Usually the device throws out reliable results when it functions properly. If you accidentally drop the device but don't notice any errors while taking new measurements you don't have to worry. The main component which has the most influence on the accuracy is stored in the computer program. Either the software works or not. Other parts which influence the accuracy like for example the drain valve or the pressure sensor are protected very carefully to avoid manipulation through aging or accidents.
In any case and after the international restrictments we recommend to let the accuracy of your device be checked by the MEDISANA support service.