Abstract:
:Geocoding a study population as completely as possible is an important data assimilation component of many spatial epidemiologic studies. Unfortunately, complete geocoding is rare in practice. The failure of a substantial proportion of study subjects' addresses to geocode has consequences for spatial analyses, some of which are not yet fully understood. This article explicitly demonstrates that the failure to geocode can be spatially clustered, and it investigates the implications of this for the detection of disease clustering. A data set of more than 9000 ground-truthed addresses from Carroll County, Iowa, which was geocoded via a standard address matching and street interpolation algorithm, is used for this purpose. Through simulation of disease processes at these addresses, the authors show that spatial clustering of geocoding failure has no effect on the marginal power to detect spatial disease clustering if the likelihood of disease is independent of the failure to geocode, but that power is substantially reduced if disease likelihood and geocoding failure are positively associated.
journal_name
Stat Medjournal_title
Statistics in medicineauthors
Zimmerman DL,Fang X,Mazumdar Sdoi
10.1002/sim.3288subject
Has Abstractpub_date
2008-09-20 00:00:00pages
4254-66issue
21eissn
0277-6715issn
1097-0258journal_volume
27pub_type
杂志文章abstract::Writing the variance of the Mantel-Haenszel estimator under the null of homogeneity and inverting the corresponding test, we arrive at an improved confidence interval for the common risk difference in stratified 2 × 2 tables. This interval outperforms a variety of other intervals currently recommended in the literatur...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6122
更新日期:2014-07-30 00:00:00
abstract::With increasingly abundant spatial data in the form of case counts or rates combined over areal regions (eg, ZIP codes, census tracts, or counties), interest turns to formal identification of difference "boundaries," or barriers on the map, in addition to the estimated statistical map itself. "Boundary" refers to a bo...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.7408
更新日期:2017-11-10 00:00:00
abstract::The 'at least as good as' criterion, introduced by Laster and Johnson for a continuous response variate, is developed here for applications with dichotomous data. This approach is adaptive in nature, as the margin of non-inferiority is not taken as a fixed difference; it varies as a function of the positive control re...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.2476
更新日期:2006-04-15 00:00:00
abstract::We present a model for describing correlated binocular data from reader-based diagnostic studies, where the same group of readers evaluates the presence or absence of certain diseases on binocular organs (e.g., fellow eyes) of patients. Multiple random effects are incorporated to meaningfully delineate various associa...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6584
更新日期:2015-12-20 00:00:00
abstract::Repeated cross-sectional samples are common in national surveys of health like the National Health Interview Survey (NHIS). Because population health outcomes generally evolve slowly, pooling data across years can improve the precision of current-year annual estimates of disease prevalence and other health outcomes. P...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3897
更新日期:2011-02-28 00:00:00
abstract::Instrumental variable estimates of causal effects can be biased when using many instruments that are only weakly associated with the exposure. We describe several techniques to reduce this bias and estimate corrected standard errors. We present our findings using a simulation study and an empirical application. For th...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6358
更新日期:2015-02-10 00:00:00
abstract::In this paper, we define a modified version τ(b) of Kendall's tau to measure the association in a pair (X,Y) of random variables subject to fixed left censoring due to known lower detection limits. We provide a nonparametric estimator of τ(b) and investigate its asymptotic properties. We then assume an Archimedean cop...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4319
更新日期:2011-11-20 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::A significant source of missing data in longitudinal epidemiological studies on elderly individuals is death. Subjects in large scale community-based longitudinal dementia studies are usually evaluated for disease status in study waves, not under continuous surveillance as in traditional cohort studies. Therefore, for...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.1506
更新日期:2003-05-15 00:00:00
abstract::In analysis of longitudinal data, the variance matrix of the parameter estimates is usually estimated by the 'sandwich' method, in which the variance for each subject is estimated by its residual products. We propose smooth bootstrap methods by perturbing the estimating functions to obtain 'bootstrapped' realizations ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3027
更新日期:2008-03-30 00:00:00
abstract::The availability of large data sets together with the growth in power and storage capabilities of computers have made the analysis of the spatial distribution of disease rates an increasingly important tool in public health research. Use of existing geographic divisions or groupings tends to result either in unstable ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780121916
更新日期:1993-10-01 00:00:00
abstract::Blinded estimation of variance allows for changing the sample size without compromising the integrity of the trial. Some of the methods that estimate the variance in a blinded manner either make untenable assumptions or are only applicable to two-treatment trials. We propose a new method for continuous endpoints that ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.2070
更新日期:2005-06-30 00:00:00
abstract::The purpose of this research was to develop appropriate methods for analysing repeated ordinal categorical data that arose in an intervention trial to prevent oesophageal cancer. The measured response was the degree of oesophageal dysplasia at 2.5 and 6 years after randomization. An important feature was that some res...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780130511
更新日期:1994-03-15 00:00:00
abstract::When estimating the average effect of a binary treatment (or exposure) on an outcome, methods that incorporate propensity scores, the G-formula, or targeted maximum likelihood estimation (TMLE) are preferred over naïve regression approaches, which are biased under misspecification of a parametric outcome model. In con...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.7628
更新日期:2018-07-20 00:00:00
abstract::In many chronic diseases, therapy aims to prevent or reduce the frequency of episodes of a disease manifestation, for example cardiac ischaemic episodes or epileptic seizures. Entry criteria for clinical trials typically include a minimum number of episodes within a baseline period, and regression to the mean should b...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780130806
更新日期:1994-04-30 00:00:00
abstract::In the analysis of composite endpoints in a clinical trial, time to first event analysis techniques such as the logrank test and Cox proportional hazard test do not take into account the multiplicity, importance, and the severity of events in the composite endpoint. Several generalized pairwise comparison analysis met...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.8388
更新日期:2019-12-30 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
pub_type: 杂志文章
doi:10.1002/(sici)1097-0258(19960415)15:7/9<845::aid-s
更新日期:1996-04-15 00:00:00
abstract::In medical research, risk difference (RD) and number needed to treat (NNT) measures for survival times have been mainly proposed without consideration of covariates. In this paper, we develop adjusted RD and NNT measures for use in observational studies with survival time outcomes within the framework of the Cox propo...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3793
更新日期:2010-03-30 00:00:00
abstract::In the analysis of survival data, there are often competing events that preclude an event of interest from occurring. Regression analysis with competing risks is typically undertaken using a cause-specific proportional hazards model. However, modern alternative methods exist for the analysis of the subdistribution haz...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4123
更新日期:2011-03-15 00:00:00
abstract::In many chronic disease processes subjects are at risk of two or more types of events. We describe a bivariate mixed Poisson model in which a copula function is used to model the association between two gamma distributed random effects. The resulting model is a bivariate negative binomial process in which each type of...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3830
更新日期:2010-03-15 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::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::Multi-state models are useful for modelling disease progression where the state space of the process is used to represent the discrete disease status of subjects. Often, the disease process is only observed at clinical visits, and the schedule of these visits can depend on the disease status of patients. In such situa...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6582
更新日期:2015-12-20 00:00:00
abstract::Several relative risk models for survival time data in drug combination therapy are derived and their properties are discussed. The main intention of this paper is to clarify the differences among the models in order to help to choose the appropriate one in a given situation. The models are motivated by discussing the...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780091216
更新日期:1990-12-01 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::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::When estimating the probability of natural conception from observational data on couples with an unfulfilled child wish, the start of assisted reproductive therapy (ART) is a competing event that cannot be assumed to be independent of natural conception. In clinical practice, interest lies in the probability of natura...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6280
更新日期:2014-11-20 00:00:00
abstract::We consider methods for selecting the joint specification of the mean and variance functions in statistical models for rates or counts. Based on analyses of diagnosis-specific hospital discharge rates in Michigan, we show that a Poisson model with an extra variance component for the systematic variation is superior to...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780100908
更新日期:1991-09-01 00:00:00
abstract::Biomedical studies often measure variables with error. Examples in the literature include investigation of the association between the change in some outcome variable (blood pressure, cholesterol level etc.) and a set of explanatory variables (age, smoking status etc.). Typically, one fits linear regression models to ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/(sici)1097-0258(19981130)17:22<2597::aid-s
更新日期:1998-11-30 00:00:00
abstract::The aim of this paper is to demonstrate the effect of excluding incomplete observations and competing events when calculating cross-sectional measures of NHS waiting times, and to obtain a more accurate estimate of the 'time-to-admission' of those listed on NHS waiting lists using life-table methods. The official 'tim...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/1097-0258(20000815)19:15<2037::aid-sim606>
更新日期:2000-08-15 00:00:00