This retrospective study reviewed 15,000 medical records following hospital discharge to determine the rate and characteristics of preventable adverse events. Using a random sample of records, the study design required a physician and a nurse to review charts and identify 18 criteria associated with an adverse event. These events were subsequently reviewed by two study investigators to judge preventability. Results indicated a significant number of adverse events in both elderly (>65) and nonelderly patient populations. A detailed table in the paper presents the number and types of events recorded. The authors conclude that elderly patients experience higher rates of falls, preventable adverse drug events, and events related to procedures; these findings suggest potential areas for safety interventions.