The Data Elements of an EHR

I've recently been asked to provide a list of the data elements of an EHR which might be used as part of the ARRA mandate to exchange data as part of meaningful use. There are a nearly infinite number of actors, actions and events for data exchange, but in the interest of getting "data liquidity" in healthcare, here are the elements that are most commonly used and represent a great starting point for healthcare information exchange. I always strive for parsimony of standards - the fewest that we need for the purpose. Below you'll see that I've included the standards that support the systems we have in place today as well as the XML/Web-based standards that support newer web-centric systems and healthcare information exchanges.

Demographics
Content: HL7 2.x for messaging, CCD for document summaries
Vocabulary: HITSP Harmonized codesets for gender, marital status

Problem List
Content: HL7 2.x for messaging, CCD for document summaries
Vocabulary: SNOMED-CT

Medications
Content: NCPDP script for messaging, CCD for document summaries
Vocabulary: RxNorm and Structured SIG

Allergies
Content: HL7 2.x for messaging, CCD for document summaries
Vocabulary: UNII for foods and substances, NDF-RT for medication class, RxNorm for Medications

Progress Notes and Other Narrative Documents (History and Physical, Operative Notes, Discharge Summary)
Content: HL7 2.x for messaging, CCD for document summaries
Vocabulary: CDA Templates

Departmental Reports (Pathology/Cytology, GI, Pulmonary, Cardiology etc.)
Content: HL7 2.x for messaging, CCD for document summaries
Vocabulary: SNOMED-CT

Laboratory Results
Content: HL7 2.x for messaging, CCD for document summaries
Vocabulary: LOINC for lab name, UCUM for units of measure, SNOMED-CT for test ordering reason

Microbiology
Content: HL7 2.x for messaging, CCD for document summaries
Vocabulary: LOINC for lab name/observation

Images
Content: DICOM

Administrative Transactions (Benefits/Eligibility, Referral/Authorization, Claims/Remittance)
Content: X12
Vocabulary: X12, CAQH CORE

Quality Measures
Content: Derived from all the data elements above
Vocabulary: Derived from all the data elements above

Privacy and Security
Transport: HTTPS, SOAP/REST
Transport Orchestration: WS*
Authorization/Access Control: XACML

Given that meaningful use needs to be achieved by 2011-2012, it's clear that we cannot rip and replace existing hospital information systems and EHRs. We need to leverage them, upgrade them over time, and install new systems in an incremental fashion. This is really true of any change in healthcare. If we had a greenfield, we would design healthcare delivery, payment, and infrastructure entirely differently. Unfortunately, we do not have a greenfield, we have limited resources, and limited time to achieve healthcare reform, so we need to leverage what we have and evolve it in phases.

HITSP will be reformatting and streamlining its previous work over the next 90 days to support ARRA, the HIT Standards and Policies Committees, and ONC. I hope you agree that the list of EHR data elements above is practical, achievable now, and reasonable.