Incorporation of frailties into a non-proportional hazard regression model and its diagnostics for reliability modeling of downhole safety valves

by   Francisco Louzada, et al.

In this paper, our proposal consists of incorporating frailty into a statistical methodology for modeling time-to-event data, based on non-proportional hazards regression model. Specifically, we use the generalized time-dependent logistic (GTDL) model with a frailty term introduced in the hazard function to control for unobservable heterogeneity among the sampling units. We also add a regression in the parameter that measures the effect of time, since it can directly reflect the influence of covariates on the effect of time-to-failure. The practical relevance of the proposed model is illustrated in a real problem based on a data set for downhole safety valves (DHSVs) used in offshore oil and gas production wells. The reliability estimation of DHSVs can be used, among others, to predict the blowout occurrence, assess the workover demand and aid decision-making actions.



There are no comments yet.


page 1

page 3


Robust and Efficient Estimation in the Parametric Cox Regression Model under Random Censoring

Cox proportional hazard regression model is a popular tool to analyze th...

A New Count Regression Model including Gauss Hypergeometric Function with an application to model demand of health services

In this paper, an alternative count distribution suitable for modeling o...

Multiplicative Effect Modeling: The General Case

Generalized linear models, such as logistic regression, are widely used ...

Phase I dose-escalation trials with more than one dosing regimen

Traditionally, phase I dose-escalation oncology trials are designed to f...

A flexible parametric accelerated failure time model

Accelerated failure time (AFT) models are used widely in medical researc...

Analysis of time-to-event for observational studies: Guidance to the use of intensity models

This paper provides guidance for researchers with some mathematical back...

Application of the Cox Regression Model for Analysis of Railway Safety Performance

The assessment of in-service safety performance is an important task, no...
This week in AI

Get the week's most popular data science and artificial intelligence research sent straight to your inbox every Saturday.