Description and measurement of study variables included in the analysis
| Variable | Description | Measurement |
| Sexual behaviour | Participants who reported no condom use during their first and last episode of sexual intercourse and/or had more than one sexual partner during their lifetime and/or had sex with non-regular partners were categorised as being involved in high sexual risk-taking behaviour. Participants who totally abstained from sexual intercourse or those who had had sexual intercourse with only one sexual partner or with a regular partner, but reported using a condom during their first and last sexual episode of intercourse were categorised as being involved in low sexual risk-taking behaviour.30 | High, Low |
| Contraceptive use | Contraceptive use was measured using a question with ’Yes or No' response options: ’The last time you had sexual intercourse, did you or your partner use any method of birth control, such as withdrawal, rhythm (safe time), birth control pills, or any other method to prevent pregnancy?' Those participants who respond ’Yes' were contraceptive users and those participants who respond ’No' were non-users. | Yes, No |
| Sexting | ’Sexting' characteristics were assessed using the following two parameters with ’Yes or No' response options.9.
Sexting receivers were those who answered ’Yes' for question #1 only. Sexting senders were those who answered ’Yes' for question #2 only. NB. Each response could be complemented by those both sending and receiving. | Yes, No |
| Pornography watching | ’Pornography' was assessed by asking participants: ’Have you ever watched magazine and/or films, images, videos, pictures that contain sexually explicit material depicting naked or semi-naked bodies engaged in genital stimulation or sexual acts (pornography)?' Those who answered ‘Yes’ were categorised as pornography viewers ever and those who did not were categorised as non-viewers. | Yes, No |
| For those who watched pornography, the question ’In the past 6 months, did you watch films, images, videos, pictures that contain sexually explicit material depicting naked or semi-naked bodies engaged in genital stimulation or sexual acts (pornography)?' was asked. Those who answered ‘Yes’ were categorised as current pornography viewers and those who did not were categorised as non-viewers currently. | Yes, No |