Table 1 Frequency distribution of the studied patients and controls according to sociodemographic characteristics

  Mean ± SD.

32.1 ± 8.3

39.7 ± 11.9

U = 7528.0^*

< 0.001^*

29.4 ± 8.6

35.9 ± 10.3

  Median (min.–max.)

32 (18–45)

38 (21–60)

28 (18–45)

34 (22–55)

  Mean ± SD.

36.8 ± 9.2

30.9 ± 10

U = 7578.0^*

< 0.001^*

35.8 ± 10.9

30.6 ± 8.9

  Median (min.–max.)

34 (24–60)

29 (18–47)

30 (24–60)

29 (18–47)

  Mean ± SD.

7.8 ± 6.4

11.0 ± 10.0

U = 10164.0

0.067

7.4 ± 6.4

8.9 ± 6.9

  Median (min.–max.)

5 (0.6–20)

6 (0.6–30)

5 (1–20)

6 (2–25)

  High education

102 (41.1)

40 (42.6)

χ² = 1.044

0.593

36 (35.3)

42 (52.5)

  Up to secondary education

86 (34.7)

36 (38.3)

48 (47.1)

20 (25)

  Not educated

60 (24.2)

18 (19.1)

18 (17.6)

18 (22.5)

  Employer

68 (27.4)

24 (25.5)

χ² = 17.519^*

< 0.001^*

36 (35.3)

28 (35)

  Not employer

76 (30.6)

50 (53.2)

24 (23.5)

40 (50)

  Not working

104 (41.9)

20 (21.3)

42 (41.2)

12 (15)

  Urban

152 (61.3)

56 (59.6)

χ² = 0.084

0.772

60 (58.8)

50 (62.5)

  Rural

96 (38.7)

38 (40.4)

42 (41.2)

30 (37.5)

  Mean ± SD.

2.3 ± 1.8

2.6 ± 2.9

U = 11140.0

0.521

2.1 ± 1.6

2 ± 1.4

  Median (min.–max.)

2 (0–6)

2 (0–7)

2 (0–5)

2 (0–5)

  Mean ± SD.

2.8 ± 2.5

6.6 ± 6.9

U = 7978.0^*

< 0.001^*

2.5 ± 2.5

4.4 ± 5.2

  Median (min.–max.)

2 (0–10)

4 (0–25)

2 (0–8)

2 (0–18)

  Smoker

26 (10.5)

50 (53.2)

χ² = 24.598^*

< 0.001^*

14 (13.7)

40 (50)

  Non smoker

222 (89.5)

44 (46.8)

88 (86.3)

40 (50)

  Mean ± SD.

27.1 ± 4.5

25.6 ± 4.7

U = 9536.0^*

0.009^*

28.1 ± 3.7

26.9 ± 4.7

  Median (min.–max.)

27 (19–36)

25 (19–36)

29.0 (22–36)

27 (20–37)

  Mean ± SD.

7.0 ± 5.8

8.4 ± 5.4

U = 10672.0

0.224

8.7 ± 4.9

10.5 ± 4.7

  Median (min.–max.)

6 (1–20)

8 (1–20)

8 (2–20)

10 (3–20)