Sample size re-estimation in blinded hybrid-control design using inverse probability weighting

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Kojima, Masahiro, Orihara, Shunichiro, Hanada, Keisuke, Ohigashi, Tomohiro
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866915350672572416
author Kojima, Masahiro
Orihara, Shunichiro
Hanada, Keisuke
Ohigashi, Tomohiro
author_facet Kojima, Masahiro
Orihara, Shunichiro
Hanada, Keisuke
Ohigashi, Tomohiro
contents With the increasing availability of data from historical studies and real-world data sources, hybrid control designs that incorporate external data into the evaluation of current studies are being increasingly adopted. In these designs, it is necessary to pre-specify during the planning phase the extent to which information will be borrowed from historical control data. However, if substantial differences in baseline covariate distributions between the current and historical studies are identified at the final analysis, the amount of effective borrowing may be limited, potentially resulting in lower actual power than originally targeted. In this paper, we propose two sample size re-estimation strategies that can be applied during the course of the blinded current study. Both strategies utilize inverse probability weighting (IPW) based on the probability of assignment to either the current or historical study. When large discrepancies in baseline covariates are detected, the proposed strategies adjust the sample size upward to prevent a loss of statistical power. The performance of the proposed strategies is evaluated through simulation studies, and their practical implementation is demonstrated using a case study based on two actual randomized clinical studies.
format Preprint
id arxiv_https___arxiv_org_abs_2506_15913
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Sample size re-estimation in blinded hybrid-control design using inverse probability weighting
Kojima, Masahiro
Orihara, Shunichiro
Hanada, Keisuke
Ohigashi, Tomohiro
Methodology
With the increasing availability of data from historical studies and real-world data sources, hybrid control designs that incorporate external data into the evaluation of current studies are being increasingly adopted. In these designs, it is necessary to pre-specify during the planning phase the extent to which information will be borrowed from historical control data. However, if substantial differences in baseline covariate distributions between the current and historical studies are identified at the final analysis, the amount of effective borrowing may be limited, potentially resulting in lower actual power than originally targeted. In this paper, we propose two sample size re-estimation strategies that can be applied during the course of the blinded current study. Both strategies utilize inverse probability weighting (IPW) based on the probability of assignment to either the current or historical study. When large discrepancies in baseline covariates are detected, the proposed strategies adjust the sample size upward to prevent a loss of statistical power. The performance of the proposed strategies is evaluated through simulation studies, and their practical implementation is demonstrated using a case study based on two actual randomized clinical studies.
title Sample size re-estimation in blinded hybrid-control design using inverse probability weighting
topic Methodology
url https://arxiv.org/abs/2506.15913