Adverse drug events account for many preventable ED visits and hospital admissions. Canadian researchers have recently published a descriptive study that examined repeat adverse drug events associated with outpatient medications. Clinical pharmacists and physicians independently evaluated patients who visited the emergency department for adverse drug events in three hospitals: among 12 977 patients, 1178 were diagnosed with 1296 adverse drug events at the point of care and 32.5% (421 of 1296; 95% confidence interval [CI] 29.8%–35.1%) were repeat events, of which 75.3% (317 of 421; 95% CI 71.1%–79.5%) were deemed probably or definitely preventable as re-exposure to the implicated drug or where repeat withdrawal of an indicated medication was inconsistent with best medical practice. The odds of a repeat event were increased if the patient had renal failure or a mental health diagnosis. Moderate and severe ADRs accounted for many of the events documented. Read the full study here