The Proportional Hazards (PH) model is an important type of failure time regression model which relates the occurrence probability of critical failures to influential factors. However, little research work has been done on detecting changes in the PH models fitted based on different sets of reliability data. This paper develops the methods for change detection in the Cox PH models, also known a...

This paper analyzes the impact of childbearing history on later-life mortality for ever-married men and women using high-quality historical longitudinal microlevel data for southern Sweden. The main advantage of using historical data is that it makes it possible to investigate the experience of many birth cohorts with medium to high fertility, thereby facilitating estimation of the effects of t...

According to the article[2], we present a new method for post-selection inference for l1(lasso)penalized likelihood models, including generalized regression models. Our approach generalizes the post-selection framework presented in Lee et al. (2013)[1]. The method provides P-values and confidence intervals that are asymptotically valid, conditional on the inherent selection done by the lasso. W...

Model. The primary exposure variable was a time­varying covariate that indicated whether a beneficiary had expe­ rienced an interruption of Medicaid coverage in the prior month. Confounders adjusted for in the model included demographic characteristics, type of Medicaid coverage (ie, Temporary Assistance to Needy Families [TANF], Supple­ mental Security Income [SSI], or other), non­Medicaid for...

In this paper we consider nonlinear models with an arbitrary number of covariates for which the information additionally depends on the value of the linear predictor. We establish the general result that for many optimality criteria the support points of an optimal design lie on the edges of the design region, if this design region is a polyhedron. Based on this result we show that under certai...

1. (a) Partial likelihood estimates of the coefficients in the proportional hazards model using , are shown below with standard errors. Those results suggest that, after adjusting for effects of the other variables in the model, patient-donor age interaction ( ), low risk for acute myelotic leukemia ( ) and the FAB morphology score ( ) have significant associations with disease free survival. 1...

First hitting time models are a technique of modeling a stochastic process as it approaches or avoids a boundary, also known as a threshold. The process itself may be unobservable, making this a difficult problem. Regression techniques, however, can be employed to model the data as it compares to the threshold, creating a class of first hitting time models called threshold regression models. Su...

In this article, we show the general relation between standardization methods and marginal structural models. Standardization has been recognized as a method to control confounding and to estimate causal parameters of interest. Because standardization requires stratification by confounders, the sparse-data problem will occur when stratified by many confounders and one then might have an unstabl...

Probabilistic models over strings have played a key role in developing methods that take into consideration indels as phylogenetically informative events. There is an extensive literature on using automata and transducers on phylogenies to do inference on these probabilistic models, in which an important theoretical question is the complexity of computing the normalization of a class of string-...

BACKGROUND Self-perception of uselessness is associated with increased mortality risk in older adults. However, it is unknown whether and to what extent changes in perceived uselessness are associated with mortality risk. METHODS Using four waves of national longitudinal data of older adults from China (2005, 2008, 2011, and 2014), this study examines the association between changes in percei...