The Annals of Applied Statistics

A Bayesian approach to the evaluation of risk-based microbiological criteria for Campylobacter in broiler meat

Jukka Ranta, Roland Lindqvist, Ingrid Hansson, Pirkko Tuominen, and Maarten Nauta

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Shifting from traditional hazard-based food safety management toward risk-based management requires statistical methods for evaluating intermediate targets in food production, such as microbiological criteria (MC), in terms of their effects on human risk of illness. A fully risk-based evaluation of MC involves several uncertainties that are related to both the underlying Quantitative Microbiological Risk Assessment (QMRA) model and the production-specific sample data on the prevalence and concentrations of microbes in production batches. We used Bayesian modeling for statistical inference and evidence synthesis of two sample data sets. Thus, parameter uncertainty was represented by a joint posterior distribution, which we then used to predict the risk and to evaluate the criteria for acceptance of production batches. We also applied the Bayesian model to compare alternative criteria, accounting for the statistical uncertainty of parameters, conditional on the data sets. Comparison of the posterior mean relative risk, $E(\mathit{RR}|\mathrm{data})=E(P(\mathrm{illness}|\mathrm{criterion\ is\ met})/P(\mathrm{illness})|\mathrm{data})$, and relative posterior risk, $\mathit{RPR}=P(\mathrm{illness}|\mathrm{data,\ criterion\ is\ met})/P(\mathrm{illness}|\mathrm{data})$, showed very similar results, but computing is more efficient for RPR. Based on the sample data, together with the QMRA model, one could achieve a relative risk of 0.4 by insisting that the default criterion be fulfilled for acceptance of each batch.

Article information

Ann. Appl. Stat., Volume 9, Number 3 (2015), 1415-1432.

Received: March 2014
Revised: May 2015
First available in Project Euclid: 2 November 2015

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Bayesian modeling hierarchical models evidence synthesis uncertainty OpenBUGS 2D Monte Carlo quantitative microbiological risk assessment food safety Campylobacter


Ranta, Jukka; Lindqvist, Roland; Hansson, Ingrid; Tuominen, Pirkko; Nauta, Maarten. A Bayesian approach to the evaluation of risk-based microbiological criteria for Campylobacter in broiler meat. Ann. Appl. Stat. 9 (2015), no. 3, 1415--1432. doi:10.1214/15-AOAS845.

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Supplemental materials

  • Appendix: A Bayesian approach to the evaluation of risk-based microbiological criteria for Campylobacter in broiler meat. More details of computations and the BUGS codes are described in the supplementary materials.