Annually, about 93,000 nursing home (NH) residents die in the U.S. due to adverse drug events (ADEs), though many of them are preventable. ADEs are medication-induced injuries such as a drop in blood pressure or blood glucose, bleeding and falls. My dissertation can help identify causes of ADEs and reduce their impact on NH residents by investigating multiple organization factors (people (staff/residents), tasks, technologies, collaboration, and internal conditions) affecting ADEs in NHS.