Dynamic thresholds and a summary ROC curve: Assessing prognostic accuracy of longitudinal markers.

abstract：:Interval-censored survival data often occur in medical studies, especially in clinical trials. In this case, many authors have considered estimation of a survival function. There is, however, relatively little discussion on estimating the variance of estimated survival functions. For right-censored data, a special cas...

journal_title：Statistics in medicine

authors： Sun J

更新日期：2001-04-30 00:00:00

abstract：:Day and Walter derived methods of joint maximum likelihood estimation for the sojourn time distribution and the false negative rate for a screening programme. Their methods are not directly applicable to a programme which uses alternate screening by two modalities whose sojourn times and false negative rates will diff...

journal_title：Statistics in medicine

authors： Alexander FE

更新日期：1989-06-01 00:00:00

abstract：:A Non-Parametric Maximum Likelihood approach to the estimation of relative risks in the context of disease mapping is discussed and a NPML approximation to conditional autoregressive models is proposed. NPML estimates have been compared to other proposed solutions (Maximum Likelihood via Monte Carlo Scoring, Hierarchi...

journal_title：Statistics in medicine

authors： Biggeri A,Marchi M,Lagazio C,Martuzzi M,Böhning D

更新日期：2000-09-15 00:00:00

abstract：:Maps of estimated disease rates over multiple time periods are useful tools for gaining etiologic insights regarding potential exposures associated with specific locations and times. In this paper, we describe an extension of the Gangnon-Clayton model for spatial clustering to spatio-temporal data. As in the purely sp...

journal_title：Statistics in medicine

authors： Gangnon RE

更新日期：2010-09-30 00:00:00

abstract：:The semi-Markov assumption emphasizes the importance of time spent in a state. In order to compute this type of multistate model, most transition times are always considered to be exactly identified or right censored. However, in the longitudinal analysis of chronic diseases, investigators are often confronted with in...

journal_title：Statistics in medicine

authors： Foucher Y,Giral M,Soulillou JP,Daures JP

更新日期：2007-12-30 00:00:00

abstract：:In lifetime data, like cancer studies, there may be long term survivors, which lead to heavy censoring at the end of the follow-up period. Since a standard survival model is not appropriate to handle these data, a cure model is needed. In the literature, covariate hypothesis tests for cure models are limited to parame...

journal_title：Statistics in medicine

authors： López-Cheda A,Jácome MA,Van Keilegom I,Cao R

更新日期：2020-07-30 00:00:00

abstract：:Logistic regression analysis may well be used to develop a prognostic model for a dichotomous outcome. Especially when limited data are available, it is difficult to determine an appropriate selection of covariables for inclusion in such models. Also, predictions may be improved by applying some sort of shrinkage in t...

journal_title：Statistics in medicine

authors： Steyerberg EW,Eijkemans MJ,Harrell FE Jr,Habbema JD

更新日期：2000-04-30 00:00:00

abstract：:Pooling biospecimens prior to performing lab assays can help reduce lab costs, preserve specimens, and reduce information loss when subject to a limit of detection. Because many biomarkers measured in epidemiological studies are positive and right-skewed, proper analysis of pooled specimens requires special methods. I...

journal_title：Statistics in medicine

authors： Mitchell EM,Lyles RH,Schisterman EF

更新日期：2015-07-30 00:00:00

abstract：:In different fields of applications including, but not limited to, behavioral, environmental, medical sciences, and econometrics, the use of panel data regression models has become increasingly popular as a general framework for making meaningful statistical inferences. However, when the ordinary least squares (OLS) m...

journal_title：Statistics in medicine

authors： Hamiye Beyaztas B,Bandyopadhyay S

更新日期：2020-12-20 00:00:00

abstract：:We present a new method of detection and inference for spatial clusters of a disease. To avoid ad hoc procedures to test for clustering, we have a clearly defined alternative hypothesis and our test statistic is based on the likelihood ratio. The proposed test can detect clusters of any size, located anywhere in the s...

journal_title：Statistics in medicine

authors： Kulldorff M,Nagarwalla N

更新日期：1995-04-30 00:00:00

abstract：:Juvenile dermatomyositis (JDM) is a rare autoimmune disease that may lead to serious complications, even to death. We develop a 2-state Markov regression model in a Bayesian framework to characterise disease progression in JDM over time and gain a better understanding of the factors influencing disease risk. The trans...

journal_title：Statistics in medicine

authors： De Iorio M,Gallot N,Valcarcel B,Wedderburn L

更新日期：2018-05-10 00:00:00

abstract：:Random forest is a supervised learning method that combines many classification or regression trees for prediction. Here we describe an extension of the random forest method for building event risk prediction models in survival analysis with competing risks. In case of right-censored data, the event status at the pred...

journal_title：Statistics in medicine

authors： Mogensen UB,Gerds TA

更新日期：2013-08-15 00:00:00

abstract：:The incremental life expectancy, defined as the difference in mean survival times between two treatment groups, is a crucial quantity of interest in cost-effectiveness analyses. Usually, this quantity is very difficult to estimate from censored survival data with a limited follow-up period. The paper develops estimati...

journal_title：Statistics in medicine

authors： Titman AC

更新日期：2016-09-10 00:00:00

abstract：:Epidermal nerve fibre (ENF) density and morphology are used to study small fibre involvement in diabetic, HIV, chemotherapy induced and other neuropathies. ENF density and summed length of ENFs per epidermal surface area are reduced, and ENFs may appear more clustered within the epidermis in subjects with small fibre ...

journal_title：Statistics in medicine

authors： Andersson C,Guttorp P,Särkkä A

更新日期：2016-10-30 00:00:00

abstract：:We point out that the conventional methods for ties correction may be seriously biased when censoring times depend on covariates. A simple modification to the Efron correction method is suggested which works remarkably well in simulation studies. The method corresponds closely to breaking ties by random ordering. The ...

journal_title：Statistics in medicine

authors： Samuelsen SO,Wisløff TF,Skrondal A

更新日期：2005-10-30 00:00:00

abstract：:The first randomized clinical trial at the National Cancer Institute (NCI), planned in 1954, commenced in 1955 for the treatment of patients with acute leukaemia. The programme in clinical trials at NCI had strong influence from the clinician and administrator, C. Gordon Zubrod, who introduced the randomized clinical ...

journal_title：Statistics in medicine

authors： Gehan EA,Schneiderman MA

更新日期：1990-08-01 00:00:00

abstract：:Reference ranges which take time (such as age) into account are often required in medicine, but simple, systematic and efficient statistical methods for constructing them are lacking. A method is described which is based on low order polynomial curves (linear, quadratic or occasionally cubic), together with guidelines...

journal_title：Statistics in medicine

authors： Royston P

更新日期：1991-05-01 00:00:00

abstract：:In many chronic disease processes subjects are at risk of two or more types of events. We describe a bivariate mixed Poisson model in which a copula function is used to model the association between two gamma distributed random effects. The resulting model is a bivariate negative binomial process in which each type of...

journal_title：Statistics in medicine

authors： Cook RJ,Lawless JF,Lee KA

更新日期：2010-03-15 00:00:00

abstract：:There is an increasing interest in the use of propensity score methods to estimate causal effects in observational studies. However, recent systematic reviews have demonstrated that propensity score methods are inconsistently used and frequently poorly applied in the medical literature. In this study, we compared the ...

journal_title：Statistics in medicine

authors： Austin PC,Mamdani MM

更新日期：2006-06-30 00:00:00

abstract：:A preference trial is a special form of cross-over trial where clinical conditions determine when patients change treatment, in a prescribed order. This can be modelled using a geometric distribution. The model can be simply fitted using standard logistic regression methodology. The procedure is applied to a trial stu...

journal_title：Statistics in medicine

authors： Lindsey JK,Jones B

更新日期：1996-02-28 00:00:00

abstract：:Disease incidence predictions are useful for a number of administrative and scientific purposes. The simplest ones are made using trend extrapolation, on either an arithmetic or a logarithmic scale. This paper shows how approximate confidence prediction intervals can be calculated for such predictions, both for the to...

journal_title：Statistics in medicine

authors： Hakulinen T,Dyba T

更新日期：1994-08-15 00:00:00

abstract：:Correlation is always a concern in the analysis of clustered data. One area of interest is to develop a general correlation modelling approach for high dimensional data with unbalanced hierarchical and heterogeneous data structures, e.g. multilevel data. Commonly used correlation structures might have limitation for s...

journal_title：Statistics in medicine

authors： Chao EC

更新日期：2006-07-30 00:00:00

abstract：:Multilevel mixed effects survival models are used in the analysis of clustered survival data, such as repeated events, multicenter clinical trials, and individual participant data (IPD) meta-analyses, to investigate heterogeneity in baseline risk and covariate effects. In this paper, we extend parametric frailty model...

journal_title：Statistics in medicine

authors： Crowther MJ,Look MP,Riley RD

更新日期：2014-09-28 00:00:00

abstract：:A method is proposed to infer the randomized treatment effect on survival after an adjustment for a post-randomization variable. The post-randomization variable is made independent of the treatment assignment and is considered a surrogate for baseline prognostic factors. The relationship between the post-randomization...

journal_title：Statistics in medicine

authors： Heller G

更新日期：2001-11-30 00:00:00

abstract：:Flexible survival models are in need when modelling data from long term follow-up studies. In many cases, the assumption of proportionality imposed by a Cox model will not be valid. Instead, a model that can identify time varying effects of fixed covariates can be used. Although there are several approaches that deal ...

journal_title：Statistics in medicine

authors： Perperoglou A

更新日期：2016-12-10 00:00:00

abstract：:An important problem in oncology is comparing chemotherapy (chemo) agents in terms of their effects on survival or progression-free survival time. When the goal is to evaluate individual agents, a difficulty commonly encountered with observational data is that many patients receive a chemo combination including two or...

journal_title：Statistics in medicine

authors： Thall PF,Liu DD,Berrak SG,Wolff JE

更新日期：2011-07-10 00:00:00

abstract：:Subjective judgements of complex variables are commonly recorded as ordered categorical data. The rank-invariant properties of such data are well known, and there are various statistical approaches to the analysis and modelling of ordinal data. This paper focuses on the non-additive property of ordered categorical dat...

journal_title：Statistics in medicine

authors： Svensson E

更新日期：1998-12-30 00:00:00

abstract：:Arming the immune system against cancer has emerged as a powerful tool in oncology during recent years. Instead of poisoning a tumor or destroying it with radiation, therapeutic cancer vaccine, a type of cancer immunotherapy, unleashes the immune system to combat cancer. This indirect mechanism-of-action of vaccines p...

journal_title：Statistics in medicine

authors： Xu Z,Zhen B,Park Y,Zhu B

更新日期：2017-02-20 00:00:00

abstract：:Nutritional exposures are often measured with considerable error in commonly used surrogate instruments such as the food frequency questionnaire (FFQ) (denoted by Q(i) for the ith subject). The error can be both systematic and random. The diet record (DR) denoted by R(i) for the ith subject is considered an alloyed go...

journal_title：Statistics in medicine

authors： Rosner B,Michels KB,Chen YH,Day NE

更新日期：2008-08-15 00:00:00

abstract：:New combination regimens evaluated in phase II cancer clinical trials often show promising results compared to the standard therapy for a disease system. Selection of patients with a better prognosis can be a prominent factor for this optimism. For most disease systems, prognostic variables that are related to the out...

journal_title：Statistics in medicine

authors： Mazumdar M,Fazzari M,Panageas KS

更新日期：2001-03-30 00:00:00