Table 1 Summary of Subgroup Analyses of Polypharmacy Prevalence

Mean age of participants

36 (29,43)

10.88

1

< 0.01

<  65 years

25 (16,35)

238,592.68

20

< 0.0001

≥ 65 years

45 (37,54)

4,378,199.84

25

< 0.0001

Sex

32 (26,39)

0.04

1

0. 85

Male

32 (22,41)

1,484,546.49

21

< 0.0001

Female

33 (23,43)

1,754,816.42

21

< 0.0001

Health care setting

40 (32,49)

13.55

2

< 0.01

Inpatient

52 (38,66)

36,809.71

10

< 0.0001

Outpatient

47 (33,62)

910,219.51

12

< 0.0001

Community

20 (6,35)

12,462,667.1

10

< 0.0001

Numerical cut off for medications

32 (26,38)

7.90

1

< 0.01

≥ 2 medications

22 (10,35)

22,184,826.88

9

< 0.0001

≥ 5 medications

40 (0, 47)

16,672,729.06

43

< 0.0001

Measurement indicator

33 (28,38)

0.01

2

P = 0.91

Simultaneous

33 (27,40)

9,353,584.02

50

< 0.0001

Cumulative

33 (25,41)

12,926,693.67

37

< 0.0001

Methodological quality

33 (28,38)

0.37

1

0.54

High quality

34 (29.39)

21,220,449.4

83

< 0.0001

Low quality

27 (0,57)

5005.5

4

< 0.0001

Country of publication

37 (31,44)

2.19

2

0.33

North America

51 (24,79)

30372.7

4

< 0.0001

Asia

36 (24,48)

377564.9

11

< 0.0001

Europe

36 (27,44)

20277561.9

33

<0.001

Study design

33 (28,38)

9.93

2

0.31

Cross-sectional

37 (31,43)

20,427,507.22

63

< 0.0001

Cohort

23 (9,38)

326,083.41

11

< 0.0001

Case-control

24 (17,31)

365,802.26

12

< 0.0001