E p u ba h e a d o f p r i n t
Declarations Data availabilityScan-China is not an open-access database. De-identification data is available on the premise of ethic approvals, once the formal email application with study proposal, statistical analysis plan, contribution statement, etc. are considered meaningful.
Ethics approvalThe project was approved by the Institutional Review Board (IRB) of Ethics Committee of Inner Mongolia autonomous region Center for disease control and prevention (IRB No. NMCDCIRB2021001).Informed consent was confirmed by the IRB. The project has applied for registration in the China Clinical Trial Registration Center.