Clinical Decision Support System (CDSS) development patterns. Drug interaction checking, dose validation, clinical scoring (NEWS2, qSOFA), alert severity classification, and integration into EMR workflows. Use when building clinical decision support — drug interaction checks, dose validation, clinic

Healthcare CDSS Development Patterns Patterns for building Clinical Decision Support Systems that integrate into EMR workflows. CDSS modules are patient safety critical — zero tolerance for false negatives. When to Use Implementing drug interaction checking Building dose validation engines Implementing clinical scoring systems (NEWS2, qSOFA, APACHE, GCS) Designing alert systems for abnormal clinical values Building medication order entry with safety checks Integrating lab result interpretation with clinical context How It Works The CDSS engine is a pure function library with zero side effects . Input clinical data, output alerts. This makes it fully testable. Three primary modules: 1. checkInteractions(newDrug, currentMeds, allergies) — Checks a new drug against current medications and known allergies. Returns severity sorted InteractionAlert[] . Uses DrugInteractionPair data model. 2. validateDose(drug, dose, route, weight, age, renalFunction) — Validates a prescribed dose against weight based, age adjusted, and renal adjusted rules. Returns DoseValidationResult . 3. calculateNEWS2(vitals) — National Early Warning Score 2 from NEWS2Input . Returns NEWS2Result with total score, risk level, and escalation guidance. Drug Interaction Checking Interaction pairs must be bidirectional : if Drug A interacts with Drug B, then Drug B interacts with Drug A. Dose Validation Clinical Scoring: NEWS2 Scoring tables must match the Royal College of Physicians specification exactly. Alert Severity and UI Behavior Severity UI Behavior Clinician Action Required Critical Block action. Non dismissable modal. Red. Must document override reason to proceed Major Warning banner inline. Orange. Must acknowledge before proceeding Minor Info note inline. Yellow. Awareness only, no action required Critical alerts must NEVER be auto dismissed or implemented as toast notifications. Override reasons must be stored in the audit trail. Testing CDSS (Zero Tolerance for False Negatives) Pass criteria: 100%. A single missed interaction is a patient safety event. Anti Patterns Making CDSS checks optional or skippable without documented reason Implementing interaction checks as toast notifications Using any types for drug or clinical data Hardcoding interaction pairs instead of using a maintainable data structure Silently catching errors in CDSS engine (must surface failures loudly) Skipping weight based validation when weight is not available (must block, not pass) Examples Example 1: Drug Interaction Check Example 2: Dose Validation Example 3: NEWS2 Scoring

healthcare-cdss-patterns