Table 1 Search strategy applied in Cochrane Library database

1

MeSH descriptor: (postoperative cognitive complications) explode all trees

2

((postoperative*) or (cognitive*) or (dysfunction*) or (complications*) or (disorder*) or (surgery*) or (operation*)):ti, ab, kw

3

Or 1-2

4

MeSH descriptor: (anesthesia, general) explode all trees

5

MeSH descriptor: (propofol) explode all trees

6

((anesthesia*) or (anesthestics*) or (propofol*) or (Anesthesia S/I-60*) or (Anesthesia S/I-40*) or (Anesthesia S/I-40A*) or (Anesthesia S/I-40H*) or (Anesthesia S/I-40S*) or (Diprivan*)):ti, ab, kw

7

Or 4-6

8

MeSH descriptor: (randomized controlled trial) explode all trees

9

((random*) or (randomly*) or (blind*) or (controlled trial*) or (clinical trial*) or (control*) or (study*) or (trial*)):ti, ab, kw

10

Or 8-9

11

3 and 7 and 10