How serious is bias in effect estimation in randomised trials with survival data given risk heterogeneity and informative censoring?

abstract：:Many complex diseases are known to be affected by the interactions between genetic variants and environmental exposures beyond the main genetic and environmental effects. Study of gene-environment (G×E) interactions is important for elucidating the disease etiology. Existing Bayesian methods for G×E interaction studie...

journal_title：Statistics in medicine

authors： Ren J,Zhou F,Li X,Chen Q,Zhang H,Ma S,Jiang Y,Wu C

更新日期：2020-02-28 00:00:00

abstract：:In this article, we investigate procedures for comparing two independent Poisson variates that are observed over unequal sampling frames (i.e. time intervals, populations, areas or any combination thereof). We consider two statistics (with and without the logarithmic transformation) for testing the equality of two Poi...

journal_title：Statistics in medicine

authors： Ng HK,Tang ML

更新日期：2005-03-30 00:00:00

abstract：:Confounding is a major concern in observational studies. To adjust for confounding bias, the potential confounder(s) for a study must first be identified and measured. But this is not always possible. The unmeasured factors may also exhibit effect modification, and this further complicates the situation. In this paper...

journal_title：Statistics in medicine

authors： Lee WC

更新日期：2011-04-30 00:00:00

abstract：:In applications such as medical statistics and genetics, we encounter situations where a large number of highly correlated predictors explain a response. For example, the response may be a disease indicator and the predictors may be treatment indicators or single nucleotide polymorphisms (SNPs). Constructing a good pr...

journal_title：Statistics in medicine

authors： Sperrin M,Jaki T

更新日期：2010-10-30 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：:In the recent two decades, data mining methods for signal detection have been developed for drug safety surveillance, using large post-market safety data. Several of these methods assume that the number of reports for each drug-adverse event combination is a Poisson random variable with mean proportional to the unknow...

journal_title：Statistics in medicine

authors： Hu N,Huang L,Tiwari RC

更新日期：2015-08-30 00:00:00

abstract：:A method for detecting deviations from the Loewe additive drug combination reference model for in vitro drug combination experimentation is described. It is often difficult to fit a response surface model to drug combination data, especially in situations where the experimental design contains a sparse set of combinat...

journal_title：Statistics in medicine

authors： Novick SJ

更新日期：2013-12-20 00:00:00

abstract：BACKGROUND:The need to deliver interventions targeting multiple diseases in a cost-effective manner calls for integrated disease control efforts. Consequently, maps are required that show where the risk of co-infection is particularly high. Co-infection risk is preferably estimated via Bayesian geostatistical multinomi...

journal_title：Statistics in medicine

authors： Schur N,Gosoniu L,Raso G,Utzinger J,Vounatsou P

更新日期：2011-06-30 00:00:00

abstract：:Multivariate finite mixture models have been applied to the identification of dietary patterns. These models are known to have many parameters, and consequently large samples are usually required. We present a special case of a multivariate mixture model that reduces the number of parameters to be estimated and seems ...

journal_title：Statistics in medicine

authors： Rita Gaio A,Costa JP,Santos AC,Ramos E,Lopes C

更新日期：2012-08-30 00:00:00

abstract：:Meta-analyses of clinical trials are increasingly seeking to go beyond estimating the effect of a treatment and may also aim to investigate the effect of other covariates and how they alter treatment effectiveness. This requires the estimation of treatment-covariate interactions. Meta-regression can be used to estimat...

journal_title：Statistics in medicine

authors： Simmonds MC,Higgins JP

更新日期：2007-07-10 00:00:00

abstract：:In this paper, we proposed a mechanistic breast cancer survival model based on the axillary lymph node chain structure, considering lymph nodes as a potential dissemination arrangement. We assume a naive breast cancer treatment protocol consisting of exposing patients first to a chemotherapy treatment on r intervals a...

journal_title：Statistics in medicine

authors： Cobre J,Castro Perdoná GS,Peria FM,Louzada F

更新日期：2013-04-30 00:00:00

abstract：:Providing personalized treatments designed to maximize benefits and minimizing harms is of tremendous current medical interest. One problem in this area is the evaluation of the interaction between the treatment and other predictor variables. Treatment effects in subgroups having the same direction but different magni...

journal_title：Statistics in medicine

authors： Chen W,Ghosh D,Raghunathan TE,Norkin M,Sargent DJ,Bepler G

更新日期：2012-12-10 00:00:00

abstract：:The serial dilution assay (for example, an in vitro antimicrobic susceptibility test or a serum antibody titer assay) is an important technique in biomedical research. The structure of the experiment forces grouping of the threshold concentrations into intervals. Statistical methods to analyse threshold concentrations...

journal_title：Statistics in medicine

authors： Hamilton MA,Rinaldi MG

更新日期：1988-04-01 00:00:00

abstract：:We develop reinforcement learning trials for discovering individualized treatment regimens for life-threatening diseases such as cancer. A temporal-difference learning method called Q-learning is utilized that involves learning an optimal policy from a single training set of finite longitudinal patient trajectories. A...

journal_title：Statistics in medicine

authors： Zhao Y,Kosorok MR,Zeng D

更新日期：2009-11-20 00:00:00

abstract：:Lower urinary tract symptoms can indicate the presence of urinary tract infection (UTI), a condition that if it becomes chronic requires expensive and time consuming care as well as leading to reduced quality of life. Detecting the presence and gravity of an infection from the earliest symptoms is then highly valuable...

journal_title：Statistics in medicine

authors： Barcella W,Iorio MD,Baio G,Malone-Lee J

更新日期：2016-04-15 00:00:00

abstract：:Paired data from matched case-control studies are commonly used to estimate the association between the exposure to a risk factor and the occurrence of a disease. The odds ratio is typically used to quantify this association. Difficulties in estimating the true odds ratio with matched pairs arise, however, when the ex...

journal_title：Statistics in medicine

authors： Miller KM,Looney SW

更新日期：2012-11-30 00:00:00

abstract：:Prevalence data provided by cancer registries are generally biased, since the patients that were diagnosed before the starting of the registry's activity cannot be included in the statistics. The relevance of this incompleteness bias is estimated in this paper. Incidence and relative survival are modelled as parametri...

journal_title：Statistics in medicine

authors： Capocaccia R,De Angelis R

更新日期：1997-02-28 00:00:00

abstract：:In US states with small subpopulations, the observed mortality rates are often zero, particularly among young ages. Because in life tables, death rates are reported mostly on a log scale, zero mortality rates are problematic. To overcome the observed zero death rates problem, appropriate probability models are used. U...

journal_title：Statistics in medicine

authors： Voulgaraki A,Wei R,Kedem B

更新日期：2015-05-20 00:00:00

abstract：:Geocoding a study population as completely as possible is an important data assimilation component of many spatial epidemiologic studies. Unfortunately, complete geocoding is rare in practice. The failure of a substantial proportion of study subjects' addresses to geocode has consequences for spatial analyses, some of...

journal_title：Statistics in medicine

authors： Zimmerman DL,Fang X,Mazumdar S

更新日期：2008-09-20 00:00:00

abstract：:Obtaining accurate estimates of the performance of a diagnostic test for some population of patients might be difficult when the sample of subjects used for this purpose is not representative for the whole population. Thus, in the motivating example of this paper a test is evaluated by comparing its results with those...

journal_title：Statistics in medicine

authors： Buzoianu M,Kadane JB

更新日期：2008-06-15 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：:A popular method for analysing repeated-measures data is generalized estimating equations (GEE). When response data are missing at random (MAR), two modifications of GEE use inverse-probability weighting and imputation. The weighted GEE (WGEE) method involves weighting observations by their inverse probability of bein...

journal_title：Statistics in medicine

authors： Seaman S,Copas A

更新日期：2009-03-15 00:00:00

abstract：:In many biomedical and epidemiological studies, data are often clustered due to longitudinal follow up or repeated sampling. While in some clustered data the cluster size is pre-determined, in others it may be correlated with the outcome of subunits, resulting in informative cluster size. When the cluster size is info...

journal_title：Statistics in medicine

authors： Chen Z,Zhang B,Albert PS

更新日期：2011-07-10 00:00:00

abstract：:In this paper, we develop methods to combine multiple biomarker trajectories into a composite diagnostic marker using functional data analysis (FDA) to achieve better diagnostic accuracy in monitoring disease recurrence in the setting of a prospective cohort study. In such studies, the disease status is usually verifi...

journal_title：Statistics in medicine

authors： Li H,Gatsonis C

更新日期：2019-05-20 00:00:00

abstract：:Often in randomized clinical trials and observational studies in occupational and environmental health, a non-negative continuously distributed response variable denoting some metabolites of environmental toxicants is measured in treatment and control groups. When observations occur in both unexposed and exposed subje...

journal_title：Statistics in medicine

authors： Chu H,Nie L,Kensler TW

更新日期：2008-06-15 00:00:00

abstract：:With reference to a real data on cataract surgery, we discuss the problem of zero-inflated circular-circular regression when both covariate and response are circular random variables and a large proportion of the responses are zeros. The regression model is proposed, and the estimation procedure for the parameters is ...

journal_title：Statistics in medicine

authors： Jha J,Biswas A

更新日期：2018-01-15 00:00:00

abstract：:Residuals in normal regression are used to assess a model's goodness-of-fit (GOF) and discover directions for improving the model. However, there is a lack of residuals with a characterized reference distribution for censored regression. In this article, we propose to diagnose censored regression with normalized rando...

journal_title：Statistics in medicine

authors： Li L,Wu T,Feng C

更新日期：2020-12-13 00:00:00

abstract：:We propose a new design for dose finding for cytotoxic agents in two ordered groups of patients. By ordered groups, we mean that prior to the study there is clinical information that would indicate that for a given dose one group would be more susceptible to toxicities than patients in the other group. The designs are...

journal_title：Statistics in medicine

authors： Conaway MR,Wages NA

更新日期：2017-01-30 00:00:00

abstract：:Writing the variance of the Mantel-Haenszel estimator under the null of homogeneity and inverting the corresponding test, we arrive at an improved confidence interval for the common risk difference in stratified 2 × 2 tables. This interval outperforms a variety of other intervals currently recommended in the literatur...

journal_title：Statistics in medicine

authors： Klingenberg B

更新日期：2014-07-30 00:00:00

abstract：:When interpreting screening mammograms radiologists decide whether suspicious abnormalities exist that warrant the recall of the patient for further testing. Previous work has found significant differences in interpretation among radiologists; their false-positive and false-negative rates have been shown to vary widel...

journal_title：Statistics in medicine

authors： Woodard DB,Gelfand AE,Barlow WE,Elmore JG

更新日期：2007-03-30 00:00:00