External quality assessment scheme for haematology in Germany.

Quality control in haematology is performed in Germany for 20 years. Both cell count, haemoglobin measurement and differential count on smear with morphology exercise and probably diagnosis will be demanded by the participants. Until now this quality control is not mandatory, even efforts are done to change this circumstance, given by the main input of diagnostic value due to haematology results. So this regulation will be changed very soon, in order to submit haematological laboratories to governmental control, effected by the BAK (Bundesärztekammer), as already is done in clinical chemistry. For this EQA the participants cannot expected any financial support by any organization, nor public health, nor private assurance. The role of referee laboratories and reference values as well as difficulties for the adequate reference material are discussed. For the differential count other limits have to be established: recognition of pathological blood films is one of the most important point (in sense of morphological exercise) to ensure broad knowledge of "flag interpretation". Since the last year quality control for reticulocyte count and flow cytometry for immune status and leukemia-differentiation has been established.