Device events in tobacco studies may consist of device problems (which may or may not result in adverse events), device-reported warnings or alarms, calibration events, and replacement of parts. This information is represented in the Device Events (DE) and associated domains. In device studies, cases where the device did not perform as expected are typically called "events" or "incidents," rather than "problems" or "malfunctions," because often the true cause of the issue cannot be determined until a cause analysis is performed. This may or may not be a concern for a given trial depending upon whether the device has already been approved by regulators. Typically, post-approval device studies are less concerned about root-issue attribution.
There is more than one approach to identifying devices in studies. The method chosen will depend upon the granularity at which the sponsor needs to track the devices and will affect how the data are modeled. A device can be identified as a single unit (e.g., a syringe), or its components can be separately identified (e.g., barrel, plunger, needle). The level of granularity a sponsor chooses will be influenced by whether the components will be replaced and/or tracked, and how device/adverse event relationships and actions taken will be assessed.