What characterizes a verbal referral?

A verbal referral is characterized by an informal telephone notice from the primary care physician. This type of referral does not involve any formal documentation and is typically communicated directly between healthcare providers through a conversation. It serves as a quicker way for a primary care physician to guide a patient to a specialist, ensuring that the patient can receive timely care without the delay that may occur with written referrals.

The context of the other options helps clarify this. A self-referral by a patient does not involve communication from a primary care physician, nor does it offer the guidance that is typically expected in a referral process. A written request from the physician, while formal and structured, is not considered verbal in nature. An electronic transfer of medical records pertains to the documentation and sharing of patient information rather than the initial referral process itself. Thus, the essence of a verbal referral lies in its direct and informal nature, as captured in the correct answer.