[Quality control of coagulation tests (author's transl)].

The results of quality control of coagulation tests from intralaboratory control programmes are reported and compared with interlaboratory surveys. The test programme includes the following assays: the thromboplastin time (Quick), the partial thromboplastin time and the thrombotest. It can be seen from the results of the thromboplastin time that reliable figures were obtained from intralaboratory quality control examinations only (CV=7% to 13%). In comparison to these results great differences were found in interlaboratory surveys (CV=15% to 30%). The result of interlaboratory surveys of the thrombotest demonstrated a CV of 15% to 20%. The intralaboratory quality control of the partial thromboplastin time showed satisfactory reliability (CV=7.4%). Satisfactory conformity of results was obtained between different laboratories only by using common reagents (CV=8.7%). Possible factors responsible for deviations in laboratory examinations are discussed and proposals for improvement in the realibility of coagulation tests are made.