What phrase describes the medical staff's approval for a registry to directly contact patients for follow-up?

The phrase that best describes the medical staff's approval for a registry to directly contact patients for follow-up is "Blanket permission." This term indicates a broad authorization granted by the medical staff, allowing the registry to reach out to patients without needing to obtain individual consent each time. This is crucial in ensuring that follow-up data collection can be performed efficiently, as it streamlines the process and alleviates the need for multiple requests for patient contact approval.

The concept of "patient consent," while relevant, typically refers to individual patients giving their approval for a specific action or intervention, rather than a generalized approval that covers multiple instances of contact. "Legal authorization" may imply a more formal or regulatory framework that is not as commonly used in this specific context of communication between registries and patients. Thus, "Blanket permission" is the most accurate reflection of the medical staff's comprehensive approval for registry activities.