Trajectories network analysis of chronic diseases among middle-aged and older adults: evidence from the China Health and Retirement Longitudinal Study (CHARLS).

"Declarations Ethics approval and consent to participateAll methods concerning human participants in our study were conducted in accordance with the ethical standards laid out in the 1964 Declaration of Helsinki and its subsequent amendments. Ethical approval for all waves of the CHARLS study was obtained from the Institutional Review Board (IRB) at Peking University. The IRB approval number for the main household survey, including anthropometrics, is IRB00001052-11015. The IRB approval number for biomarkers collection is IRB00001052-11014. Written signed informed consent was obtained at recruitment from all participants, including legal representatives for illiterate participants. Consent for publicationAll authors approved the final manuscript and the submission to this journal. Competing interestsThe authors declare no competing interests. Competing interests The authors declare no competing interests."

"Funding This work is supported by Key Program of Department of Science and Technology of Guangdong Province (2021B1111610004). The funding had no role in study design and data analyses."