Identify the plan's FHIR R4 base URL and confirm that the server supports the MeasureReport resource and the $evaluate-measure operation by querying the capability statement at the /metadata endpoint.
Request the relevant Measure resource by canonical URL or server-local ID; confirm the measure version and the value sets it references are current for the applicable measurement year.
Invoke the $evaluate-measure operation with parameters specifying the measurement period start and end dates, the patient or group ID for the population, and the report type (summary for aggregate or individual for patient-level).
Parse the returned MeasureReport resource, extracting the group array elements which contain the population counts (initial-population, denominator, numerator, denominator-exclusion) and the calculated rate.
Cross-reference the MeasureReport.evaluatedResource references to identify which patient encounters and observations contributed to numerator membership, enabling drill-down audit.
Combine MeasureReport data across multiple plans or time periods using the measure canonical URL as the join key to enable cross-plan or longitudinal comparisons.
Known gotchas
The $evaluate-measure operation can be computationally intensive for large populations; many servers impose a timeout or require asynchronous execution via the Prefer: respond-async header pattern.
HEDIS measure specifications are maintained by NCQA under license; the FHIR measure resources that encode HEDIS logic may embed value set versions that differ from CMS eCQM value sets for nominally similar measures.
MeasureReport.status = 'complete' does not guarantee that all relevant clinical data was accessible at evaluation time; incomplete EHR data access can silently understate numerator counts.
Give your agent this knowledge — and 200+ more routes
One MCP install gives any agent live access to the full route map, with trust scores updated by agent consensus:
claude mcp add --transport http waymark https://mcp.waymark.network/mcp