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Version: v0.2.0

Transform an order and its schedule

In an order message each ORC starts an order, and the segment after it says what is ordered: an OBR for a service (a test, a procedure), an RXO for a medication. toFhir turns the first into a ServiceRequest and the second into a MedicationRequest. A TQ1 in the order carries its schedule.

Transform a service order​

ORM^O01 and OML^O21 are the two order messages the guide publishes a message map for.

import { parseHL7 } from "@cosyte/hl7";
import { serializeResource } from "@cosyte/fhir";
import { toFhir } from "@cosyte/transform";

const raw = [
  "MSH|^~\\&|CPOE|HOSP|LAB|HOSP|20260721150000-0500||OML^O21^OML_O21|MSG0003|P|2.5.1",
  "PID|1||MRN12345^^^HOSP^MR||Public^Jane^Q||19800115|F",
  "ORC|NW|PLACER1|FILLER1||||||20260721140000-0500",
  "OBR|1|PLACER1|FILLER1|24331-1^Lipid Panel^LN|R",
].join("\r");

const { bundle } = toFhir(parseHL7(raw));
const json = JSON.parse(serializeResource(bundle)) as {
  entry: { resource: Record<string, unknown> & { resourceType: string } }[];
};
const request = json.entry.find((e) => e.resource.resourceType === "ServiceRequest")?.resource;

request?.["status"]; // => "active"
request?.["intent"]; // => "order"
request?.["priority"]; // => "routine"

status comes from ORC-1 through the guide's order-control map (NW, a new order, is active), and priority from OBR-5 through the priority map. A control code the map has no target for leaves status absent, and the request is withheld with TRANSFORM_RESOURCE_INVALID, because FHIR requires it.

import { REQUEST_STATUS_MAP, SERVICE_REQUEST_PRIORITY_MAP } from "@cosyte/transform";

REQUEST_STATUS_MAP["NW"]; // => "active"
REQUEST_STATUS_MAP["DC"]; // => "revoked"
SERVICE_REQUEST_PRIORITY_MAP["S"]; // => "stat"

Transform a medication order with a schedule​

A pharmacy order carries an RXO, its route in RXR, and its schedule in TQ1. Pharmacy messages such as OMP^O09 have no message map in the guide, so the graph is built from the segment maps and flagged TRANSFORM_SEGMENT_ASSEMBLED.

import { parseHL7 } from "@cosyte/hl7";
import { serializeResource } from "@cosyte/fhir";
import { toFhir } from "@cosyte/transform";

const raw = [
  "MSH|^~\\&|CPOE|HOSP|PHARM|HOSP|20260721150000-0500||OMP^O09|MSG0004|P|2.5.1",
  "PID|1||MRN12345^^^HOSP^MR||Public^Jane^Q||19800115|F",
  "ORC|NW|PLACER2|FILLER2||||||20260721141000-0500",
  "TQ1|1||Q6H^^^^6^h||||20260721|20260728",
  "RXO|197361^Amoxicillin 250 MG Oral Tablet^RXNORM|250||mg^milligram^UCUM",
  "RXR|PO^Oral^HL70162",
].join("\r");

const { bundle, issues } = toFhir(parseHL7(raw));
const json = JSON.parse(serializeResource(bundle)) as {
  entry: { resource: Record<string, unknown> & { resourceType: string } }[];
};
const order = json.entry.find((e) => e.resource.resourceType === "MedicationRequest")?.resource;
const dosage = (order?.["dosageInstruction"] as Record<string, unknown>[])[0];

order?.["status"]; // => "unknown"
dosage?.["timing"]; // => { repeat: { boundsPeriod: { start: "2026-07-21", end: "2026-07-28" }, period: 6, periodUnit: "h" }, code: { coding: [{ system: "http://terminology.hl7.org/CodeSystem/v2-0335", code: "Q6H" }] } }
issues.map((i) => i.code).includes("TRANSFORM_SEGMENT_ASSEMBLED"); // => true

Two things to read there:

  • status is unknown. The guide grounds no MedicationRequest.status, so the library writes the code FHIR provides for exactly that and raises TRANSFORM_REQUIRED_ELEMENT_UNKNOWN.
  • The schedule is whole. TQ1-3 gave the repeat code and the period, TQ1-7 and TQ1-8 the bounds. On a ServiceRequest the same schedule goes to occurrenceTiming.

Know when the schedule is withheld​

A schedule that is only partly understood reads to the receiver as a complete instruction. "Every 6 hours, but only between meals" must not arrive as "every 6 hours". So if any part of a TQ1 cannot be mapped, the whole Timing is left out and an issue names the field that caused it. Here TQ1-3 carries two repeat patterns:

import { parseHL7 } from "@cosyte/hl7";
import { toFhir } from "@cosyte/transform";

const raw = [
  "MSH|^~\\&|CPOE|HOSP|PHARM|HOSP|20260721150000-0500||OMP^O09|MSG0005|P|2.5.1",
  "PID|1||MRN12345^^^HOSP^MR||Public^Jane^Q||19800115|F",
  "ORC|NW|PLACER2|FILLER2||||||20260721141000-0500",
  "TQ1|1||Q6H^^^^6^h~Q8H^^^^8^h||||20260721|20260728",
  "RXO|197361^Amoxicillin 250 MG Oral Tablet^RXNORM|250||mg^milligram^UCUM",
  "RXR|PO^Oral^HL70162",
].join("\r");

const { issues } = toFhir(parseHL7(raw));
const dropped = issues.find((i) => i.fhirPath === "MedicationRequest.dosageInstruction.timing");

dropped?.code; // => "TRANSFORM_ELEMENT_DROPPED"
dropped?.v2Location; // => "TQ1.3"

No boundsPeriod survives a withheld schedule either, even when TQ1-7 and TQ1-8 were usable on their own: a pair of dates with no schedule would read as an open regimen the message never ordered. Mapping scope lists the causes.

Reference​