Information is considered to be confidential when only the investigator(s) or individuals on the research/project team can identify which responses came from which individual subjects. Researchers/quality improvement project leaders are responsible for making every effort to protect confidential information to prevent anyone outside of the study/project team from connecting individual subjects to their individual responses.
Information is considered anonymous when even the investigators or individuals on the research/project team cannot match the responses to the individual subjects who provided them. This may be the result of not collecting any identifying information or recording information using only non-identifiable codes. No identifying information should be collected unless it is essential to a well-designed study protocol.
Adapted from: Confidentiality vs. anonymity. Retrieved from http://www.irb.vt.edu/pages/confidentiality.htm retrieved October 19, 2012