To examine the impact of frailty status on the risk of multimorbidity among middle-aged and older adults in China.

Utilizing the China Health and Retirement Longitudinal Study (CHARLS) database, data from 2011 were employed as the baseline for enrollment, and participants who completed follow-up assessments from 2013 to 2020 were matched by ID. The study included middle-aged and older adults aged 45 years and above who were free of multimorbidity at baseline. The questionnaire encompassed basic information, frailty assessments, and evaluations of chronic disease. The Cox regression model was applied to analyze the relationship between frailty and incident multimorbidity.

A total of 4 832 participants were included in the study. The mean age of participants at baseline was (61.09±9.52) years, with 50.12% (2 422 individuals) being men. During the follow-up period, 2 502 individuals (51.78%) developed multimorbidity. The results of the Cox regression model, after adjusting for covariates, indicated that compared with robust individuals at baseline, those in the pre-frailty (HR=1.127, 95% CI: 1.035-1.227) and frailty (HR=1.363, 95% CI: 1.126-1.650) categories were at a higher risk of developing multimorbidity.

Frailty is associated with an increased risk of incident multimorbidity among middle-aged and older adults in China. Both pre-frailty and frailty significantly elevate the risk of multimorbidity. Frailty should be considered a crucial pre-interventional stage in the prevention of chronic diseases to mitigate the risk of multimorbidity.