Ethical international research on human subjects research in the absence of local institutional review boards.

International health-related research on human subjects entails unique ethical responsibilities and difficulties. Often, these difficulties are augmented by the lack of a local ethical review infrastructure. In a recent cross-national study conducted by us, three critical components of ethical regulation were identified--external oversight, local oversight and subject involvement--and integrated into the study design. These three concepts are outlined and established as an important aspect of ensuring ethical coherence in the local context, particularly when reviews by the local institutional review boards cannot practically be obtained. The three levels of ethical oversight identified are suggested to be the framework within which future field studies on human subjects are developed and a standard for maintaining ethical rigorousness in research on humans.