Fig. 4

The ranks of the risk factors derived from three different machine learning methods. The unit of age is year; the education levels were classified as the following: illiteracy, elementary, junior, senior, college, graduate school and doctor degree. The Fried Frailty Phenotype: Participants were scored on five items, for which scores of 1–2 (inclusive) indicate pre-frailty, and over 3 (inclusive) is frailty