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Censoring Mechanism (censoring + mechanism)
Selected AbstractsDemand for traditional medicine in Taiwan: a mixed Gaussian,Poisson model approachHEALTH ECONOMICS, Issue 3 2001Steven T. Yen Abstract Hurdle count models are used to examine the participation and consumption decisions in Chinese medicine use. Motivated by a household production model, a second censoring mechanism is introduced into existing single-hurdle models, and the resulting specification accommodates conscientious abstainers, as well as economic non-consumers, and admits excessive zeros in the sample. In contrast to previous studies that found few predictors, empirical results based on a Taiwanese national sample suggest that Western medicine is a gross substitute to Chinese medicine, and both time price and money price play more important roles than income. Insurance, lifestyle and demographics also determine the use of Chinese medicine. Copyright © 2001 John Wiley & Sons, Ltd. [source] Monitoring processes with data censored owing to competing risks by using exponentially weighted moving average control chartsJOURNAL OF THE ROYAL STATISTICAL SOCIETY: SERIES C (APPLIED STATISTICS), Issue 3 2001Stefan H. Steiner In industry, process monitoring is widely employed to detect process changes rapidly. However, in some industrial applications observations are censored. For example, when testing breaking strengths and failure times often a limited stress test is performed. With censored observations, a direct application of traditional monitoring procedures is not appropriate. When the censoring occurs due to competing risks, we propose a control chart based on conditional expected values to detect changes in the mean strength. To protect against possible confounding caused by changes in the mean of the censoring mechanism we also suggest a similar chart to detect changes in the mean censoring level. We provide an example of monitoring bond strength to illustrate the application of this methodology. [source] A Copula Approach for Detecting Prognostic Genes Associated With Survival Outcome in Microarray StudiesBIOMETRICS, Issue 4 2007Kouros Owzar Summary A challenging and crucial issue in clinical studies in cancer involving gene microarray experiments is the discovery, among a large number of genes, of a relatively small panel of genes whose elements are associated with a relevant clinical outcome variable such as time-to-death or time-to-recurrence of disease. A semiparametric approach, using dependence functions known as copulas, is considered to quantify and estimate the pairwise association between the outcome and each gene expression. These time-to-event type endpoints are typically subject to censoring as not all events are realized at the time of the analysis. Furthermore, given that the total number of genes is typically large, it is imperative to control a relevant error rate in any gene discovery procedure. The proposed method addresses the two aforementioned issues by direct incorporation of the censoring mechanism and by appropriate statistical adjustment for multiplicity. The performance of the proposed method is studied through simulation and illustrated with an application using a case study in lung cancer. [source] Analysis of failure time data under competing censoring mechanismsJOURNAL OF THE ROYAL STATISTICAL SOCIETY: SERIES B (STATISTICAL METHODOLOGY), Issue 3 2007Andrea Rotnitzky Summary., We derive estimators of the survival curve of a failure time in the presence of competing right censoring mechanisms. Our approach allows for the possibility that some or all of the competing censoring mechanisms are associated with the end point, even after adjustment for recorded prognostic factors. It also allows the degree of residual association to be possibly different for distinct censoring processes. Our methods generalize from one to several competing censoring mechanisms the methods of Scharfstein and Robins. [source] | ||||||||||