Table 1.
Descriptive statistics showing selected baseline characteristics and outcomes.
| Mean | Std dev | |
|---|---|---|
| Baseline variables n = 1,304 | ||
| Age | 15.56 | 0.82 |
| Grade 9 | 0.44 | 0.50 |
| Grade 10 | 0.51 | 0.50 |
| Gender: Girl | 0.57 | 0.49 |
| Gender: Boy | 0.41 | 0.49 |
| Only or mostly attracted to same-gender people | 0.05 | 0.21 |
| Only or mostly attracted to different-gender people | 0.82 | 0.38 |
| Attracted to both male and female gender people equally | 0.08 | 0.28 |
| Other sexual orientation | 0.03 | 0.18 |
| Black | 0.78 | 0.40 |
| Latino | 0.03 | 0.16 |
| White | 0.11 | 0.31 |
| Multiracial | 0.09 | 0.29 |
| Other race | 0.02 | 0.13 |
| Ever skipped school | 0.19 | 0.39 |
| Substance use scale | 0.10 | 0.20 |
| Relationship status: Single | 0.53 | 0.50 |
| Relationship status: Casually dating | 0.21 | 0.41 |
| Relationship status: Serious relationship | 0.22 | 0.41 |
| Relationship status: Engaged | 0.04 | 0.18 |
| Ever had sex | 0.30 | 0.46 |
| Had sex in last three months | 0.18 | 0.39 |
| How many times had sex in the last three months | 1.53 | 8.23 |
| Number of partners (vaginal sex), last three months | 0.79 | 3.42 |
| Had sex without a condom, last three months | 0.13 | 0.34 |
| How many times had sex without a condom, last three months | 0.91 | 7.23 |
| Had vaginal sex without birth control, last three months | 0.09 | 0.29 |
| How many times had vaginal sex without birth control, last three months | 0.49 | 4.38 |
| Summer between baseline and follow-up survey | 0.53 | 0.50 |
|
Pre-sexual behaviors (n = 833) Variables are on a [0,1] scale where higher scores represent more of a given activity | ||
| Sexting scale | 0.32 | 0.32 |
| Touching scale | 0.24 | 0.37 |
| Opportunity scale | 0.48 | 0.38 |
| Kissing scale | 0.49 | 0.43 |
| Ever been in a relationship | 0.80 | 0.40 |
| Pressure scale | 0.40 | 0.36 |
| Outcome variables | ||
| Sex in the last three months (n = 1,294) | 0.29 | 0.46 |
| Sex without a condom in the last three months (n = 1,282) | 0.20 | 0.40 |
| Initiated sex (among the sexually inexperienced) (n = 833) | 0.24 | 0.43 |
Notes: Observations include the analytic sample—those with complete baseline data and data for at least one outcome. Cole et al. 2022 define covariates and outcomes in detail. Pre-sexual behavior categories include aggregated responses to questions about sending or receiving nude photos, touching, opportunities for having sex (has ever hung out alone with or lain with someone they were attracted to), kissing, self-described relationship history, and feeling peer pressure to have sex.