Table 2.

Summary of codebook organizing themes, definitions, and exemplary quotes.

Theme		Definition	Quote
Receptivity to texting from the ED
Preference		Interested in receiving information via text messages rather than by phone or email	It will be easier than email or calling on the phone because I might not get the phone or signal...I am always texting. [Participant #3]
Comfort		Considered text messages to be safe, because they are confidential and will Not cause embarrassment or harm	If my mom passes by while my phone is charging...and she sees that (text)...‘Oh Mom, it’s just the clinic. They have a new texting thing. Yeah Mom, come on. We’re not living in the 90s anymore’…She’d actually be very happy with that. [Participant #7]
MD-patient   relationship		Text messages sent by a physician are trustworthy and motivating	I think she (older sister) would be comfortable with it because I am actually talking to a doctor, not like a regular person. [Participant #2]
Preferred content of text messages
Information		Chose messages that contain sexual health facts not previously known to them	It’ll be good to write (about) STDs and stuff, because it’s not only about pregnancy. [Participant #1]
Services		Emphasized the importance of a respectful staff at free and confidential clinics	You have to make sure you tell them that their information is confidential. And that it’s free...because most of my friends don’t have insurance. [Participant #11]
Self-efficacy		Favored messages commenting on the belief in one’s capacity to achieve a behavior	You are responsible for your own body. [Participant #10]
Links		Interested in links to videos, quizzes, websites, or events	If you want more information, you can just click on the link. [Participant #13]
Preferred text message structure
Word choice		Preferred simple, nonaccusatory words	If you choose to have unprotected sex, you are choosing to get pregnant...I think that one might be a little bit too accusatory...I don’t like being told what to do. [Participant #9]
Order		Messages should have a certain order and contain a header	Because sometimes we get those...random messages from like my phone company…And I just delete them. [Participant #6]
Customization		Commented on personalized text messages	Those girls...think they’re going to be with that boyfriend for the rest of their lives. And the boyfriend tells them “Oh, we don’t need to use condoms because it’s only me”...They don’t want to get pregnant because they have hopes and dreams...But then there is the totally different girl who’s sleeping with anyone. And she doesn’t want to get pregnant and she doesn’t use contraception either. So maybe those are two separate girls that you can have two separate sorts of text messages for. [Participant #14]
Preferred schedule of text message delivery
Random versus   selected times		Favored random timing of messages over selected time	I think definitely send them randomly for the element of surprise...if people are expecting it and know it’s coming, they going to like, ‘Oh, I know what this is. I don’t need it, delete it.’ [Participant #9]
Day		Reached no consensus on which days text messages should be sent	Maybe on the weekends, because usually the weekends are when mistakes happen. [Participant #11]
Time		Selected texts to be sent in the afternoon and early evening	Definitely not after 8 o’clock because that’s just creepy...after 8 o’clock is when the condom commercials come on, and sex...stuff like that. [Participant #7]
Frequency		Ranged in opinions of message delivery from twice a day to once a month	Don’t nag them like every day. [Participant #10]