Validation of PATHFx 2.0: An open-source tool for estimating survival in patients undergoing pathologic fracture fixation

Treatment decisions in patients with metastatic bone disease rely on accurate survival estimation. We developed the original PATHFx models using expensive, proprietary software and now seek to provide a more cost-effective solution. Using open-source machine learning software to create PATHFx version 2.0, we asked whether PATHFx 2.0 could be created using open-source methods and externally validated in two unique patient populations. The training set of a well-characterized, database records of 189 patients and the bnlearn package within R Version 3.5.1 (R Foundation for Statistical Computing), was used to establish a series of Bayesian belief network models designed to predict survival at 1, 3, 6, 12, 18, and 24 months. Each was externally validated in both a Scandinavian (n = 815 patients) and a Japanese (n = 261 patients) data set. Brier scores and receiver operating characteristic curves to assessed discriminatory ability. Decision curve analysis (DCA) evaluated whether models should be used clinically. DCA showed that the model should be used clinically at all time points in the Scandinavian data set. For the 1-month time point, DCA of the Japanese data set suggested to expect better outcomes assuming all patients will survive greater than 1 month. Brier scores for each curve demonstrate that the models are accurate at each time point. Statement of Clinical Significance: we successfully transitioned to PATHFx 2.0 using open-source software and externally validated it in two unique patient populations, which can be used as a cost-effective option to guide surgical decisions in patients with metastatic bone disease.     

影响2型糖尿病老年患者并发周围神经病变的logistic分析

目的 探讨2型糖尿病老年患者并发周围神经病变的影响因素。方法 选取2016年2月—2018年7月本院治疗的2型糖尿病老年患者120例作为研究对象,统计并发周围神经病变发生情况,根据有无发生周围神经病变分为DPN组57例和非DPN组63例,并对其影响因素进行调查分析。结果 DPN组患者与非DPN组患者的年龄、糖尿病病程、吸烟史、饮酒史、高血压病史、高血脂病史、BMI指数、FPG、HbA1c、UA水平差异有统计学意义(P<0.05),DPN组患者与非DPN组患者的性别、ALT、AST水平差异无统计学意义(P>0.05);Logisitic回归分析结果显示,年龄、糖尿病病程、吸烟史、饮酒史、高血压病史、高血脂病史、BMI指数、FPG、HbA1c、UA水平是2型糖尿病老年患者并发周围神经病变的影响因素。结论 年龄、糖尿病病程、吸烟史、饮酒史、高血压病史、高血脂病史、BMI指数、FPG、HbA1c、UA水平是2型糖尿病老年患者并发周围神经病变的影响因素,应积极采取有效措施进行控制糖尿病周围神经病变的发生与发展,提高2型糖尿病老年患者的生活质量。     

Defunciones por COVID-19: no están todas las que son y no son todas las que están

The death counts from COVID-19 have generated public controversy. The regional health councils’ need for information regardind the cases, has generated a variety of formats and procedures, used to report this information. Consecuently, this data has not always been communicated in a comparable maner to the Ministry of Health. The compilation of mortality statistics is complex. Central and autonomous public administrations are involved, and not in the same way. The medical death certificate (DC) is the main source of information that allows to specify place of occurrence and causes of death. The on-line registration of the DC in the computerized civil registry and/or digital medical records, would allow to establish a statistical processing circuit, and to obtain a death count more quickly according to causes of death in the event of a health emergency. This requires a multi-level institutional agreement for a total telematics statistic process of death causes in Spain.     

Mean differences and individual changes in nursing students' attitudes toward statistics: The role of math background and personality traits

Nursing students have compulsory statistics courses in their degree program, but they usually have negative attitudes toward statistics that may hinder their learning. The present study aims: (i) to investigate nurse students’ attitudes toward statistics and the relationships with mathematical background and personality traits; (ii) to stress individual changes in attitude that occur during the course; and (iii) to explore if mathematical background and personality traits influence these changes. We adopted a one-group pre-post survey study. Fifty nursing students were enrolled in an introductory statistics course at the Sapienza University of Rome in Italy during the 2018–2019 academic year. Participants were surveyed at the beginning and end of the course administering a multidimensional measure of attitude toward statistics. Multiple regression analyses were run to establish the relative impact of mathematical background and Big Five personality factors on attitude components, as well as the changes in these attitude components. Results confirmed the predictive role of mathematic competence on some attitude dimensions and showed that also personality traits influenced attitudes toward statistics. However, the observed changes in attitudes during the course were minimally influenced by these factors. Findings suggest that course pedagogy can enhance students’ attitudes regardless their mathematical background and personality.     

Cluster‐based permutation tests of MEG/EEG data do not establish significance of effect latency or location

Cluster‐based permutation tests are gaining an almost universal acceptance as inferential procedures in cognitive neuroscience. They elegantly handle the multiple comparisons problem in high‐dimensional magnetoencephalographic and EEG data. Unfortunately, the power of this procedure comes hand in hand with the allure for unwarranted interpretations of the inferential output, the most prominent of which is the overestimation of the temporal, spatial, and frequency precision of statistical claims. This leads researchers to statements about the onset or offset of a certain effect that is not supported by the permutation test. In this article, we outline problems and common pitfalls of using and interpreting cluster‐based permutation tests. We illustrate these with simulated data in order to promote a more intuitive understanding of the method. We hope that raising awareness about these issues will be beneficial to common scientific practices, while at the same time increasing the popularity of cluster‐based permutation procedures.     

Recent Advances in Pathology: the 2019 Annual Review Issue of The Journal of Pathology

In this Annual Review Issue of The Journal of Pathology, we present 15 invited reviews on topical aspects of pathology, ranging from the impacts of the microbiome in human disease through mechanisms of cell death and autophagy to recent advances in immunity and the uses of genomics for understanding, classifying and treating human cancers. Each of the reviews is authored by experts in their fields and our intention is to provide comprehensive updates in specific areas of pathology in which there has been considerable recent progress. Copyright © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Multisample adjusted U‐statistics that account for confounding covariates

Multisample U‐statistics encompass a wide class of test statistics that allow the comparison of 2 or more distributions. U‐statistics are especially powerful because they can be applied to both numeric and nonnumeric data, eg, ordinal and categorical data where a pairwise similarity or distance‐like measure between categories is available. However, when comparing the distribution of a variable across 2 or more groups, observed differences may be due to confounding covariates. For example, in a case‐control study, the distribution of exposure in cases may differ from that in controls entirely because of variables that are related to both exposure and case status and are distributed differently among case and control participants. We propose to use individually reweighted data (ie, using the stratification score for retrospective data or the propensity score for prospective data) to construct adjusted U‐statistics that can test the equality of distributions across 2 (or more) groups in the presence of confounding covariates. Asymptotic normality of our adjusted U‐statistics is established and a closed form expression of their asymptotic variance is presented. The utility of our approach is demonstrated through simulation studies, as well as in an analysis of data from a case‐control study conducted among African‐Americans, comparing whether the similarity in haplotypes (ie, sets of adjacent genetic loci inherited from the same parent) occurring in a case and a control participant differs from the similarity in haplotypes occurring in 2 control participants.     

A study on craniofacial morphology of Japanese subjects with normal occlusion and esthetic profile

This study was designed to properly characterize the cephalometric values of Japanese individuals with both normal occlusion and esthetic profiles. Multivariate statistics were applied to analyze the collected data. Cephalometric values identified are expected to help in the simplification of orthodontic diagnosis. Lateral cephalometric radiographs from 50 men and 50 women with normal occlusion were traced and the dimensions of hard and soft tissues recorded. The corresponding values were classified by cluster analysis, and selected representative values were subjected to principal component analysis. From these values, characteristics of hard and soft tissue morphology were extracted. The subjects were grouped by sex, and subdivided into esthetic and unesthetic profile groups. The principal component scores from each group were plotted on a scattergram and the characteristics of each group investigated. The hard tissue characteristics in men with esthetic profiles were primarily vertical factors, including a tendency for smaller lower facial heights, a smaller mandibular plane angle, and a larger Nasion-ANS/ANS-Menton (N-ANS/ANS-Me). Soft tissue features included a more posteriorly placed maxilla and a high nasal crest. These features yield a less marked maxillary prognathism and a greater nose prominence. In females, hard tissue characteristics associated with esthetic profiles primarily involved the cranial base and posterior facial area. These included a smaller saddle angle, larger articulare angle, and smaller Sella-Articulare/Articlare-Gonion (S-Ar/Ar-Go). Female soft tissue characteristics primarily included retracted upper and lower lips, a shallow inferior sulcus with a smaller lower lip-Frankfort plane angle, and a shorter mentolabial sulcus and subnasale perpendicular-upper lip.     

Application of matched pair procedures to site-specific data in periodontal research

Application of standard statistical procedures to site-specific data in periodontal research is invalid unless site-to-site dependencies are accounted for. In this paper, we present the adjustments required for valid application of matched pair procedures, including the paired t-test and McNemar's chi 2 test for correlated proportions. Examples are given involving data arising from: (1) the comparison of pre- and post-treatment clinical measurements; (ii) split-mouth protocols.