This study evaluated methods for medical device event surveillance to help identify and classify an important source of adverse events. Investigators used a number of different strategies to capture device-related events, which included a computer-based system, discharge codes (ICD-9), work logs, and patient survey results. They analyzed more than 7000 identified problems and discovered that very few events were captured by more than one surveillance strategy. Their findings suggest that voluntary reporting alone vastly underestimates the rate of medical device-related errors. Furthermore, future investigation to better understand the incidence and nature of such events must occur to frame necessary prevention efforts.