On choosing the number of interim analyses in clinical trials.

abstract：:Several large-sample confidence intervals for the ratio of independent binomial proportions are compared in terms of exact coverage probability and width. A non-iterative approximate Bayesian interval is derived and its frequency properties are superior to all of the non-iterative confidence intervals considered. The ...

journal_title：Statistics in medicine

authors： Price RM,Bonett DG

更新日期：2008-11-20 00:00:00

abstract：:When analyzing time to disease recurrence, we sometimes need to work with data where all the recurrences are recorded, but no information is available on the possible deaths. This may occur when studying diseases of benign nature where patients are only seen at disease recurrences or in poorly-designed registries of b...

journal_title：Statistics in medicine

authors： Štupnik T,Pohar Perme M

更新日期：2016-03-30 00:00:00

abstract：:Genetic networks for gene expression data are often built by graphical models, which in turn are built from pair-wise correlations of gene expression levels. A key feature of building graphical models is the evaluation of conditional independence of two traits, given other traits. When conditional independence can be ...

journal_title：Statistics in medicine

authors： Yu Z,Wang L,Hildebrandt MA,Schaid DJ

更新日期：2008-08-30 00:00:00

abstract：:Prevention studies, as distinguished from studies investigating treatments for established disease, present some distinct challenges. Perhaps the most extensive experience with preventive agents is in the area of infectious diseases; vaccines have been extremely effective in preventing many such diseases. Vaccines hav...

journal_title：Statistics in medicine

authors： Ellenberg SS

更新日期：2004-01-30 00:00:00

abstract：:We consider recurrent events of the same type that occur during alternating restraint and non-restraint time periods. This research is motivated by a study on juvenile recidivism, where the probationers were followed for re-offenses during alternating placement periods and free-time periods. During the placement perio...

journal_title：Statistics in medicine

authors： Li X,Chen Y,Li R

更新日期：2017-02-20 00:00:00

abstract：:We propose a goodness-of-fit test statistic for linear regression with heterogeneous variance, which is asymptotically chi-square if the given model is correct. The test statistic is computed as a quadratic form of observed minus predicted responses. We apply the method to a linear regression for an ordinal categorica...

journal_title：Statistics in medicine

authors： Lipsitz SR,Buoncristiani JF

更新日期：1994-01-30 00:00:00

abstract：:Risk prediction procedures can be quite useful for the patient's treatment selection, prevention strategy, or disease management in evidence-based medicine. Often, potentially important new predictors are available in addition to the conventional markers. The question is how to quantify the improvement from the new ma...

journal_title：Statistics in medicine

authors： Uno H,Tian L,Cai T,Kohane IS,Wei LJ

更新日期：2013-06-30 00:00:00

abstract：:To study the spread of sexually transmitted diseases (STDs) using social/sexual mixing models, one must have quantitative information about sexual mixing. An unavoidable complication in gathering such information by survey is that members of the surveyed population will almost certainly have sexual contacts outside th...

journal_title：Statistics in medicine

authors： Rubin G,Umbach D,Shyu SF,Castillo-Chavez C

更新日期：1992-09-15 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：:It is often of interest to use observational data to estimate the causal effect of a target exposure or treatment on an outcome. When estimating the treatment effect, it is essential to appropriately adjust for selection bias due to observed confounders using, for example, propensity score weighting. Selection bias du...

journal_title：Statistics in medicine

authors： Parast L,Griffin BA

更新日期：2020-08-15 00:00:00

abstract：:Identification of key factors associated with the risk of developing cardiovascular disease and quantification of this risk using multivariable prediction algorithms are among the major advances made in preventive cardiology and cardiovascular epidemiology in the 20th century. The ongoing discovery of new risk markers...

journal_title：Statistics in medicine

authors： Pencina MJ,D'Agostino RB Sr,D'Agostino RB Jr,Vasan RS

更新日期：2008-01-30 00:00:00

abstract：:The authors measure the efficacy of three methods for predicting the time to infection for susceptible individuals in a population undergoing an HIV epidemic. The methods differ in whether they require detailed information of the contact network and whether they require knowledge of the initial source of infection. Ef...

journal_title：Statistics in medicine

authors： Altmann M,Wee BC,Willard K,Peterson D,Gatewood LC

更新日期：1994-01-15 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：:While genome-wide association studies (GWASs) have been widely used to uncover associations between diseases and genetic variants, standard SNP-level GWASs often lack the power to identify SNPs that individually have a moderate effect size but jointly contribute to the disease. To overcome this problem, pathway-based ...

journal_title：Statistics in medicine

authors： Yang Y,Basu S,Zhang L

更新日期：2020-03-15 00:00:00

abstract：:Variation in heart disease (HD) mortality rates across census tracts is greater than expected given binomial error and available explanatory variables. We extended an extra-binomial variation model for rates standardized by the direct method. The overdispersion parameter accounted for 36 per cent of the observed varia...

journal_title：Statistics in medicine

authors： Jarjoura D,Logue E

更新日期：1990-10-01 00:00:00

abstract：:There are many settings in which the distribution of error in a mismeasured covariate varies with the value of another covariate. Take, for example, the case of HIV phylogenetic cluster size, large values of which are an indication of rapid HIV transmission. Researchers wish to find behavioral correlates of HIV phylog...

journal_title：Statistics in medicine

authors： Parveen N,Moodie E,Brenner B

更新日期：2017-07-30 00:00:00

abstract：:A new method is proposed for the surveillance of Down's syndrome among newborn. Despite the strong dependence of overall risk of Down's syndrome on maternal age, it has been suggested that an environmentally induced increase in risk may be additive over all maternal ages. The surveillance method introduced here is spe...

journal_title：Statistics in medicine

authors： Lie RT,Heuch I,Irgens LM

更新日期：1993-01-15 00:00:00

abstract：:Many extensions of survival models based on the Cox proportional hazards approach have been proposed to handle clustered or multiple event data. Of particular note are five Cox-based models for recurrent event data: Andersen and Gill (AG); Wei, Lin and Weissfeld (WLW); Prentice, Williams and Peterson, total time (PWP-...

journal_title：Statistics in medicine

authors： Kelly PJ,Lim LL

更新日期：2000-01-15 00:00:00

abstract：:In this paper, we construct a partial additive regression (PAR) model to predict the survival times of cancer patients based on microarray gene expression data with right censoring. The area under time-dependent receiver operating characteristic curve is used as a model evaluation criterion. We conduct a simulation st...

journal_title：Statistics in medicine

authors： Zhao Y,Zhou Y,Zhao M

更新日期：2009-01-30 00:00:00

abstract：:The FDA permits marketing of a generic formulation of a drug G for the same indications as a standard preparation S if one can show that G is bioequivalent to S. Present implementation requires convincing evidence that the population mean difference in bioavailability (drug exposure) between the two preparations lies ...

journal_title：Statistics in medicine

authors： Sheiner LB

更新日期：1992-09-30 00:00:00

abstract：:Group sequential hypothesis testing is now widely used to analyze prospective data. If Monte Carlo simulation is used to construct the signaling threshold, the challenge is how to manage the type I error probability for each one of the multiple tests without losing control on the overall significance level. This paper...

journal_title：Statistics in medicine

authors： Silva IR

更新日期：2016-04-30 00:00:00

abstract：:The Spearman (rho(s)) and Kendall (tau) rank correlation coefficient are routinely used as measures of association between non-normally distributed random variables. However, confidence limits for rho(s) are only available under the assumption of bivariate normality and for tau under the assumption of asymptotic norma...

journal_title：Statistics in medicine

authors： Rosner B,Glynn RJ

更新日期：2007-02-10 00:00:00

abstract：:Proportional odds regression models for multinomial probabilities based on ordered categories have been generalized in two somewhat different directions. Models having scale as well as location parameters for adjustment of boundaries (on an unobservable, underlying continuum) between categories have been employed in t...

journal_title：Statistics in medicine

authors： Cox C

更新日期：1995-06-15 00:00:00

abstract：:In this paper, we consider fitting a flexible and interpretable additive regression model in a data-rich setting. We wish to avoid pre-specifying the functional form of the conditional association between each covariate and the response, while still retaining interpretability of the fitted functions. A number of recen...

journal_title：Statistics in medicine

authors： Petersen A,Witten D

更新日期：2019-02-20 00:00:00

abstract：:The setting of a quarantine time for an emerging infectious disease will depend on current knowledge concerning incubation times. Methods for the analysis of information on incubation times are investigated with a particular focus on inference regarding a possible maximum incubation time, after which an exposed indivi...

journal_title：Statistics in medicine

authors： Farewell VT,Herzberg AM,James KW,Ho LM,Leung GM

更新日期：2005-11-30 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：:This paper describes a method for estimating the risk from a disease over a set of contiguous geographical regions, when data on a potentially important covariate, such as race, are not available. Conditions under which the extra margin can be recovered are suggested. An application to prostate cancer mortality among ...

journal_title：Statistics in medicine

authors： Byers S,Besag J

更新日期：2000-09-15 00:00:00

abstract：:In this paper, we develop a method for the simultaneous estimation of spectral density functions (SDFs) for a collection of stationary time series that share some common features. Due to the similarities among the SDFs, the log-SDF can be represented using a common set of basis functions. The basis shared by the colle...

journal_title：Statistics in medicine

authors： Maadooliat M,Sun Y,Chen T

更新日期：2018-12-30 00:00:00

abstract：:For genome-wide association studies, we propose a new method for identifying significant biological pathways. In this approach, we aggregate data across single-nucleotide polymorphisms to obtain summary measures at the gene level. We then use a hierarchical Bayesian model, which takes the gene-level summary measures a...

journal_title：Statistics in medicine

authors： Shahbaba B,Shachaf CM,Yu Z

更新日期：2012-05-10 00:00:00

abstract：:In epidemiological studies we often want to learn about the direct effect of an exposure on an outcome, i.e. the effect that is not relayed by a specific intermediate variable. In the literature, there are two common definitions of direct effects; controlled and natural. When the intermediate variable and the outcome ...

journal_title：Statistics in medicine

authors： Sjölander A

更新日期：2009-02-15 00:00:00