Primary Exposure
In the “sexual behavior” questionnaire, men were asked by” ever had
vaginal sex with a woman”, ”ever had oral sex with a woman”, ”ever
had anal sex with a woman”, ”ever had any sex w/man: anal, oral”, and
women were asked by ”ever had vaginal sex with a man”, ”ever had oral
sex on a man”, ”ever had anal sex with a man”, ”ever had any kind of
sex w/woman”. Based on the sexual behavior of the population, we
categorized individuals into two groups: sexual identity and sexual
type. The sexual identity group comprised individuals with no sex,
heterosexual, homosexual, bisexual, or unclear. The sexual type group
consisted of individuals with no sex, heterosexual vaginal sex,
heterosexual oral sex, heterosexual anal sex, heterosexual multiple
types, bisexual sex, male homosexual sex, female homosexual sex, or
unclear.