Models for the propensity score that contemplate the positivity assumption and their application to missing data and causality.

abstract：:The proposed guidelines for the assessment of the effect of new pharmaceutical agents on the QT interval (beginning of QRS complex to end of T wave on the electrocardiogram) are based on the maximum of a series over time of simple one-sided 95 per cent upper confidence bounds. This procedure is typically very conserva...

journal_title：Statistics in medicine

authors： Boos DD,Hoffman D,Kringle R,Zhang J

更新日期：2007-09-10 00:00:00

abstract：:Two correction methods are considered for multiple logistic regression models with some covariates measured with error. Both methods are based on approximating the complicated regression model between the response and the observed covariates with simpler models. The first model is the logistic approximation proposed b...

journal_title：Statistics in medicine

authors： Kuha J

更新日期：1994-06-15 00:00:00

abstract：:Cross-sectional designs are often used to monitor the proportion of infections and other post-surgical complications acquired in hospitals. However, conventional methods for estimating incidence proportions when applied to cross-sectional data may provide estimators that are highly biased, as cross-sectional designs t...

journal_title：Statistics in medicine

authors： Fluss R,Mandel M,Freedman LS,Weiss IS,Zohar AE,Haklai Z,Gordon ES,Simchen E

更新日期：2013-06-30 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：: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：:Members of a cohort of workers in chemical industry (the so-called Boehringer cohort) exposed to 2, 3, 7, 8-tetrachlorodibenzo-para-dioxin (TCDD) from 1950 to 1984 were subject in the years 1985-1986 and 1992-1994 to an extensive biomonitoring programme on the TCDD levels of the individual workers. For establishing a ...

journal_title：Statistics in medicine

authors： Heinzl H,Mittlböck M,Edler L

更新日期：2008-05-30 00:00:00

abstract：:We consider using observational data to estimate the effect of a treatment on disease recurrence, when the decision to initiate treatment is based on longitudinal factors associated with the risk of recurrence. The effect of salvage androgen deprivation therapy (SADT) on the risk of recurrence of prostate cancer is in...

journal_title：Statistics in medicine

authors： Kennedy EH,Taylor JM,Schaubel DE,Williams S

更新日期：2010-11-10 00:00:00

abstract：:Causal inference for non-censored response variables, such as binary or quantitative outcomes, is often based on either (1) direct standardization ('G-formula') or (2) inverse probability of treatment assignment weights ('propensity score'). To do causal inference in survival analysis, one needs to address right-censo...

journal_title：Statistics in medicine

authors： Andersen PK,Syriopoulou E,Parner ET

更新日期：2017-07-30 00:00:00

abstract：:We have formulated the problem of determining whether there has been an upturn in HIV-1 seroconversion incidence over the first five years of follow-up in the Multicenter AIDS Cohort Study (MACS) as that of locating the minimum of a quadratic regression or examination of two-knot piecewise spline models. Under a quadr...

journal_title：Statistics in medicine

authors： Zhou SY,Kingsley LA,Taylor JM,Chmiel JS,He DY,Hoover DR

更新日期：1993-01-30 00:00:00

abstract：:This article introduces a global hypothesis test intended for studies with multiple endpoints. Our test makes use of a priori predictions about the direction of the result of each endpoint and we weight these predictions using the sample correlation matrix. The global alternative hypothesis concerns a parameter, ...

journal_title：Statistics in medicine

authors： Montgomery RN,Mahnken JD

更新日期：2020-12-10 00:00:00

abstract：:In genetic association studies, mixed effects models have been widely used in detecting the pleiotropy effects which occur when one gene affects multiple phenotype traits. In particular, bivariate mixed effects models are useful for describing the association of a gene with a continuous trait and a binary trait. Howev...

journal_title：Statistics in medicine

authors： Zhang Q,Yi GY

更新日期：2020-11-20 00:00:00

abstract：:The power to detect a treatment effect in cluster randomized trials can be increased by increasing the number of clusters. An alternative is to include covariates into the regression model that relates treatment condition to outcome. In this paper, formulae are derived in order to evaluate both strategies on basis of ...

journal_title：Statistics in medicine

authors： Moerbeek M

更新日期：2006-08-15 00:00:00

abstract：:We examine the properties of several tests for goodness-of-fit for multinomial logistic regression. One test is based on a strategy of sorting the observations according to the complement of the estimated probability for the reference outcome category and then grouping the subjects into g equal-sized groups. A g x c c...

journal_title：Statistics in medicine

authors： Fagerland MW,Hosmer DW,Bofin AM

更新日期：2008-09-20 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：: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：:Parameters for latent transition analysis (LTA) are easily estimated by maximum likelihood (ML) or Bayesian method via Markov chain Monte Carlo (MCMC). However, unusual features in the likelihood can cause difficulties in ML and Bayesian inference and estimation, especially with small samples. In this study we explore...

journal_title：Statistics in medicine

authors： Chung H,Lanza ST,Loken E

更新日期：2008-05-20 00:00:00

abstract：:The weighted average treatment effect is a causal measure for the comparison of interventions in a specific target population, which may be different from the population where data are sampled from. For instance, when the goal is to introduce a new treatment to a target population, the question is what efficacy (or ef...

journal_title：Statistics in medicine

authors： Tao Y,Fu H

更新日期：2019-02-10 00:00:00

abstract：:The continual reassessment method (CRM) is an adaptive design for Phase I trials whose operating characteristics, including appropriate sample size, probability of correctly identifying the maximum tolerated dose, and the expected proportion of participants assigned to each dose, can only be determined via simulation....

journal_title：Statistics in medicine

authors： Braun TM

更新日期：2020-09-16 00:00:00

abstract：:This article deals with determination of a sample size that guarantees the success of a trial. We follow a Bayesian approach and we say an experiment is successful if it yields a large posterior probability that an unknown parameter of interest (an unknown treatment effect or an effects-difference) is greater than a c...

journal_title：Statistics in medicine

authors： Brutti P,De Santis F,Gubbiotti S

更新日期：2008-06-15 00:00:00

abstract：:With considerable current interest in longitudinal epidemiologic studies, little is available regarding sample size requirements. This paper considers a method for analysis of longitudinal data, where one compares the mean rates of change for two or more groups, and proposes a statistic for use in determining sample s...

journal_title：Statistics in medicine

authors： Lefante JJ

更新日期：1990-04-01 00:00:00

abstract：:Methodology for the meta-analysis of individual patient data with survival end-points is proposed. Motivated by questions about the reliance on hazard ratios as summary measures of treatment effects, a parametric approach is considered and percentile ratios are introduced as an alternative to hazard ratios. The genera...

journal_title：Statistics in medicine

authors： Siannis F,Barrett JK,Farewell VT,Tierney JF

更新日期：2010-12-20 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：:Vaccination in populations can have several kinds of effects. Establishing that vaccination produces population-level effects beyond the direct effects in the vaccinated individuals can have important consequences for public health policy. Formal methods have been developed for study designs and analysis that can esti...

journal_title：Statistics in medicine

authors： Halloran ME,Hudgens MG

更新日期：2018-01-30 00:00:00

abstract：:We propose the use of Gaussian mixed models to analyse statistically 24 hour ambulatory blood pressure data from clinical trials. We develop specific models and apply them to data from a clinical study that compares two angiotensin-converting enzyme inhibitors. We investigate and discuss computing issues related to th...

journal_title：Statistics in medicine

authors： Selwyn MR,Difranco DM

更新日期：1993-09-30 00:00:00

abstract：:The receiver operating characteristic (ROC) curve can be utilized to evaluate the performance of diagnostic tests. The area under the ROC curve (AUC) is a widely used summary index for comparing multiple ROC curves. Both parametric and nonparametric methods have been developed to estimate and compare the AUCs. However...

journal_title：Statistics in medicine

authors： Yao W,Li Z,Graubard BI

更新日期：2015-04-15 00:00:00

abstract：:To benefit Alzheimer's disease research, a central data co-ordinating centre (CDCC) is planned that will systematically collect data from 27 Alzheimer's disease centres (ADCs) located nationwide. This CDCC will combine, analyse and disseminate epidemiologic, demographic, clinical and neuropathological data to research...

journal_title：Statistics in medicine

authors： Cronin-Stubbs D,DeKosky ST,Morris JC,Evans DA

更新日期：2000-06-15 00:00:00

abstract：:Age-period-cohort (APC) analysis is widely used in cancer epidemiology to model trends in cancer rates. We develop methods for comparative APC analysis of two independent cause-specific hazard rates assuming that an APC model holds for each one. We construct linear hypothesis tests to determine whether the two hazards...

journal_title：Statistics in medicine

authors： Rosenberg PS,Anderson WF

更新日期：2010-05-20 00:00:00

abstract：:The focus of this paper is the development of a range of cluster detection diagnostics that can be used to assess the degree to which a clustering method recovers the true clustering behaviour of small area data. The diagnostics proposed range from individual region specific diagnostics to neighbourhood diagnostics, a...

journal_title：Statistics in medicine

authors： Hossain MM,Lawson AB

更新日期：2006-03-15 00:00:00

abstract：:We develop analysis methods for clinical trials with time-to-event outcomes which correct for treatment changes during follow-up, yet are based on comparisons of randomized groups and not of selected groups. A causal model relating observed event times to event times that would have been observed under other treatment...

journal_title：Statistics in medicine

authors： White IR,Babiker AG,Walker S,Darbyshire JH

更新日期：1999-10-15 00:00:00

abstract：:The generalized estimating equations (GEE) approach is commonly used to model incomplete longitudinal binary data. When drop-outs are missing at random through dependence on observed responses (MAR), GEE may give biased parameter estimates in the model for the marginal means. A weighted estimating equations approach g...

journal_title：Statistics in medicine

authors： Preisser JS,Lohman KK,Rathouz PJ

更新日期：2002-10-30 00:00:00