On Sample Size Determination for Augmented Tests Based on Restricted Mean Survival Time in Randomized Clinical Trials

Hattori, Satoshi; Uno, Hajime

Biometrical Journal, 2025, 67(2), e70046

Number of Access:44（2025-06-05 02:19 Counts）

Identifier to cite or link to this item: https://hdl.handle.net/11094/100969

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Title
On Sample Size Determination for Augmented Tests Based on Restricted Mean Survival Time in Randomized Clinical Trials
Creator
NRID
1000050425154 1000050425154
researchmap permalink
hattori_satoshi hattori_satoshi
Scopus Author ID
35728877500 35728877500
CreatorName
Hattori, Satoshi
CreatorName
Uno, Hajime
Subject
augmentation
blinded sample size re-estimation
martingale residual
nonproportional hazards
Description
Hattori S., Uno H.. On Sample Size Determination for Augmented Tests Based on Restricted Mean Survival Time in Randomized Clinical Trials. Biometrical Journal 67, e70046 (2025); https://doi.org/10.1002/bimj.70046.
Abstract
Restricted mean survival time (RMST) is gaining attention as a measure to quantify the treatment effect on survival outcomes in randomized clinical trials. Several methods to determine sample size based on the RMST-based tests have been proposed. However, to the best of our knowledge, there is no discussion about the power and sample size regarding the augmented version of RMST-based tests, which utilize baseline covariates for a gain in estimation efficiency and in power for testing no treatment effect. The conventional event-driven study design based on the logrank test allows us to calculate the power for a given hazard ratio without specifying the survival functions. In contrast, the existing sample size determination methods for the RMST-based tests relies on the adequacy of the assumptions of the entire survival curves of two groups. Furthermore, to handle the augmented test, the correlation between the baseline covariates and the martingale residuals must be handled. To address these issues, we propose an approximated sample size formula for the augmented version of the RMST-based test, which does not require specifying the entire survival curve in the treatment group, and also a sample size recalculation approach to update the correlations between the baseline covariates and the martingale residuals with the blinded data. The proposed procedure will enable the studies to have the target power for a given RMST difference even when correct survival functions cannot be specified at the design stage.
Publisher
John Wiley and Sons Inc
Source Title
Biometrical Journal
Volume (Issue)
67(2)
Page
e70046
Date of Issued
2025-03-24
Language
English
Handle URL
https://hdl.handle.net/11094/100969
PISSN
03233847
eISSN
15214036
Relation.isIdenticalTo
DOI (Publisher Version)
https://doi.org/10.1002/bimj.70046
Access Rights
open access
CopyRight
This article is licensed under a Creative Commons Attribution 4.0 International License.
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Category
学術雑誌論文 Journal Article