The present invention relates to an extracorporeal blood treatment device comprising at least one output unit for outputting at least one report to a user of the blood treatment device, wherein the blood treatment device is configured to output at least one report by means of the output device after the end of a specific period of time since the switching on of the blood treatment device and/or on the occurrence of a specific event, said report relating to one or more pieces of information relating to the validity of a test carried out at the blood treatment device.