A new profile likelihood confidence interval for the mean probability of detection in collaborative studies of binary test methods
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A confidence interval for the probability of detection across laboratories (LPOD) for qualitative methods, described in the AOAC INTERNATIONAL guidelines for validation of microbiological methods for food and environmental surfaces, is considered. It is demonstrated that under certain conditions, the observed confidence of this confidence interval can be rather low, so that statistical minimum requirements are not fulfilled. A new profile likelihood confidence interval based on a latent random laboratory effect approach is proposed. Observed confidence levels for this confidence interval demonstrate its applicability already for a small number of laboratories.
KeywordsPOD Collaborative study Confidence interval Qualitative test Validation Latent random effect Observed confidence Coverage
The authors wish to thank the anonymous reviewers for their valuable comments and suggestions to improve the quality of the paper.
- 4.Wehling P, LaBudde RA, Brunelle SL, Nelson MT (2011) Probability of detection (POD) as a statistical model for the validation of qualitative methods. JAOAC 94:335–347Google Scholar
- 5.AOAC INTERNATIONAL (2012) Methods committee guidelines for validation of microbiological methods for food and environmental surfaces. AOAC Pre-Publication DraftGoogle Scholar
- 10.ISO 5725-2 (2002) Accuracy (trueness and precision) of measurement methods and results—part 2: basic method for the determination of repeatability and reproducibility of a standard measurement method (ISO 5725-2:1994 including Technical Corrigendum 1:2002)Google Scholar
- 11.QuoData Web Services, Validation of qualitative methods, http://quodata.de/en/web-services.html, Accessed Feb 18, 2013
- 12.PROLabTM, http://quodata.de/en/software/for-interlaboratory-tests/prolab.html, Accessed Feb, 18 2013