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Procedures for the statistical evaluation of method comparisons and instrument tests often have a requirement for distributional properties of the experimental data, but this requirement is frequently not met. In our paper we propose a new linear regression procedure with no special assumptions regarding the distribution of the samples and the measurement(More)
In part I of this series (H. Passing & W. Bablok (1983), J. Clin. Chem. Clin. Biochem. 21, 709-720) we described a new biometrical procedure for the evaluation of method comparison studies. In part II we now discuss its properties and compare them with those of other established procedures by means of a simulation study. We demonstrate that the reliability(More)
Evaluation of analytical instruments in clinical laboratories should be carried out in a systematic and uniform manner in order to provide data which can be compared and reproduced by different users, manufacturers and officials. Concepts for such an evaluation of instruments with continuous measurement values are presented in the ECCLS guidelines [1]. To(More)
The biometrical treatment of laboratory data may require the estimation of a regression line for the transformation of one set of measurements to another. The regression procedure introduced in part I (1) of our work does not always yield unbiased results in such situations, since its estimators are not scale invariant. In part III we present the parameter(More)
It is current practice to record the performance of immunoassays by means of precision profiles (according to Ekins), in which the variation coefficient (relative standard deviation) is plotted against the analyte concentration. On the other hand, precision profiles are only occasionally used for evaluating the performance of conventional clinical-chemical(More)
  • H Passing
  • 1981
We compare 4 statistical models for the establishment of assigned values in a control serum which are based on the assumption of a normal distribution. The first model results in mean +/- 2s, whereas each of the following 3 models are based on a special analysis of variance. We studied by means of appropriate statistical tests the distributional properties(More)
From the study described in part 1 of this series (Passing, H. et al. (1981), this j. 19, 1137-1144) it has been derived in part 3 (Passing, H. (1981), this j. 19, 1153--1166) that 6 reference laboratories are appropriate for the establishment of assigned values and their uncertainty intervals in a control serum. From the same study the two outstanding(More)
We describe a study by which the establishment of assigned values of a control serum was simulated. The study covered two controls: The internal known control and a blind control. Seven constituents were analyzed in 10 or 11 laboratories, respectively, yielding a total of 72 sets of analytical values. Each set covered double determinations within(More)
In continuation of the three previous workshops on this theme, the Passing-Bablok method was recapitulated and compared with standardized main component analysis. Participants in the workshop recommended both methods in place of the classical regression analysis. An essential advantage of the standardized main component is that it is more easily understood(More)