Statistics in Biosciences最新文献_第10页

Spatial Weighted Analysis of Malnutrition Among Children in Nigeria: A Bayesian Approach 尼日利亚儿童营养不良的空间加权分析:贝叶斯方法

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Statistics in Biosciences Pub Date : 2021-03-05 DOI: 10.1007/s12561-021-09303-9

O. Egbon, Omodolapo Somo-Aina, E. Gayawan

引用次数: 8

Average Response over Time as Estimand: An Alternative Implementation of the While on Treatment Strategy 平均反应随时间的估计:一种替代实施的同时治疗策略

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Statistics in Biosciences Pub Date : 2021-02-18 DOI: 10.1007/s12561-021-09301-x

Naitee Ting, Lihong Huang, Q. Deng, J. Cappelleri

引用次数: 2

Positive Stable Shared Frailty Models Based on Additive Hazards 基于加性风险的正稳定共享脆弱性模型

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Statistics in Biosciences Pub Date : 2021-01-03 DOI: 10.1007/s12561-020-09299-8

David D. Hanagal

引用次数: 1

On a Statistical Transmission Model in Analysis of the Early Phase of COVID-19 Outbreak. 基于统计传播模型的新冠肺炎疫情早期分析

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Statistics in Biosciences Pub Date : 2021-01-01 Epub Date: 2020-04-02 DOI: 10.1007/s12561-020-09277-0

Yifan Zhu, Ying Qing Chen

{"title":"On a Statistical Transmission Model in Analysis of the Early Phase of COVID-19 Outbreak.","authors":"Yifan Zhu, Ying Qing Chen","doi":"10.1007/s12561-020-09277-0","DOIUrl":"https://doi.org/10.1007/s12561-020-09277-0","url":null,"abstract":"Since December 2019, a disease caused by a novel strain of coronavirus (COVID-19) had infected many people and the cumulative confirmed cases have reached almost 180,000 as of 17, March 2020. The COVID-19 outbreak was believed to have emerged from a seafood market in Wuhan, a metropolis city of more than 11 million population in Hubei province, China. We introduced a statistical disease transmission model using case symptom onset data to estimate the transmissibility of the early-phase outbreak in China, and provided sensitivity analyses with various assumptions of disease natural history of the COVID-19. We fitted the transmission model to several publicly available sources of the outbreak data until 11, February 2020, and estimated lock down intervention efficacy of Wuhan city. The estimated <math><msub><mi>R</mi> <mn>0</mn></msub> </math> was between 2.7 and 4.2 from plausible distribution assumptions of the incubation period and relative infectivity over the infectious period. 95% confidence interval of <math><msub><mi>R</mi> <mn>0</mn></msub> </math> were also reported. Potential issues such as data quality concerns and comparison of different modelling approaches were discussed.","PeriodicalId":45094,"journal":{"name":"Statistics in Biosciences","volume":"13 1","pages":"1-17"},"PeriodicalIF":1.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s12561-020-09277-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37836121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 52

Variable Selection in Threshold Regression Model with Applications to HIV Drug Adherence Data. 阈值回归模型的变量选择及其在HIV药物依从性数据中的应用。

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Statistics in Biosciences Pub Date : 2020-12-01 Epub Date: 2020-06-17 DOI: 10.1007/s12561-020-09284-1

Takumi Saegusa, Tianzhou Ma, Gang Li, Ying Qing Chen, Mei-Ling Ting Lee

{"title":"Variable Selection in Threshold Regression Model with Applications to HIV Drug Adherence Data.","authors":"Takumi Saegusa, Tianzhou Ma, Gang Li, Ying Qing Chen, Mei-Ling Ting Lee","doi":"10.1007/s12561-020-09284-1","DOIUrl":"https://doi.org/10.1007/s12561-020-09284-1","url":null,"abstract":"The threshold regression model is an effective alternative to the Cox proportional hazards regression model when the proportional hazards assumption is not met. This paper considers variable selection for threshold regression. This model has separate regression functions for the initial health status and the speed of degradation in health. This flexibility is an important advantage when considering relevant risk factors for a complex time-to-event model where one needs to decide which variables should be included in the regression function for the initial health status, in the function for the speed of degradation in health, or in both functions. In this paper, we extend the broken adaptive ridge (BAR) method, originally designed for variable selection for one regression function, to simultaneous variable selection for both regression functions needed in the threshold regression model. We establish variable selection consistency of the proposed method and asymptotic normality of the estimator of non-zero regression coefficients. Simulation results show that our method outperformed threshold regression without variable selection and variable selection based on the Akaike information criterion. We apply the proposed method to data from an HIV drug adherence study in which electronic monitoring of drug intake is used to identify risk factors for non- adherence.","PeriodicalId":45094,"journal":{"name":"Statistics in Biosciences","volume":" ","pages":"376-398"},"PeriodicalIF":1.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s12561-020-09284-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25540342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

On a Shape-Invariant Hazard Regression Model with application to an HIV Prevention Study of Mother-to-Child Transmission. 形状不变风险回归模型在HIV母婴传播预防研究中的应用。

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Statistics in Biosciences Pub Date : 2020-12-01 Epub Date: 2019-10-19 DOI: 10.1007/s12561-019-09260-4

Cheng Zheng, Ying Qing Chen

{"title":"On a Shape-Invariant Hazard Regression Model with application to an HIV Prevention Study of Mother-to-Child Transmission.","authors":"Cheng Zheng, Ying Qing Chen","doi":"10.1007/s12561-019-09260-4","DOIUrl":"https://doi.org/10.1007/s12561-019-09260-4","url":null,"abstract":"In survival analysis, Cox model is widely used for most clinical trial data. Alternatives include the additive hazard model, the accelerated failure time (AFT) model and a more general transformation model. All these models assume that the effects for all covariates are on the same scale. However, it is possible that for different covariates, the effects are on different scales. In this paper, we propose a shape-invariant hazard regression model that allows us to estimate the multiplicative treatment effect with adjustment of covariates that have non-multiplicative effects. We propose moment-based inference procedures for the regression parameters. We also discuss the risk prediction and the goodness of fit test for our proposed model. Numerical studies show good finite sample performance of our proposed estimator. We applied our method to the HIVNET 012 study, a milestone trial of single-dose nevirapine in prevention of mother-to-child transmission of HIV. From the HIVNET 012 data analysis, single-dose nevirapine treatment is shown to improve 18-month infant survival significantly with appropriate adjustment of the maternal CD4 counts and the virus load.","PeriodicalId":45094,"journal":{"name":"Statistics in Biosciences","volume":" ","pages":"340-352"},"PeriodicalIF":1.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s12561-019-09260-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38716824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Designing HIV Vaccine Efficacy Trials in the Context of Highly Effective Non-vaccine Prevention Modalities. 在高度有效的非疫苗预防模式背景下设计艾滋病疫苗疗效试验。

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Statistics in Biosciences Pub Date : 2020-12-01 Epub Date: 2020-10-22 DOI: 10.1007/s12561-020-09292-1

Holly Janes, Yifan Zhu, Elizabeth R Brown

{"title":"Designing HIV Vaccine Efficacy Trials in the Context of Highly Effective Non-vaccine Prevention Modalities.","authors":"Holly Janes, Yifan Zhu, Elizabeth R Brown","doi":"10.1007/s12561-020-09292-1","DOIUrl":"10.1007/s12561-020-09292-1","url":null,"abstract":"The evolving HIV prevention landscape poses challenges to the statistical design of future trials of candidate HIV vaccines. Study designs must address the anticipated reduction in HIV incidence due to adding new prevention modalities to the standard prevention package provided to trial participants, and must also accommodate individual choices of participants with regard to the use of these modalities. We explore four potential trial designs that address these challenges, with a focus on accommodating the newest addition to the prevention package-antiretroviral-based oral pre-exposure prophylaxis (PrEP). The designs differ with respect to how individuals who take up oral PrEP at screening are handled. An All-Comers Design enrolls and randomizes all eligible individuals, a Decliners Design enrolls and randomizes only those who decline PrEP at screening, and Single and Multi-Stage Run-In Designs enroll all but randomize only those who decline PrEP or show inadequate adherence to PrEP after one or multiple run-in periods. We compare these designs with respect to required sample sizes, study duration, and resource requirements, using a simulation model that incorporates data on HIV risk and PrEP uptake and adherence among men who have sex with men (MSM) in the Americas. We advocate considering Run-In Designs for some future contexts, and identify their advantages and tradeoffs relative to the other designs. The design concepts apply beyond HIV vaccines to other prevention modalities being developed with the aim to achieve further reductions in HIV incidence.","PeriodicalId":45094,"journal":{"name":"Statistics in Biosciences","volume":"12 3","pages":"468-494"},"PeriodicalIF":0.8,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10022814/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9155515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A METHOD FOR ESTIMATING THE PROPORTION OF HIV INFECTED PERSONS THAT HAVE BEEN DIAGNOSED AND APPLICATION TO CHINA. HIV感染者确诊比例估算方法及其在中国的应用。

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Statistics in Biosciences Pub Date : 2020-12-01 Epub Date: 2019-04-29 DOI: 10.1007/s12561-019-09240-8

Ron Brookmeyer, Zunyou Wu

{"title":"A METHOD FOR ESTIMATING THE PROPORTION OF HIV INFECTED PERSONS THAT HAVE BEEN DIAGNOSED AND APPLICATION TO CHINA.","authors":"Ron Brookmeyer, Zunyou Wu","doi":"10.1007/s12561-019-09240-8","DOIUrl":"https://doi.org/10.1007/s12561-019-09240-8","url":null,"abstract":"Estimation of the proportion of living HIV infected persons that have been diagnosed is critical for tracking progress toward meeting the UNAIDS goal that all persons who need HIV treatment receive it. The objective of this article is to develop a method for estimating that proportion. The methodological problem is that persons with undiagnosed HIV infection are not directly observable and are a \"hidden\" population. Here we propose a methodology for estimating the proportion diagnosed that is relatively simple to implement. The key idea is that in many settings certain health conditions such as pregnancy or an upcoming surgery lead to mandatory HIV tests. The size of the undiagnosed infected population can be estimated from the numbers of infected persons diagnosed by mandatory tests and an estimate of the rate that persons in the undiagnosed infected population receive mandatory tests. We discuss approaches for estimating the rate of mandatory testing in the undiagnosed population, such as surgical or pregnancy rates. We develop estimators of the proportion diagnosed and confidence interval procedures. Sample size considerations and sensitivity analyses to underlying assumptions are considered. The proposed methods can be performed at a local level and within demographic strata. Implementation of the method is simple and requires neither historical HIV/AIDS surveillance data nor biomarkers such as CD4 cell counts. The methods are applied to data from Dehong Prefecture in Yunnan Province, China.","PeriodicalId":45094,"journal":{"name":"Statistics in Biosciences","volume":" ","pages":"267-278"},"PeriodicalIF":1.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s12561-019-09240-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25504727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Comparison of HIV prevalence among antenatal clinic attendees estimated from routine testing and unlinked anonymous testing. 通过常规检测和不相关匿名检测估计的产前诊所参加者中艾滋病毒流行率的比较。

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Statistics in Biosciences Pub Date : 2020-12-01 Epub Date: 2020-02-28 DOI: 10.1007/s12561-020-09265-4

Ben Sheng, Jeffrey W Eaton, Mary Mahy, Le Bao

{"title":"Comparison of HIV prevalence among antenatal clinic attendees estimated from routine testing and unlinked anonymous testing.","authors":"Ben Sheng, Jeffrey W Eaton, Mary Mahy, Le Bao","doi":"10.1007/s12561-020-09265-4","DOIUrl":"10.1007/s12561-020-09265-4","url":null,"abstract":"In 2015, WHO and UNAIDS released new guidance recommending that countries transition from conducting antenatal clinic (ANC) unlinked anonymous testing (ANC-UAT) for tracking HIV prevalence trends among pregnant women to using ANC routine testing (ANC-RT) data, which are more consistent and economic to collect. This transition could pose challenges for distinguishing whether changes in observed prevalence are due to a change in underlying population prevalence or due to a change in the testing approach. We compared the HIV prevalence measured from ANC-UAT and ANCRT in 15 countries that had both data sources in overlapping years. We used linear mixed-e effects model (LMM) to estimate the RT-to-UAT calibration parameter as well as other unobserved quantities. We summarized the results at different levels of aggregation (e.g., country, urban, rural, and province). Based on our analysis, the HIV prevalence measured by ANC-UAT and ANC-RT data are consistent in most countries. Therefore, if large discrepancy is observed between ANC-UAT and ANC-RT at the same location, we recommend that people should be cautious and investigate the reason. For countries that lack information to estimate the calibration parameter, we propose an informative prior distribution of mean 0 and standard deviation 0.2 for the RT-to-UAT calibration parameter.","PeriodicalId":45094,"journal":{"name":"Statistics in Biosciences","volume":" ","pages":"279-294"},"PeriodicalIF":0.8,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7863791/pdf/nihms-1569770.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25343660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A New Algorithm for Convex Biclustering and Its Extension to the Compositional Data 一种新的凸双聚类算法及其在合成数据中的推广

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Statistics in Biosciences Pub Date : 2020-11-24 DOI: 10.1007/s12561-022-09356-4

Binhuan Wang, Lanqiu Yao, Jiyuan Hu, Huilin Li

引用次数: 0