@article{williams_ommen_hannig_2023, title={GENERALIZED FIDUCIAL FACTOR: AN ALTERNATIVE TO THE BAYES FACTOR FOR FORENSIC IDENTIFICATION OF SOURCE PROBLEMS}, volume={17}, ISSN={["1941-7330"]}, DOI={10.1214/22-AOAS1632}, abstractNote={One formulation of forensic identification of source problems is to determine the source of trace evidence, for instance, glass fragments found on a suspect for a crime. The current state of the science is to compute a Bayes factor comparing the marginal distribution of measurements of trace evidence under two competing propositions for whether or not the unknown source evidence originated from a specific source. The obvious problem with such an approach is the ability to tailor the prior distributions (placed on the features/parameters of the statistical model for the measurements of trace evidence) in favor of the defense or prosecution which is further complicated by the fact that the typical number of measurements of trace evidence is typically sufficiently small that prior choice/specification has a strong influence on the value of the Bayes factor. To remedy this problem of prior specification and choice, we develop an alternative to the Bayes factor, within the framework of generalized fiducial inference, that we term a generalized fiducial factor. Furthermore, we demonstrate empirically, on synthetic and real Netherlands Forensic Institute casework data, deficiencies in Bayes factor and classical/frequentist likelihood ratio approaches.}, number={1}, journal={ANNALS OF APPLIED STATISTICS}, author={Williams, Jonathan P. and Ommen, Danica M. and Hannig, Jan}, year={2023}, month={Mar}, pages={378–402} }
 @article{williams_xie_hannig_2022, title={The EAS approach for graphical selection consistency in vector autoregression models}, ISSN={["1708-945X"]}, DOI={10.1002/cjs.11726}, abstractNote={en}, journal={CANADIAN JOURNAL OF STATISTICS-REVUE CANADIENNE DE STATISTIQUE}, author={Williams, Jonathan P. and Xie, Yuying and Hannig, Jan}, year={2022}, month={Sep} }
 @article{nghiem_williams_afoakwah_huynh_ng_byrnes_2021, title={Can Administrative Health Data Improve the Gold Standard? Evidence from a Model of the Progression of Myocardial Infarction}, volume={18}, ISSN={["1660-4601"]}, DOI={10.3390/ijerph18147385}, abstractNote={Background: Myocardial infarction (MI), remains one of the leading causes of death and disability globally but publications on the progression of MI using data from the real world are limited. Multistate models have been widely used to estimate transition rates between disease states to evaluate the cost-effectiveness of healthcare interventions. We apply a Bayesian multistate hidden Markov model to investigate the progression of MI using a longitudinal dataset from Queensland, Australia. Objective: To apply a new model to investigate the progression of myocardial infarction (MI) and to show the potential to use administrative data for economic evaluation and modeling disease progression. Methods: The cohort includes 135,399 patients admitted to public hospitals in Queensland, Australia, in 2010 treatment of cardiovascular diseases. Any subsequent hospitalizations of these patients were followed until 2015. This study focused on the sub-cohort of 8705 patients hospitalized for MI. We apply a Bayesian multistate hidden Markov model to estimate transition rates between health states of MI patients and adjust for delayed enrolment biases and misclassification errors. We also estimate the association between age, sex, and ethnicity with the progression of MI. Results: On average, the risk of developing Non-ST segment elevation myocardial infarction (NSTEMI) was 8.7%, and ST-segment elevation myocardial infarction (STEMI) was 4.3%. The risk varied with age, sex, and ethnicity. The progression rates to STEMI or NSTEMI were higher among males, Indigenous, or elderly patients. For example, the risk of STEMI among males was 4.35%, while the corresponding figure for females was 3.71%. After adjustment for misclassification, the probability of STEMI increased by 1.2%, while NSTEMI increased by 1.4%. Conclusions: This study shows that administrative health data were useful to estimate factors determining the risk of MI and the progression of this health condition. It also shows that misclassification may cause the incidence of MI to be under-estimated.}, number={14}, journal={INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH}, author={Nghiem, Son and Williams, Jonathan and Afoakwah, Clifford and Huynh, Quan and Ng, Shu-kay and Byrnes, Joshua}, year={2021}, month={Jul} }
 @article{williams_2021, title={Discussion of "A Gibbs Sampler for a Class of Random Convex Polytopes"}, volume={116}, ISSN={["1537-274X"]}, DOI={10.1080/01621459.2021.1946405}, abstractNote={I commend the authors for their efforts in revisiting the DS framework for statistical inference, but from a computational perspective. It is perhaps untraditional for the Theory and Methods sectio...}, number={535}, journal={JOURNAL OF THE AMERICAN STATISTICAL ASSOCIATION}, author={Williams, Jonathan P.}, year={2021}, month={Jul}, pages={1198–1200} }
 @article{oh_foster_williams_zheng_ru_lunn_mowat_2019, title={Diagnostic utility of clinical and laboratory test parameters for differentiating between sudden acquired retinal degeneration syndrome and pituitary‐dependent hyperadrenocorticism in dogs}, volume={22}, ISSN={1463-5216 1463-5224}, url={http://dx.doi.org/10.1111/vop.12661}, DOI={10.1111/vop.12661}, abstractNote={Objective To identify discriminating factors, using clinical ophthalmic examination findings and routine laboratory testing, that differentiate dogs with early sudden acquired retinal degeneration (SARDS; vision loss <6 weeks’ duration), age- and breed-matched control dogs, and dogs with pituitary-dependent hyperadrenocorticism (PDH). Animals Client-owned dogs: 15 with SARDS with <6 weeks duration of vision loss, 14 age- and breed-matched control dogs, and 13 dogs with confirmed PDH. Procedures Dogs underwent ophthalmic examination, electroretinography (ERG) fundus photography, and spectral-domain optical coherence tomography (SD-OCT) in addition to physical examination, urinalysis, serum biochemistry, complete blood count, and adrenocorticotrophic hormone (ACTH) stimulation testing. Statistical analysis was performed using receiver operating curve area under the curve analysis, principal component analysis with sparse partial least squares analysis, and one-way ANOVA. Results Dogs with SARDS all had absent vision and ERG a- and b-waves. SD-OCT demonstrated that dogs with SARDS had significantly thicker inner retina, thinner outer nuclear layer, and thicker photoreceptor inner/outer segment measurements than either controls or dogs with PDH. Discriminating laboratory parameters between dogs with SARDS and PDH with high specificity included post-ACTH serum cortisol (<19.3 μg/dL), AST:ALT ratio (>0.343), and urine specific gravity (>1.030). Conclusions and Clinical Relevance We have identified significant discriminators between SARDS and PDH. This work provides the basis for future studies that could identify and examine dogs with SARDS prior to vision loss, which may extend the potential therapeutic window for SARDS.}, number={6}, journal={Veterinary Ophthalmology}, publisher={Wiley}, author={Oh, Annie and Foster, Melanie L. and Williams, Jonathan G. and Zheng, Chaowen and Ru, Hongyu and Lunn, Katharine F. and Mowat, Freya M.}, year={2019}, month={Mar}, pages={842–858} }