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Article History

Received: 16 October 2025

Accepted: 21 April 2026

First Online: 2 May 2026

Competing interests

: The authors declare no competing interests.

: This study was based on a publicly available dataset and involved secondary data analysis. The data were derived from the China Longitudinal Ageing Social Survey (CLASS), conducted by Renmin University of China. The CLASS survey, a large-scale national sociological research project, was approved by the Ethics Committee of the School of Statistics, Renmin University of China; however, the corresponding ethics approval number has not been publicly released. As a sociological rather than medical study, CLASS adheres to the ethical principles outlined in the Declaration of Helsinki and does not involve human experimentation as defined therein. All participants provided written informed consent prior to participation, and all data were collected solely for sociological research purposes, with strict measures to ensure confidentiality and anonymity. Since this study involved secondary analysis of fully anonymized public data, no additional approval from an Institutional Review Board or further informed consent from participants was required. Data access was authorized by the CLASS research team in accordance with their guidelines for secondary data use. This article does not contain any studies with human participants performed by any of the authors.

: In the data collection of the China Longitudinal Ageing Social Survey (CLASS), all participants signed the informed consent at the time of participation. The details of the informed consent process are maintained by the Institute of Gerontology at Renmin University of China and the National Survey Research Center. This article does not contain any studies with human participants performed by any of the authors.