Table 2

Characteristics of the study population (n=1231)

CharacteristicsnMean±SD/%
Age (years)123119.21±1.026
BMI
 Lean38431.2
 Normal77162.6
 Overweight504.1
 Obese262.1
Ethnicity
 Han110689.8
 Non-Han12510.2
University
 C114812.0
 C249340.1
 C359047.9
Major
 Medical37630.5
 Non-medical85569.5
Mother’s education
 Middle school and lower66854.3
 High school and above56345.7
Father’s education
 Middle school and lower54143.9
 High school and above69056.1
Average household income (¥)
 23 821 and less80065.0
 Greater than 23 82143135.0
History of mother’s dysmenorrhea
 Yes50240.8
 No31225.3
 Unknown41733.9
  • BMI, body mass index.