Figure 1: Flow chart of study patient selection.

Among 33,654 elderly who had at least 2 SPMSQ and eGFR tests during the follow-up period, 2477 experienced an eGFR increase, 29,386 experienced stable eGFR changes, and 1791 experienced severe eGFR decline. The risks of cognitive deterioration and all-cause mortality were analyzed for the 3 groups.