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Implementation of the Gibbs sampler for estimating the accuracy of multiple binary diagnostic tests in one population has been investigated. This method, proposed by Joseph, Gyorkos and Coupal, makes use of a Bayesian approach and is used in the absence of a gold standard to estimate the prevalence, the sensitivity and specificity of medical diagnostic tests. The expressions that allow this method to be implemented for an arbitrary number of tests are given. By using the convergence diagnostics procedure of Raftery and Lewis, the relation between the number of iterations of Gibbs sampling and the precision of the estimated quantiles of the posterior distributions is derived. An example concerning a data set of gastro-esophageal reflux disease patients collected to evaluate the accuracy of the water siphon test compared with 24 h pH-monitoring, endoscopy and histology tests is presented. The main message that emerges from our analysis is that implementation of the Gibbs sampler to estimate the parameters of multiple binary diagnostic tests can be critical and convergence diagnostic is advised for this method. The factors which affect the convergence of the chains to the posterior distributions and those that influence the precision of their quantiles are analyzed. [ABSTRACT FROM AUTHOR]

Background: Anti-Leishmania antibodies are increasingly investigated in cats for epidemiological studies or for the diagnosis of clinical feline leishmaniosis. The immunofluorescent antibody test (IFAT), the enzyme-linked immunosorbent assay (ELISA) and western blot (WB) are the serological tests more frequently used. The aim of the present study was to assess diagnostic performance of IFAT, ELISA and WB to detect anti-L. infantum antibodies in feline serum samples obtained from endemic (n = 76) and non-endemic (n = 64) areas and from cats affected by feline leishmaniosis (n = 21) by a Bayesian approach without a gold standard. Methods: Cut-offs were set at 80 titre for IFAT and 40 ELISA units for ELISA. WB was considered positive in presence of at least a 18 KDa band. Statistical analysis was performed through a written routine with MATLAB software in the Bayesian framework. The latent data and observations from the joint posterior were simulated in the Bayesian approach by an iterative Markov Chain Monte Carlo technique using the Gibbs sampler for estimating sensitivity and specificity of the three tests. Results: The median seroprevalence in the sample used for evaluating the performance of tests was estimated at 0.27 [credible interval (CI) = 0.20-0.34]. The median sensitivity of the three different methods was 0.97 (CI: 0.86-1.00), 0.75 (CI: 0.61-0.87) and 0.70 (CI: 0.56-0.83) for WB, IFAT and ELISA, respectively. Median specificity reached 0.99 (CI: 0.96-1.00) with WB, 0.97 (CI: 0.93-0.99) with IFAT and 0.98 (CI: 0.94-1.00) with ELISA. IFAT was more sensitive than ELISA (75 vs 70%) for the detection of subclinical infection while ELISA was better for diagnosing clinical leishmaniosis when compared with IFAT (98 vs 97%). Conclusions: The overall performance of all serological techniques was good and the most accurate test for anti-Leishmania antibody detection in feline serum samples was WB. [ABSTRACT FROM AUTHOR]

Objectives The aim of this study was to show the potential of Bayesian analysis in statistical modelling of dental caries data. Because of the bounded nature of the dmft ( DMFT) index, zero-inflated binomial ( ZIB) and beta-binomial ( ZIBB) models were considered. The effects of incorporating prior information available about the parameters of models were also shown. Methods The data set used in this study was the Belo Horizonte Caries Prevention ( BELCAP) study (Böhning et al. (1999)), consisting of five variables collected among 797 Brazilian school children designed to evaluate four programmes for reducing caries. Only the eight primary molar teeth were considered in the data set. A data augmentation algorithm was used for estimation. Firstly, noninformative priors were used to express our lack of knowledge about the regression parameters. Secondly, prior information about the probability of being a structural zero dmft and the probability of being caries affected in the subpopulation of susceptible children was incorporated. Results With noninformative priors, the best fitting model was the ZIBB. Education ( OR = 0.76, 95% CrI: 0.59, 0.99), all interventions ( OR = 0.46, 95% CrI: 0.35, 0.62), rinsing ( OR = 0.61, 95% CrI: 0.47, 0.80) and hygiene ( OR = 0.65, 95% CrI: 0.49, 0.86) were demonstrated to be factors protecting children from being caries affected. Being male increased the probability of being caries diseased ( OR = 1.19, 95% CrI: 1.01, 1.42). However, after incorporating informative priors, ZIB models' estimates were not influenced, while ZIBB models reduced deviance and confirmed the association with all interventions and rinsing only. Discussion In our application, Bayesian estimates showed a similar accuracy and precision than likelihood-based estimates, although they offered many computational advantages and the possibility of expressing all forms of uncertainty in terms of probability. The overdispersion parameter could expound why the introduction of prior information had significant effects on the parameters of the ZIBB model, while ZIB estimates remained unchanged. Finally, the best performance of ZIBB compared to the ZIB model was shown to catch overdispersion in data. [ABSTRACT FROM AUTHOR]

Purpose: Local neck symptoms (LNS) may be related to goiter, but are also reported by patients suffering from laryngeal–pharyngeal reflux (LPR). The aim of this study was to investigate whether LPR could play a role in the persistence of some LNS after total thyroidectomy (TT). Methods: A consecutive case series of 160 patients with multinodular goiter (MNG) candidate for TT were included in this study. Each patient was closely studied for both the thyroid pathology and reflux disease before and 6 months after surgery to assess the persistence of LNS after surgery. Results: Only throat discomfort showed a significant improvement (p = 0.031) after surgery. On the other hand, swallowing and voice disorders persisted after surgery in 82.3% and 77.3% of patients, respectively (p = 0.250 and p = 0.062), such as the correlated reflux laryngopharyngitis (p = 0.5). Conclusions: LPR can be considered a predisposing factor or an important concurrent causa to the persistence of LNS after TT, in particular for swallowing disorders and voice disorders. In patients with non-toxic MNG who complain of local neck symptoms, the investigation of a possible coexistence of a reflux disease is appropriate before surgery. Patients should be informed about the possibility that some symptoms can persist even after removal of the goiter. [ABSTRACT FROM AUTHOR]

The concept of openness to research output has been strengthened by the current EU funding research programme Horizon 2020. In early 2017 the BISA (Bibliosan for Open Science) inter-institutional Working Group, including scientific information experts mainly from Istituto Superiore di Sanità (ISS, Italian National Institute of Health), carried out a survey on the practical handling of research data produced by Bibliosan affiliated institutions, the Italian Biomedical Research Libraries Network promoted by the Italian Ministry of Health. The BISA online questionnaire collected over 2,400 responses obtained from 58 Bibliosan institutions. Among the various aspects of data management covered by the BISA questionnaire, that one referring to the need of a policy and guidelines, to be adopted by Bibliosan research institutions, for dealing with research data was deeply investigated. [ABSTRACT FROM AUTHOR]

Background: Cats can be carriers of infected arthropods and be infected with several vector-borne pathogens (VBP) but there is limited knowledge about their pathogenic role in cats. Results: A cross-sectional controlled study investigated the clinical status and antibody (Bartonella henselae, Rickettsia conorii, Ehrlichia canis, Anaplasma phagocytophilum, Babesia microti and Leishmania infantum) and/or blood PCR (Mycoplasma spp., Bartonella spp., Rickettsia spp., Ehrlichia/Anaplasma spp., piroplasmids, L. infantum, Hepatozoon felis) prevalence in 197 cats. Outdoor cats lacking ectoparasiticide treatment or hosting ectoparasites (study group [SG], n = 134) and indoor cats treated against ectoparasites (control group [CG], n = 63) were enrolled. Clinical data and retroviral co-infections were compared between the two groups. Multivariable analysis tested associations between variables and VBP exposure. Lymphadenia, stomatitis, and various haematological abnormalities were statistically more frequent in SG. Antibodies against R. conorii, B. henselae, A. phagocytophylum, B. microti, E. canis and L. infantum were detected. Bartonella henselae, Bartonella clarridgeiae, Mycoplasma haemofelis, “Candidatus Mycoplasma haemominutum” and “Candidatus Mycoplasma turicensis” DNA were identified. Very high antibody (87.8%) and PCR (40.1%) positivity to at least one pathogen were detected and were significantly higher in SG. Co-infections were confirmed in about one-third of the cats and were more frequent in SG cats. Molecular and overall (antibody and PCR) positivity to Bartonella and antibody positivity to R. conorii were higher in SG. Multivariable analysis found significant associations of Bartonella spp. infection with Feline Immunodeficiency Virus (FIV) infection and increased globulins, and of Mycoplasma spp. infection with adult age, FIV infection, anaemia, and increased creatinine. Conclusions: A very high prevalence of exposure to zoonotic VBP was found in cats, with Rickettsia and Bartonella infections being most prevalent. Some risk factors were documented namely for Mycoplasma spp. and Bartonella spp. The lifestyle of cats is clinically relevant and requires specific preventative measures to protect their health. [ABSTRACT FROM AUTHOR]