Microbiology Methods for ERP Review 3-2020

was calculated as the number of positive outcomes divided by the total number of trials. Laboratory POD (LPOD) values were calculated as the total POD values for all collaborators. The LPOD was calculated for the candidate presumptive results, LPOD CP, the candidate confirmatory results (including false negative results), LPOD CC , the difference in the candidate presumptive and confirmatory results, dLPOD CP, presumptive candidate results that confirmed positive (excluding false negative results), LPOD C, the reference method, LPOD R , and the difference in the confirmed candidate and reference methods, dLPOD C . A dLPOD C confidence interval not containing the point zero would indicate a statistically significant difference between the candidate method and the reference method at the 95 % confidence level. In addition to POD values, the repeatability standard deviation (s r ), the among laboratory repeatability standard deviation (s L ), the reproducibility standard deviation (s R ) and the standard error were calculated. 12

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