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Proficiency Tests (This information is reprinted from the October 2000 ASCLD/LAB Newsletter and is of particular interest to all examiners working in accredited laboratories.) One of the most frequent maxims used concerning proficiency test samples is that they should be handled as “regular” case work. What does the ASCLD/LAB Board of Directors think? Should proficiency tests be handled like case work? Well, yes and no. Proficiency tests should attempt to test your whole quality system, which would include receipt, handling, analysis, technical review, administrative review and reporting. With the typical proficiency samples, it is difficult to truly mimic an actual case sample, so the analysis, review and reporting stages are usually being tested. Proficiency tests are designed to “evaluate the competence of analysts, support personnel and the quality of performance of a laboratory.” The proficiency test should test analytical methods, how they are applied and the resulting data. The proficiency test should not be subject to policies adopted by a laboratory for efficiency or expediency. Concerns recently brought to the Board have included a situation whereby a laboratory adopted a latent print comparison policy on case work which stated that once a suspect is identified on a particular surface, additional latent prints on that surface do not need to be compared. In casework, this is a way of managing your resources. In proficiency testing, this may result in only a few of the proficiency test latent prints being compared which would lead to incomplete results sent to the provider. A proficiency test will be subject to the full complement of available laboratory examinations without regard to efficiency or expediency. In another case a laboratory failed to detect a controlled substance on botanical material. The laboratory did not make it a practice to extract botanical material for controlled substances since the policy of their prosecutor's office was not to prosecute these types of cases. In this instance, not finding a controlled substance was inconsistent with the consensus answer. Despite whatever operational policy a laboratory might maintain, this would be a situation where the laboratory has not demonstrated the competence of the analyst and the quality performance of the laboratory in analyzing a not infrequent type of controlled substance submission. A laboratory with this type of policy should seriously review their analytical procedures regarding these types of cases. Another issue frequently raised is proficiency testing being performed like case work in group analysis, where by several analysts work the same proficiency test sample, arrive at the consensus answer and report that answer. If you don't perform and review case work this way, you should not do proficiency testing this way. However, if your laboratory requires that a casework conclusion be verified by re--analysis of an actual case sample or result, that action is an acceptable proficiency test practice. Contrast this with a team analysis scenario that can occur in disciplines such as DNA. If you normally have a technician prepare a sample for DNA typing by an analyst, both can share a proficiency test to the extent that they perform these duties on casework. The proficiency test is worked like a “regular” case. What's the bottom line answer? Do casework like casework, but do proficiency tests in such a manner that the competence of analysts, support personnel, and the quality of performance of a laboratory can be evaluated.
This article was printed in “THE PRINT” |