Indication of frailty transitions on 2-year adverse health outcomes among older Chinese inpatients: Insight from a multicenter prospective cohort study - Miao Yu; Jiaqi Ding; Xinjuan Wu; Xianxiu Wen; Jingfen Jin; Hui Wang; Dongmei Lv; Shengxiu Zhao; Jing Jiao; Tao Xu (PLoS ONE, 2025)