Final answer:
The correct action when observing an unauthorized staff member reading a patient's medical record is to inform them that access is restricted to those involved in the patient's care with a legitimate need for information, and to enforce patient privacy and confidentiality regulations.
Step-by-step explanation:
If you notice a nursing staff member from another unit, who is not involved in your patient's care, reading the chart of one of your patients, the first thing you should do is inform this staff person that the medical record is only available for staff involved in the patient's care with a legitimate need for information. Patient confidentiality and privacy regulations, such as the Health Insurance Portability and Accountability Act (HIPAA) in the United States, dictate that all patient information must be kept confidential and only accessible to those directly involved in the patient's care. Violating these regulations is a serious offense, and it is important for nursing professionals to enforce these rules to protect patient privacy.