Research involves the DoD when:

• The research is funded by a DoD component, or
• The research involves cooperation, collaboration, or other type of agreement with a component of the DoD or its personnel, or
• The research uses DoD resources, including its equipment, property, facilities, assets, personnel, or identifiable data or specimens from living individuals, or
• The subject population will intentionally include personnel (military and/or civilian) from a component of the DoD.  (DoD Instruction, Glossary - DoD-supported Research Involving Human Subjects)

DoD policies do not apply when US military personnel incidentally participate as subjects in a study that is not DoD-supported and US military personnel are not the intended target population.