Development and validation of the social frailty scale for the older adult in China - Hou, ChaoMing; Gong, XiaoYan; Bai, DingXi; Ji, WenTing; Chen, Huan; Lu, XianYing; Chen, XinYu; Dong, Xiaohui; Gao, Jing (Frontiers in Public Health, 2025)