[Effort in standardization of control survey using pooled fresh serum in Okayama Prefecture].

Control survey of the clinical laboratories in Okayama Prefecture has been continued once a year for 18 years using commercially available control serum. The purpose of our control survey is to minimize the difference of laboratory test data among laboratories. It is clear, however, that one time a year survey leads to miss-evaluation of the difference in laboratory test result. Furthermore the data difference caused by difference of assay methods, for example dry chemistry and wet chemistry, is not properly evaluated by control survey using control serum, since test result is affected by matrix effect. Therefore we have developed a monthly control survey program, Okayama cross-check program, using pooled fresh serum among laboratories of middle-large scale hospitals and commercial laboratories in Okayama prefecture. In this paper we describe the details of Okayama cross-check program and the usefulness of the program to reduce the difference among laboratory facilities. This result was attained by cooperation of the Okayama prefectural medical association, Okayama association of medical technologists, and commercial laboratories in Okayama.