Measures Participants provided information about their

Measures

Participants provided information about their social and demographic characteristics, including age (categorized as 15–19 or 20–24), residence (rural or urban) and education (attending or completed high school vs. not attending or dropped out). In addition, detailed information on sexual behavior was collected from each young person. They were asked to report if they had ever had vaginal or anal sex, and the age at which each of these events had first occurred. The distinction between vaginal and anal intercourse was defined for participants in detail, so that there was no confusion as to what was meant by sexual intercourse. As per World Health Organization guidelines for adolescent HIV prevention programs, early sexual debut was defined as having had vaginal sex for the first time at age 14 or younger.²⁴ For convenience, we refer to sexual debut after age 14 as a later debut.

Respondents were asked about the age of their first sexual partner (which we used to calculate age differences between the respondent and his or her partner), and whether the partner was a main partner (spouse, boyfriend or girlfriend), a regular casual partner (someone who was not a main partner, but with whom the respondent had had sex on an ongoing basis), a nonregular casual partner (someone who was not a main partner, and with whom the respondent had had sex only one or two times) or a sex worker. Respondents also reported the length of their relationship with their first partner and whether the relationship was ongoing; whether they had had sex with their first partner in the past 12 months, and if so, how often they had had sex with that partner in the past month; whether they had used a condom the first time they had had sex; whether they had used a condom the last time they had had sex with their first partner; whether they had always, sometimes or never used condoms with their first partner; whether they had ever had transactional sex with their first partner; whether their first partner had ever physically forced them to have sex; and whether they had ever used a contraceptive method with their first partner (and if so, what type). Finally, participants were asked to rate two aspects of their sexual debut: the degree to which they had wanted to have sex (really wanted, wanted, did not want or really did not want) and been willing to have sex (willing, persuaded, tricked, or forced or raped).*