A master patient index in a clinical research stack does work that looks invisible until it goes wrong. Subjects enrolled at three sites end up with three different identifiers; cross-site visits become hard to reconcile; the sponsor's data
Designing Your Own OperationOutcome for a Custom Validator
The moment a team writes a custom FHIR validator or a domain-specific rule engine, the question comes up: how should the diagnostic output be shaped? The answer is almost always OperationOutcome — it is the spec's mechanism for reporting...
When an OperationOutcome Should Be an Alert vs a Log
Not every OperationOutcome deserves an alert, and not every one deserves to be logged and forgotten. Somewhere in the middle is where the alerting policy lives, and getting it right is the difference between an on-call rotation that stays...
Location vs Expression: Pointing at the Offending Element
OperationOutcome carries two closely related fields that both do the same job: location and expression. Both are pointers into the resource under evaluation, saying "here is the offending element." One is older and being deprecated; the...
issue.code Vocabulary and What It Actually Means
The issue.code field on OperationOutcome carries a small vocabulary of categorical reasons. Each code implies a different fix, and knowing the top ten by heart saves the trip to the spec on every incident. The site's OperationOutcome...
Severity vs Diagnostic Details: Which One Drives Your Next Step
An OperationOutcome carries two very different fields that both look diagnostic: severity and diagnostics. They serve different purposes, and consulting them in the wrong order is a common time-waster. Severity is a machine-readable enum...
Reading an OperationOutcome for the First Time
The first OperationOutcome a developer encounters usually arrives at the worst moment. A validation failed, a write got rejected, a search returned something strange, and the response body is a JSON structure the caller has not read...
Top 3 Terminology Servers for Adverse Event Coding Workflows
Adverse-event coding is where a terminology server earns its keep in clinical research. The work is high-stakes (every AE feeds a safety database that regulators read), volume-heavy at study startup, and tightly coupled to MedDRA hierarchy
Reading server errors
When a $validate call kicks back an OperationOutcome payload, the OperationOutcome reader posted here groups the issues and adds a plain-English hint.
Open-Source vs Commercial Terminology Servers for Clinical Research
The open-source vs commercial question for terminology servers in clinical research looks like the same question that comes up everywhere else in healthcare IT. It is not. The licensed vocabularies that research depends on (MedDRA, WHODrug)