Abstract:
:In failure time studies involving a chronic disease such as cancer, several competing causes of mortality may be operating. Commonly, the conventional statistical technique of Kaplan-Meier, which is only meaningfully interpreted by assuming independence of failure types and the censoring mechanism, is employed in clinical research involving competing risks data. Some authors have advocated the use of a cause-specific cumulative incidence function which takes into account the existence of other events within a competing risks framework, without making any assumption about independence. Lunn and McNeil have proposed an approach based on an extension of the Cox proportional hazards regression, which enables direct comparisons between failure types. We have extended this approach to estimate cause-specific cumulative incidence. As it is often not easy to follow competing risks methodology in the literature, this paper sets out systematically the assumptions made and the steps taken to implement four different methods of analysing competing risks data using cumulative incidence rates or the Kaplan-Meier estimates of cause-specific failure probabilities. The data obtained from a randomized trial of patients with osteosarcoma were used to compare these four approaches. As illustrated using the osteosarcoma data, the estimates of the classical Kaplan-Meier methods have larger numerical values than the cause-specific cumulative incidence. On the other hand, estimates of the cause-specific cumulative incidence rates from the conventional method and the modified Cox method are highly comparable.
journal_name
Stat Medjournal_title
Statistics in medicineauthors
Tai BC,Machin D,White I,Gebski V,EOI (The European Osteosarcoma Intergroup).doi
10.1002/sim.711subject
Has Abstractpub_date
2001-03-15 00:00:00pages
661-84issue
5eissn
0277-6715issn
1097-0258journal_volume
20pub_type
临床试验,杂志文章,多中心研究,随机对照试验abstract::The asymptotic Pearson's chi-squared test and Fisher's exact test have long been the most used for testing association in 2x2 tables. Unconditional tests preserve the significance level and generally are more powerful than Fisher's exact test for moderate to small samples, but previously were disadvantaged by being co...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3531
更新日期:2009-03-30 00:00:00
abstract::Statisticians have long argued that randomized controlled trials should be sufficiently large to achieve their purpose, and for common diseases with major public health implications this has brought many benefits. However, there are many instances where it is unrealistic to expect clinicians to provide the information...
journal_title:Statistics in medicine
pub_type: 杂志文章,评审
doi:10.1002/sim.4780140204
更新日期:1995-01-30 00:00:00
abstract::The case-control study is a simple and an useful method to characterize the effect of a gene, the effect of an exposure, as well as the interaction between the two. The control-free case-only study is yet an even simpler design, if interest is centered on gene-environment interaction only. It requires the sometimes pl...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4028
更新日期:2010-10-30 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
pub_type: 杂志文章
doi:10.1002/sim.6564
更新日期:2015-11-30 00:00:00
abstract::In the development of a new treatment in oncology, phase II trials play a key role. On the basis of the data obtained during phase II, it is decided whether the treatment should be studied further. Therefore, the decision to be made on the basis of the data of a phase II trial must be as accurate as possible. For ethi...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.5585
更新日期:2012-12-30 00:00:00
abstract::We provide a Bayesian analysis of data categorized into two levels of age (younger than 50 years, at least 50 years) and three levels of bone mineral density (normal, osteopenia, osteoporosis) for white females at least 20 years old in the third National Health and Nutrition Examination Survey. For the sample, the age...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.1985
更新日期:2005-04-15 00:00:00
abstract::Crossover studies have been successfully conducted in the case of continuous responses. Existing procedures of analysis for ordinal responses, on the other hand, are rarely satisfactory unless strict, usually unrealistic, assumptions are made. In this paper we investigate a random effects model and show that the model...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780100611
更新日期:1991-06-01 00:00:00
abstract::Epidermal nerve fibre (ENF) density and morphology are used to study small fibre involvement in diabetic, HIV, chemotherapy induced and other neuropathies. ENF density and summed length of ENFs per epidermal surface area are reduced, and ENFs may appear more clustered within the epidermis in subjects with small fibre ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.7009
更新日期:2016-10-30 00:00:00
abstract::Two important qualities of controlled clinical trials are that they reduce dependence on historical standards for evaluating therapy and separate the effect of treatment from the confounding influence of time. Whatever the theory of the clinical trial, however, time has not easily been banished from the analysis of me...
journal_title:Statistics in medicine
pub_type: 杂志文章,评审
doi:10.1002/sim.4780081106
更新日期:1989-11-01 00:00:00
abstract::We consider the problem of identifying a subgroup of patients who may have an enhanced treatment effect in a randomized clinical trial, and it is desirable that the subgroup be defined by a limited number of covariates. For this problem, the development of a standard, pre-determined strategy may help to avoid the well...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4322
更新日期:2011-10-30 00:00:00
abstract::The original article to which this Correction refers was published in Statistics in Medicine 2000 19(14): 1901-1914. ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/1097-0258(20001115)19:21<3017::aid-sim785>
更新日期:2000-11-15 00:00:00
abstract::Methods for dealing with tied event times in the Cox proportional hazards model are well developed. Also, the partial likelihood provides a natural way to handle covariates that change over time. However, ties between event times and the times that discrete time-varying covariates change have not been systematically s...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.5683
更新日期:2013-06-30 00:00:00
abstract::This paper describes a method for estimating the risk from a disease over a set of contiguous geographical regions, when data on a potentially important covariate, such as race, are not available. Conditions under which the extra margin can be recovered are suggested. An application to prostate cancer mortality among ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/1097-0258(20000915/30)19:17/18<2243::aid-s
更新日期:2000-09-15 00:00:00
abstract::Rao proposed and compared several approaches for predicting future observations in a growth curve model. The assessment of associated prediction efficiency for different prediction methods were evaluated by Cross-Validation Assessment Error (CVAE). He used three data sets, each with a limited number of subjects (13-27...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780132103
更新日期:1994-11-15 00:00:00
abstract::In longitudinal studies, missing observations occur commonly. It has been well known that biased results could be produced if missingness is not properly handled in the analysis. Authors have developed many methods with the focus on either incomplete response or missing covariate observations, but rarely on both. The ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.5536
更新日期:2013-02-28 00:00:00
abstract::Two correction methods are considered for multiple logistic regression models with some covariates measured with error. Both methods are based on approximating the complicated regression model between the response and the observed covariates with simpler models. The first model is the logistic approximation proposed b...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780131105
更新日期:1994-06-15 00:00:00
abstract::We consider evaluation and comparison of the diagnostic accuracy of biomarkers with continuous test outcomes, possibly correlated due to repeated measurements. We develop nonparametric group sequential testing procedures to evaluate and compare the area of biomarkers under their receiver operating characteristic curve...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3203
更新日期:2008-05-10 00:00:00
abstract::The statistical analysis of spatially correlated data has become an important scientific research topic lately. The analysis of the mortality or morbidity rates observed at different areas may help to decide if people living in certain locations are considered at higher risk than others. Once the statistical model for...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/1097-0258(20000730)19:14<1915::aid-sim503>
更新日期:2000-07-30 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::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::Delay in the outcome variable is challenging for outcome-adaptive randomization, as it creates a lag between the number of subjects accrued and the information known at the time of the analysis. Motivated by a real-life pediatric ulcerative colitis trial, we consider a case where a short-term predictor is available fo...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6222
更新日期:2014-10-15 00:00:00
abstract::This paper gives a standard error for Cohen's Kappa, conditional on the margins of the observed r x r table. An explicit formula is given for the 2 x 2 table, and a procedure for the more general situation. A parsimonious log-linear model is suggested for the general case and an approximate confidence interval for kap...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780100512
更新日期:1991-05-01 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::Although prostate cancer and benign prostatic hyperplasia are major health problems in U.S. men, little is known about the early stages of the natural history of prostate disease. A molecular biomarker called prostate specific antigen (PSA), together with a unique longitudinal bank of frozen serum, now allows a histor...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780130520
更新日期:1994-03-15 00:00:00
abstract::Many Americans rely on cardiac surgical procedures and devices such as pacemakers and thrombolytic catheters to treat or manage their cardiovascular diseases. However, the failure of these cardiac devices and procedures could have grave consequences. One reason cardiac devices tended to fail was due to physician error...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.7906
更新日期:2018-12-10 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::Vaccination in populations can have several kinds of effects. Establishing that vaccination produces population-level effects beyond the direct effects in the vaccinated individuals can have important consequences for public health policy. Formal methods have been developed for study designs and analysis that can esti...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.7392
更新日期:2018-01-30 00:00:00
abstract::Three-arm trials including the experimental treatment, an active reference treatment and a placebo are recommended in the guidelines of the ICH and EMEA/CPMP as a useful approach to the assessment of assay sensitivity. Generally, the acceptable non-inferiority margin Δ has been defined as the maximum clinically irrele...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4099
更新日期:2011-02-10 00:00:00
abstract::Relative survival is used to estimate patient survival excluding causes of death not related to the disease of interest. Rather than using cause of death information from death certificates, which is often poorly recorded, relative survival compares the observed survival to that expected in a matched group from the ge...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.2399
更新日期:2005-12-30 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