Machine learning model for predicting hospital-acquired functional decline in older patients with postoperative cardiovascular surgery
Ryotaro Hiramatsu, Shinsuke Imaoka, Shohei Minata, Hidenori Sako, Noboru Sato
Ryotaro Hiramatsu, Shinsuke Imaoka, Shohei Minata, Department of Rehabilitation, Oita Oka Hospital, Oita 870-0192, Japan
Hidenori Sako, Department of Cardiovascular Surgery, Oita Oka Hospital, Oita 870-0192, Japan
Noboru Sato, Digital Promotion Bureau, Keiwakai Social Healthcare Corporation, Oita 870-0192, Japan
Co-first authors: Ryotaro Hiramatsu and Noboru Sato.
Co-corresponding authors: Shinsuke Imaoka and Shohei Minata.
Author contributions: Hiramatsu R, Sato N, Imaoka S, and Minata S conceptualized and designed the study; Sato N and Hiramatsu R were responsible for the comprehensive data management and established the clinical database; Sako H and Minata S assisted in data collection; Minata S, Imaoka S, and Sato N performed the statistical analysis; Hiramatsu R, Imaoka S, Sato N, and Minata S contributed to the analysis and interpretation of the data; Hiramatsu R and Sato N wrote the original draft of the manuscript. All authors have read and approved the final manuscript. Hiramatsu R and Sato N contributed equally to this work and are identified as the co-first authors. Hiramatsu R led the conceptual framework and primary drafting of the manuscript, integrating clinical rehabilitative insights. Sato N was instrumental in designing the data architecture, managing the longitudinal clinical data, and preparing the manuscript’s methodology section. Both authors’ combined efforts were essential for the study’s execution and the completion of the first draft. Imaoka S and Minata S served as the co-corresponding authors. Imaoka S provided overall strategic supervision and secured the necessary institutional resources, focusing on the clinical validity of the research. Minata S oversaw the rigorous statistical modeling and was responsible for the advanced data re-interpretation and validation. Both Imaoka S and Minata S shared the responsibility for critical intellectual revisions, managed the peer-review process, and take full responsibility for the integrity and academic standards of the published work.
Institutional review board statement: This study was reviewed and approved by the Institutional Review Board of Oita Oka Hospital (approval No. A0078).
Informed consent statement: Informed consent was obtained in the form of an opt-out procedure.
Conflict-of-interest statement: All authors declare that they have no conflict of interest to disclose.
Data sharing statement: The data that support the findings of this study are available from the corresponding author upon reasonable request.
Open Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
https://creativecommons.org/Licenses/by-nc/4.0/ Corresponding author: Shinsuke Imaoka, PhD, Research Fellow, Department of Rehabilitation, Oita Oka Hospital, 3-7-11 Nishitsurusaki, Oita 870-0192, Japan.
imaoka2734@keiwakai.oita.jp
Received: December 15, 2025
Revised: January 8, 2026
Accepted: January 23, 2026
Published online: February 6, 2026
Processing time: 53 Days and 23.7 Hours
