Frailty trajectories and determinants in Chinese older adults: A longitudinal study

•Frailty was measured using two instruments (FRAIL scale and frailty index).•Four FRAIL trajectories were identified and three FI trajectories were identified.•A portion of Chinese older adults were experiencing a rapid progression of frailty.•Different interventions and care should be developed for older people in different frailty trajectories. This study aimed to enrich the research on frailty trajectories by using FRAIL scale and frailty index (FI), and analyze the determinants of the different trajectories in older Chinese. 2268 older adults from the Chinese Longitudinal Healthy Longevity Survey were included. The FRAIL scale was constructed from 5 items and FI was constructed from 39 deficits. Latent Class Trajectory Model was used to depict frailty trajectories. Lasso - logistic model was applied to exploration of influencing factors. Four FRAIL trajectories and three FI trajectories were identified. Women, smoking, illiteracy, more than two chronic diseases, and poor instrumental activities of daily living (all p