Under most state statutes, doctors and health care providers generally have duties to report incidence of certain sexually transmitted diseases, child abuse, communicable diseases, HIV/AIDS, or other conditions deemed to be risks to the health and safety of the public at large. Some states have developed registries to track the incidence of certain conditions, (e.g., certain forms of cancer) that may later help researchers discover causes. In registry cases, personal data about the patients is released only to the necessary local, state, or federal personnel, and the data usually does not contain “patient identifiers.”