Table 3 Subgroup analysis by study characteristics on the association between preoperative malnutrition and postoperative delirium

Location

0.97

 Asian

3

2.36 (1.30 − 4.28)

48%

 < 0.01

 European

4

2.40 (1.39 − 4.13)

33%

 < 0.01

Type of surgery

0.15

 Cardiac

3

1.76 (0.96 − 3.22)

42%

0.07

 Non-cardiac

4

3.04 (1.99 − 4.62)

0%

 < 0.001

Malnutrition evaluation

0.15

 MNA-SF

4

3.04 (1.99 − 4.62)

0%

 < 0.001

 Others

3

1.76 (0.96 − 3.22)

42%

0.07

POD diagnosis

0.68

 CAM

4

2.59 (1.45 − 4.63)

46%

 < 0.01

 DSM-IV

3

2.20 (1.27 − 3.79)

31%

 < 0.01

Study quality

0.09

 NOS 7–8

3

3.50 (1.96 − 6.25)

0%

 < 0.001

 NOS 9

4

1.92 (1.30 − 2.83)

22%

 < 0.01