https://sci-hub.se/10.1001/jamainternmed.2019.3500

In this cross-sectional, nationally representative study of 13 310 American women aged 18 to 44 years, 6.5% reported forced sexual initiation (mean age at forced sexual initiation, 15.6 years). Forced sexual initiation appeared to be associated with multiple adverse reproductive, gynecologic, and general health outcomes after adjustment for demographic confounders.

They categorized women as having experienced forced sexual initiation if they responded “not voluntary” to the question, “Would you say that this first vaginal intercourse [with a male] was voluntary or not voluntary, that is, did you choose to have sex of your own free will or not?”

They categorized women responding “voluntary” to this question as having experienced voluntary sexual initiation. All respondents who reported that their first sexual encounter was not voluntary were then asked the following questions regarding themethod of sexual coercion. “Were you given alcohol or drugs?” “Did you do what he said because he was bigger than you or a grown-up, and you were young?” “Were you told that the relationshipwould end if you didn’t have sex?” “Were you pressured into it by his words or actions, but without threat of harm?” “Were you threatened with physical harm or injury?” “Were you physically hurt or injured?” “Were you physically held down?” Participants could report more than 1 type of coercion.