ble among active component service members, 366 among reserve component members, and 4,754 among non-service member beneficiaries. Service members working in repair/engineering occupations accounted for the greatest proportion of confirmed CO poisoning cases among active component members and the second greatest proportion among reserve component members. Compared to suspected cases, confirmed/probable cases were more often associated with intentional self-harm and undetermined causes of injury, whereas suspected cases were more often coded as unintentional. Confirmed/probable active component and non-service member beneficiary cases were more likely than their respective suspected case counterparts to receive care in inpatient settings. The need for improvements in ICD coding to reduce the percentage of CO poisoning cases coded with unknown injury intent and/or unknown CO poisoning source is discussed.