Do QT-Prolonging Drugs Cause Major Adverse Cardiac Events in Hospitalized Adults?

There are 28 non-cardiology medications from multiple families costing more than $13 billion annually in Canada, categorized as 'Known' QT-prolonging medications (QTPmeds) based on very low levels of evidence. The association between many commonly used medications listed as known QTPmeds and actual major adverse cardiac events (MACE) is weak. Meanwhile, QTPmeds-related warnings are ubiquitous in every healthcare setting, triggering 'hard stop' disruption millions of times per day to front line clinicians. Poor quality medication safety alerts are increasingly recognized as a source of inferior patient care and provider burnout which detracts from healthcare sustainability. In this study, anonymized hospital electronic medical record data from more than 990,000 adult patients across Ontario will be used to compare patients who experience MACE with those who do not, measuring their real-t