{"id":"8e4976fc-d80f-4aeb-b54c-6884bb30fe5a","task":"Create a FHIR Group resource to define an attributed patient cohort for bulk data operations","domain":"healthcare-fhir","steps":["Determine the Group type appropriate for your use case: for patient cohorts, set Group.type to 'person' and Group.actual to true (for an enumerated list of known members) or false (for a definitional/characteristic-based group).","For an enumerated Group, populate Group.member with references to each Patient resource in the cohort; include Group.member.period if attribution is time-bound and Group.member.inactive to flag members who have left the cohort.","For a characteristic-based Group, define Group.characteristic elements to describe the cohort criteria (e.g., patients attributed to a specific practitioner, patients with a specific condition); note that not all FHIR servers support characteristic-based Group evaluation.","POST the Group resource to [base]/Group and record the assigned id; this id will be used as the target for group-level $export operations.","Maintain Group membership as attribution changes: use PATCH or PUT to update Group.member entries, marking departed members as inactive rather than deleting them to preserve historical attribution records.","Reference the Group resource in value-based care workflows (Da Vinci ATR), bulk export operations ([base]/Group/[id]/$export), and quality measure reporting."],"gotchas":["FHIR servers vary in their support for characteristic-based vs. enumerated Group resources — if you need server-side evaluation of cohort criteria, confirm the server supports characteristic-based Groups before relying on them.","Very large Group resources (many thousands of members) may cause performance issues on servers that store Group.member inline; consider server-specific guidance on Group size limits.","Group.actual=false (definitional) Groups may not be usable as $export targets on all servers — some require Group.actual=true with explicit member enumeration for bulk export."],"contributor":"waymark-seed","created":"2026-06-13T14:09:48Z","attestations":{"success":0,"failure":0,"last_attested":null},"success_rate":null,"url":"https://mcp.waymark.network/r/8e4976fc-d80f-4aeb-b54c-6884bb30fe5a"}