Table 2 Menstrual characteristics of participants

Age at menarche ( n  = 269)

  < 12

17

6.3 (3.9–9.9)

 12–14

222

82.5 (77.5–86.6)

 15–17

30

11.2 (7.9–15.5)

Regular menstrual periods (inter- cycle difference ≤ 9 days)? ( n  = 275)

 Irregular menstruation

57

20.7 (16.4–25.9)

 Regular menstruation

218

79.3 (74.0–83.7)

Duration of menstrual cycle in days, n  = 275

 Normal cycle (24.0–38.0 days)

246

89.4 (85.2–92.5)

 Frequent menstruation (< 24.0 days)

20

7.3 (4.7–11.0)

 Infrequent menstruation (> 38.0 days)

9

3.3 (1.7–6.2)

Intermenstrual bleeding

 No

254

92.4 (88.5–94.9)

 Yes

21

7.6 (5.01–11.5)

Dysmenorrhea (painful periods)

 No

100

36.4 (30.8–42.2)

 Yes

175

63.6 (57.7–69.1)

Frequency of menstrual pain ( n  = 175)

 All periods

82

46.8 (39.5–54.3)

 Some periods

71

40.6 (33.4–48.1)

 Occasionally

22

12.6 (8.4–18.4)

Pain severity ( n  = 175)

 Mild

34

19.4 (14.1–26.0)

 Moderate

98

56.0 (28.5–63.2)

 Severe

43

24.6 (18.70–31.6)

Premenstrual symptoms

 Painful breast on touching

111

40.4 (34.7–46.3)

 Difficulty concentrating

56

20.4 (15.9–25.6)

 Depression/ Mood changes

167

60.7 (54.8–66.3)

Presence of premenstrual syndrome symptoms

 No

17

6.2 (3.9–9.7)

 Yes

258

93.8 (90.2–96.1)

Consultations because of menstrual problems ^a

 Doctor

38

13.8

 School nurse

21

7.6

 Parent

72

26.2

 Friend

66

24.0

 None

142

51.6

Missed class (es) in the last 2 months because of a menstrual problem

 No

245

89.1

 Yes

30

10.9

What is your perception about menstrual pain

 Normal occurrence, yes

152

55.3

 Bad occurrence, tolerable, yes

87

31.6

 Bad occurrence requires treatment

28

10.2

 Missing

8

2.9

Do you think your periods are normal?

 No

12

4.4

 Yes

193

70.2

 Unsure

70

25.4

Had at least one disorder

 No

6

2.2

 Yes

269

97.8