Abstract:
:The relationship between association and surrogacy has been the focus of much debate in the surrogate marker literature. Recently, the individual causal association (ICA) has been introduced as a metric of surrogacy in the causal inference framework, when both the surrogate and the true endpoint are normally distributed and when both are binary. Earlier work on the normal case has demonstrated that, although the ICA and the adjusted association are related metrics, their relationship strongly depends on unidentifiable parameters and, consequently, the association between both endpoints conveys little information on the validity of the surrogate. In addition, in the normal setting, the magnitude of the ICA does not depend on the mean of the outcomes. The latter implies that identifiable parameters such as mean responses and treatment effects provide no information on the validity of the surrogate. In the present work it is shown that this is fundamentally different in the binary case. We demonstrate that the observed association between the outcomes as well as the success rates in both treatment groups are quite predictive for the ICA. It is shown that finding a good surrogate will be more likely when the association between the endpoints is large, there are sizeable treatment effects and the success rates for both endpoints are similar in both treatment groups. These results are demonstrated using extensive simulations and illustrated on a case study in multi-drug resistant tuberculosis.
journal_name
Stat Medjournal_title
Statistics in medicineauthors
Meyvisch P,Alonso A,Van der Elst W,Molenberghs Gdoi
10.1002/sim.8698subject
Has Abstractpub_date
2020-11-20 00:00:00pages
3867-3878issue
26eissn
0277-6715issn
1097-0258journal_volume
39pub_type
杂志文章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
pub_type: 杂志文章
doi:10.1002/sim.8549
更新日期:2020-08-15 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
pub_type: 杂志文章
doi:10.1002/sim.3984
更新日期:2010-09-30 00:00:00
abstract::Results from an analysis of traffic accidents from a study of the police records of four police stations in the Bangkok metropolis are presented. The main emphasis in this study was put on the development of a measure for traffic accident density. The traffic flow was estimated at the various study locations by traine...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780142113
更新日期:1995-11-15 00:00:00
abstract::Summarizing the information of many studies using a meta-analysis becomes more and more important, also in the field of diagnostic studies. The special challenge in meta-analysis of diagnostic accuracy studies is that in general sensitivity and specificity are co-primary endpoints. Across the studies both endpoints ar...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6583
更新日期:2015-12-20 00:00:00
abstract::While there has been extensive research developing gene-environment interaction (GEI) methods in case-control studies, little attention has been given to sparse and efficient modeling of GEI in longitudinal studies. In a two-way table for GEI with rows and columns as categorical variables, a conventional saturated int...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6281
更新日期:2014-12-20 00:00:00
abstract::The 'landmark' and 'Simon and Makuch' non-parametric estimators of the survival function are commonly used to contrast the survival experience of time-dependent treatment groups in applications such as stem cell transplant versus chemotherapy in leukemia. However, the theoretical survival functions corresponding to th...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6765
更新日期:2016-03-30 00:00:00
abstract::Longitudinal studies with repeated measures are often subject to non-response. Methods currently employed to alleviate the difficulties caused by missing data are typically unsatisfactory, especially when the cause of the missingness is related to the outcomes. We present an approach for incomplete categorical data in...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.982
更新日期:2002-01-30 00:00:00
abstract::We propose a new, less costly, design to test the equivalence of digital versus analogue mammography in terms of sensitivity and specificity. Because breast cancer is a rare event among asymptomatic women, the sample size for testing equivalence of sensitivity is larger than that for testing equivalence of specificity...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/(sici)1097-0258(19981015)17:19<2219::aid-s
更新日期:1998-10-15 00:00:00
abstract::Among subjects who have experienced a biological event, such as menarche, menopause or a delivery, one cannot distinguish the effects of time since the event from age at the event due to the linear dependency among these time variables and age at study ('current age'). This is a well-known problem that also exists in ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/(SICI)1097-0258(19960730)15:14<1545::AID-S
更新日期:1996-07-30 00:00:00
abstract::Phase II trials often test the null hypothesis H(0): p
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.2653
更新日期:2007-03-30 00:00:00
abstract::Immigration-death models are proposed to analyse the infection dynamics in longitudinal studies of panels of heavily parasitized human hosts where parasites have been typed at regular intervals by PCR. Immigration refers to the acquisition of a new parasitic genotype, occurring at rate lambda, and death refers to the ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.2189
更新日期:2005-11-15 00:00:00
abstract::Multilevel mixed effects survival models are used in the analysis of clustered survival data, such as repeated events, multicenter clinical trials, and individual participant data (IPD) meta-analyses, to investigate heterogeneity in baseline risk and covariate effects. In this paper, we extend parametric frailty model...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6191
更新日期:2014-09-28 00:00:00
abstract::We present a method to estimate the time-dependent vaccine efficacy from the cohort-specific vaccination coverage and from data on the vaccination status of cases and apply it to a measles epidemic in Germany which involved 529 cases, 88 of whom were vaccinated and 370 unvaccinated (for the remaining 71 cases the vacc...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.1043
更新日期:2002-08-30 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
pub_type: 杂志文章
doi:10.1002/sim.6496
更新日期:2015-07-30 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
pub_type: 杂志文章
doi:10.1002/sim.3501
更新日期:2009-02-28 00:00:00
abstract::Prediction performance of a risk scoring system needs to be carefully assessed before its adoption in clinical practice. Clinical preventive care often uses risk scores to screen asymptomatic population. The primary clinical interest is to predict the risk of having an event by a prespecified future time t0 . Accuracy...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.7606
更新日期:2018-05-10 00:00:00
abstract::The time-dependent change of HIV particle load, i.e. HIV dynamics, is likely to be controlled by a multitude of quantitative trait loci (QTL) that interact with each other as well as with various developmental and environmental factors in a coordinated manner. In this article, we have derived a new statistical model f...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.2489
更新日期:2006-11-30 00:00:00
abstract::We extend the method proposed in a recent work by the Authors for trial-level general surrogate evaluation to allow combinations of biomarkers and provide a procedure for finding the "best" combination of biomarkers based on the absolute prediction error summary of surrogate quality. We use a nonparametric Bayesian mo...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.7996
更新日期:2019-03-30 00:00:00
abstract::When interpreting screening mammograms radiologists decide whether suspicious abnormalities exist that warrant the recall of the patient for further testing. Previous work has found significant differences in interpretation among radiologists; their false-positive and false-negative rates have been shown to vary widel...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.2633
更新日期:2007-03-30 00:00:00
abstract::We consider the design of both cohort and case-control studies in which an initial ('stage 1') sample of complete data on an error-free disease indicator (D), a correct ('gold standard') dichotomous exposure measurement (X) and an error-prone exposure measurement (Z) are available. We calculate the amount of additiona...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780142307
更新日期:1995-12-15 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
pub_type: 杂志文章
doi:10.1002/sim.2469
更新日期:2006-11-15 00:00:00
abstract::A few large multi-centre male-only heart trials done in the 1970s and 1980s have been seen as ill-conceived because they did not include females. The purpose here is to revisit two of those trials and to consider consequences in terms of cost and power had they been designed to include females. ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/(sici)1097-0258(19990215)18:3<241::aid-sim
更新日期:1999-02-15 00:00:00
abstract::The Cardiac Arrythmia Suppression Trial was stopped much earlier than planned. Statistical considerations played a very important role in the decision. Flexible group sequential testing was developed for the trial by implementing a Lan and DeMets procedure with use of the permutation test. We compute P-values from the...
journal_title:Statistics in medicine
pub_type: 临床试验,杂志文章,多中心研究,随机对照试验
doi:10.1002/sim.4780090915
更新日期:1990-09-01 00:00:00
abstract::The problem for assessing biosimilarity and drug interchangeability of follow-on biologics (biosimilar products) is studied. Unlike the generic products, the development of biosimilar products is much more complicated because of fundamental differences in functional structures and manufacturing processes. As a result,...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.5571
更新日期:2013-02-10 00:00:00
abstract::Multiple imputation by chained equations is a flexible and practical approach to handling missing data. We describe the principles of the method and show how to impute categorical and quantitative variables, including skewed variables. We give guidance on how to specify the imputation model and how many imputations ar...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4067
更新日期:2011-02-20 00:00:00
abstract::Longitudinal designs are important in medical research and in many other disciplines. Complete longitudinal studies, in which each subject is evaluated at each measurement occasion, are often very expensive and motivate a search for more efficient designs. Recently developed statistical methods foster the use of inten...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780111411
更新日期:1992-10-01 00:00:00
abstract::Incomplete and unbalanced multivariate data often arise in longitudinal studies due to missing or unequally-timed repeated measurements and/or the presence of time-varying covariates. A general approach to analysing such data is through maximum likelihood analysis using a linear model for the expected responses, and s...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780070132
更新日期:1988-01-01 00:00:00
abstract::Many neuroscientists are interested in how connectomes (graphical representations of functional connectivity between areas of the brain) change in relation to covariates. In statistics, changes like this are analyzed using regression, where the outcomes or dependent variables are regressed onto the covariates. However...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.8374
更新日期:2019-12-20 00:00:00
abstract::Clinical studies that involve the recording of two or more distinct and well-defined events on each subject give rise to multiple event data. Treatment comparisons are usually reported in univariate analyses of time to first event or number of events observed. However, this approach may not uncover the 'full story' of...
journal_title:Statistics in medicine
pub_type: 临床试验,杂志文章,多中心研究,随机对照试验
doi:10.1002/(sici)1097-0258(19970430)16:8<941::aid-sim
更新日期:1997-04-30 00:00:00
abstract::During a course of human immunodeficiency virus (HIV-1) infection, the viral load usually increases sharply to a peak following infection and then drops rapidly to a steady state, where it remains until progression to AIDS. This steady state is often referred to as the viral set point. It is believed that the HIV vira...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3038
更新日期:2008-01-15 00:00:00