A unified implementation of parametric proportional hazards (PH) and accelerated failure time (AFT) models for right-censored or intervalcensored and left-truncated data is described. The description here is válid for time-constant covariates, but the necessary modifications for handling time-varying covariates are implemented in eha. Note that only piecewise constant time variation is handled.

The accelerated failure time (AFT) model is a well-known alternative to the Cox proportional hazard model for analyzing time-to-event data. In this paper we consider fitting an AFT model to right censored data when a predictor variable is subject to measurement errors. First, without measurement errors, estimation of the model parameters in the AFT model is a challenging task due to the presenc...

Effects such as student dropout and the non-normal distribution of duration data confound the exploration of tutor efficiency, time-intutor vs. tutor performance, in intelligent tutors. We use an accelerated failure time (AFT) model to analyze the effects of using automatically generated hints in Deep Thought, a propositional logic tutor. AFT is a branch of survival analysis, a statistical tech...

In this paper, a new servicing strategy with imperfect repair is defined and studied for the manufacturer of a product sold with a two-dimensional warranty. The strategy is based on a specified region of the warranty defined in terms of age and usage, with the first failure in the region rectified by an imperfect repair and all other failures being minimally repaired. Product failures are model...

Bridge deck deterioration modeling is critical to infrastructure management. Deterioration traditionally done using deterministic models, stochastic and recently basic machine learning methods. The advanced learning-based survival such as random forest, have not been adapted for use in This paper introduces forest models bridge compare their performance with a commonly used traditional model, t...

We study residuals of parametric accelerated failure time (AFT) models for censored data, with the main aim of inferring the correct functional form of possibly misspecified covariates. We demonstrate the use of the methods by a simulated example and by applications to two reliability data sets. We also consider briefly a corresponding approach for parametric proportional hazards models.

Kendall and Gehan estimating functions are used to estimate the regression parameter in accelerated failure time (AFT) model with censored observations. The accelerated failure time model is the preferred survival analysis method because it maintains a consistent association between the covariate and the survival time. The jackknife empirical likelihood method is used because it overcomes compu...

Abstract The mean residual life function (mrlf) of a subject is defined as the expected remaining lifetime of the subject given that the subject has survived up to a given time. The commonly used regression models as proportional mean residual life (PMRL) and linear mean residual life (LMRL) have limited applications due to adhoc restriction on the parameter space. The regression model we propo...

Accelerated failure time (AFT) model is commonly applied in engineering studies to address the failure rate of a machine. In humans, survival profile of transplant patients is among the rare scenarios whereby AFT is applicable. To date, it is uncertain whether reliable risk estimates and age-specific mortality trajectories have been published using conventional statistics approach. By investiga...

BACKGROUND The aim of this study is to evaluate the prognostic factors of overall survival (OS) after haematopoietic stem cell transplant (HSCT) in acute lymphoblastic leukaemia (ALL) patients using accelerated failure time (AFT), Cox proportional hazard (PH), and Cox time-varying coefficient models. METHODS 206 patients were enrolled after HSCH in Shariati Hospital between 1993 and 2007. The...