The wiki page will document the DAF terminology to aid the community in the upcoming work group discussions.

Data Access Mechanisms:
Data Access mechanism refers to how the data is accessed. This is commonly done via queries. These queries fall into different categories based on the type of information used to create the queries. Examples of Data Access mechanisms include Document Metadata based access, Data Element based access, Quality Measure based access which are defined below.


Document Metadata based access: 
Document Metadata based DAF Queries are created using the metadata associated with clinical documents. The metadata associated with clinical documents is typically captured as part of clinical workflows. Examples of metadata include

• Type of the clinical documents (for e.g Office Visit Summaries, Discharge Summaries, Operative Notes, History and Physical notes) used to record various clinical encounters.
• Patient identifier information such as patient id or mrn.
• Metadata such as time of creation, modification time, Practice Type, and other ebRS/ebRIM based metadata as documented in IHE ITI TF: 2a : 3.18.4.1.2.3.7

Data Element based access: 
Data Element based DAF Queries are created using information that is part of the patient's clinical record. Information that is typically present within a patient's record include

• Patient Demographics information such as race, ethnicity, gender, age.
• Lab Results information
• Medications, Immunizations, Problems etc.

Quality Measure based access: 
Quality Measure based DAF Queries are created using using quality measures such as NQF0059, NQF0038 etc. 
More information about quality measures can be obtained from the following locations:

• CMS Clinical Quality Measures
• AHRQ Quality Measures
• NQF Quality Measure Tools and Reports

Granularity of Data being returned:
Granularity of Data being returned refers to the information that is returned due to the execution of a DAF query. This is commonly known as Query Results. Query Results can contain individual Patient Level Data or aggregate Population Level data which are defined below.

Patient Level Data: 
When the granularity of data access is “Patient Level Data”, the HealthIT systems responding to the queries are expected to return information for each patient(s) that meets the query criteria. For example,

• If the query is about a single patient, the query results will be specific to the identified patient.
• In the case where the query identifies generic criteria such as “age > 50 and HbA1c >7%”, the query results should contain discrete information for each patient who meets the specified criteria.
• Standards such as C-CDA, FHIR, QRDA Category I and HL7 v2.5.1 message formats are used to encode individual patient level data.

Population Level Data:
When the granularity of data access is “Population Level Data”, the HealthIT systems responding to the queries are expected to return summary information about the population that meets the criteria. Population information could be 

• Number of patients that meet a criteria.
• Percentage of Patients that meet a criteria.
• De-identified Patient List Report (Patient List Report is essentially a list of patients)
• Standards such as QRDA Category III Report and conceptual QRDA Category II Report are used to encode population level data.

Other Relevant Terminology

Trusted Healthcare Organization: 
In the context of Data Access Framework, a trusted external healthcare organization can be either a Covered Entity or a Business Associate as defined by HIPAA rule. A trusted healthcare organization is defined as an independent legal entity, with which a pre-established agreement and/or relationship is in place with the requesting organization to share patient information.