Systemkontrolle is the check that the entire measuring system is still doing what it should, and the word system carries the weight in that sentence. The system is not the instrument alone. It is the device together with the strip or cassette currently in use, the reagent lot, the control material and the person performing the measurement. A check limited to the instrument leaves out most of the places a wrong number actually comes from.
In practice it is a measurement of control material with a known target value, run exactly as a customer sample would be run, by someone who runs them, on the consumables presently in the drawer. The result is compared with the acceptable range and recorded with the date, the device, the lot number and the initials of whoever carried it out. That record is the evidence that the system was sound at that hour, and it belongs in the pharmacy Standardarbeitsanweisung as a fixed step rather than a habit, so the schedule survives a change of shift.
Two things it is not. It does not set the scale on which values are read, since that is Kalibrierung and it happens before any control is measured. It is also not external comparison. In a Ringversuch an unknown sample arrives from outside and the pharmacy result is judged against other participants, which tests the pharmacy against the wider world rather than against its own device yesterday. Within the pharmacy the routine check and the wider interne Qualitätskontrolle describe the same daily work seen from slightly different angles.
The schedule is usually a check at the start of a testing session, with every new lot of strips or reagent, after maintenance, after a repair and whenever storage conditions have been in doubt, with the intervals taken from the Gebrauchsanweisung of the device.
A failed check has consequences that reach backwards. The Point-of-Care-Test is withdrawn for that parameter until the cause is found, and every result measured since the last good check is treated as unconfirmed, including the ones already handed to customers that day. The pharmacy notes which measurements fall into that window, contacts those people and offers a repeat measurement, without commenting on what the earlier value might have meant.
This glossary entry is general information about German pharmacy law and practice. It is not legal advice. For binding guidance on your own pharmacy, contact your Landesapothekerkammer.
