Abstract:
:Genome-wide association studies are characterized by a huge number of statistical tests performed to discover new disease-related genetic variants [in the form of single-nucleotide polymorphisms (SNPs)] in human DNA. Many SNPs have been identified for cross-sectionally measured phenotypes. However, there is a growing interest in genetic determinants of the evolution of traits over time. Dealing with correlated observations from the same individual, we need to apply advanced statistical techniques. The linear mixed model is popular but also much more computationally demanding than fitting a linear regression model to independent observations. We propose a conditional two-step approach as an approximate method to explore the longitudinal relationship between the trait and the SNP. In a simulation study, we compare several fast methods with respect to their accuracy and speed. The conditional two-step approach is applied to relate SNPs to longitudinal bone mineral density responses collected in the Rotterdam Study.
journal_name
Stat Medjournal_title
Statistics in medicineauthors
Sikorska K,Rivadeneira F,Groenen PJ,Hofman A,Uitterlinden AG,Eilers PH,Lesaffre Edoi
10.1002/sim.5517subject
Has Abstractpub_date
2013-01-15 00:00:00pages
165-80issue
1eissn
0277-6715issn
1097-0258journal_volume
32pub_type
杂志文章abstract::One Sentence Summary: A Bayesian repeated measures model based on quantitative muscle strength data from a prospective Natural History Study was developed to determine disease progression and design clinical trials for GNE myopathy, a rare and slowly progressive muscle disease. GNE myopathy is a rare muscle disease ch...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.8050
更新日期:2019-04-15 00:00:00
abstract::The validity and practical utility of observational medical research depends critically on good study design, excellent data quality, appropriate statistical methods and accurate interpretation of results. Statistical methodology has seen substantial development in recent times. Unfortunately, many of these methodolog...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6265
更新日期:2014-12-30 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
pub_type: 杂志文章
doi:10.1002/sim.3175
更新日期:2008-06-15 00:00:00
abstract::We examine the common clinical belief that there is an interaction between epilepsy type and the two standard anti-epileptic drugs, valproate and carbamazepine, using data from several randomized clinical trials. Epilepsy type is not always easy to define, and three possible reclassifications are investigated to see w...
journal_title:Statistics in medicine
pub_type: 杂志文章,meta分析
doi:10.1002/sim.1044
更新日期:2002-09-30 00:00:00
abstract::Systematic reviews often provide recommendations for further research. When meta-analyses are inconclusive, such recommendations typically argue for further studies to be conducted. However, the nature and amount of future research should depend on the nature and amount of the existing research. We propose a method ba...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.5524
更新日期:2013-01-15 00:00:00
abstract::Phase II studies in oncology are frequently conducted as two-stage single-arm trials with a binary endpoint indicating tumor response. As a common feature of these designs, the sample sizes of the two stages and the decision rules for the interim and the final analysis have to be pre-specified and adhered to strictly ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6479
更新日期:2015-06-15 00:00:00
abstract::Population dynamic models, commonly used tools in the study of epidemics and other complex population processes, are implicit non-linear mathematical equations. Inference based on such models can be difficult due to the problems associated with high dimensional parameters that may be non-identified and complex likelih...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.1258
更新日期:2002-12-15 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
pub_type: 杂志文章
doi:10.1002/sim.7289
更新日期:2017-07-30 00:00:00
abstract::In an individually matched case-control study, effects of potential risk factors are ascertained through conditional logistic regression (CLR). Extension of CLR to situations with multiple disease or reference categories has been made through polychotomous CLR and is shown to be more efficient than carrying out separa...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.2790
更新日期:2007-07-30 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
pub_type: 杂志文章
doi:10.1002/sim.3493
更新日期:2009-02-15 00:00:00
abstract::Down's syndrome screening is currently carried out using a combination of biochemical markers measured in maternal serum samples; these include MSAFP, Total hCG, uE3 and Free beta-hCG. Recently a number of papers have compared the effectiveness of different combinations of these markers. Some recommend MSAFP, Total hC...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/(sici)1097-0258(19970715)16:13<1481::aid-s
更新日期:1997-07-15 00:00:00
abstract::Graphical methods are often used to check goodness-of-fit of models to data. It is common to plot residuals against a reference distribution so that when the model fits the data, the configuration should be close to a straight line. Since the resemblance to a straight line is often unclear, it has been suggested to ad...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780141607
更新日期:1995-08-30 00:00:00
abstract::A relationship between baseline risk and treatment effect is increasingly investigated as a possible explanation of between-study heterogeneity in clinical trial meta-analysis. An approach that is still often applied in the medical literature is to plot the estimated treatment effects against the estimated measures of...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/1097-0258(20001230)19:24<3497::aid-sim830>
更新日期:2000-12-30 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
pub_type: 杂志文章
doi:10.1002/sim.4780111202
更新日期:1992-09-15 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
pub_type: 杂志文章
doi:10.1002/sim.7404
更新日期:2017-10-30 00:00:00
abstract::Among many other uses, positron emission tomography (PET) can be used in studies to estimate the density of a neuroreceptor at each location throughout the brain by measuring the concentration of a radiotracer over time and modeling its kinetics. There are a variety of kinetic models in common usage and these typicall...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3510
更新日期:2009-03-15 00:00:00
abstract::Longitudinal studies are often concerned with estimating the recurrence rate of a non-fatal event. In many cases, only the total number of events occurring during successive time intervals is known. We compared a mixed Poisson-gamma regression method proposed by Thall and a quasi-likelihood method proposed by Zeger an...
journal_title:Statistics in medicine
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1002/sim.4780121406
更新日期:1993-07-30 00:00:00
abstract::Korn and Whittemore have presented methods for analyzing longitudinal data where the number of observations per individual is large relative to the number of variables considered for each subject. However, this is often not the case in epidemiologic studies, since one usually collects data at relatively few time point...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780040407
更新日期:1985-10-01 00:00:00
abstract::Our objective is to develop a model to estimate the relative risk of disease in each area, Ai, i=1, ... , n, of a region and to identify areas of unusually high or low risk. We use a product partition model (PPM) in which we assume that the true relative risks can be partitioned into a number of components or sets of ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3253
更新日期:2008-08-30 00:00:00
abstract::We compared eight nominal 95 per cent confidence intervals for the ratio of two Poisson parameters, both assumed small, on their true coverage (the probability that the interval includes the ratio of Poisson parameters) and median width. The commonly used log-linear interval, justified by asymptotic considerations, pr...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3234
更新日期:2008-09-10 00:00:00
abstract::Although population-based molecular association studies are becoming increasingly popular, methodology for the meta-analysis of these studies has been neglected, particularly with regard to two issues: testing Hardy-Weinberg equilibrium (HWE), and pooling results in a manner that reflects a biological model of gene ef...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.2010
更新日期:2005-05-15 00:00:00
abstract::Both the variation of positive responses (negative responses) among individuals and the internal correlation among responses for the same individual affect the precision of the estimate of sensitivity (specificity). To estimate the sensitivity (specificity) of a medical diagnostic test, this paper proposes a Bayesian ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780081007
更新日期:1989-10-01 00:00:00
abstract::Multi-type recurrent event data arise when two or more different kinds of events may occur repeatedly over a period of observation. The scientific objectives in such settings are often to describe features of the marginal processes and to study the association between the different types of events. Interval-censored m...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.1936
更新日期:2005-03-15 00:00:00
abstract::Conditional power (CP) is the probability that the final study result will be statistically significant, given the data observed thus far and a specific assumption about the pattern of the data to be observed in the remainder of the study, such as assuming the original design effect, or the effect estimated from the c...
journal_title:Statistics in medicine
pub_type: 杂志文章,评审
doi:10.1002/sim.2151
更新日期:2005-09-30 00:00:00
abstract::In this paper, we discuss statistical inference for a 2 × 2 table under inverse sampling, where the total number of cases is fixed by design. We demonstrate that the exact unconditional distributions of some relevant statistics differ from the distributions under conventional sampling, where the sample size is fixed b...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6511
更新日期:2015-08-30 00:00:00
abstract::Cancer patients, chronic kidney disease patients, and subjects infected with HIV are routinely monitored over time using biomarkers that represent key health status indicators. Furthermore, biomarkers are frequently used to guide initiation of new treatments or to inform changes in intervention strategies. Since key m...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.7675
更新日期:2018-08-15 00:00:00
abstract::Recently, there has been much work on early phase cancer designs that incorporate both toxicity and efficacy data, called phase I-II designs because they combine elements of both phases. However, they do not explicitly address the phase II hypothesis test of H0 : p ≤ p0 , where p is the probability of efficacy at the ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6124
更新日期:2014-07-20 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
pub_type: 杂志文章
doi:10.1002/sim.4239
更新日期:2011-07-10 00:00:00
abstract::In natural history studies of chronic disease, it is of interest to understand the evolution of key variables that measure aspects of disease progression. This is particularly true for immunological variables among persons infected with the human immunodeficiency virus (HIV). The natural time scale for such studies is...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780131103
更新日期:1994-06-15 00:00:00
abstract::A number of variance formulae for the attributable fraction have been presented, but none is consistent in sparse data, such as found in individually matched case-control studies. This paper employs Mantel-Haenszel estimation to derive variance estimators for attributable fractions that are dually consistent, that is,...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780060607
更新日期:1987-09-01 00:00:00