Efficient Estimation for Functional Accelerated Failure Time Model

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Liu, Changyu, Su, Wen, Liu, Kin-Yat, Yin, Guosheng, Zhao, Xingqiu
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866910322451808256
author Liu, Changyu
Su, Wen
Liu, Kin-Yat
Yin, Guosheng
Zhao, Xingqiu
author_facet Liu, Changyu
Su, Wen
Liu, Kin-Yat
Yin, Guosheng
Zhao, Xingqiu
contents We propose a functional accelerated failure time model to characterize effects of both functional and scalar covariates on the time to event of interest, and provide regularity conditions to guarantee model identifiability. For efficient estimation of model parameters, we develop a sieve maximum likelihood approach where parametric and nonparametric coefficients are bundled with an unknown baseline hazard function in the likelihood function. Not only do the bundled parameters cause immense numerical difficulties, but they also result in new challenges in theoretical development. By developing a general theoretical framework, we overcome the challenges arising from the bundled parameters and derive the convergence rate of the proposed estimator. Furthermore, we prove that the finite-dimensional estimator is $\sqrt{n}$-consistent, asymptotically normal and achieves the semiparametric information bound. The proposed inference procedures are evaluated by extensive simulation studies and illustrated with an application to the sequential organ failure assessment data from the Improving Care of Acute Lung Injury Patients study.
format Preprint
id arxiv_https___arxiv_org_abs_2402_05395
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Efficient Estimation for Functional Accelerated Failure Time Model
Liu, Changyu
Su, Wen
Liu, Kin-Yat
Yin, Guosheng
Zhao, Xingqiu
Methodology
We propose a functional accelerated failure time model to characterize effects of both functional and scalar covariates on the time to event of interest, and provide regularity conditions to guarantee model identifiability. For efficient estimation of model parameters, we develop a sieve maximum likelihood approach where parametric and nonparametric coefficients are bundled with an unknown baseline hazard function in the likelihood function. Not only do the bundled parameters cause immense numerical difficulties, but they also result in new challenges in theoretical development. By developing a general theoretical framework, we overcome the challenges arising from the bundled parameters and derive the convergence rate of the proposed estimator. Furthermore, we prove that the finite-dimensional estimator is $\sqrt{n}$-consistent, asymptotically normal and achieves the semiparametric information bound. The proposed inference procedures are evaluated by extensive simulation studies and illustrated with an application to the sequential organ failure assessment data from the Improving Care of Acute Lung Injury Patients study.
title Efficient Estimation for Functional Accelerated Failure Time Model
topic Methodology
url https://arxiv.org/abs/2402.05395