Information Technologies in Healthcare
Domain 3 tests the systems and standards that carry clinical data, plus the availability and safety trade-offs that make healthcare IT different from general IT.
Interoperability standards
- HL7 v2 - pipe-delimited messages; ADT (registration), ORM (orders), ORU (results). Still the mainstay of hospital interfaces.
- HL7 CDA - XML clinical documents such as continuity-of-care documents.
- FHIR - RESTful resources and APIs; the basis of modern patient-access and payer APIs.
- DICOM - imaging objects and worklists.
- X12 - 837 claims, 835 remittance; NCPDP for pharmacy claims.
Architecture you should be able to sketch
EHR core with modules, interface engine, master patient index, PACS, laboratory information system, pharmacy and eMAR with barcode medication administration, HIE connections, data warehouse, and a growing population of networked medical devices (IoMT).
Availability is a clinical control
Downtime procedures, paper fallback, tested backups, RTO/RPO targets, and change control with clinical sign-off. Medical devices need a maintained inventory, network segmentation, and vendor-coordinated patching - a device outage is a patient-safety event, not just an IT ticket.
Worked example
Clinicians report that chemistry results are not appearing in the EHR. Reasoning order: check the interface engine queue for stuck messages, confirm the LIS is producing ORU messages, read the HL7 ACK for rejection errors, verify LOINC-to-local code mapping after a recent LIS upgrade, and only then escalate to the vendor - while activating the results-callback downtime procedure so care continues. The technical fix and the clinical workaround run in parallel.
Traps
- Treating HL7 v2 and FHIR as interchangeable.
- Patching medical devices on the standard IT cadence without vendor validation.
- Assuming transport encryption protects stored data.
- Forgetting that electronic prescribing of controlled substances requires DEA-compliant two-factor authentication.