Zero‐inflated regression models for radiation‐induced chromosome aberration data: A comparative study

Abstract

yliveir D w r¡ % nd iin e kD to hen nd riguer sD w nuel nd eins uryD iliz eth nd uigD edro nd othk mmD u i @PHITA 9 eroEin) ted regression models for r di tionEindu ed hromosome err tion d t X omp r tive studyF9D fiometri l journ lFD SV @PAF ppF PSWEPUWFFurther information on publisher's website:httpXGGdxFdoiForgGIHFIHHPG imjFPHIRHHPQQPublisher's copyright statement:his is the epted version of the following rti leX yliveir D w r¡ % D iin e kD to henD riguer sD w nuelD eins uryD iliz ethD uigD edro nd othk mmD u i @PHITA eroEin) ted regression models for r di tionEindu ed hromosome err tion d t X omp r tive studyF fiometri l journ lD SV@PAX PSWEPUWD whi h h s een pu lished in (n l form t httpXGGdxFdoiForgGIHFIHHPG imjFPHIRHHPQQF his rti le m y e used for nonE ommer i l purposes in ord n e ith ileyE gr erms nd gonditions for selfE r hivingF Additional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. Within the field of cytogenetic biodosimetry, Poisson regression is the classical approach for modelling the number of chromosome aberrations as a function of radiation dose. However, it is common to find data that exhibit overdispersion. In practice, the assumption of equidispersion may be violated due to unobserved heterogeneity in the cell population, which will render the variance of observed aberration counts larger than their mean, and/or the frequency of zero counts greater than expected for the Poisson distribution. This phenomenon is observable for both full and partial body exposure, but more pronounced for the latter. In this work, different methodologies for analysing cytogenetic chromosomal aberrations datasets are compared, with special focus on zero-inflated Poisson and zero-inflated negative binomial models. A score test for testing for zero-inflation in Poisson regression models under the identity link is also developed.

Population‐Based Pharmacokinetic and Exposure‐Efficacy Analyses of Peginterferon Beta‐1a in Patients With Relapsing Multiple Sclerosis

“…ARR has been commonly used as a primary efficacy endpoint in phase 3 MS clinical trials . Because of data overdispersion, negative binomial regression is often used to analyze the data . In cases with excessive 0 counts, the ZIP and zero‐inflated negative binomial models are gaining popularity .…”

“…30 Because of data overdispersion, negative binomial regression is often used to analyze the data. 5,[31][32][33] In cases with excessive 0 counts, the ZIP and zero-inflated negative binomial models are gaining popularity. [31][32][33][34] However, there are some limitations of zero-inflated models.…”

Uncertainty of fast biological radiation dose assessment for emergency response scenarios

“…Several publications have demonstrated that distributions other than the Poisson may be more applicable to yields of chromosome aberrations (e.g. Ainsbury et al 2013;Higueras et al 2015, Oliveira et al 2016, for example, and thus it is possible that radiation dose estimates may be more accurately described by alternative distributions to the Poisson. The Bayesian approach allows much more accurate characterization of the dose distribution as it is based on the combined information regarding the potential dose and exposure scenario, the calibration coefficients and the yield of aberrations.…”

Editorial: Special issue on models for continuous data with a spike at zero

“…Oliveira et al. () investigate data on the number of chromosome aberrations in cytogenetic biodosimetry. Given the discrete nature of the response, this paper offers a bridge between well‐established modeling techniques in the zero‐inflated count data context, and the extension of such methodologies to the wider context of semicontinuous data.…”

“…These articles cover different areas, all of interest to the biometric community, and give insights and suggestions on how such kind of situations can be efficiently handled. Oliveira et al (2016) investigate data on the number of chromosome aberrations in cytogenetic biodosimetry. Given the discrete nature of the response, this paper offers a bridge between well-established modeling techniques in the zero-inflated count data context, and the extension of such methodologies to the wider context of semicontinuous data.…”