An Electronic Phenotype Series for Measuring Adherence to the Wake Up and Breathe Protocol in Mechanically Ventilated ICU Patients.

Objective: The Wake Up and Breathe protocol integrates daily spontaneous awakening and breathing trials to facilitate earlier weaning from mechanical ventilation, improving outcomes for patients with acute respiratory failure. Measuring adherence to this multistep, interprofessional practice is essential but is challenged by informatics complexity and the risk of metric-specific gaming. Our objective was to define and validate an electronic phenotype series enabling retrospective, scalable, and reliable measurement of protocol adherence using real-world electronic health record data from a multi-hospital warehouse, with the patient-day as the unit of analysis and agreement against manual chart review of 200 stratified patient-days assessed using Cohen's Kappa. Results: Seven phenotypes were defined: two for upstream eligibility, four for protocol process steps, and one for a downstream outcome. Agreement with chart review ranged from moderate to near-perfect, with lower agreement linked to documentation granularity and rapid clinical events. This phenotype series offers a reusable framework for measuring adoption of the Wake Up and Breathe protocol and supports scalable quality measurement and retrospective analysis across ICU settings, though some protocol components remain unmeasured given current data availability.