Table 1 Characteristics of study participants and the prevalence of polypharmacy and number of medications in each subgroup

Gender

 Male

73,373 (44.8)

27,426 (37.4)

1.00 (1.0–1.0)

4472 (6.1)

 Female

90,397 (55.2)

47,078 (52.1)

1.58 (1.6–1.6)

10,026 (11.1)

Age

 < 50 y

87,555 (53.5)

30,276 (34.6)

0.79 (0.8–0.8)

3119 (3.6)

 50–64

65,684 (40.1)

37,012 (56.3)

1.82 (1.8–1.8)

8983 (13.7)

 ≥ 65

10,531 (6.4)

7216 (68.5)

2.61 (2.6–2.7)

2396 (22.8)

Residence

 Urban

115,916 (70.8)

54,891 (47.4)

1.41 (1.4–1.4)

11,200 (9.7)

 Rural

47,854 (29.2)

19,613 (41)

1.11 (1.1–1.1)

3298 (6.9)

Ethnicity

 Other

73,655 (45.0)

33,058 (44.9)

1.27 (1.3–1.3)

6019 (8.2)

 Azari

41,019 (25.0)

15,263 (37.2)

1.03 (1.0–1.0)

2670 (6.5)

 Fars

49,095 (30.0)

26,182 (53.3)

1.64 (1.6–1.7)

5809 (11.8)

Marital Status

 Single

3438 (2.1)

1077 (31.3)

0.71 (0.7–0.8)

107 (3.1)

 Married

149,122 (91.1)

66,561 (44.6)

1.27 (1.3–1.3)

12,454 (8.4)

 Widowed

9321 (5.7)

6049 (64.9)

2.34 (2.3–2.4)

1796 (19.3)

 Divorced

1811 (1.1)

775 (42.8)

1.19 (1.1–1.3)

134 (7.4)

 Other

78 (0.0)

42 (53.8)

1.78 (1.2–2.4)

7 (9.0)

BMI

 Underweight

2974 (1.8)

1088 (36.6)

0.80 (0.7–0.8)

107 (3.6)

 Normal

42,193 (25.8)

16,316 (38.7)

1.01 (1.0–1.0)

2533 (6.0)

 Overweight

66,428 (40.6)

30,302 (45.6)

1.3 (1.3–1.3)

5596 (8.4)

 Obese

52,175 (31.9)

26,798 (51.4)

1.63 (1.6–1.6)

6262 (12)

Physical activity

 Low

54,366 (33.4)

28,075 (51.6)

1.67 (1.6–1.7)

6849 (12.6)

 Moderate

54,303 (33.3)

25,823 (47.6)

1.35 (1.3–1.4)

4775 (8.8)

 High

54,319 (33.3)

20,420 (37.6)

0.96 (0.9-1.0)

2857 (5.3)

Smoking

 non-smoker

127,490 (78.2)

59,500 (46.7)

1.37 (1.4–1.4)

11,744 (9.2)

 Smoker

35,479 (21.8)

14,970 (42.2)

1.17 (1.1–1.2)

2747 (7.7)

Opium use

 No

147,667 (90.2)

66,683 (45.2)

1.31 (1.3–1.3)

12,941 (8.8)

 Yes

16,103 (9.8)

7821 (48.6)

1.38 (1.4–1.4)

1557 (9.7)

Hookah use

 No

151,010 (92.2)

68,636 (45.5)

1.31 (1.3–1.3)

13,248 (8.8)

 Yes

12,760 (7.8)

5868 (46)

1.37 (1.3–1.4)

1250 (9.8)

Alcohol use

 No

152,515 (93.6)

70,412 (46.2)

1.35 (1.3–1.4)

13,890 (9.1)

 Yes

10,449 (6.4)

4057 (38.8)

0.98 (0.9-1.0)

601 (5.8)

Individual SES

 Low

42,668 (26.2)

19,822 (46.5)

1.42 (1.4–1.4)

4361 (10.2)

 Low-middle

41,671 (25.6)

19,036 (45.7)

1.37 (1.4–1.4)

4042 (9.7)

 Middle-high

42,230 (25.9)

19,400 (45.9)

1.29 (1.3–1.3)

3545 (8.4)

 High

36,494 (22.4)

16,098 (44.1)

1.18 (1.2–1.2)

2539 (7.0)

Community Level SES

 Low

55,323 (33.8)

25,753 (46.6)

1.35 (1.3–1.4)

5144 (9.3)

 Middle

54,650 (33.4)

22,614 (41.4)

1.14 (1.1–1.2)

3840 (7.0)

 High

53,797 (32.8)

26,137 (48.6)

1.46 (1.4–1.5)

5514 (10.2)

Individual Education Level

 Low

58,139 (35.6)

29,576 (50.9)

1.65 (1.6–1.7)

7247 (12.5)

 High

105,394 (64.4)

44,899 (42.6)

1.14 (1.1–1.2)

7250 (6.9)

Community Education Level

 Low

50,008 (30.5)

19,768 (39.5)

1.05 (1.0-1.1)

3253 (6.5)

 Middle

63,790 (39)

27,132 (42.5)

1.24 (1.2–1.3)

5324 (8.3)

 High

49,972 (30.5)

27,604 (55.2)

1.69 (1.7–1.7)

5921 (11.8)