Frailty transitions and relevant factors in midlife: A longitudinal analysis of the ELSA cohort with multi-state Markov models

BACKGROUND: Frailty is an ageing-related health condition, but it is not restricted to older adults. Understanding the characteristics of frailty transitions and relevant factors in midlife would benefit frailty prevention and management later in life. METHODS: Data on 3405 participants aged between 50 and 64 were selected from the English Longitudinal Study of Ageing (ELSA) across six waves (2008-2018). Frailty status at each wave was evaluated by a 52-item frailty index (FI), defining frailty as FI ≥ 0.25, pre-frailty as FI ≥ 0.12 and robustness as FI < 0.12. Multi-state Markov models were constructed to explore frailty transitions, and socioeconomic, behavioral and nutritional factors related to changes in frailty status. RESULTS: The incidence and improvement rates of frailty were 5.23 and 1.15 per 100 person-years, respectively. Among socioeconomic factors, high gross wealth (HR = 1.61, 95%CI [1.12, 2.33]) increased the likelihood of transition from frailty to pre-frailty. Among behavioral factors, using the internet (HR = 0.65, 95%CI [0.53, 0.80]) inhibited the progression from robustness to pre-frailty. Regular alcohol consumption (HR = 1.55, 95%CI [1.14, 2.11]) promoted a shift from pre-frailty to robustness. Living with others (HR = 0.52, 95%CI [0.39, 0.69]) and participating in voluntary activities (HR = 0.86, 95%CI [0.80, 0.94]) lessened progression from pre-frailty to frailty. Moderate (HR = 2.49, 95%CI [1.50, 4.14]) and vigorous (HR = 2.93, 95%CI [1.42, 6.07]) physical activity promoted the transition from frailty to pre-frailty. Among nutrition-related factors, high hemoglobin concentration (HR = 0.15, 95%CI [0.05, 0.47]) inhibited the development from robustness to frailty. CONCLUSION: Encouraging healthy lifestyle, active social participation, and balanced nutrition may be beneficial to middle-aged people in diminishing the development of frailty.