Table 2 The prevalence and likelihood of constipation in different demographic groups and dietary factors

Demographic features

%

95% CI

p value

Odds ratio (95% CI)

p value

Odds ratio (95% CI)

p value

Overall

15.6

13.2–18.0

Sex

< 0.001**

 Men

10.6

7.6–13.6

Reference

Reference

 Women

19.7

16.2–23.3

2.07 (1.40–3.04)

< 0.001**

2.08 (1.39–3.10)

< 0.001**

Age groups

< 0.001**

 18–38 years

23.5

18.6–28.3

Reference

Reference

 39–54 years

13.3

9.5–17.2

0.50 (0.33–0.77)

0.002**

0.49 (0.31–0.77)

0.002**

 55–80 years

9.9

6.4–13.3

0.36 (0.22–0.57)

< 0.001**

0.38 (0.23–0.64)

< 0.001**

Educational level

0.13

 Primary

11.7

6.8–16.6

Reference

Reference

 Secondary

14.8

11.1–18.5

1.31 (0.76–2.27)

0.33

1.32 (0.74–2.37)

0.35

 Tertiary

18.3

14.2–22.3

1.69 (0.98–2.89)

0.06

1.63 (0.90–2.94)

0.11

Living environment

0.21

 Rural

13.5

9.7–17.3

Reference

 Urban

16.7

13.7–19.8

1.28 (0.87–1.90)

0.21

Body mass index

0.21

 Underweight

12.5

−1.8–26.8

0.70 (0.21–2.43)

0.58

0.58 (0.16–2.04)

0.40

 Normal weight

16.9

13.3–20.5

Reference

Reference

 Overweight

12.2

8.4–15.9

0.68 (0.44–1.06)

0.09

0.96 (0.60–1.52)

0.85

 Obese

18.9

12.7–25.0

1.15 (0.72–1.84)

0.57

1.72 (1.02–2.90)

0.04*

Dietary factors

 Water intake < 1.5 L/day

21.5

16.3–26.6

0.003**^a

1.78 (1.22–2.60) ^a

0.003**

1.70 (1.14–2.53)^a

0.01*

 Vegetables < 3 spoons/day

22.5

16.9–27.9

0.001**^a

1.88 (1.28–2.77) ^a

0.001**

1.53 (1.02–2.30)^a

0.04*

 Fruits < 2 pieces/day

16.7

13.3–20.1

0.33^a

1.20 (0.83–1.73) ^a

0.33

 Whole grain bread < 3 slices/day

17.8

13.3–22.1

0.23^a

1.26 (0.87–1.84)^a

0.23