Table 2

Adolescent characteristics and family history of the participants

VariableEndometriosis group
n=157
Control group
n=156
P value
Age at menarche (years), mean±1 SD12.7±1.513.0±1.60.11*
Missing, n (%)1(0.6%)7(4.5%)
Severe dysmenorrhea in adolescence, n (%)




Never5(3.2%)30(20.1%)
Rarely13(8.3%)36(24.2%)
Sometimes31(19.9%)43(28.9%)<0.001†
Often45(28.8%)21(14.1%)
Always62(39.7%)19(12.8%)
Missing1(0.6%)7(4.5%)
Absenteeism from school due to dysmenorrhea, n (%)




Never28(17.8%)99(66.4%)
Rarely23(14.6%)26(17.4%)
Sometimes52(33.1%)17(11.4%)<0.001†
Often38(24.2%)5(3.4%)
Always16(10.2%)2(1.3%)
Missing0(0%)7(4.5%)
Use of painkillers for dysmenorrhea in adolescence, n (%)




Never20(12.8%)56(37.6%)
Rarely15(9.6%)30(20.1%)
Sometimes36(23.1%)40(26.8%)<0.001†
Often39(25.0%)10(6.7%)
Always46(29.5%)13(8.7%)
Missing1(0.6%)7(4.5%)
Use of oral contraceptives for dysmenorrhea in adolescence, n (%)
Yes60(38.2%)17(11.5%)<0.001‡
No97(61.8%)131(88.5%)
Missing0(0%)8(5.1%)
Family history of endometriosis, n (%)
Yes42(26.8%)7(4.5%)<0.001‡
Not yes§115(73.2%)149(95.5%)
  • *Independent samples t-test.

  • †Linear-by-linear association χ2 test.

  • ‡Pearson’s χ2 test.

  • §Not yes: no/irrelevant/missing.