Sex-specific transitions of frailty states and modifiable determinants in community-dwelling older adults: a 16-year Chinese nationwide cohort study

Background Evidence on sex differences in transitions of frailty states remains inconclusive. This study therefore aimed to analyze sex-specific transitions in frailty states and their modifiable determinants in older Chinese adults. Methods We analyzed data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) collected between 2002 and 2018. Frailty states were characterized using a frailty index. A multi-state Markov model was used to estimate transition intensities, probabilities, and mean sojourn times between states, and to assess the impact of demographic, social, and lifestyle factors on these transitions. Results The study included 8,445 participants (mean age 82.62 ± 10.64 years; 50.18% male). The median follow-up time was 6.02 years (IQR: 2.59–9.12). Men had a lower likelihood of transitioning from robust to pre-frail (transition intensity: 0.229, 95% CI: 0.215–0.243) than women (0.297, 95% CI: 0.279–0.316). However, men were more likely to revert from pre-frail to robust (0.170, 95% CI: 0.155–0.188) compared to women (0.137, 95% CI: 0.125–0.151). In contrast, the transition intensities between pre-frail and frail states were comparable between sexes. Furthermore, the determinants of frailty states transitions differed by sex: lifestyle factors (exercise and dietary patterns) were primary influencers in men, whereas social determinants (education level, social participation, and marital status) played a more prominent role in women. Conclusions Frailty states transition in late life follows distinct, sex-specific pathways shaped by differential exposure to modifiable risks. To promote healthy aging, sex-specific public health strategies are recommended, focusing on behavioral interventions for men and enhanced social support for women.