DetectedIssue — Problem detected in care

The structured channel through which a clinical decision support engine raises an alert: drug-drug interaction, contraindication, known allergy, duplicate prescription, abnormal biology value, protocol deviation.

Purpose of the resource

A modern EHR embeds Clinical Decision Support (CDS) engines that continuously monitor clinical actions. When a risk is identified — drug-drug interaction, declared allergy, out-of-range dose, pregnancy contraindication, deviation from a care protocol — a DetectedIssue is raised. It is read by the prescriber or the nurse, and may block an action (hard stop) or be overridden with justification (soft stop).

The CDS engine may live inside the EHR, be externalised as a CDS Hooks service, or be integrated into a medical device (dose-error reducing infusion pump, ECG with automatic arrhythmia detection…).

Key fields

JSON example

Warfarin + aspirin interaction detected by a CDS engine, high severity, class evidence:

{
  "resourceType": "DetectedIssue",
  "id": "drug-drug-interaction-example",
  "identifier": [{ "system": "http://example.org/issues", "value": "DI-2026-001234" }],
  "status": "preliminary",
  "category": [{
    "coding": [{
      "system": "http://terminology.hl7.org/CodeSystem/v3-ActCode",
      "code": "DRG",
      "display": "Drug-Drug Interaction"
    }]
  }],
  "code": {
    "coding": [{
      "system": "http://terminology.hl7.org/CodeSystem/v3-ActCode",
      "code": "DDI",
      "display": "Drug-Drug Interaction Alert"
    }]
  },
  "severity": "high",
  "subject": { "reference": "Patient/example" },
  "identifiedDateTime": "2026-05-16T10:25:30+02:00",
  "author": { "reference": "Device/cds-engine" },
  "implicated": [
    { "reference": "MedicationRequest/warfarin-rx", "display": "Warfarin 5 mg" },
    { "reference": "MedicationRequest/aspirin-rx", "display": "Aspirin 100 mg" }
  ],
  "evidence": [{
    "code": [{
      "coding": [{
        "system": "http://terminology.hl7.org/CodeSystem/issue-evidence",
        "code": "drug-class-interaction"
      }]
    }],
    "detail": [{ "reference": "DocumentReference/lexicomp-monograph-warfarin" }]
  }],
  "detail": "Concurrent use of warfarin and aspirin increases risk of major bleeding (RR 2.3). Consider PPI co-prescription or alternative antiplatelet.",
  "reference": "https://pubmed.ncbi.nlm.nih.gov/example-12345"
}

Typical use cases

• Drug-drug interactions: classic CDS for safe e-prescribing.
• Allergies / contraindications: history check before prescription.
• Duplicate prescription: same molecule prescribed by several providers.
• Abnormal biology values: serum potassium > 6.0 mmol/L → automatic alert.
• Protocol deviation: dose outside allowed range, follow-up not performed.
• Pharmaco-genomic vigilance: CYP2C19 poor metaboliser + clopidogrel.

Common pitfalls

• Alert fatigue: firing 100 DetectedIssues per hospitalised patient overloads the prescriber. Filter by severity and contextualise.
• No mitigation recorded: not filling mitigation after an override leaves the alert open. Always document override + reason.
• Incomplete implicated: if an interaction involves 3 drugs but implicated only references 2, the alert is unusable.
• Non-standard clinical code: use v3-ActCode or a validated CDS reference (ATC, ICD10, SNOMED CT).
• Status forgotten: moving an issue to mitigated or final after resolution lets the active list stay clean.

Related resources

• MedicationRequest, ServiceRequest, Procedure — clinical actions to verify.
• AllergyIntolerance, Condition — history that motivates detection.
• GuidanceResponse — response from a CDS Hooks service.
• RequestOrchestration — orchestration of multiple orders with checks.
• AdverseEvent — if the detected issue materialised into an adverse outcome.

See also: MedicationRequest — the prescription and AllergyIntolerance — declared allergy.