Designing a study to evaluate the benefit of a biomarker for selecting patient treatment.

abstract：:Thomas et al. presented the application of empirical-Bayes methods to the problem of multiple inference in epidemiologic studies. One limitation of their approach, which they noted, was the need to assume exchangeable log relative-risk parameters, and independent relative-risk estimates. Numerical integration was also...

journal_title：Statistics in medicine

authors： Greenland S

更新日期：1992-01-30 00:00:00

abstract：:Correlated response data arise often in biomedical studies. The generalized estimation equation (GEE) approach is widely used in regression analysis for such data. However, there are few methods available to check the adequacy of regression models in GEE. In this paper, a graphical method is proposed based on Cook and...

journal_title：Statistics in medicine

authors： Pan W,Connett JE,Porzio GC,Weisberg S

更新日期：2001-10-15 00:00:00

abstract：:With the increasing availability of detailed clinical information, there is optimism that treatment choices can be selectively directed to those individuals most likely to benefit. While standard clinical trials can establish whether a treatment appears to be effective on average, subsequent work is needed to determin...

journal_title：Statistics in medicine

authors： Sitlani CM,Heagerty PJ

更新日期：2014-07-30 00:00:00

abstract：:In longitudinal studies, missing observations occur commonly. It has been well known that biased results could be produced if missingness is not properly handled in the analysis. Authors have developed many methods with the focus on either incomplete response or missing covariate observations, but rarely on both. The ...

journal_title：Statistics in medicine

authors： Li H,Yi GY

更新日期：2013-02-28 00:00:00

abstract：:This paper develops methods of analysis for active extension clinical trials. Under this design, patients are randomized to treatment or placebo for a period of time (period 1), and then all patients receive treatment for an additional period of time (period 2). We assume a continuous outcome is measured at baseline a...

journal_title：Statistics in medicine

authors： Hu Z,Follmann D

更新日期：2007-05-30 00:00:00

abstract：:Biomarkers, increasingly used in biomedical studies for the diagnosis and prognosis of acute and chronic diseases, provide insight into the effectiveness of treatments and potential pathways that can be used to guide future treatment targets. The measurement of these markers is often limited by the sensitivity of the ...

journal_title：Statistics in medicine

authors： Lee M,Kong L,Weissfeld L

更新日期：2012-07-30 00:00:00

abstract：:Log-linear models for capture-recapture type data are widely used for estimating sizes of populations. Log-linear methods model conditional interactions between the sources. Often, however, the marginal associations are more appropriate and easier for the practitioner to conceptualize. Analyses here of previously publ...

journal_title：Statistics in medicine

authors： Regal RR,Hook EB

更新日期：1998-01-15 00:00:00

abstract：:The mutation and natural selection phenomenon can and often does cause the failure of antimicrobial, herbicidal, pesticide and cancer treatments selection pressures. This phenomenon operates in a mathematically predictable behavior, which when understood leads to approaches to reduce and prevent the failure of the use...

journal_title：Statistics in medicine

authors： Kleinman A

更新日期：2014-12-20 00:00:00

abstract：:When sample size is recalculated using unblinded interim data, use of the usual t-test at the end of a study may lead to an elevated type I error rate. This paper describes a numerical quadrature investigation to calculate the true probability of rejection as a function of the time of the recalculation, the magnitude ...

journal_title：Statistics in medicine

authors： Wittes J,Schabenberger O,Zucker D,Brittain E,Proschan M

更新日期：1999-12-30 00:00:00

abstract：:Cox proportional hazard regression model is a popular tool to analyze the relationship between a censored lifetime variable with other relevant factors. The semiparametric Cox model is widely used to study different types of data arising from applied disciplines such as medical science, biology, and reliability studie...

journal_title：Statistics in medicine

authors： Ghosh A,Basu A

更新日期：2019-11-30 00:00:00

abstract：:When asking 'what is known' about a drug or therapy or program at any time, both researchers and practitioners often confront more than a single study. Facing a variety of findings, where conflicts may outweigh agreement, how can a reviewer constructively approach the task? In this discussion, I will outline some ques...

journal_title：Statistics in medicine

authors： Light RJ

更新日期：1987-04-01 00:00:00

abstract：:In record linkage studies, unique identifiers are often not available, and therefore, the linkage procedure depends on combinations of partially identifying variables with low discriminating power. As a consequence, wrongly linked covariate and outcome pairs will be created and bias further analysis of the linked data...

journal_title：Statistics in medicine

authors： Hof MH,Zwinderman AH

更新日期：2012-12-30 00:00:00

abstract：:We give up-to-date methods for estimating the age-specific incidence of a disease and for estimating the effect of risk factors. We recommend taking age as the basic time scale of the analysis; then, the hazard function can be interpreted as the age-specific incidence of the disease. This choice raises a delayed entry...

journal_title：Statistics in medicine

authors： Commenges D,Letenneur L,Joly P,Alioum A,Dartigues JF

更新日期：1998-09-15 00:00:00

abstract：:We propose an innovative and practically relevant clustering method to find common task-related brain regions among different subjects who respond to the same set of stimuli. Using functional magnetic resonance imaging (fMRI) time series data, we first cluster the voxels within each subject on a voxel by voxel basis. ...

journal_title：Statistics in medicine

authors： Ye J,Li Y,Lazar NA,Schaeffer DJ,McDowell JE

更新日期：2016-07-10 00:00:00

abstract：:If the sample size for a t-test is calculated on the basis of a prior estimate of the variance then the power of the test at the treatment difference of interest is not robust to misspecification of the variance. We propose a t-test for a two-treatment comparison based on Stein's two-stage test which involves the use ...

journal_title：Statistics in medicine

authors： Denne JS,Jennison C

更新日期：1999-07-15 00:00:00

abstract：:We present methods for binomial regression when the outcome is determined using the results of a single diagnostic test with imperfect sensitivity and specificity. We present our model, illustrate it with the analysis of real data, and provide an example of WinBUGS program code for performing such an analysis. Conditi...

journal_title：Statistics in medicine

authors： McInturff P,Johnson WO,Cowling D,Gardner IA

更新日期：2004-04-15 00:00:00

abstract：:Statistical inference based on correlated count measurements are frequently performed in biomedical studies. Most of existing sample size calculation methods for count outcomes are developed under the Poisson model. Deviation from the Poisson assumption (equality of mean and variance) has been widely documented in pra...

journal_title：Statistics in medicine

authors： Li D,Zhang S,Cao J

更新日期：2019-12-10 00:00:00

abstract：:Multistate models are increasingly being used to model complex disease profiles. By modelling transitions between disease states, accounting for competing events at each transition, we can gain a much richer understanding of patient trajectories and how risk factors impact over the entire disease pathway. In this arti...

journal_title：Statistics in medicine

authors： Crowther MJ,Lambert PC

更新日期：2017-12-20 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：:For the analysis of time to event data in contraceptive studies when individuals are subject to competing causes for discontinuation, some authors have recently advocated the use of the cumulative incidence rate as a more appropriate measure to summarize data than the complement of the Kaplan-Meier estimate of discont...

journal_title：Statistics in medicine

authors： Farley TM,Ali MM,Slaymaker E

更新日期：2001-12-15 00:00:00

abstract：:Before introducing a new measurement tool it is necessary to evaluate its performance. Several statistical methods have been developed, or used, to evaluate the reliability and validity of a new assessment method in such circumstances. In this paper we review some commonly used methods. Data from a study that was cond...

journal_title：Statistics in medicine

authors： White SA,van den Broek NR

更新日期：2004-05-30 00:00:00

abstract：:In this paper, we investigate the impact of time-invariant covariates when fitting transition mixed models. This is carried out by emphasizing on the role of baseline responses on the estimation process. Transition models are allowed for two cases of exogenous and endogenous baseline responses. We illustrate these con...

journal_title：Statistics in medicine

authors： Rikhtehgaran R,Kazemi I,Verbeke G

更新日期：2014-11-30 00:00:00

abstract：:We propose a joint model for a time-to-event outcome and a quantile of a continuous response repeatedly measured over time. The quantile and survival processes are associated via shared latent and manifest variables. Our joint model provides a flexible approach to handle informative dropout in quantile regression. A M...

journal_title：Statistics in medicine

authors： Farcomeni A,Viviani S

更新日期：2015-03-30 00:00:00

abstract：:Assessing the QT prolongation potential of a drug is typically done based on pivotal safety studies called thorough QT studies. Model-based estimation of the drug-induced QT prolongation at the estimated mean maximum drug concentration could increase efficiency over the currently used intersection-union test. However,...

journal_title：Statistics in medicine

authors： Dosne AG,Bergstrand M,Karlsson MO,Renard D,Heimann G

更新日期：2017-10-30 00:00:00

abstract：:The design of a cross-sectional survey to estimate the age-specific incidence of an irreversible disease is considered, where the incidence rate is not changing over time and the risk of mortality is not affected by the onset of disease. The sample is assumed to give information on the current age and disease status o...

journal_title：Statistics in medicine

authors： Marschner IC

更新日期：1994-11-30 00:00:00

abstract：:The two tailed Fisher's exact P value is extremely sensitive to small perturbations in 2 x 2 contingency tables. An example indicates that a 1 per cent increase in the denominator of one treatment group results in a 32 per cent drop in the exact P value, but a mere 0.1 per cent decrease in the treatment success rate. ...

journal_title：Statistics in medicine

authors： Dupont WD

更新日期：1986-11-01 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：:A common but not necessarily logical requirement in drug development is that a 'limit of quantitation' be set for chemical assays and that observations that fall below the limit should not be treated as real data but should be labelled as below the limit and set aside for special treatment. We examine five of seven ap...

journal_title：Statistics in medicine

authors： Senn S,Holford N,Hockey H

更新日期：2012-12-30 00:00:00

abstract：:When estimating the probability of natural conception from observational data on couples with an unfulfilled child wish, the start of assisted reproductive therapy (ART) is a competing event that cannot be assumed to be independent of natural conception. In clinical practice, interest lies in the probability of natura...

journal_title：Statistics in medicine

authors： van Geloven N,Geskus RB,Mol BW,Zwinderman AH

更新日期：2014-11-20 00:00:00

abstract：:We consider a general model for anomaly detection in a longitudinal cohort mortality pattern based on logistic joinpoint regression with unknown joinpoints. We discuss backward and forward sequential procedures for selecting both the locations and the number of joinpoints. Estimation of the model parameters and the se...

journal_title：Statistics in medicine

authors： Czajkowski M,Gill R,Rempala G

更新日期：2008-04-30 00:00:00