Domain

“Level 7” refers to the highest implementation protocol level in the Open System Interconnection (OSI) model.

This corresponds to the conceptual definition of an application‑to‑application interface.

The HL7 Version 2.7 standard currently addresses the interfaces among various healthcare IT systems that send or receive:

• Patient admissions/registration
• Discharge or transfer (ADT) data
• Queries
• Resource and patient scheduling
• Orders, results, clinical observations
• Billing
• Master file update information
• Medical records
• Scheduling
• Patient referral
• Patient care
• Clinical laboratory automation
• Application management and personnel management messages

Initially, the efforts of HL7 were focused on reducing paper processing, improving cash flow, and improving management decision making.

It has evolved into a distinct focus on streamlining and improving clinical and ancillary services, including bedside (in hospitals and other inpatient environments) and “patient‑side” systems (in ambulatory settings).

Within the past 15 years, interest has developed in integrating all information related to the delivery of healthcare to a patient over his or her lifetime (electronic medical records).

In the last 5 years they have begun focusing on the challenges of integrating the health data in these electronic medical records (or electronic health records – EHRs) among patient care organizations and across entire countries.