Which of the following is a common standard for clinical data exchange?

The correct answer is HL7 (Health Level 7) because it has long been recognized as a standard framework for the exchange, integration, sharing, and retrieval of electronic health information. HL7 is specifically designed to support the integration of various healthcare applications and to facilitate communication among different healthcare systems. It sets protocols and guidelines for data interchange in healthcare, ensuring that disparate systems can effectively communicate and understand each other's data.

HL7 has established several versions and messaging standards over the years that are widely adopted in different healthcare settings, providing a robust foundation for clinical data exchange, especially in terms of administrative and clinical data.

While FHIR (Fast Healthcare Interoperability Resources) is indeed a newer standard specifically designed to improve interoperability and is gaining traction, HL7 has a longer history and broader adoption which makes it a cornerstone in the context of clinical data exchange.

DICOM is focused specifically on imaging data and is not a standard for general clinical data exchange. SNOMED CT is a clinical terminology that provides a standardized language to describe clinical concepts, but it is not designed for the actual exchange of data between systems. Thus, HL7 stands out as the most established standard focused on clinical data exchange.