Effects and non-effects of paired identical observations in comparing proportions with binary matched-pairs data.

abstract：:We obtained maximum likelihood estimates (MLEs) of the proportion cured pi c and mean log survival time mu t for a sample of 4355 patients with intraocular melanoma whose survival times subsequent to treatment were assumed to follow a log-normal distribution. Following stratification by tumour size, MLEs of pi c and m...

journal_title：Statistics in medicine

authors： Gamel JW,McLean IW,Rosenberg SH

更新日期：1990-08-01 00:00:00

abstract：:The goal of screening programmes for cancer is early detection and treatment with a consequent reduction in mortality from the disease. Screening programmes need to assess the true benefit of screening, that is, the length of time of extension of survival beyond the time of advancement of diagnosis (lead-time). This p...

journal_title：Statistics in medicine

authors： Xu JL,Prorok PC

更新日期：1995-12-30 00:00:00

abstract：:The log-rank test is the most powerful non-parametric test for detecting a proportional hazards alternative and thus is the most commonly used testing procedure for comparing time-to-event distributions between different treatments in clinical trials. When the log-rank test is used for the primary data analysis, the s...

journal_title：Statistics in medicine

authors： Zhang D,Quan H

更新日期：2009-02-28 00:00:00

abstract：:Comparative studies of the accuracy of diagnostic procedures often use a paired design to gain in efficiency. Standard methods for analysing data from paired designs require complete observations. In many studies, however, one of the test results may be missing for some patients. In this paper, we propose a simple cor...

journal_title：Statistics in medicine

authors： Zhou XH,Gatsonis CA

更新日期：1996-08-15 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

abstract：:Biomarkers that predict the efficacy of treatment can potentially improve clinical outcomes and decrease medical costs by allowing treatment to be provided only to those most likely to benefit. We consider the design of a randomized clinical trial in which one objective is to evaluate a treatment selection marker. The...

journal_title：Statistics in medicine

authors： Janes H,Brown MD,Pepe MS

更新日期：2015-11-30 00:00:00

abstract：:In this paper we present a simple method for constructing (1- alpha)100 per cent confidence intervals for binomial proportions with near nominal coverage for all underlying proportion parameters on the unit interval. This new method uses, with a slight modification, the standard normal approximation technique taught i...

journal_title：Statistics in medicine

authors： Borkowf CB

更新日期：2006-11-15 00:00:00

abstract：:We present some practical extensions and applications of a strategy proposed by Thall, Simon and Estey for designing and monitoring single-arm clinical trials with multiple outcomes. We show by application how the strategy may be applied to construct designs for phase IIA activity trials and phase II equivalence trial...

journal_title：Statistics in medicine

authors： Thall PF,Sung HG

更新日期：1998-07-30 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：:The randomized clinical trial, LU19, conducted by the Medical Research Council Lung Cancer Working Party, was designed to compare ACE (doxorubicin, cyclophosphamide and etoposide) chemotherapy plus G-CSF (granulocyte colony-stimulating factor) at 2-week intervals versus ACE chemotherapy alone at standard 3-week interv...

journal_title：Statistics in medicine

authors： Qian W,Parmar MK,Sambrook RJ,Fayers PM,Girling DJ,Stephens RJ

更新日期：2000-10-15 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：: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：:Biological drug products are therapeutic moieties manufactured by a living system or organisms. These are important life-saving drug products for patients with unmet medical needs. Because of expensive cost, only a few patients have access to life-saving biological products. Most of the early biological products will ...

journal_title：Statistics in medicine

authors： Lin JR,Chow SC,Chang CH,Lin YC,Liu JP

更新日期：2013-02-10 00:00:00

abstract：:The additional time to complete a three-period two-treatment (3P2T) cross-over trial may cause a greater number of patient dropouts than with a two-period trial. This paper develops maximum likelihood (ML), single imputation and multiple imputation missing data analysis methods for the 3P2T cross-over designs. We use ...

journal_title：Statistics in medicine

authors： Richardson BA,Flack VF

更新日期：1996-01-30 00:00:00

abstract：:We study the competing risks model and show that the cause j cumulative incidence function integrated from 0 to τ has a natural interpretation as the expected number of life years lost due to cause j before time τ. This is analogous to the τ-restricted mean lifetime, which is the survival function integrated from 0 to...

journal_title：Statistics in medicine

authors： Andersen PK

更新日期：2013-12-30 00:00:00

abstract：:We study prevalence-dependent diagnostic accuracy measures, specifically, positive and negative predictive values. These measures permit an assessment of the clinical utility of diagnostic tests across populations with different disease prevalences. In many cases, prevalence may not be known with certainty and the eva...

journal_title：Statistics in medicine

authors： Li J,Fine JP,Safdar N

更新日期：2007-07-30 00:00:00

abstract：:A problem occurring in chronic disease modeling is the estimation of transition probabilities of moving from one state of a categorical risk factor to another. Transitions could be obtained from a cohort study, but often such data may not be available. However, under the assumption that transitions remain stable over ...

journal_title：Statistics in medicine

authors： Kassteele Jv,Hoogenveen RT,Engelfriet PM,Baal PH,Boshuizen HC

更新日期：2012-03-15 00:00:00

abstract：:In a long-running longitudinal study using complex machinery to obtain measurements, it is sometimes necessary to replace the machine. This can result in lack of continuity in the measurements that can overwhelm any treatment effect or time trend. We propose a Bayesian procedure implemented using Markov chain Monte Ca...

journal_title：Statistics in medicine

authors： Ambrosius WT,Hui SL

更新日期：2004-09-30 00:00:00

abstract：:Given N points or events occurring according to some probability distribution in the unit interval (0, 1), the simple scan statistic is defined to be the maximum number of points in any sub-interval of length d. In many areas, as in epidemiology, it is used to test the null hypothesis that the events are random, again...

journal_title：Statistics in medicine

authors： Nagarwalla N

更新日期：1996-04-15 00:00:00

abstract：:The Response Evaluation Criteria in Solid Tumors are used as standard guidelines for the clinical evaluation of cancer treatments. The assessment is based on the anatomical tumor burden: change in size of target lesions and evolution of nontarget lesions (NTL). Despite unquestionable advantages of this standard tool, ...

journal_title：Statistics in medicine

authors： Król A,Tournigand C,Michiels S,Rondeau V

更新日期：2018-06-15 00:00:00

abstract：:Between-community variance or community-by-time variance is one of the key factors driving the cost of conducting group randomized trials, which are often very expensive. We investigated empirically whether between-community variance could be reduced by controlling individual- and/or community-level covariates and ide...

journal_title：Statistics in medicine

authors： Feng Z,Diehr P,Yasui Y,Evans B,Beresford S,Koepsell TD

更新日期：1999-03-15 00:00:00

abstract：:A decision-theoretic framework is proposed for designing sequential dose-finding trials with multiple outcomes. The optimal strategy is solvable theoretically via backward induction. However, for dose-finding studies involving k doses, the computational complexity is the same as the bandit problem with k-dependent arm...

journal_title：Statistics in medicine

authors： Fan SK,Wang YG

更新日期：2006-05-30 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

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：:Tumour registry linkage, chart review and patient self-report are all commonly used ascertainment methods in cancer epidemiology. These methods are used for estimating the incidence or prevalence of different cancer types in a population, and for investigating the effects of possible risk factors for cancer. Tumour re...

journal_title：Statistics in medicine

authors： Bernatsky S,Joseph L,Bélisle P,Boivin JF,Rajan R,Moore A,Clarke A

更新日期：2005-08-15 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：:The use of classification and regression tree (CART) methodology is explored for the diagnosis of patients complaining of anterior chest pain. The results are compared with those previously obtained using correspondence analysis and independent Bayes classification. The technique is shown to be of potential value for ...

journal_title：Statistics in medicine

authors： Crichton NJ,Hinde JP,Marchini J

更新日期：1997-04-15 00:00:00

abstract：:In this paper we describe Bonferroni-based multiple testing procedures (MTPs) as strategies to split and recycle test mass. Here, 'test mass' refers to (parts of) the nominal level alpha at which the family-wise error rate is controlled. Briefly, test mass is split between different null hypotheses, and whenever a nul...

journal_title：Statistics in medicine

authors： Burman CF,Sonesson C,Guilbaud O

更新日期：2009-02-28 00:00:00

abstract：:Although transportation safety has greatly improved over the past 2 decades, motor vehicle crash injuries remain a leading cause of morbidity and mortality, particularly among young drivers. Driver errors and behaviors such as speeding and distraction contribute disproportionately to crashes among inexperienced novice...

journal_title：Statistics in medicine

authors： Simons-Morton B

更新日期：2017-10-30 00:00:00

abstract：:This paper assesses the coverage probability of commonly used confidence intervals for the standardized mortality ratio (SMR) when death certificates are missing. It also proposes alternative confidence interval approaches with coverage probabilities close to .95. In epidemiology, the SMR is an important measure of ri...

journal_title：Statistics in medicine

authors： Timkova J,Kotik L,Tomasek L

更新日期：2017-11-30 00:00:00