Evidence map›Paper›PMID 36271175›Full record

ArticleLifetime data analysis2023

Cox regression can be collapsible and Aalen regression can be non-collapsible.

Sven Ove Samuelsen

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Article in Lifetime data analysis, 2023. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

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2citing papers in PubMed
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1 · What the graph read from it

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3 · Its place in the literature

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2 citing papers in PubMed.

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4 · The record

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5 · Who and what money

Authors and funding

1 author.

Sven Ove SamuelsenDepartment of Mathematics, University of Oslo, P.O.1053, 0316, Blindern, Oslo, Norway. osamuels@math.uio.no.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

It is well-known that the additive hazards model is collapsible, in the sense that when omitting one covariate from a model with two independent covariates, the marginal model is still an additive hazards model with the same regression coefficient or function for the remaining covariate. In contrast, for the proportional hazards model under the same covariate assumption, the marginal model is no longer a proportional hazards model and is not collapsible. These results, however, relate to the model specification and not to the regression parameter estimators. We point out that if covariates in risk sets at all event times are independent then both Cox and Aalen regression estimators are collapsible, in the sense that the parameter estimators in the full and marginal models are consistent for the same value. Vice-versa, if this assumption fails, then the estimates will change systematically both for Cox and Aalen regression. In particular, if the data are generated by an Aalen model with censoring independent of covariates both Cox and Aalen regression is collapsible, but if generated by a proportional hazards model neither estimators are. We will also discuss settings where survival times are generated by proportional hazards models with censoring patterns providing uncorrelated covariates and hence collapsible Cox and Aalen regression estimates. Furthermore, possible consequences for instrumental variable analyses are discussed.

Indexed as

Proportional Hazards ModelsHumansSurvival AnalysisAdditive hazards modelsInstrumental variablesLinear hazards modelsMatched cohort studyProportional hazards modelsRandomized clinical study

Identifiers

PMID36271175
PMCPMC10006274

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