Table 1

Summary of studies included in the review

Study	CASP score out of 10	Country where study undertaken	Population and setting	Method/Data gathering	Aims/Objectives	Key findings
Glikman and Elkayam27	8	Israel	Students enrolled in various departments of a teacher-education college (n=264) Participants’ mean age was 31.6 years	Quantitative Used surveys— questionnaire	To understand the beliefs of college students on the importance of discussing the issue of sexual orientation with pupils, and in different educational settings.	School counsellors were considered to be the most appropriate figure to discuss sexual orientation with students. Having witnessed homophobic behaviour enhanced the importance of education around this topic. Education students are not well informed on the subject of sexual orientation, either in terms of general knowledge or the tools available to them.
Donovana and Hester31	7	UK	Four focus groups with lesbians, gay men, heterosexual women and men; and 67 interviews with heterosexual women and men, and those with experience of same-sex relationships regardless of how they defined their sexuality	Multimethod research project Nationwide survey— followed by focus groups and Interviews	To compare love and violence in heterosexual and same-sex relationships.	There are a limited number of places where young people can learn about relationships. Young people thinking about exploring alternate sexualities require inclusion in sex and relationship education. Need to focus on ideas, beliefs and expectations of love, care, equality, power and intimacy regardless of gender and sexuality.
Mustanski et al 34	5.5	USA (online)	LGBTQI+ youth aged16–20 years (n=202)	Mixed methods Pretest survey Intervention 2 weeks later—post-test survey	To assess the feasibility, acceptability and initial efﬁcacy of an innovative online sexual health promotion programme tailored for LGBTI+ youth.	Participants reported learning more in this online programme than in school-based sex education. Most improved areas of learning reported were in relation to sexual functioning, HIV and STIs and contraceptives.
Buston and Hart30	7	Scotland	25 schools (non-denominational) co-educational state schools 60 lessons, teachers (n=173), pupils (n=7630)	Multimethod evaluative study SHARE (Sexual Health and Relationships: Safe, Happy and Responsible) programme delivered over 3-year period (intervention) Or Sex education ‘as usual’ (control)	To establish if a specifically designed teacher led sex education programme would reduce sexual risk taking.	Heterosexism in school sex education does exist. Teachers report not having the language to discuss inclusive sex and sexuality education. Constraining factors to including LGBT in sex education identified at both school and societal level. Teachers own values prevent them from delivering non-heterosexist sex education.
Rhodes33	6	USA (online)	Male chat room users (n=619) Web address and chat room name not published to protect participant identity	Mixed method Intervention 6 hours per day in chat group Chat transcripts analysed and coded for themes Demographic data analysed using SPSSStatistics for Windows, Version 23.0.	To explore an online intervention to reduce sexual risk in a chatroom frequented by men who have sex with men (MSM).	Many men expressed interest in sexual risk reduction information. Chatters comfortable asking questions due to anonymity of online chatroom. Health educator was able to provide information on testing locations. Information sought from chatters in relation to: coming out, youth resources, STI screening and condom use.
Hillier and Mitchell29	9	Australia	Same-sex-attracted youth (n=1749) aged 14–21 years	A self-complete survey either online or in printed format Analysed Quantitative using SPSS Qualitative was coded in Excel	To examine whether same-sex-attracted young people are being exposed to appropriate and relevant sex education at school, and if they are not whether it is necessary that sex education be inclusive of sexual difference.	Many of these youth were sexually active at an earlier age than their heterosexual peers. They were five times more likely to report having been diagnosed with an STI than their heterosexual peers. Accurate knowledge about STIs and pregnancy is needed.
Gowen and Winges-Yanez16	9	Oregon, USA	LGBTQI+ participants (n=30) in two LGBTI youth organisations in Oregon	5 semi-structured focus groups Digitally recorded and transcribed for analysis and coded into themes	To examine perspectives of LGBTQI+ youth on their experiences with school-based sexuality education in order to create a framework of LGBTI+Q inclusive sexuality education.	Current sexuality education is very exclusive of LGBTQ youth. Participants wish to experience discussions regarding gender and sexual orientation in order to feel directly acknowledged. No part of the existing curriculum was suggested for subtraction, only some additions and reframing of current materials was proposed.
Baams et al 26	7	Utrecht, The Netherlands	Dutch adolescents (n=601) from six different high schools in grades 10–12 Representing urban, suburban and rural areas	3 wave longitudinal research project The first wave was conducted in Fall 2014, followed by two subsequent measurements after 4 and 8 months This study focuses on the first and third measurement waves	To examine whether the content or extensiveness of sexuality education at the beginning of the school year is related to a decrease in LGBTI+Q name-calling and an increase in the willingness to intervene when witnessing LGBTI+Q name-calling at the end of the school year.	Sexual orientation and gender are rarely covered in sexuality education. There is a need to cover resources and how to access services in sexuality education. Teachers are believed to feel inadequate to teach about sexual diversity.
MacMaster et al 20	4	California, USA	Asian and Pacific Islander MSM in Santa Clara County, California. Number of participants and demographic data was not provided	Qualitative chat room discussions	To test the impact of an internet-based outreach to ‘high-risk’ MSM living in Santa Clara County.	Successfully demonstrated the feasibility and impact of an internet-based programme to reach often overlooked at risk populations. Programme resulted in 46 referrals for HIV testing.
Formby23	9	England, UK	Findings from three small studies drawn together LGBTI+ youth (n=375) aged 13–23 years	Qualitative Self-completion surveys and/or in-depth interviews/focus groups	To examine inﬂuences on sexual activity, conceptualisations/understandings of sexual health and ‘safe sex’, and expectations in relation to safer sex.	Young people would like discussion and information on same sex relationships in SRE. Ways to improve provision include well-informed external speakers. Alcohol and drug use was a factor in sexual decision making. There is a need for appropriate sexual health information, and access to safer-sex supplies. Internet key to accessing sexual health information.
Lindroth et al 32	8	Sweden	Descriptive statistics from web-based survey (n=796) and qualitative interview study with transgender people (n=20) Total n=816	Mixed methods Descriptive statistics from a previous web-based survey and previous qualitative interview study with transgender people were combined	To explore and describe holistic sexual health and sexual health determinants among transgender people in Sweden.	Not being able to fully live sexually as one wishes, and being dissatisfied with one’s sex life have implications for everyday life. Access to gender confirming operations is described as a vital component for sexual health. Feelings of anxiety, uncertainty or fear in sexual situations hinders sexual health. More than one-third reported not knowing where one can be treated with respect while getting tested for HIV and other STIs.
Sherlock22	5	Sweden and Ireland	Sexuality education professionals in Ireland (n=17) and Sweden (n=17)	Qualitative Interviews	To examine the sociopolitical inﬂuences on sexuality education in Sweden and Ireland.	Both countries complain of sparse teacher training, curriculum updates and programme reviews. More research, discussions and engagements with sexuality education issues are needed in Ireland and Sweden. Policy barriers (religious) and gaps in curricular implementation require urgent attention and funding in both countries.
DeHaan et al 35	8	USA (online)	LGBTI+ youth (n=32) Aged 16–24 years	60–90 min semi-structured interviews Transcribed into EthnoNotes a mixed methods analysis programme	To investigate the interplay between online and ofﬂine explorations of multiple dimensions of sexual health, which include sexually transmitted infections (STIs), sexual identities, romantic relationships and sexual behaviour.	LGBT population more likely to turn to the internet for information and connection. Internet is the main source of information. Youth actively searched online for offline services such as testing, doctors and LGBT sensitive services. Youths open to receiving information online.
Hobaica and Kwon18	8	Washington, USA	N=12 people from sexual minorities (SM) SM included: lesbian, gay, bisexual, queer, pansexual, demisexual and asexual	Qualitative study, 40–90 minsemi-structured interviews	To explore SM experiences of sexual health education.	Heteronormative sex education may contribute to poor physical health outcomes for SMs. Participants reported that inclusive sex education would concurrently benefit heterosexual students. Inclusive curricula would increase self-esteem and confidence for SM students. Importance of incorporating role models of various identities into curriculums to reduce negative stigma.
Riggs and Bartholomaeus21	9	Adelaide, Australia	Seven videos by transgender young people (n=5) aged 18–25 years	Analyse discussions of intimacy from the perspectives of transgender young people as narrated in a sample of YouTube videos	To examine what transgender young people would like to see covered in sexuality education.	Sex education needs to address sexuality and gender, extending beyond heterosexual norms. As potential friends, classmates and intimate partners of their transgender peers, cisgender students should be educated in an inclusive manner. Educators and sex education programmes must develop ways of talking about bodies and intimacy with a more diverse approach to understanding gender and embodiment.
Abbott et al 14	8	UK	Eightsemi-structured interviews with relationship and sexuality education teachers (n=2)	Qualitative discursive psychological approach used to analyse interview data	An analysis of how teachers uphold heteronormative sex and relationship education.	Teachers reported those who engage in same sex relationships as isolated. Teachers require regular updating of their knowledge around sex, sexuality and issues affecting young people. Teachers need to be made aware of ways in which they can promote inclusivity.
Hoefer and Hoefer19	7	Texas, USA	N=16 students at a Southwestern University who identified as one or more of the following: female, LGBT or person of colour	Qualitative recorded in-person interviews	To examine the impact of abstinence-only sex education curricula.	Particularly prevalent were messages in this education about women, LGBTQ and sex as shameful and scary. These messages left long-lasting impacts on the way participants felt about themselves, their peers and sexuality. Refusal to discuss LGBTQ issues allowed students to move into adulthood feeling confused and guilty.
Haley et al 17	9	Seattle, USA	Transgender and non-binary (TNB) youth (n=11), parents (n=5) and healthcare affiliates (n=5) from Seattle Children’s gender clinic	Qualitative In-depth interviews analysed using thematic analysis	To use insights of TNB youth, parents of TNB youth and healthcare affiliates to understand deficits in sex education experienced by TNB youth.	TNB youth have unique sex education needs that are not commonly covered in standard sex education. Inadequate information leads TNB youth to seek information from potentially inaccurate, unfiltered sources. Negative outcomes had been experienced by many participants including STIs, pregnancy, unsafe binding, unsanitary sex toy use and shame about their bodies and sexual desires. Sex education needs to be inclusive and may need reframing to be transinclusive.
Cahill et al 15	9	USA	Youth serving professionals including: adolescent health providers, school nurses, youth workers, and school educators (n=34)	Qualitative study	To explore barriers and facilitators that professionals face in delivering HIV preventive services and education.	Educational materials should be free, disseminated in a variety of formats (online and downloadable) and evidence based. Tools should be specifically designed for youth and should involve peer education and use popular technologies. Training programme needs to include basics about sexual orientation, gender identity and approaches for HIV risk reduction to enable the provision of affirming services.
Pampati et al 36	9	International	Sexual and gender minority youth (with a mean age of between 10 and 24 years)	Systematic review	To synthesise the diverse body of literature on sexual and gender minority youth and sexual health education.	A synthesis of the characteristics of inclusive sexual health education are detailed. Interventions in sexual health education covered a wide range of topics including HIV, STI’s, risk reduction approaches, prosocial skills. Content should be delivered via relatable individuals is crucial in terms of programme delivery.
Andrzejewski et al 37	8	USA	Websites with sexual and reproductive health content for adolescents and young adults	Systematic Google search	To characterise the strengths and weaknesses of sexual and gender minority related messages from websites that address sexual and reproductive health for young people.	Websites regularly use aggregate terms to define the sexual health needs of all minority populations of constructs. Websites and messages sometimes conflate the constructs of sexual orientation and gender identity. Few websites discuss topics of particular relevance to sexual and gender minority youth such as Pre-Exposure Prophylaxis (PrEP) andPost Exposure Prophylaxis (PEP); however, the majority include information on pregnancy.
Nelson et al.28	6	USA	Adolescent males interested in sex with males aged 14–17 years, cisgender, self-identify as gay, bisexual or are sexually attracted to males, reside in the USA and had an email address	Quantitative Study	To determine where adolescent males interested in sex with males receive sexual health information, clarify their preferences and explore relations with sexual behaviour.	Adolescents regularly (>66%) used websites for information regarding sex. Group required information on having safe and comfortable anal sex, types of sex, condoms, lubrication. Sexual health information should include visual representation, communication techniques, types of sexual behaviours and the influence of pornography.
Formby and Donovan24	9	England	Young people aged 14–25 years who identified as a gender or sexual minority	Qualitative study	To examiner what LGBT inclusive sex and relationships education should address in practice.	Young people reported varied experiences of sex and relationship education and the settings which they received the education were sometimes perceived as inherently homophobic. Pornography was sometimes used as a form of sex education by LGBT young people. Peer education was seen as a potentially useful resource when considering sex and relationship education.
Narushima et al 25	8	Canada	Young people involved in the Youth Engagement Project in Canada	Qualitative study	To explore the perspectives and experiences of youth to identify the key elements of innovation, strength-focused and youth-driven sexual health education that will reduce sexual health disparities among marginalised youth.	Young people noted the importance of finding the LGBT community to gain acceptance. Sex education was noted as too biology based and heteronormative. Sex education needed to include sexual orientation, gender identity and relationships. Support and discussion for parents and teachers is important to facilitate better education and support for young people.

CASP, Critical Appraisal Skills Programme; LGBTQI+, Lesbian, Gay, Bisexual, Transgendeer, Queer, Intersex.