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作者：Duembgen, Lutz; Freitag-Wolf, Sandra; Jongbloed, Geurt
作者单位：University of Bern; University of Kiel; Vrije Universiteit Amsterdam
摘要：In this article we consider three nonparametric maximum likelihood estimators based on mixed-case interval-censored data. Apart from the unrestricted estimator, we consider estimators under the assumption that the underlying distribution function of event times is concave or unimodal. Characterizations of the estimates are derived, and algorithms are proposed for their computation. The estimators are shown to be asymptotically consistent, and the benefits of additional constraints are illustra...
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作者：Zhang, Min; Strawderman, Robert L.; Cowen, Mark E.; T Wells, Martin
作者单位：Purdue University System; Purdue University; Cornell University; Saint Joseph Mercy Health System (SJMHS)
摘要：Profiling is currently an important, and hotly debated, topic in health care and other industries looking for ways to control costs, increase profitability, and increase service quality. Managed care in particular has seen a proliferation in the use of statistical profiling methodology, particularly with regard to monitoring expenditure data. This article focuses on the specific problem of developing statistical methods appropriate for profiling physician contributions to patient pharmacy expe...
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作者：Hennerfeind, Andrea; Brezger, Andreas; Fahrmeir, Ludwig
作者单位：University of Munich
摘要：Survival data often contain small-area geographical or spatial information, such as the residence of individuals. In many cases, the impact of such spatial effects on hazard rates is of considerable substantive interest. Therefore, extensions of known survival or hazard rate models to spatial models have been suggested. Mostly, a spatial component is added to the usual linear predictor of the Cox model. In this article flexible continuous-time geoaddifive models are proposed, extending the Cox...
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作者：Lee, Chu-In Charles; Peng, Jianan; Liu, Lin
作者单位：Memorial University Newfoundland; Acadia University; University of California System; University of California San Diego
摘要：In many experiments, researchers are interested in comparing several treatment means with a control mean. When there are some treatments significantly better than the control, it is often of interest to evaluate the difference between the best treatment mean and the control mean and to identify the best treatment. In this article we derive lower confidence bounds for the aforementioned difference for the case that treatments are at least as effective as the control and for the case that no res...
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作者：Koenker, Roger; Xiao, Zhijie
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作者：Robinson, John W.; Zeger, Scott L.; Forrest, Christopher B.
作者单位：Johns Hopkins University; Johns Hopkins Bloomberg School of Public Health; Johns Hopkins University; Johns Hopkins Bloomberg School of Public Health
摘要：Procedures for analyzing and comparing health care providers' effects on health services delivery and outcomes have been referred to as provider profiling. In a typical profiling procedure, patient-level responses are measured for clusters of patients treated by providers that in turn can be considered statistically exchangeable. Thus a hierarchical model naturally represents the structure of the data. When provider effects on multiple responses are profiled, a multivariate model rather than a...
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作者：Hedayat, A. S.; Stufken, John; Yang, Min
作者单位：University of Illinois System; University of Illinois Chicago; University of Illinois Chicago Hospital; University System of Georgia; University of Georgia; University of Missouri System; University of Missouri Columbia
摘要：Most studies on optimal crossover designs are based on models that assume subject effects to be fixed effects. In this article we identify and study optimal and efficient designs for a model with random subject effects. With the number of periods not exceeding the number of treatments, we find that totally balanced designs are universally optimal for treatment effects in a large subclass of competing designs. However, in the entire class of designs, totally balanced designs are in general not ...
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作者：Hong, Guanglei; Raudenbush, Stephen W.
作者单位：University of Toronto; University Health Network Toronto; University of Chicago
摘要：This article considers the policy of retaining low-achieving children in kindergarten rather than promoting them to first grade. Under the stable unit treatment value assumption (SUTVA) as articulated by Rubin, each child at risk of retention has two potential outcomes: Y(1) if retained and Y(0) if promoted. But SUTVA is questionable, because a child's potential outcomes will plausibly depend on which school that child attends and also on treatment assignments of other children. We develop a c...
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作者：Lohr, Sharon; Rao, J. N. K.
作者单位：Arizona State University; Arizona State University-Tempe; Carleton University
摘要：Multiple-frame surveys are commonly used to decrease costs of sampling or to reduce undercoverage that could occur if only one sampling frame were used. We describe potential uses and examples of multiple-frame surveys. We then derive optimal linear estimators and pseudomaximum likelihood estimators for the population total when samples are taken independently from each frame using probability sampling designs. We explore the properties of these estimators theoretically and through a simulatio...
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作者：Rotnitzky, Andrea; Faraggi, David; Schisterman, Enrique
作者单位：Universidad Torcuato Di Tella; Harvard University; Harvard T.H. Chan School of Public Health; University of Haifa; National Institutes of Health (NIH) - USA; NIH Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
摘要：The area under the receiver operating characteristic curve (AUC) is a popular summary measure of the efficacy of a medical diagnostic test to discriminate between healthy and diseased subjects. A frequently encountered problem in studies that evaluate a new diagnostic test is that not all patients undergo disease verification because the verification test is expensive, invasive, or both. Furthermore, the decision to send patients to verification often depends on the new test and on other predi...
