From February 2017, information about the work of the MRC/CSO Social and Public Health Sciences Unit, University of Glasgow is available and updated on the University of Glasgow website.

SHARE School Sex Education Trial

This study evaluated whether a specially designed, theoretically-informed, school sex education programme had any effect on young people's sexual risk-taking behaviour and the quality of their sexual relationships SHARE website. It was designed and run in collaboration with Gillian Raab (Napier University, Edinburgh), Charles Abraham (University of Sussex), Graham Hart (SPHSU and now University College London) and Sue Scott (University of Keele). Twenty-five schools in the east of Scotland were allocated, through a balanced randomisation, either to deliver the new programme (called SHARE) or to continue with their existing sex education. Two successive cohorts of S3 pupils (aged 13/14) were recruited in 1996 and 1997 (N = 7,616), and 5,854 participated in the initial follow-up at age 15/16.


At this stage outcome data were collected through self-complete questionnaires in exam conditions, the main outcome being exposure to unsafe sex. Secondary outcomes included non use of contraception, regret of sexual encounters, pressure exerted in sexual encounters, and practical sexual health knowledge. At age 20 NHS data were sought to establish the impact of the intervention on pregnancies and terminations using routinely collected data not subject to reporting bias and only to minimal attrition. The primary endpoint was the cumulative incidence of terminations by age 20.


A process evaluation investigated the extent and quality of delivery of sex education in both programme and comparison schools, the mechanisms through which it might work and contextual factors that might facilitate or impede effectiveness. This was done through teacher questionnaires and interviews, pupil interviews, group discussions and classroom observation.


Process evaluation


Nearly all teachers using the new programme welcomed the SHARE teacher training and preferred the SHARE pack to previous sex education. Two of the three main objectives of the training were fulfilled: making teachers more comfortable and confident to deliver sex education, and preparing them to deliver the SHARE pack. However, the introduction of social-psychologically informed skills based exercises, radically different to those normally followed, was the least successful aspect of the training.



Apart from the teacher training, faithful delivery of the SHARE programme was facilitated by its compatibility with existing Personal and Social Education (PSE) provision and senior management support. It was hindered by competition for curriculum time, brevity of lessons, low priority accorded to PSE by senior management, and teachers' limited experience and ability in using role-play. In six of the 13 intervention schools timetabling and teacher mobility led to non-trained teachers delivering the programme to a few classes. In ten schools nearly all pupils in both cohorts received over 15 of the 20 SHARE sessions, including skills-based lessons on sexual negotiation and condom use. In three schools most of the sample did not receive this ‘minimum package'.


Many pupils were embarrassed in sex education lessons, a problem exacerbated by mixed sex classes. Discomfort inhibited their participation in lessons and sometimes encouraged disruption. However, teachers could play an important role in minimizing the problem by protecting pupils through maintaining firm discipline, by relating to pupils ‘as a friend', by encouraging trust within the classroom, and by making sex education fun.


Outcome evaluation


The interim findings from the SHARE trial showed that, in comparison with conventional sex education, SHARE was evaluated more highly by both pupils and teachers, it increased practical sexual health knowledge, and it slightly improved the quality of sexual relationships, primarily through reduced regret. However, the programme had only an extremely small (positive) effect on four of the many cognitions targeted, and by the mean age of 16 years, 1 month, there was no impact on age of first intercourse, levels of sexual activity, or condom or contraceptive use. The lack of behavioural impact has been confirmed at final follow-up. Using data from the NHS, by the age of 20 there was no significant effect of SHARE on either pregnancies or terminations.


The extent to which teacher-delivered sex education can influence young people's sexual behaviour might already have been reached by conventional provision. In order to have a greater impact on sexual health outcomes for young people, complementary interventions should be considered. The social patterning of conceptions and terminations, evident from the between-school variations in this study, suggests that effective programmes should address fundamental socio-economic divisions in society, while the influence of parenting factors on sexual experience points to strategies involving parents. To date, the most promising programmes have greater scope and duration than school sex education and aim to change future life opportunities for young people.



Parkes A, Strange V, Wight D, Bonell C, Copas A, Henderson M, Buston K, Stephenson J, Johnson A, Allen E, Hart G. Comparison of teenagers' early same-sex and heterosexual behavior: UK data from the SHARE and RIPPLE studies. Journal of Adolescent Health 2011;48:27-35

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Wight D. The effectiveness of school based sex education: what do rigorous evaluations in Britain tell us?. Education and Health 2011;29:67-73

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Henderson M, Wight D, Nixon C, Hart G. Retaining young people in a longitudinal sexual health survey: a trial of strategies to maintain participation. BMC Medical Research Methodology 2010;10

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Parkes A, Wight D, Henderson M, West P. Does early sexual debut reduce teenagers' participation in tertiary education? Evidence from the SHARE longitudinal study. Journal of Adolescence 2010;33:741-54

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Parkes A, Wight D, Henderson M, Stephenson J, Strange V. Contraceptive method at first sexual intercourse and subsequent pregnancy risk: findings from a secondary analysis of sixteen year-old girls from the RIPPLE and SHARE studies. Journal of Adolescent Health 2009;44:55-63

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Buston K, Williamson LM, Hart G. Young women under 16 with experience of sexual intercourse: who becomes pregnant?. Journal of Epidemiology & Community Health 2007;61:221-5

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Henderson M, Wight D, Raab G, Abraham C, Parkes A, Scott S, Hart G. Impact of a theoretically based sex education programme (SHARE) delivered by teachers on NHS registered conceptions and terminations: final results of cluster randomised trial. BMJ 2007;334:133-5

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Wight D, Stephenson J. School-based sex education: evaluating teacher-delivered (SHARE) and peer-delivered (RIPPLE) programmes. In: Baker P, Guthrie K, Hutchinson C, Kane R, Wellings K, editors Teenage pregnancy and reproductive health. London: RCOG Press, 2007:263-74.


Buston K, Wight D. The salience and utility of school sex education to young men. Sex Education 2006;6:135-150


Harper H. The role of research in policy development: school sex education policy in Scotland since devolution [PhD], MRC Social and Public Health Sciences Unit 2005.

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Henderson M, West P, Raab G.. School effects on health behaviours. Education and Health 2005;23:57-60

Parkes A, Henderson M, Wight D. Do sexual health services encourage teenagers to use condoms? A longitudinal study. Journal of Family Planning and Reproductive Health Care 2005;31:271-280

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Wight D. Peer-led sex education did not reduce the proportion of pupils having unprotected first intercourse before age 16: a review. Evidence-based Obstetrics & Gynecology. 2005;7:72-3


Abraham C, Henderson M, Der G. Cognitive impact of a research-based school sex education programme. Psychology & Health 2004;19:689-703

Buston K, Wight D. Pupils' participation in sex education lessons: understanding variation across classes. Sex Education 2004;4:285-301

Parkes A, Wight D, Henderson M. Teenagers' use of sexual health services: perceived need, knowledge and ability to access. Journal of Family Planning and Reproductive Health Care 2004;30:217-24

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Wight D, Dixon H. SHARE: sexual health and relationships - safe, happy and responsible. Education and Health 2004;22:3-7

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Henderson M, Wight D, Raab G. Methodology for balanced randomisation: the SHARE trial. MRC/CSO Social and Public Health Sciences Unit Working Paper no. 11, Glasgow, 2003

Wight D, Buston K. Meeting needs but not changing goals: evaluation of in-service teacher training for sex education. Oxford Review of Education 2003;29:521-543

Wight D, Obasi A. Unpacking the Black Box: the importance of process data to explain outcomes. In: Stephenson J, Imrie J, Bonell C, editors Effective sexual health interventions: issues in experimental evaluation. Oxford: Oxford University Press, 2003:151-166.


Abraham C, Buston K, Hart G, Henderson M, Wight D, Raab G, Scott S. Overview from SHARE sex education project. Young people and sexual health: report of a deliberative seminar, 2002

Buston K, Wight D, Hart G, Scott S. Implementation of a teacher-delivered sex education programme: obstacles and facilitating factors. Health Education Research 2002;17:59-72

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Buston K, Wight D, Hart G. Inside the sex education classroom: the importance of context in engaging pupils. Culture, Health & Sexuality 2002;4:317-335

Buston K, Wight D. The salience and utility of school sex education to young women. Sex Education 2002;2:233-50

Wight D, Raab G, Henderson M, Abraham C, Buston K, Hart G, Scott S. The limits of teacher-delivered sex education: interim behavioural outcomes from a randomised trial. BMJ 2002;324:1430-33

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Buston K, Hart G. Heterosexism and homophobia in Scottish school sex education: exploring the nature of the problem. Journal of Adolescence 2001;24:95-109


Buston K, Wight D, Scott S. Difficulty and diversity: the context and practice of sex education. British Journal of Sociology of Education 2001;22:353-368

Raab G, Butcher I. Balance in cluster randomised trials. Statistics in Medicine 2001;20:351-65


Raab G, Butcher I. Randomisation inference for balanced cluster-randomised trials. Clinical Trials 2001;2:130-140


Wight D, Abraham C. From psycho-social theory to sustainable classroom practice: developing a research-based teacher-delivered sex education programme. Health Education Research 2000;15:25-38

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Wight D, Abraham C, Scott S. Towards a psycho-social theoretical framework for sexual health promotion. Health Education Research 1998;13:317-330

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Wight D. Does sex education make a difference?. Health Education 1997:52-6


Hart GJ, Wight D. Ethical issues in setting up a randomised controlled trial of health education for children: the case of teacher-led sex education in Scotland. In: Oakley A, Roberts H, editors Evaluating social interventions. London: Barnardos, 1996:66-81.

External Collaborators


  • SHARE Sexual Health and Relationships: a specially-designed school sex education programme, as well as the RCT that evaluated it
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