Video Abstract
Although lesbian, gay, bisexual and other sexual minority (LGB+) girls are more likely than heterosexual girls to be pregnant during adolescence, relevant pregnancy prevention programming is lacking.
A national randomized controlled trial was conducted with 948 14- to 18-year-old cisgender LGB+ girls assigned to either Girl2Girl or an attention-matched control group. Participants were recruited on social media between January 2017 and January 2018 and enrolled over the telephone. Between 5 and 10 text messages were sent daily for 7 weeks. Both experimental arms ended with a 1-week booster delivered 12 weeks subsequently.
A total of 799 (84%) participants completed the intervention end survey. Participants were, on average, 16.1 years of age (SD: 1.2 years). Forty-three percent were minority race; 24% were Hispanic ethnicity. Fifteen percent lived in a rural area and 29% came from a low-income household. Girl2Girl was associated with significantly higher rates of condom-protected sex (adjusted odds ratio [aOR] = 1.48, P < .001), current use of birth control other than condoms (aOR = 1.60, P = .02), and intentions to use birth control among those not currently on birth control (aOR = 1.93, P = .001). Differences in pregnancy were clinically but not statistically significant (aOR = 0.43, P = .23). Abstinence (aOR = 0.82, P = .34), intentions to be abstinent (aOR = 0.95, P = .77), and intentions to use condoms (aOR = 1.09, P = .59) were similar by study arm.
Girl2Girl appears to be associated with increases in pregnancy preventive behaviors for LGB+ girls, at least in the short-term. Comprehensive text messaging–based interventions could be used more widely to promote adolescent sexual health behaviors across the United States.
Although sexual minority girls are more likely than heterosexual girls to be pregnant as a teenagers, pregnancy prevention programs tailored to the lived experiences of these girls are lacking.
Girl2Girl positively impacts condom use and uptake of other types of contraception for sexual minority girls, at least in the short-term. Findings further suggest that intensive programming delivered over a long period is acceptable to sexual minority girls.
Although adolescent pregnancy rates in the United States have decreased over the past 40 years, just under 200 000 girls, 15 to 19 years old, became pregnant in 2017.1 Cisgender sexual minority girls, who comprise an estimated 10% to 15% of female youth,2 face differential risk: It may seem counterintuitive given assumptions that cisgender lesbian, gay, bisexual, and other sexual minority (LGB+) girls are only having sex with other girls, but researchers consistently find that they are significantly more likely to get pregnant than heterosexual girls.3–5 Cisgender LGB+ girls also are more likely than their heterosexual female peers to have sex at a younger age,2,4,6,7 report more lifetime and recent numbers of female or male sexual partners,2,4,6,8 and are less likely to use barrier methods to prevent sexually transmitted infections or pregnancy.2,7,9
Access to school-based sex education varies widely across the United States10 : 19 states require an abstinence-only perspective and 39 require that abstinence is presented as an option; only 20 states require contraception to be included in the sexual education curriculum. Despite the heightened risks of pregnancy and sexually transmitted infections that cisgender LGB+ girls face, sex education that addresses these disparities is often scarce or inadequate.11,12 Indeed, although 11 states and the District of Columbia require LGBT+ inclusive sex education, an additional 7 require that homosexuality be presented negatively and/or that heterosexuality be presented as the only acceptable sexual identity.
To address the lack of sexual health programming for many sexual minority adolescents, we developed and tested Girl2Girl, a text messaging-based pregnancy prevention program tailored to the unique needs of sexually experienced and inexperienced cisgender LGB+ adolescent girls. In this study, we report the preliminary outcomes of the randomized controlled trial (RCT) at intervention end, 5 months after program enrollment. Information about the iterative, user-centered intervention development, which included 269 cisgender LGB+ girls from across the country, is available elsewhere.13 Findings from the current investigation will contribute to the growing literature examining behavioral outcomes associated with text messaging-delivered behavior change content, particularly that which targets complex behaviors, such as pregnancy prevention.
Methods
Girls were recruited and enrolled between January 23, 2017, and January 12, 2018. After completing the baseline survey, they were randomized and began the 5-month program. Most participants completed the intervention or control program and their survey by May 31, 2018.
Advarra Institutional Review Board, an Office of Human Research Protections–approved institutional review board, reviewed and approved the research protocol. We were granted a waiver of parental permission so that girls would not have to put themselves in a potentially unsafe situation by disclosing their sexual identity to their parents to obtain permission to participate in the study. The waiver also prevented sampling bias that would have occurred by including only girls who were out to their parents.
Participants
Girls were recruited across the United States. To be eligible for the study, participants were (1) aged 14 to 18 years, (2) cisgender female (ie, assigned female sex at birth and endorsed a female gender identity), (3) sexual minority (eg, lesbian, bisexual), (4) in high school or the equivalent (including those who did not finish or dropped out), (5) English speaking, (6) exclusive users of a cell phone (ie, they do not share the phone with someone else) with an unlimited text messaging plan, (7) users of text messaging for at least 6 months, (8) intending to have the same cell number for the next year, and (9) able to provide informed assent for those <18 years of age and consent for those 18 years of age, including an acceptable score on the “capacity to consent” and self-safety assessment.14 Exclusion criteria included knowing another girl enrolled in the RCT and having participated in a previous intervention development activity.
Description of the Intervention and Control Group Content
Girl2Girl is a 20-week, text messaging–based teenage pregnancy prevention program. For the first 7 weeks, participants are sent between 4 and 12 messages per day. They then enter a 12 week “latency” period when they receive ∼1 to 2 messages per week. Finally, participants receive 4 to 12 messages daily for a review week. This “booster” delivers messages that reiterate the main concepts discussed in the first 7 weeks of the program.
Intervention content is guided by the information, motivation, behavioral skills model15,16 and focuses on pregnancy prevention information (eg, how one gets pregnant), motivations (eg, reasons to initiate birth control), and behavioral skills (eg, how to use barriers). Additional content describes topics and scenarios that are relevant to sexual decision-making for sexual minority girls (eg, aspects of a healthy relationships).17,18 Content is tailored on the basis of participants’ self-reported sexual experience (ever versus never had sex) and sexual identity (lesbian or gay versus all others, except for girls who identified as queer; in this case, their sexual attractions determined which content they received). Content was not further tailored to the individual.
As described elsewhere,13 most program messages are unidirectional (see Table 1). Bidirectional, interactive components included (1) links to brief online videos in the messages that aimed to reinforce behavioral skills; (2) G2Genie, an on-demand advice text line that provided information about sex, relationships, and the LGBT+ community19,20 ; (3) “leveling up” by answering a text message question correctly about the week’s content; and (4) being awarded “badges,” which was a gif sent over text, for achieving behavioral skills they were presented in the program (eg, getting barriers; talking to a health provider about contraception).
Example Girl2Girl Program Messages That are Unidirectional and Bidirectional
. | Example Intervention Test Message . |
---|---|
Unidirectional messages by domain . | . |
Teenage pregnancy prevention information | I get that you’re into girls, not guys. Here’s the thing: LGB+ girls are 2–4 times MORE likely to get pregnant than hetero girls. Totally unexpected, huh?a |
About 1 in 20 teen girls are on an intrauterine device (IUD) or an implant. They can be great: They last 3–10 years so you get it put in and forget about it. | |
Being on your period doesn’t protect you because sperm can live in your vagina for up to 5 days. So your period can be over, but sperm are still swimming around. | |
Teenage pregnancy prevention motivation | There are a lot of reasons why LGB+ girls are more likely to get pregnant. Some assume they’re never going to have sex that involved a penis so they don't have condoms. |
Maybe surprisingly, women in committed relationships with women can have high STD rates. In fact, 13% to 30% of women having sex with women have HPV (source: bit.ly/1SMlxH6) | |
A girl told me: “Most people won’t look bad at you for buying condoms or going to a gyno to get birth control. No shame. It’s only natural.” Too right! | |
Some women say the female condom has more sensation than a male condom. And it rubs against your clitoris during sex - bonus! | |
Dental dams/condoms prevent STDs and pregnancy but a backup never hurts - like having a car charger in case your phone goes dead. And that's birth control! | |
Teenage pregnancy prevention behavioral skills | It's fast and simple: Unroll the male condom. Cut off the tip of the condom. Cut down the length of the tube. Unfold to a square. Done! |
Unsure how to ask about birth control? Tell the provider you have questions about it and they’ll take it from there. Don’t worry - they talk to teens every day. | |
No need to wait for a crisis. Go online to see where the nearest store is. Too far to get to? Buy the morning after pill online so you have it if you need it. | |
Socio-cultural factors | Dating violence can also happen. 2 in 5 LGB+ girls have been victims. 1 in 3 were violent themselves. It's not ok to use hurtful words or physical force. |
If you or someone you know is assaulted, *please* get help. RAINN is amazing - they have an online chat (ohl.rainn.org/online) and a hotline: 800-656-4673. | |
It’s common for us to question our sexual attractions and identity. Or for these to change over time. It’s OK to take time to explore and discover who you are. | |
Bidirectional messages by domain | |
Level-up | Initial message: I'm not sure where the last 2 weeks went, but here we are! This is for Level 2. True or False: You need your parents' permission for the morning after pill. |
Correct response from participant: Yessss! You are absolutely right. You can get emergency contraception at many drug stores or online and you don't need your parent’s ok. Hellllooo Level 2! | |
Incorrect response form participant: Good news! You can get emergency contraception at many drug stores or online and you don’t need your parent’s ok. | |
G2Genie | Texting the keyword “condom” to G2Genie: If condoms (aka cut up to be dental dams) are too expensive, go to a clinic and get them for free. The icondom app can help you find free stuff too. The Internet is magical! |
Badges | Initial message: Great! So, what’s your dental dam/condom status at the moment? Do you have one in your possession (like in your bedroom, school bag, etc)? Let me know (yes/no). |
Participant says yes: Nice! You earned your Go Getter Girl Badge! | |
Participant says no: It might seem really hard to get dental dams/condoms: they’re expensive, they can be embarrassing to buy, and maybe you don’t know where to get them. What stops you: Parents, Cost, IDK where to go, Embarrassed, Not having sex, Not having sex w/a guy, Waiting to have sex, In a relationship, No transport, Other. | |
“No” participant responds she is not having sex with a guy: I totally get that you're not having sex with a guy but practicing now to buy condoms now just makes it easier to them if you need them later on. |
. | Example Intervention Test Message . |
---|---|
Unidirectional messages by domain . | . |
Teenage pregnancy prevention information | I get that you’re into girls, not guys. Here’s the thing: LGB+ girls are 2–4 times MORE likely to get pregnant than hetero girls. Totally unexpected, huh?a |
About 1 in 20 teen girls are on an intrauterine device (IUD) or an implant. They can be great: They last 3–10 years so you get it put in and forget about it. | |
Being on your period doesn’t protect you because sperm can live in your vagina for up to 5 days. So your period can be over, but sperm are still swimming around. | |
Teenage pregnancy prevention motivation | There are a lot of reasons why LGB+ girls are more likely to get pregnant. Some assume they’re never going to have sex that involved a penis so they don't have condoms. |
Maybe surprisingly, women in committed relationships with women can have high STD rates. In fact, 13% to 30% of women having sex with women have HPV (source: bit.ly/1SMlxH6) | |
A girl told me: “Most people won’t look bad at you for buying condoms or going to a gyno to get birth control. No shame. It’s only natural.” Too right! | |
Some women say the female condom has more sensation than a male condom. And it rubs against your clitoris during sex - bonus! | |
Dental dams/condoms prevent STDs and pregnancy but a backup never hurts - like having a car charger in case your phone goes dead. And that's birth control! | |
Teenage pregnancy prevention behavioral skills | It's fast and simple: Unroll the male condom. Cut off the tip of the condom. Cut down the length of the tube. Unfold to a square. Done! |
Unsure how to ask about birth control? Tell the provider you have questions about it and they’ll take it from there. Don’t worry - they talk to teens every day. | |
No need to wait for a crisis. Go online to see where the nearest store is. Too far to get to? Buy the morning after pill online so you have it if you need it. | |
Socio-cultural factors | Dating violence can also happen. 2 in 5 LGB+ girls have been victims. 1 in 3 were violent themselves. It's not ok to use hurtful words or physical force. |
If you or someone you know is assaulted, *please* get help. RAINN is amazing - they have an online chat (ohl.rainn.org/online) and a hotline: 800-656-4673. | |
It’s common for us to question our sexual attractions and identity. Or for these to change over time. It’s OK to take time to explore and discover who you are. | |
Bidirectional messages by domain | |
Level-up | Initial message: I'm not sure where the last 2 weeks went, but here we are! This is for Level 2. True or False: You need your parents' permission for the morning after pill. |
Correct response from participant: Yessss! You are absolutely right. You can get emergency contraception at many drug stores or online and you don't need your parent’s ok. Hellllooo Level 2! | |
Incorrect response form participant: Good news! You can get emergency contraception at many drug stores or online and you don’t need your parent’s ok. | |
G2Genie | Texting the keyword “condom” to G2Genie: If condoms (aka cut up to be dental dams) are too expensive, go to a clinic and get them for free. The icondom app can help you find free stuff too. The Internet is magical! |
Badges | Initial message: Great! So, what’s your dental dam/condom status at the moment? Do you have one in your possession (like in your bedroom, school bag, etc)? Let me know (yes/no). |
Participant says yes: Nice! You earned your Go Getter Girl Badge! | |
Participant says no: It might seem really hard to get dental dams/condoms: they’re expensive, they can be embarrassing to buy, and maybe you don’t know where to get them. What stops you: Parents, Cost, IDK where to go, Embarrassed, Not having sex, Not having sex w/a guy, Waiting to have sex, In a relationship, No transport, Other. | |
“No” participant responds she is not having sex with a guy: I totally get that you're not having sex with a guy but practicing now to buy condoms now just makes it easier to them if you need them later on. |
This message is written specifically for lesbian or same-sex attracted girls.
Girl2Girl participants also were paired with another participant, their “text buddy.”19,20 As part of the program content, buddies received messages that encouraged them to provide social support to one other and practice skills taught in the program. Intervention participants accepted a Buddy Code of Conduct, which outlined acceptable and unacceptable behavior. Buddy messages were routed through the study server so that participants’ phone numbers were not disclosed to buddies. Buddy conversations were monitored by research staff from 6 am to 10 pm PST to ensure harmful messages were not being sent.
The control arm received a similar intensity and duration of messaging as the intervention. Content addressed topics relevant to adolescents, including diet, exercise, and how to deal with bullying. To help blind this arm, 2 days of pregnancy prevention content readily available online were included. Interactive components (eg, Text Buddy) were not available to this group.
Recruitment and Retention Procedures
Participants were recruited through online advertisements on Facebook and Instagram. The ads were targeted to users who indicated on their profile that they were female, between 14 and 18 years of age, and “interested in females” or “interested in males and females.” Youth who clicked on the advertisement were directed to the online screener form.
Potentially eligible youth were contacted in order of receipt of screeners while also considering preset demographic targets to ensure sample diversity. For example, once the targeted number of non-Hispanic white girls was enrolled, additional demographically similar candidates were not contacted. Enrollment occurred over the phone with research staff. Once eligibility was confirmed and informed assent and consent were obtained, participants were emailed a unique link to the baseline survey. Girls were randomized to a study arm after they completed the survey.
Randomization
Participants were randomly assigned to the Girl2Girl intervention (n = 473) or the attention-matched control group (n = 475) at a 1-to-1 randomization allocation ratio. The random allocation was stratified by (1) sexual experience and (2) sexual identity.21 Participants, but not researchers, were blind to arm allocation.
Power
Effect size estimates for samples that include both sexually experienced and inexperienced LGB+ youth are ill-defined because, as noted above, pregnancy programs for LGB+ adolescent women are lacking. To inform our power estimates about sexual abstinence, we used data from the authors’ Girl2Girl “recruitment pilot” study. Among the 257 14- to 18-year-old sexual minority girls surveyed, 22% had never had penile-vaginal sex (M.Y., unpublished data). A power estimate for condom use was based on data from the authors’ Teen Health and Technology survey.22 Eleven percent of LGB+ girls 14 to 18 years old reported having penile-vaginal or penile-anal sex without a condom in the past 3 months (M.Y., unpublished data). On the basis of these prevalence estimates and assuming 80% power and statistical significance set at P = .05, the minimum detectable odds ratio we could detect with a sample size of 420 girls in each experimental group (n = 840) were 0.49 for condomless sex and 1.66 for abstinence.23–27 Recruitment was more successful than anticipated, with 948 participants recruited and randomized.
Incentive
Participants received between $5 and $35 for completing the survey at intervention end; incentives varied on the basis of the mode and length of the survey they completed (see Data Collection below). Youth were not incentivized to complete the baseline survey.
Data Collection
Baseline surveys were collected online. We initially intended to collect intervention end data via text messaging. When funding uncertainties arose, we shifted to an online data collection format. As such, 299 participants completed the intervention end survey via text message and 500 completed it online. Survey mode was balanced by experimental arm: 62% of control and 63% of intervention participants completed the survey online (P = .71).
Program participation length varied for intervention participants on the basis of their responsiveness to programmatic activities. For example, those who did not respond to a level-up question or badge message were sent multiple reminders before the program content resumed. Thus, some had an intervention experience that was longer than 20 weeks.
Measures
Main outcomes included (1) condom-protected penile-vaginal sex in the past 3 months, (2) current use of contraception other than condoms, (3) abstinence from penile-vaginal sex in the past 3 months, and (4) pregnancy since program enrollment. Secondary outcomes included behavioral intentions in the next year to (5) use condoms and (6) other forms of contraception and (7) be abstinent. Outcome measures were adapted from those recommended by the Office of Adolescent Health.28 Because of the 160-character limitation in text messages, questions in the text messaging–based intervention end survey varied from the online version. Wording of outcome measures is shown in Table 2.
Girl2Girl2 RCT Outcome Measures
Measure . | Online Survey Text (Baseline and Intervention End) . | Text Messaging Survey Text (Intervention End) . | Outcomes Computation . |
---|---|---|---|
Abstinence in the past 3 mo | In the past 3 months, how many times have you had sex when a human penis went into your vagina? | Since the beginning of the G2G program on [date], how many times have you had sex when a human penis (not a toy) went in your vagina? | Those who answered 0 were coded as being abstinent. Those who reported 1 or more times at baseline were coded as being recently sexually active. |
No. condom-protected sex acts in the past 3 mo | You said you had sex when a human penis (not a toy) went into your vagina [insert number] in the past 3 months. How many times did you use a female or male condom? | And of the [×] times you had sex when a human penis went in your vagina since G2G started, how many times did you use female or male condoms? | Responses were treated as a count. |
Currently using birth control | Youth were asked 6 separate questions about whether they were currently using any types of the following methods of birth control: (1) birth control pills, (2) the shot (like Depo-Provera), (3) the patch (like Xulane), (4) the ring (like NuvaRing), (5) IUD (like Skyla, Mirena, or Paragard), and implants (like Implanon or Nexplanon). Response options were no, yes, I don’t know what this is, and do not want to answer. Those who initially said they did not know about the type of birth control were directed to a pictorial representation and a more detailed description. | Are you on birth control? I mean the pill, shot (Depo-Provera), ring (NuvaRing), patch (Xulane), an IUD (like Paragard), or implant (like Implanon). | Current use of birth control was indicated if online survey respondents answered yes to any of the 6 types of birth control queried, or text message survey respondents answered yes to the single item. |
Pregnancy since RCT enrollment | As far as you know, have you been pregnant, even if no child was born, ever/since Girl2Girl started on [insert start date]? | As far as you know, since Girl2Girl started on [date] have you been pregnant even if no child was born? | Those who said yes were coded as having been pregnant. |
Intentions to use condoms in the futurea | “If I have sex where a human penis (not a toy) goes into my vagina in the next year, I plan to use or have my partner use a female or male condom.” Response options were on a 5-point Likert scale ranging from very untrue to very true. | In the next 3 months, if you have sex when a human penis goes into your vagina, do you plan to use female or male condoms? Def not, Prob not, Prob, Def, or IDK. | Those who said “somewhat true” or very true” online or “Prob” or “Def’ via text were coded as having intentions to use condoms. |
Intentions to use birth control other than condoms in the futureb | “In the next year, do you plan to use these methods of birth control?” The 6 types of birth control described above. Response options were on a 4-point Liker scale ranging from no, definitely not to yes, definitely. | “In the next 3 months, do you plan to use birth control (the pill, shot, ring, patch, IUD, implant)? Def not, Prob not, Prob, Def, IDK, or not sure what this is.” | Those who said “Yes, probably” or “Yes, definitely” to the online survey or “Prob” or “Def” via text messaging, and said they were not currently on birth control, were coded as having intentions to use birth control. |
Intentions to be abstinent in the future | “In the next year, do you think you might have the following types of sex with a guy, or someone with a penis regardless of their gender presentation?” The specific item was: “Sex with a human penis (not a toy) that goes into your vagina.” Response options were on a 4-point Likert scale ranging from “no, definitely not” to “yes, definitely.” | “And in the next 3 months, do you think you might have sex when a human penis (not a toy) goes into your vagina? Def not, Prob not, Prob, Def, IDK.” | Those who responded “Yes, probably” or Yes, definitely” online, of “Prob” or “Def” via text were coded as having an intention to be abstinent. |
Measure . | Online Survey Text (Baseline and Intervention End) . | Text Messaging Survey Text (Intervention End) . | Outcomes Computation . |
---|---|---|---|
Abstinence in the past 3 mo | In the past 3 months, how many times have you had sex when a human penis went into your vagina? | Since the beginning of the G2G program on [date], how many times have you had sex when a human penis (not a toy) went in your vagina? | Those who answered 0 were coded as being abstinent. Those who reported 1 or more times at baseline were coded as being recently sexually active. |
No. condom-protected sex acts in the past 3 mo | You said you had sex when a human penis (not a toy) went into your vagina [insert number] in the past 3 months. How many times did you use a female or male condom? | And of the [×] times you had sex when a human penis went in your vagina since G2G started, how many times did you use female or male condoms? | Responses were treated as a count. |
Currently using birth control | Youth were asked 6 separate questions about whether they were currently using any types of the following methods of birth control: (1) birth control pills, (2) the shot (like Depo-Provera), (3) the patch (like Xulane), (4) the ring (like NuvaRing), (5) IUD (like Skyla, Mirena, or Paragard), and implants (like Implanon or Nexplanon). Response options were no, yes, I don’t know what this is, and do not want to answer. Those who initially said they did not know about the type of birth control were directed to a pictorial representation and a more detailed description. | Are you on birth control? I mean the pill, shot (Depo-Provera), ring (NuvaRing), patch (Xulane), an IUD (like Paragard), or implant (like Implanon). | Current use of birth control was indicated if online survey respondents answered yes to any of the 6 types of birth control queried, or text message survey respondents answered yes to the single item. |
Pregnancy since RCT enrollment | As far as you know, have you been pregnant, even if no child was born, ever/since Girl2Girl started on [insert start date]? | As far as you know, since Girl2Girl started on [date] have you been pregnant even if no child was born? | Those who said yes were coded as having been pregnant. |
Intentions to use condoms in the futurea | “If I have sex where a human penis (not a toy) goes into my vagina in the next year, I plan to use or have my partner use a female or male condom.” Response options were on a 5-point Likert scale ranging from very untrue to very true. | In the next 3 months, if you have sex when a human penis goes into your vagina, do you plan to use female or male condoms? Def not, Prob not, Prob, Def, or IDK. | Those who said “somewhat true” or very true” online or “Prob” or “Def’ via text were coded as having intentions to use condoms. |
Intentions to use birth control other than condoms in the futureb | “In the next year, do you plan to use these methods of birth control?” The 6 types of birth control described above. Response options were on a 4-point Liker scale ranging from no, definitely not to yes, definitely. | “In the next 3 months, do you plan to use birth control (the pill, shot, ring, patch, IUD, implant)? Def not, Prob not, Prob, Def, IDK, or not sure what this is.” | Those who said “Yes, probably” or “Yes, definitely” to the online survey or “Prob” or “Def” via text messaging, and said they were not currently on birth control, were coded as having intentions to use birth control. |
Intentions to be abstinent in the future | “In the next year, do you think you might have the following types of sex with a guy, or someone with a penis regardless of their gender presentation?” The specific item was: “Sex with a human penis (not a toy) that goes into your vagina.” Response options were on a 4-point Likert scale ranging from “no, definitely not” to “yes, definitely.” | “And in the next 3 months, do you think you might have sex when a human penis (not a toy) goes into your vagina? Def not, Prob not, Prob, Def, IDK.” | Those who responded “Yes, probably” or Yes, definitely” online, of “Prob” or “Def” via text were coded as having an intention to be abstinent. |
Two hundred and ninety-nine participants completed the intervention end survey via text message and 500, online. Online survey questions were based on those recommended by the Office of Adolescent Health. Messages were adapted by the authors for text messaging. IDK, I don’t know.
In the text messaging–based survey, this question was asked of everyone except those who said “definitely not” to the question about intentions to have penile-vaginal sex. It was asked of everyone in the online survey.
In the text messaging survey, this question was asked only of those who were not currently on birth control. In the online survey, it was asked of everyone.
Statistical Analyses
Participants who did not complete the intervention end survey were excluded from the analyses. Missing data also occurred within the intervention end survey when participants declined to answer an outcome measure. Intentions to use condoms (5%), intentions to have penile-vaginal sex (4%), and intentions to use birth control (4%) had the highest rates of decline to answer. To analyze a consistent sample across outcome measures, decline to answer was treated as outcome failure (eg, no condom-protected sex; no intention to use condoms). As a sensitivity analyses, models also were estimated with these youth eliminated from the analyses.
Analyses were intention to treat; gender identity was assessed during the enrollment call. A small number of youth (n = 10) self-reported a cisgender identity over the telephone and a noncisgender identity in the baseline survey. Because these answers were not again assessed for eligibility, these youth were included in the study sample. One of these participants’ baseline surveys was deleted. Eight completed both the baseline and follow-up surveys and are included in analyses.
Logistic regression was used to quantify the relative odds of dichotomous measures: contraception, abstinence, and behavioral intentions. Poisson regression was used to quantify the relative count of condom-protected sex acts.
Differences in behaviors at baseline were likely equally distributed between treatment and control groups because arm assignment was random. Because statistically significant differences in these characteristics might occur by chance, any baseline characteristics on which the experimental arms were imbalanced were included in multivariate models. Multivariate models also adjusted for the baseline indicator of the outcome in question (eg, condom-protected sex) and the survey mode through which the intervention end survey was completed (ie, online versus text messaging).
Analyses were performed twice: once with all youth and once for youth who reported penile-vaginal sex in the 90 days before baseline, hereafter referred to as “sexually active girls.” Girls who had sex for the first time during the observation period were not included in the latter group. The former provided an estimate of the intervention effect in the target population as a whole, and the latter provided an estimate among those at greater risk for pregnancy. We also examined behavioral intentions among youth who had not had penile-vaginal sex in the past 3 months at baseline (ie, were “not sexually active”).
Results
As shown in Fig 1, 59 of 948 participants either actively terminated their involvement in the RCT or were lost to follow-up. The remaining 94% received all program messages, thereby completing the program. Seven hundred and ninety-nine (84%) completed the intervention end survey and are included in the current analyses. No unintended harms were reported.
Intervention and control participants were equivalent on their baseline characteristics except for age, which was borderline statistically significantly different (P = .051; see Table 3).
Comparison of Baseline Characteristics of Girl2Girl RCT Participants Among Those Who Completed the Intervention End Survey (n = 799)
Youth Characteristics . | Control (n = 410) . | Intervention (n = 389) . | P . |
---|---|---|---|
Age, mean (SD) | 15.97 (1.2) | 16.14 (1.2) | .051 |
Hispanic ethnicity, n (%) | .25 | ||
No | 300 (73.2) | 302 (77.6) | |
Yes | 109 (26.6) | 85 (21.9) | |
Decline to answer | 1 (0.2) | 2 (0.5) | |
Race, n (%) | .47 | ||
White | 226 (55.1) | 232 (59.6) | |
Black or African American | 61 (14.9) | 57 (14.7) | |
Asian American | 16 (3.9) | 14 (3.6) | |
Native Hawaiian or Other Pacific Islander | 3 (0.7) | 2 (0.5) | |
American Indian or Alaska native | 9 (2.2) | 3 (0.8) | |
Multiracial | 58 (14.2) | 54 (13.9) | |
Some other race | 26 (6.3) | 23 (5.9) | |
Do not want to answer | 11 (2.7) | 4 (1.0) | |
Rural,a n (%) | 70 (17.1) | 51 (13.1) | .12 |
Income,b n (%) | .86 | ||
Lower than the average | 122 (29.8) | 110 (28.3) | |
Similar to the average | 213 (52.0) | 200 (51.4) | |
Higher than the average | 61 (14.9) | 62 (15.9) | |
Do not want to answer | 14 (3.4) | 17 (4.4) | |
Sexual identity,c n (%) | |||
Gay | 83 (20.2) | 78 (20.1) | .95 |
Lesbian | 178 (43.4) | 169 (43.4) | .99 |
Bisexual | 172 (42.0) | 170 (43.7) | .62 |
Pansexual | 106 (25.9) | 121 (31.1) | .10 |
Heterosexual | 3 (0.7) | 2 (0.5) | .70 |
Queer | 89 (21.7) | 77 (19.8) | .51 |
Asexual | 9 (2.2) | 8 (2.1) | .89 |
Questioning | 50 (12.2) | 43 (11.1) | .62 |
Unsure | 7 (1.7) | 8 (2.1) | .72 |
Do not want to answer | 0 (0) | (0) 0 | — |
Gender identity, n (%) | .55 | ||
Cisgender female | 406 (99.0) | 385 (99.0) | |
Male to female transgenderd | 1 (0.2) | 0 (0.0) | |
Male to female transgenderd | 0 (0.0) | 1 (0.3) | |
Genderqueer or pangenderd | 0 (0.0) | 1 (0.3) | |
I am unsured | 2 (0.5) | 2 (0.5) | |
Other | 1 (0.2) | 0 (0.0) | |
Do not want to answer | 0 (0) | 0 (0) | |
Ever penile-vaginal sex, n (%) | .99 | ||
No | 279 (68.1) | 263 (67.6) | |
Yes | 130 (31.7) | 125 (32.1) | |
Do not want to answer | 1 (0.2) | 1 (0.3) | |
Penile-vaginal sex in the past 3 mo, n (%) | .75 | ||
No | 342 (83.4) | 319 (82.0) | |
Yes | 67 (16.3) | 68 (17.5) | |
Do not want to answer | 1 (0.2) | 2 (0.5) | |
No. condom-protected vaginal sex acts in the past 3 mo, mean (SD) | 0.8 (5.7) | 1.1 (4.9) | .42 |
Do not want to answer | 0 (0) | 0 (0) | |
Currently on birth control, n (%) | .45 | ||
Yes, to any | 101 (24.6) | 87 (22.4) | |
Birth control pills | .82 | ||
No | 339 (82.7) | 324 (83.3) | |
Yes | 71 (17.3) | 65 (16.7) | |
I don’t know what this is | 0 (0) | 0 (0) | |
Do not want to answer | 0 (0) | 0 (0) | |
The shot | .69 | ||
No | 401 (97.8) | 382 (98.2) | |
Yes | 9 (2.2) | 7 (1.8) | |
I don’t know what this is | 0 (0) | 0 (0) | |
Do not want to answer | 0 (0) | 0 (0) | |
The patch | .62 | ||
No | 405 (98.8) | 385 (99.0) | |
Yes | 4 (1.0) | 2 (0.5) | |
I don’t know what this is | 1 (0.2) | 2 (0.5) | |
Do not want to answer | 0 (0) | 0 (0) | |
The ring | .82 | ||
No | 406 (99.0) | 384 (98.7) | |
Yes | 3 (0.7) | 3 (0.8) | |
I don’t know what this is | 1 (0.2) | 2 (0.5) | |
Do not want to answer | 0 (0) | 0 (0) | |
IUD | .15 | ||
No | 400 (97.6) | 384 (98.7) | |
Yes | 7 (1.7) | 1 (0.3) | |
I don’t know what this is | 3 (0.7) | 3 (0.8) | |
Do not want to answer | 0 (0.0) | 1 (0.3) | |
Implants | .44 | ||
No | 393 (95.9) | 379 (97.4) | |
Yes | 16 (3.9) | 9 (2.3) | |
I don’t know what this is | 1 (0.2) | 1 (0.3) | |
Do not want to answer | 0 (0) | 0 (0) | |
Ever pregnant, n (%) | .50 | ||
No | 388 (94.6) | 369 (94.9) | |
Yes | 15 (3.7) | 13 (3.3) | |
I don’t know | 5 (1.2) | 7 (1.8) | |
Do not want to answer | 0.5% (2) | 0.0% (0) |
Youth Characteristics . | Control (n = 410) . | Intervention (n = 389) . | P . |
---|---|---|---|
Age, mean (SD) | 15.97 (1.2) | 16.14 (1.2) | .051 |
Hispanic ethnicity, n (%) | .25 | ||
No | 300 (73.2) | 302 (77.6) | |
Yes | 109 (26.6) | 85 (21.9) | |
Decline to answer | 1 (0.2) | 2 (0.5) | |
Race, n (%) | .47 | ||
White | 226 (55.1) | 232 (59.6) | |
Black or African American | 61 (14.9) | 57 (14.7) | |
Asian American | 16 (3.9) | 14 (3.6) | |
Native Hawaiian or Other Pacific Islander | 3 (0.7) | 2 (0.5) | |
American Indian or Alaska native | 9 (2.2) | 3 (0.8) | |
Multiracial | 58 (14.2) | 54 (13.9) | |
Some other race | 26 (6.3) | 23 (5.9) | |
Do not want to answer | 11 (2.7) | 4 (1.0) | |
Rural,a n (%) | 70 (17.1) | 51 (13.1) | .12 |
Income,b n (%) | .86 | ||
Lower than the average | 122 (29.8) | 110 (28.3) | |
Similar to the average | 213 (52.0) | 200 (51.4) | |
Higher than the average | 61 (14.9) | 62 (15.9) | |
Do not want to answer | 14 (3.4) | 17 (4.4) | |
Sexual identity,c n (%) | |||
Gay | 83 (20.2) | 78 (20.1) | .95 |
Lesbian | 178 (43.4) | 169 (43.4) | .99 |
Bisexual | 172 (42.0) | 170 (43.7) | .62 |
Pansexual | 106 (25.9) | 121 (31.1) | .10 |
Heterosexual | 3 (0.7) | 2 (0.5) | .70 |
Queer | 89 (21.7) | 77 (19.8) | .51 |
Asexual | 9 (2.2) | 8 (2.1) | .89 |
Questioning | 50 (12.2) | 43 (11.1) | .62 |
Unsure | 7 (1.7) | 8 (2.1) | .72 |
Do not want to answer | 0 (0) | (0) 0 | — |
Gender identity, n (%) | .55 | ||
Cisgender female | 406 (99.0) | 385 (99.0) | |
Male to female transgenderd | 1 (0.2) | 0 (0.0) | |
Male to female transgenderd | 0 (0.0) | 1 (0.3) | |
Genderqueer or pangenderd | 0 (0.0) | 1 (0.3) | |
I am unsured | 2 (0.5) | 2 (0.5) | |
Other | 1 (0.2) | 0 (0.0) | |
Do not want to answer | 0 (0) | 0 (0) | |
Ever penile-vaginal sex, n (%) | .99 | ||
No | 279 (68.1) | 263 (67.6) | |
Yes | 130 (31.7) | 125 (32.1) | |
Do not want to answer | 1 (0.2) | 1 (0.3) | |
Penile-vaginal sex in the past 3 mo, n (%) | .75 | ||
No | 342 (83.4) | 319 (82.0) | |
Yes | 67 (16.3) | 68 (17.5) | |
Do not want to answer | 1 (0.2) | 2 (0.5) | |
No. condom-protected vaginal sex acts in the past 3 mo, mean (SD) | 0.8 (5.7) | 1.1 (4.9) | .42 |
Do not want to answer | 0 (0) | 0 (0) | |
Currently on birth control, n (%) | .45 | ||
Yes, to any | 101 (24.6) | 87 (22.4) | |
Birth control pills | .82 | ||
No | 339 (82.7) | 324 (83.3) | |
Yes | 71 (17.3) | 65 (16.7) | |
I don’t know what this is | 0 (0) | 0 (0) | |
Do not want to answer | 0 (0) | 0 (0) | |
The shot | .69 | ||
No | 401 (97.8) | 382 (98.2) | |
Yes | 9 (2.2) | 7 (1.8) | |
I don’t know what this is | 0 (0) | 0 (0) | |
Do not want to answer | 0 (0) | 0 (0) | |
The patch | .62 | ||
No | 405 (98.8) | 385 (99.0) | |
Yes | 4 (1.0) | 2 (0.5) | |
I don’t know what this is | 1 (0.2) | 2 (0.5) | |
Do not want to answer | 0 (0) | 0 (0) | |
The ring | .82 | ||
No | 406 (99.0) | 384 (98.7) | |
Yes | 3 (0.7) | 3 (0.8) | |
I don’t know what this is | 1 (0.2) | 2 (0.5) | |
Do not want to answer | 0 (0) | 0 (0) | |
IUD | .15 | ||
No | 400 (97.6) | 384 (98.7) | |
Yes | 7 (1.7) | 1 (0.3) | |
I don’t know what this is | 3 (0.7) | 3 (0.8) | |
Do not want to answer | 0 (0.0) | 1 (0.3) | |
Implants | .44 | ||
No | 393 (95.9) | 379 (97.4) | |
Yes | 16 (3.9) | 9 (2.3) | |
I don’t know what this is | 1 (0.2) | 1 (0.3) | |
Do not want to answer | 0 (0) | 0 (0) | |
Ever pregnant, n (%) | .50 | ||
No | 388 (94.6) | 369 (94.9) | |
Yes | 15 (3.7) | 13 (3.3) | |
I don’t know | 5 (1.2) | 7 (1.8) | |
Do not want to answer | 0.5% (2) | 0.0% (0) |
—, not applicable.
Based on the 2013 National Center for Health Statistics Urban-Rural Classification Scheme for Counties.29
Self-appraised.
Multiple response.
Gender identity was assessed during the enrollment call. A small number of youth self-reported a noncisgender identity in the baseline survey. Because these answers were not again assessed for eligibility, they were included in the sample.
Behavioral Outcomes
At RCT end, 5 months postenrollment, 22% of intervention and 19% of control participants reported penile-vaginal sex in the past 3 months; 17% and 13% reported at least 1 condom-protected sex act; and 10% and 12% reported at least 1 condomless protected sex act, respectively. The number of condom-protected sex acts ranged between 0 and 70 for intervention and 0 to 60 for control participants.
Among those who reported penile-vaginal sex in the past 3 months at baseline (ie, sexually active girls), 46% of intervention and 43% of control participants reported at least 1 condom-protected sex act in the past 3 months at intervention end; 32% and 49%, respectively, reported at least 1 condomless protected sex act over the same time period.
As shown in Table 4, the rate of condom-protected sex acts in the past 3 months was significantly higher at intervention end for those in the intervention versus control group (adjusted odds ratio [aOR] = 1.48, P < .001) after adjusting for survey mode, age, and number of condom-protected sex acts at baseline. The magnitude of association was similar when examined among sexually active girls (aOR = 1.64, P < .001). The intervention also was associated with significantly lower rates of condomless sex acts generally (aOR = 0.79, P = .007) and among sexually active girls specifically (aOR = 0.65, P < .001).
Pregnancy Preventive Behavior and Intentions Outcomes at Girl2Girl RCT Intervention End (n = 799)
Pregnancy Preventive Behaviors and Intentions . | Control (n = 410) . | Intervention (n = 389) . | IRR/OR . | 95% CI . | P . | IRR/aOR . | 95% CI . | P . |
---|---|---|---|---|---|---|---|---|
No. condom-protected sex acts in the past 3 mo . | . | . | . | . | . | . | . | . |
All youth (n = 799) mean (SD) | 1.2 (6.0) | 1.4 (5.9) | 1.21 | 1.07–1.37 | .002 | 1.48 | 1.30–1.68 | <.001 |
Youth who have had vaginal sex in the past 3 mo at baseline (n = 135) mean (SD) | 4.7 (11.9) | 5.3 (11.6) | 1.13 | 0.97–1.31 | .13 | 1.64 | 1.40–1.93 | <.001 |
No. condomless sex acts in the past 3 moa | ||||||||
All youth (n = 799) mean (SD) | 0.7 (2.3) | 0.6 (2.1) | 0.83 | 0.70–0.99 | .04 | 0.79 | 0.66–0.94 | .007 |
Youth who have had vaginal sex in the past 3 mo at baseline (n = 135) mean (SD) | 3.5 (4.4) | 2.3 (3.8) | 0.64 | 0.52–0.79 | <.001 | 0.65 | 0.53–0.80 | <.001 |
Currently using birth control, n (%) | ||||||||
All youth (n = 799) | 110 (26.8) | 121 (31.1) | 1.23 | 0.91–1.67 | .18 | 1.60 | 1.08–2.37 | .02 |
Youth who have had vaginal sex in the past 3 mo at baseline (n = 135) | 37 (55.2) | 33 (48.5) | 0.76 | 0.39–1.50 | .44 | 0.98 | 0.41–2.34 | .97 |
Abstaining from penile-vaginal sex in the past 3 mo, n (%) | ||||||||
All youth (n = 799) | 330 (80.5) | 301 (77.4) | 0.83 | 0.59–1.17 | .28 | 0.82 | 0.55–1.23 | .34 |
Youth who have had vaginal sex in the past 3 mo at baseline (n = 135) | 22 (32.8) | 26 (38.2) | 1.27 | 0.62–2.57 | .51 | 1.20 | 0.57–2.55 | .63 |
Pregnancy since program enrollment, n (%) | ||||||||
All youth (n = 799) | 8 (2.0) | 3 (0.8) | 0.39 | 0.10–1.48 | .17 | 0.43 | 0.11–1.70 | .23 |
Youth who have had vaginal sex in the past 3 mo at baseline (n = 135) | 7 (10.5) | 3 (4.4) | 0.40 | 0.10–1.60 | .19 | 0.39 | 0.09–1.73 | .21 |
Intentions to use condoms in the next year, n (%) | ||||||||
All youth (n = 799) | 265 (64.6) | 261 (67.1) | 1.12 | 0.83–1.50 | .46 | 1.09 | 0.79–1.52 | .59 |
Youth who have had vaginal sex in the past 3 mo at baseline (n = 135) | 41 (61.2) | 48 (70.6) | 1.52 | 0.74–3.12 | .25 | 1.54 | 0.72–3.30 | .26 |
Youth who have not had sex (n = 661) | 223 (65.2) | 213 (66.8) | 1.07 | 0.78–1.48 | .67 | 1.04 | 0.72–1.51 | .84 |
Intentions to use birth control in the next year,b n (%) | ||||||||
All youth (n = 568) | 99 (33.0) | 128 (47.8) | 1.86 | 1.32–2.61 | <.001 | 1.93 | 1.31–2.84 | .001 |
Youth who have had vaginal sex in the past 3 mo at baseline (n = 65) | 15 (50.0) | 27 (77.1) | 3.37 | 1.16–9.79 | .03 | 3.25 | 0.99–10.70 | .052 |
Youth who have not had sex (n = 500) | 83 (30.9) | 101 (43.7) | 1.74 | 1.21–2.51 | .003 | 1.87 | 1.24–2.84 | .003 |
Intentions to be abstinent in the next year, n (%) | ||||||||
All youth (n = 799) | 178 (43.4) | 157 (40.4) | 0.88 | 0.67–1.17 | .38 | 0.95 | 0.67–1.35 | .77 |
Youth who have had vaginal sex in the past 3 mo at baseline (n = 135) | 9 (13.4) | 7 (10.3) | 0.74 | 0.26–2.12 | .57 | 0.75 | 0.23–2.42 | .63 |
Youth who have not had sex (n = 661) | 169 (49.4) | 150 (47.0) | 0.91 | 0.67–1.23 | .54 | 0.95 | 0.65–1.38 | .79 |
Pregnancy Preventive Behaviors and Intentions . | Control (n = 410) . | Intervention (n = 389) . | IRR/OR . | 95% CI . | P . | IRR/aOR . | 95% CI . | P . |
---|---|---|---|---|---|---|---|---|
No. condom-protected sex acts in the past 3 mo . | . | . | . | . | . | . | . | . |
All youth (n = 799) mean (SD) | 1.2 (6.0) | 1.4 (5.9) | 1.21 | 1.07–1.37 | .002 | 1.48 | 1.30–1.68 | <.001 |
Youth who have had vaginal sex in the past 3 mo at baseline (n = 135) mean (SD) | 4.7 (11.9) | 5.3 (11.6) | 1.13 | 0.97–1.31 | .13 | 1.64 | 1.40–1.93 | <.001 |
No. condomless sex acts in the past 3 moa | ||||||||
All youth (n = 799) mean (SD) | 0.7 (2.3) | 0.6 (2.1) | 0.83 | 0.70–0.99 | .04 | 0.79 | 0.66–0.94 | .007 |
Youth who have had vaginal sex in the past 3 mo at baseline (n = 135) mean (SD) | 3.5 (4.4) | 2.3 (3.8) | 0.64 | 0.52–0.79 | <.001 | 0.65 | 0.53–0.80 | <.001 |
Currently using birth control, n (%) | ||||||||
All youth (n = 799) | 110 (26.8) | 121 (31.1) | 1.23 | 0.91–1.67 | .18 | 1.60 | 1.08–2.37 | .02 |
Youth who have had vaginal sex in the past 3 mo at baseline (n = 135) | 37 (55.2) | 33 (48.5) | 0.76 | 0.39–1.50 | .44 | 0.98 | 0.41–2.34 | .97 |
Abstaining from penile-vaginal sex in the past 3 mo, n (%) | ||||||||
All youth (n = 799) | 330 (80.5) | 301 (77.4) | 0.83 | 0.59–1.17 | .28 | 0.82 | 0.55–1.23 | .34 |
Youth who have had vaginal sex in the past 3 mo at baseline (n = 135) | 22 (32.8) | 26 (38.2) | 1.27 | 0.62–2.57 | .51 | 1.20 | 0.57–2.55 | .63 |
Pregnancy since program enrollment, n (%) | ||||||||
All youth (n = 799) | 8 (2.0) | 3 (0.8) | 0.39 | 0.10–1.48 | .17 | 0.43 | 0.11–1.70 | .23 |
Youth who have had vaginal sex in the past 3 mo at baseline (n = 135) | 7 (10.5) | 3 (4.4) | 0.40 | 0.10–1.60 | .19 | 0.39 | 0.09–1.73 | .21 |
Intentions to use condoms in the next year, n (%) | ||||||||
All youth (n = 799) | 265 (64.6) | 261 (67.1) | 1.12 | 0.83–1.50 | .46 | 1.09 | 0.79–1.52 | .59 |
Youth who have had vaginal sex in the past 3 mo at baseline (n = 135) | 41 (61.2) | 48 (70.6) | 1.52 | 0.74–3.12 | .25 | 1.54 | 0.72–3.30 | .26 |
Youth who have not had sex (n = 661) | 223 (65.2) | 213 (66.8) | 1.07 | 0.78–1.48 | .67 | 1.04 | 0.72–1.51 | .84 |
Intentions to use birth control in the next year,b n (%) | ||||||||
All youth (n = 568) | 99 (33.0) | 128 (47.8) | 1.86 | 1.32–2.61 | <.001 | 1.93 | 1.31–2.84 | .001 |
Youth who have had vaginal sex in the past 3 mo at baseline (n = 65) | 15 (50.0) | 27 (77.1) | 3.37 | 1.16–9.79 | .03 | 3.25 | 0.99–10.70 | .052 |
Youth who have not had sex (n = 500) | 83 (30.9) | 101 (43.7) | 1.74 | 1.21–2.51 | .003 | 1.87 | 1.24–2.84 | .003 |
Intentions to be abstinent in the next year, n (%) | ||||||||
All youth (n = 799) | 178 (43.4) | 157 (40.4) | 0.88 | 0.67–1.17 | .38 | 0.95 | 0.67–1.35 | .77 |
Youth who have had vaginal sex in the past 3 mo at baseline (n = 135) | 9 (13.4) | 7 (10.3) | 0.74 | 0.26–2.12 | .57 | 0.75 | 0.23–2.42 | .63 |
Youth who have not had sex (n = 661) | 169 (49.4) | 150 (47.0) | 0.91 | 0.67–1.23 | .54 | 0.95 | 0.65–1.38 | .79 |
Sample size for intentions does not equal 799 because 3 people who declined to answer about recent vaginal sex are not included in either category. Models adjusted for survey mode, age, and baseline indicator of outcome of interest (eg, condom use). aIRR, adjusted incident rate ratio; aOR, adjusted odds ratio; IRR, incident rate ratio; OR, odds ratio.
Because of outliers (range: 0–663, SD = 24.2), censored at 10+ acts.
Among those not currently on birth control.
The relative odds of current use of birth control other than condoms was 60% higher in the intervention versus control group (aOR = 1.60, P = .02). Differences were not significant among sexually active girls, however (aOR = 0.98, P = .97).
The relative odds of abstaining from penile-vaginal sex in the past 3 months at intervention end were statistically similar for intervention and control participants generally (aOR = 0.82, P = .34) and sexually active girls specifically (aOR = 1.20, P = .63).
The magnitude of the relative odds of pregnancy between intervention and control participants was clinically meaningful but not statistically significant in general (aOR = 0.43, P = .23) or among sexually active girls (aOR = 0.39, P = .21).
Behavioral Intentions
As shown in Table 4, the relative odds of intending to use birth control among girls who were not currently on birth control were significantly higher for those in the intervention versus control group at intervention end (aOR = 1.93, P = .001). This also was true among sexually active girls (aOR = 3.25, P = .052) and abstinent girls (aOR = 1.87, P = .003). When girls who intended to use birth control were combined with girls currently on birth control, the relative odds of being in the intervention group were significantly higher among all girls (aOR = 2.08, P < .001), as well as among sexually active (aOR = 3.02, 0.04) and abstinent (aOR = 2.10, P < .001) girls specifically (data not shown).
Intentions to use condoms (aOR = 1.09, P = .59) and intentions to be abstinent did not differ by study arm (aOR = 0.95, P = .77).
Sensitivity Analysis
Results were similar when youth who declined to answer an outcome question were dropped rather than coded as failure. Data are available on request.
Discussion
To our knowledge, Girl2Girl is the first pregnancy prevention program developed for and tested among sexual minority girls across the United States and the first comprehensive, technology-based teenage pregnancy prevention program for any group of youth. In this large-scale RCT, outcomes at intervention end suggest that Girl2Girl is associated with increased rates of condom use and increased odds of using other types of contraception. The intervention also appears to be associated with increased intentions to use birth control among girls not on birth control. Although few pregnancies were reported over the 5 months, the intervention group had half the odds of pregnancy versus the control group; given this rare event, the effect size was not statistically significant. Taken together, these findings suggest that Girl2Girl may be associated with multiple pregnancy preventive behaviors, at least in the short-term.
Girl2Girl does not appear to be effective in promoting sexual abstinence or a return to abstinence among recently sexually active girls. This may be in part because the health promotion messages were intentionally sex positive and focused on healthy relationships and use of barriers and testing, rather than solely emphasizing abstinence. Also, other researchers have documented that abstinence-focused interventions appear to have no effect on sexually active girls.30,31 Future research about sex-positive programs that includes sexually experienced and inexperienced youth might consider adding an outcome that reflects self-efficacy to consent to sex when it is wanted and demur to sex when it is not.
Limitations
Given the nature of the intervention, findings may not be generalizable to girls who do not use social media or have cell phones with a limited messaging plan. Moreover, social media advertising was targeted to girls whose profiles indicated they were “interested in” other girls. Therefore, girls who saw the ads were “out” at least on their social media profile. Findings may not be generalizable to those who are not out to others. Additionally, it is impossible to determine if a particular program message was read. This is not unlike school-based programs in which it is unknown whether students are listening to the intervention facilitator. Finally, because of funding uncertainty, surveys at intervention end were collected either via text messaging or online. Aside from potential mode differences, questions were worded slightly differently and, in some cases, referred to different time frames (eg, next 12 months versus next 3 months). To mitigate the potential impact of this, we adjusted for survey mode in multivariate models. Balancing these limitations, it should be noted that the national sample was diverse in terms of race and ethnicity, sexual identity, rural and urban setting, and age. The intervention also was novel in its intervention target (ie, sexual minority girls), delivery mechanism (ie, comprehensive text messages), and scope (ie, across the United States).
Implications
Reviews suggest that text messaging–based interventions can affect and sustain complex health behavior changes across a variety of behaviors, including HIV testing, medication adherence, physical activity, and smoking cessation.32–42 Results here provide reason for optimism that this approach can be effective with adolescent pregnancy prevention as well.
The high program completion rate suggests that sexual minority adolescent girls are willing to receive voluminous amounts of sexual health-related text messages over a relatively long period of time (ie, 5 months). Given the relative cost efficiency and wide reach of text messaging as a delivery mechanism compared with more traditional models such as facilitator-based education,43 researchers may consider using this modality to address other adolescent behavior change efforts as well.
Opportunities for future research are noted. First, it is unknown whether some or all components of the intervention (eg, Text Buddy, G2Genie, level-up questions) meaningfully contributed to behavior change. Understanding the relative contributions of these features could inform the future development of technology-based interventions that seek to include game-like program components. Second, girls of various sexual minority identities were analyzed together. Subsequent research may wish to examine outcomes for lesbian and bisexual girls separately given they differ in their sexual behaviors with girls and boys.17,44 Additionally, it would be useful to explore the optimal length of interventions such as this, as well as the timing of the booster delivery. Other important questions include whether the behavioral changes are sustained over time and if behavioral changes are noted in an effectiveness trial.
Conclusions
Sexual minority girls are significantly more likely to be pregnant during their teenage years compared to heterosexual girls and yet, limited teenage pregnancy prevention programming is available that is tailored to their needs. Findings suggest that Girl2Girl is associated with changes in teenage pregnancy preventive behaviors and behavioral intentions with both sexual minority girls who are having penile-vaginal sex and those who are not, at least in the short-term. The latter are key to a comprehensive public health approach that gives all girls the tools they need to make healthy decisions if, and when, they choose to have sex that could lead to pregnancy.
Acknowledgments
We thank the study participants and research team, particularly Katrina Nardo, Dr Myeshia Price-Feeney, and Desiree Fehmie for their contributions to the study.
This trial has been registered at www.clinicaltrials.gov (identifier NCT03029962).
Deidentified individual participant data will not be made available.
Dr Ybarra made substantial contribution to conception and design, acquisition of data, and analysis and interpretation of data and drafted the article; Ms Prescott made substantial contribution to the acquisition of data and revised the manuscript critically for important intellectual content; Drs Saewyc, Rosario, and Goodenow made substantial contribution to analysis and interpretation of data, provided consultation on the study design, and revised the manuscript critically for important intellectual content; and all authors approved the final manuscript as submitted and agree to be accountable for all aspects of the work.
FUNDING: Research reported in this publication was supported by the Office of Population Affairs (TP2AH000035) and the National Institute of Child Health and Human Development (R01HD095648). The content is solely the responsibility of the authors and does not necessarily represent the official views of the Office of Population Affairs and the National Institutes of Health. Funded by the National Institutes of Health (NIH).
References
Competing Interests
POTENTIAL CONFLICT OF INTEREST: The authors have indicated they have no potential conflicts of interest to disclose.
COMPANION ARTICLE: A companion to this article can be found online at www.pediatrics.org/cgi/doi/10.1542/2020-029801.
FINANCIAL DISCLOSURE: The authors have indicated they have no financial relationships relevant to this article to disclose.
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