Review criteria: how did you gather the information you
considered in your review?
We searched PubMed, Cochrane library, Web of Science, China National
Knowledge Infrastructure(CNKI), Wanfang, China Biology Medicine disc
(CBM), and Weipu database for the study on the association between blood
pressure variability and cognitive function. Retrieval time limit was
from the date of establishment of each database to July 15, 2021. Two
researchers independently searched and screened relevant documents. The
search results were imported into Endnote for double-checking, and then
the initial screening was carried out based on the abstracts of the
literature to eliminate irrelevant or unusable documents.