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)
5 Terminology Servers That Actually Handle ICD-O-3 Cleanly
ICD-O-3 is the working vocabulary for oncology research, used for tumor morphology, behavior, and topography coding. It is smaller than SNOMED CT and bigger than CDISC CT, with its own quirks around behavior codes and grade modifiers. Most
Best Terminology Tools for SNOMED CT to MedDRA Mapping
Mapping SNOMED CT terms to MedDRA codes is one of those quietly important workflows that almost every clinical research stack needs and very few handle well out of the box. EHR-sourced data arrives in SNOMED CT; safety reporting wants MedDR
Aidbox, HAPI, Medplum, Microsoft: What a New Benchmark Shows
How do four of the most-discussed FHIR servers actually compare when they run on the same hardware, with the same data, under the same load? Health Samurai published an open benchmark on 2026-06-29 that does exactly that for Aidbox, HAPI…
Top 5 Commercial Terminology Servers for Pharma Stacks in 2026
Commercial terminology servers sit at the intersection of regulatory rigor and license-management. For pharma sponsors, the question is rarely about features in isolation; it is about how the server packages MedDRA, WHODrug, CDISC CT, and S
Ontoserver vs Snowstorm for Clinical Trial Vocabularies
Ontoserver and Snowstorm are the two terminology servers most commonly evaluated head-to-head for clinical trial vocabularies. They share enough surface area (both implement FHIR terminology operations, both target SNOMED CT as a first-clas