Abstract:
:Statistical tests have been proposed for determining whether incident cases of adverse health effects are 'clustered' together. Several procedures, termed 'focused', specifically analyse disease surveillance data around pre-specified putative sources of environmental hazard. Little has been done to compare the performance of various proposed methods on actual models of clustering. Analytic power functions are derived for three tests of focused clustering. These functions are based on the probabilistic structure of the clustering tests and do not require simulation. The three tests are compared with respect to statistical power on hypothetical data where monotone multiplicative increases in disease risk near a putative hazard define disease clusters of varying intensity.
journal_name
Stat Medjournal_title
Statistics in medicineauthors
Waller LA,Lawson ABdoi
10.1002/sim.4780142103subject
Has Abstractpub_date
1995-11-15 00:00:00pages
2291-308issue
21-22eissn
0277-6715issn
1097-0258journal_volume
14pub_type
杂志文章abstract::The analysis of patient-reported outcomes or other psychological traits can be realized using the Rasch measurement model. When the objective of a study is to compare groups of individuals, it is important, before the study, to define a sample size such that the group comparison test will attain a given power. The Ras...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6478
更新日期:2015-07-20 00:00:00
abstract::In repeated measures settings, modeling the correlation pattern of the data can be immensely important for proper analyses. Accurate inference requires proper choice of the correlation model. Optimal efficiency of the estimation procedure demands a parsimonious parameterization of the correlation structure, with suffi...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3928
更新日期:2010-07-30 00:00:00
abstract::Hot-deck imputation is an intuitively simple and popular method of accommodating incomplete data. Users of the method will often use the usual multiple imputation variance estimator which is not appropriate in this case. However, no variance expression has yet been derived for this easily implemented method applied to...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/(sici)1097-0258(19970115)16:1<5::aid-sim46
更新日期:1997-01-15 00:00:00
abstract::Continuous-time multistate survival models can be used to describe health-related processes over time. In the presence of interval-censored times for transitions between the living states, the likelihood is constructed using transition probabilities. Models can be specified using parametric or semiparametric shapes fo...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.7604
更新日期:2018-05-10 00:00:00
abstract::We consider statistical procedures for hypothesis testing of real valued functionals of matched pairs with missing values. In order to improve the accuracy of existing methods, we propose a novel multiplication combination procedure. Dividing the observed data into dependent (completely observed) pairs and independent...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.8178
更新日期:2019-07-30 00:00:00
abstract::In noninferiority studies, a limit of indifference is used to express a tolerance in results such that the clinician would regard such results as being acceptable or 'not worse'. We applied this concept to a measure of accuracy, the Receiver Operating Characteristic (ROC) curve, for a sequence of tests. We expressed a...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.5741
更新日期:2013-07-20 00:00:00
abstract::The Spearman (rho(s)) and Kendall (tau) rank correlation coefficient are routinely used as measures of association between non-normally distributed random variables. However, confidence limits for rho(s) are only available under the assumption of bivariate normality and for tau under the assumption of asymptotic norma...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.2547
更新日期:2007-02-10 00:00:00
abstract::We applied a computationally practical form of probit analysis for multiple response variables to data on early childhood development of four psychiatric disorders: disruptive disorders (DD-attention deficit disorders, oppositional defiant disorder, conduct disorder); adjustment disorders (ADJ); emotional disorders (E...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/(sici)1097-0258(19981115)17:21<2487::aid-s
更新日期:1998-11-15 00:00:00
abstract::We consider Cox proportional hazards regression when the covariate vector includes error-prone discrete covariates along with error-free covariates, which may be discrete or continuous. The misclassification in the discrete error-prone covariates is allowed to be of any specified form. Building on the work of Nakamura...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3159
更新日期:2008-05-20 00:00:00
abstract::Confidence intervals for a standardized effect are derived after stabilizing the variance of the Welch t-statistic. Simulation studies demonstrate the viability of the resulting intervals for a wide range of parameter values and sample sizes as small as five. The methodology is extended to the combination of results f...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.2751
更新日期:2007-06-30 00:00:00
abstract::The use of data from multiple studies or centers for the validation of a clinical test or a multivariable prediction model allows researchers to investigate the test's/model's performance in multiple settings and populations. Recently, meta-analytic techniques have been proposed to summarize discrimination and calibra...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.7653
更新日期:2018-05-30 00:00:00
abstract::In behavioral, biomedical, and social-psychological sciences, it is common to encounter latent variables and heterogeneous data. Mixture structural equation models (SEMs) are very useful methods to analyze these kinds of data. Moreover, the presence of missing data, including both missing responses and missing covaria...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3915
更新日期:2010-08-15 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::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
pub_type: 杂志文章
doi:10.1002/sim.3202
更新日期:2008-09-20 00:00:00
abstract::For many HIV-infected patients, use of antiretroviral therapy (ART) results in a sustained suppression of plasma viral load to undetectable levels. However, due to lack of antigenic stimulation, this may also result in a gradual loss of cell-mediated immune (CMI) responses that help control HIV infection. In concept, ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.2555
更新日期:2007-02-10 00:00:00
abstract::Lower urinary tract symptoms can indicate the presence of urinary tract infection (UTI), a condition that if it becomes chronic requires expensive and time consuming care as well as leading to reduced quality of life. Detecting the presence and gravity of an infection from the earliest symptoms is then highly valuable...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6786
更新日期:2016-04-15 00:00:00
abstract::Day and Walter derived methods of joint maximum likelihood estimation for the sojourn time distribution and the false negative rate for a screening programme. Their methods are not directly applicable to a programme which uses alternate screening by two modalities whose sojourn times and false negative rates will diff...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780080611
更新日期:1989-06-01 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
pub_type: 杂志文章
doi:10.1002/sim.7980
更新日期:2019-02-10 00:00:00
abstract::Pattern-mixture models (PMM) and selection models (SM) are alternative approaches for statistical analysis when faced with incomplete data and a nonignorable missing-data mechanism. Both models make empirically unverifiable assumptions and need additional constraints to identify the parameters. Here, we first introduc...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6302
更新日期:2014-11-30 00:00:00
abstract::In this commentary, we revisit Sir Austin Bradford Hill's seminal Alfred Watson Memorial Lecture in 1962 through the eyes of two practicing biostatisticians of the current era. We summarize some eternal takeaway messages from Hill's lecture regarding observations and experiments translated through the modern lexicon o...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.8830
更新日期:2021-01-15 00:00:00
abstract::The FDA permits marketing of a generic formulation of a drug G for the same indications as a standard preparation S if one can show that G is bioequivalent to S. Present implementation requires convincing evidence that the population mean difference in bioavailability (drug exposure) between the two preparations lies ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780111311
更新日期:1992-09-30 00:00:00
abstract::Adaptive designs have been proposed for clinical trials in which the nuisance parameters or alternative of interest are unknown or likely to be misspecified before the trial. Although most previous works on adaptive designs and mid-course sample size re-estimation have focused on two-stage or group-sequential designs ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3201
更新日期:2008-05-10 00:00:00
abstract::In biomedical studies and clinical trials, repeated measures are often subject to some upper and/or lower limits of detection. Hence, the responses are either left or right censored. A complication arises when more than one series of responses is repeatedly collected on each subject at irregular intervals over a perio...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.8017
更新日期:2019-03-15 00:00:00
abstract::Ordinal data appear in a wide variety of scientific fields. These data are often analyzed using ordinal logistic regression models that assume proportional odds. When this assumption is not met, it may be possible to capture the lack of proportionality using a constrained structural relationship between the odds and t...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.5689
更新日期:2013-06-15 00:00:00
abstract::Sexually transmitted infections (STIs) with Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis are among the most common infectious diseases in the United States, disproportionately affecting young women. Because a significant portion of the infections present no symptoms, infection control relies...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6515
更新日期:2015-09-10 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
pub_type: 杂志文章
doi:10.1002/sim.2116
更新日期:2005-08-15 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::In US states with small subpopulations, the observed mortality rates are often zero, particularly among young ages. Because in life tables, death rates are reported mostly on a log scale, zero mortality rates are problematic. To overcome the observed zero death rates problem, appropriate probability models are used. U...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6385
更新日期:2015-05-20 00:00:00
abstract::In studies with survival or time-to-event outcomes, a competing risk is an event whose occurrence precludes the occurrence of the primary event of interest. Specialized statistical methods must be used to analyze survival data in the presence of competing risks. We conducted a review of randomized controlled trials wi...
journal_title:Statistics in medicine
pub_type: 杂志文章,评审
doi:10.1002/sim.7215
更新日期:2017-04-15 00:00:00
abstract::We propose a goodness-of-fit test statistic for linear regression with heterogeneous variance, which is asymptotically chi-square if the given model is correct. The test statistic is computed as a quadratic form of observed minus predicted responses. We apply the method to a linear regression for an ordinal categorica...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780130205
更新日期:1994-01-30 00:00:00