Thank you for your question regarding CMS190v12, Intensive Care Unit Venous Thromboembolism Prophylaxis. Within the definition “Low Risk Indicator For VTE”, this portion of the logic refers to Medication Administration for Unfractionated Heparin Intravenously and uses releventDateTime and releventPeriod:     union ( ( ( ["Medication, Administered": "Unfractionated Heparin"] UnfractionatedHeparin         where UnfractionatedHeparin.route in "Intravenous route"     )       union ["Medication, Administered": "Direct Thrombin Inhibitor"]       union ["Medication, Administered": "Glycoprotein IIb IIIa Inhibitors"] ) AnticoagulantMedication       return {         id: AnticoagulantMedication.id,         LowRiskDatetime: start of Global."NormalizeInterval" ( AnticoagulantMedication.relevantDatetime, AnticoagulantMedication.relevantPeriod )       }   )   QDM 5.6 defines Timing: relevant dateTime references the time the medication is administered if it was given or taken at a single point in time. relevantPeriod references a start and stop time for a single medication administration if the administration event occurred over a time interval (e.g., an intravenous infusion). When referring to infusion, the documentation of relevant period would include the start and stop time. If you are referring to a single administration, it would be the time of administration.