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Main Authors: Bakoyannis, Giorgos, Rontogiannis, Aristofanis, Zhang, Ying, Tu, Wanzhu, Mwangi, Ann, Yiannoutsos, Constantin T.
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2511.20980
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author Bakoyannis, Giorgos
Rontogiannis, Aristofanis
Zhang, Ying
Tu, Wanzhu
Mwangi, Ann
Yiannoutsos, Constantin T.
author_facet Bakoyannis, Giorgos
Rontogiannis, Aristofanis
Zhang, Ying
Tu, Wanzhu
Mwangi, Ann
Yiannoutsos, Constantin T.
contents Analysis of competing risks data is often complicated by the incomplete or selectively missing information on the cause of failure. Standard approaches typically assume that the cause of failure is missing at random (MAR), an assumption that is generally untestable and frequently implausible in observational studies. We propose a novel sensitivity analysis framework for the proportional cause-specific hazards model that accommodates missing-not-at-random (MNAR) scenarios. A sensitivity parameter is used to quantify the association between missingness and the unobserved cause of failure. Regression coefficients are estimated as functions of this parameter, and a simultaneous confidence band is constructed via a wild bootstrap procedure. This allows identification of a range of MNAR scenarios for which effects remain statistically significant; we refer to this range as a robustness interval. The validity of the proposed approach is justified both theoretically, via empirical process theory, and empirically, through simulation studies. We apply the method to the analysis of data from an HIV cohort study in sub-Saharan Africa, where a substantial proportion of causes of failure are missing and the MAR assumption is implausible. The analysis shows that key findings regarding risk factors for care interruption and mortality are robust across a broad spectrum of MNAR scenarios, underscoring the method's utility in situations with MNAR causes of failure.
format Preprint
id arxiv_https___arxiv_org_abs_2511_20980
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Robustness intervals for competing risks analysis with causes of failure missing not at random
Bakoyannis, Giorgos
Rontogiannis, Aristofanis
Zhang, Ying
Tu, Wanzhu
Mwangi, Ann
Yiannoutsos, Constantin T.
Methodology
Analysis of competing risks data is often complicated by the incomplete or selectively missing information on the cause of failure. Standard approaches typically assume that the cause of failure is missing at random (MAR), an assumption that is generally untestable and frequently implausible in observational studies. We propose a novel sensitivity analysis framework for the proportional cause-specific hazards model that accommodates missing-not-at-random (MNAR) scenarios. A sensitivity parameter is used to quantify the association between missingness and the unobserved cause of failure. Regression coefficients are estimated as functions of this parameter, and a simultaneous confidence band is constructed via a wild bootstrap procedure. This allows identification of a range of MNAR scenarios for which effects remain statistically significant; we refer to this range as a robustness interval. The validity of the proposed approach is justified both theoretically, via empirical process theory, and empirically, through simulation studies. We apply the method to the analysis of data from an HIV cohort study in sub-Saharan Africa, where a substantial proportion of causes of failure are missing and the MAR assumption is implausible. The analysis shows that key findings regarding risk factors for care interruption and mortality are robust across a broad spectrum of MNAR scenarios, underscoring the method's utility in situations with MNAR causes of failure.
title Robustness intervals for competing risks analysis with causes of failure missing not at random
topic Methodology
url https://arxiv.org/abs/2511.20980