Analytical performance characteristics should be judged against objective quality specifications.

The discipline of clinical chemistry is dynamic. Even a superficial glance at contents pages of the Journal over recent years demonstrates a marked evolution of the field. Appropriately, the Information for authors has also changed over the years to reflect new concepts of what constitutes an acceptable publication. Readers of the Journal may have noticed an addition to the 1999 Information for authors (1 ), under the heading Description of Analytical Methods and Results, namely: “Analytical quality. Results obtained for the performance characteristics should be compared objectively to welldocumented quality specifications, e.g., published data on the state of the art, performance required by regulatory bodies such as CLIA ‘88, or recommendations documented by expert professional groups”. In addition, quality specifications can be derived from analysis of performance on clinical decision-making. Many manuscripts deal with the development of new analytical methods or evaluation of commercially available analytical systems. Experimental designs and statistical techniques used to derive data on imprecision and bias are generally more than satisfactory. This is hardly surprising in view of the very many published protocols for the evaluation of methods (2 ). In contrast, objective analysis of whether the imprecision and bias are satisfactory is often less well done. This is not a new phenomenon. Although the idea of utilizing quality specifications in assessing the acceptability of method performance was firmly stated in 1974 (3 ), it was pointed out more than a decade ago that few evaluators actually did compare the performance achieved with preset quality specifications (4, 5 ). This seems rather difficult to understand because quality specifications based on the state of the art (6 ), the views of an expert individual (7 ), and biological variation (8 ) had been available for many years. Indeed, even a superficial reading of the more recent literature would demonstrate that many papers, reviews, conference proceedings, and book chapters deal with the generation and application of quality specifications (9 ). It may be that there are too many contradictory published recommendations, and it might not be easy for authors to select the most appropriate. In addition, new strategies to set quality specifications continue to appear, which might suggest that there is no ubiquitous professional consensus. Moreover, industry does not appear to use professionally set quality specifications as major considerations in either development or marketing. In spite of these difficulties, there are many quality specifications against which experimental data can be compared, at least for tests reported on ratio (and difference) scales, and we suggest the following approach, which like the types of evidence and grading of recommendations used in clinical practice guidelines (10 ) can be placed in a hierarchy of objectivity, the best being first and the worst being last.