Information Systems and Technology
What to know
This domain covers the EHR/EMR, clinical decision support (CDS), CPOE, eMAR/BCMA, and the architecture behind them: servers, interfaces, and standards. Know interoperability standards: HL7 v2 for messaging, FHIR for modern APIs, DICOM for imaging, LOINC for labs, SNOMED CT for clinical terms, ICD-10 for billing/diagnosis, and RxNorm for medications. Understand interface engines and the difference between point-to-point and interface-engine (hub) integrations. Know HL7 message structure conceptually (ADT for admissions/transfers/discharges, ORM/ORU for orders/results). Familiarity with CDS Hooks, SMART on FHIR, and meaningful use / promoting interoperability program goals helps.
Traps
- Confusing terminology (SNOMED, LOINC) with messaging (HL7, FHIR) standards-they solve different problems.
- Assuming CPOE equals CDS; CPOE is order entry, CDS is the logic that guides decisions.
- Forgetting downtime procedures and business continuity-questions love the scenario where the EHR is unavailable and paper/backup processes must exist.
- Overlooking usability (human factors) as a technology requirement, not just a nice-to-have.
Worked example / rule of thumb
A lab result must flow from the lab system to the EHR. Map it: the lab sends an HL7 ORU message through the interface engine, which maps the lab's local code to LOINC before posting. Rule of thumb: terminology standard for the meaning, messaging standard for the transport, interface engine for the translation.
Key concepts
EHR/EMR, CPOE, CDS, eMAR/BCMA, HL7/FHIR, DICOM, LOINC/SNOMED/ICD-10/RxNorm, interface engines, downtime/continuity, usability.