RESULTS
Descriptive analysis
A total of 979 adolescent girls were invited to participate and none refused. Twenty-six girls were excluded from analysis mainly because of age or primary or secondary amenorrhea: two were under 15 years; 10 were over 19 years; two had primary amenorrhea; 10 secondary amenorrhea with progestogen-only pill; one had only 1 month of menarche; and for one the cause was unknown (S1).
The population and cycle characteristics are described in Table 1. Sixty-three percent (n=600) of the girls were enrolled in the public sector. The average age of the whole population was 16.9 years (± 1.0) and the average age of menarche was 12.5 years (± 1.4). Most (88.3%, n=835) had regular cycles, and the menstrual periods were heavy for 58.4% (n=548) of the girls. A first-degree family history of dysmenorrhea was reported by 43.2% (n=412) of the girls.
Around a third (36.6%, n=347) of the girls claimed to have had sexual relations. Contraception was used by 41.6% (n=396) and was an oral contraceptive pill (OCP) for 72.2% (n=286). Of the girls taking oral contraception, 67% (n=192) were able to say what kind they were taking and 93% (n=178) of these were using a combined OCP (COCP). Nearly all (93%, n=266) were taking an OCP for reasons other than contraception and to decrease dysmenorrhea for 62% (n=165) (Table 1).
In the group of girls with dysmenorrhea, menstruation was associated with asthenia for 92.8% (n=819), headache for 77.7% (n=686), bloating for 74.9% (n=655), and nausea for 39% (n=345). Moreover, 43.3% (n=383) reported already having missed school, 74.9% (n=660) difficulties in attending school and 76.3% (n=669) poor quality sleep because of their periods (Figure 1).