Evaluation of non-core laboratories.

The CAP Interlaboratory Survey data from the non-core laboratories identified by Paule and Mandel were examined. Some laboratories were designated non-core because they submitted one or more values that were widely discrepant and were caused by unit problems, decimal shifts, or reversal of the specimens. A second group of laboratories submitted a number of discrepant results that appeared to be caused by problems within the laboratories. A third group submitted results that appeared acceptable, and the exclusion and the effectiveness of the criteria differed for each of the three analytes. The findings suggest that examination of data from excluded laboratories can provide a valuable source of information to supplement the central data.