Vicki Strange

Process evaluation in randomised controlled trials of complex interventions

Most randomised controlled trials focus on outcomes, not on the processes involved in implementing an intervention. Using an example from school based health promotion, this paper argues that including a process evaluation would improve the science of many randomised controlled trials

Pupil-led sex education in England (RIPPLE study): cluster-randomised intervention trial

BACKGROUND Improvement of sex education in schools is a key part of the UK governments strategy to reduce teenage pregnancy in England. We examined the effectiveness of one form of peer-led sex education in a school-based randomised trial of over 8000 pupils. METHODS 29 schools were randomised to either peer-led sex education (intervention) or to continue their usual teacher-led sex education (control). In intervention schools, peer educators aged 16-17 years delivered three sessions of sex education to 13-14 year-old pupils from the same schools. Primary outcome was unprotected (without condom) first heterosexual intercourse by age 16 years. Analysis was by intention to treat. FINDINGS By age 16 years, significantly fewer girls reported intercourse in the peer-led arm than in the control arm, but proportions were similar for boys. The proportions of pupils reporting unprotected first sex did not differ for girls (8.4% intervention vs 8.3% control) or for boys (6.2% vs 4.7%). Stratified estimates of the difference between arms were -0.4% (95% CI -3.7% to 2.8%, p=0.79) for girls and -1.4% (-4.4% to 1.6%, p=0.36) for boys. At follow-up (mean age 16.0 years [SD 0.32]), girls in the intervention arm reported fewer unintended pregnancies, although the difference was borderline (2.3% vs 3.3%, p=0.07). Girls and boys were more satisfied with peer-led than teacher-led sex education, but 57% of girls and 32% of boys wanted sex education in single-sex groups. INTERPRETATION Peer-led sex education was effective in some ways, but broader strategies are needed to improve young peoples sexual health. The role of single-sex sessions should be investigated further.

Assessment of generalisability in trials of health interventions: suggested framework and systematic review

Most evaluations of new treatments use highly selected populations, making it difficult to decide whether they would work elsewhere. Systematic evaluation and reporting of applicability is required

What do young people want from sex education? The results of a needs assessment from a peer-led sex education programme.

This paper presents data on the need for sexual health information and advice of 4353 students aged 13/14 years in 13 English secondary schools. Data were collected by peer educators as part of a sex education programme, and through a questionnaire survey administered by researchers. Data illustrate young peoples need for concrete information and advice on issues related to physical development and puberty; transmission of sexually transmitted diseases; accessing and using condoms and other contraception; using sexual health services; managing relationships and dealing with jealousy, love and sexual attraction; how people have sex; sexual pleasure; masturbation; and homosexuality. Differences between the concerns and interests raised by young people and current UK guidance on sex and relationships education are examined, and the implications of these findings for designing future policy and effective school based sex education programmes are discussed. The paper highlights some of the wider social norms around sex and sexuality that influence young peoples understanding and sexual behaviour, and the importance of addressing these within sex education is noted. Factors influencing the processes of expressing and assessing needs are explored.

Health outcomes of youth development programme in England: prospective matched comparison study

Objective To evaluate the effectiveness of youth development in reducing teenage pregnancy, substance use, and other outcomes. Design Prospective matched comparison study. Setting 54 youth service sites in England. Participants Young people (n=2724) aged 13-15 years at baseline deemed by professionals as at risk of teenage pregnancy, substance misuse, or school exclusion or to be vulnerable. Intervention Intensive, multicomponent youth development programme including sex and drugs education (Young People’s Development Programme) versus standard youth provision. Main outcome measures Various, including pregnancy, weekly cannabis use, and monthly drunkenness at 18 months. Results Young women in the intervention group more commonly reported pregnancy than did those in the comparison group (16% v 6%; adjusted odds ratio 3.55, 95% confidence interval 1.32 to 9.50). Young women in the intervention group also more commonly reported early heterosexual experience (58% v 33%; adjusted odds ratio 2.53, 1.09 to 5.92) and expectation of teenage parenthood (34% v 24%; 1.61, 1.07 to 2.43). Conclusions No evidence was found that the intervention was effective in delaying heterosexual experience or reducing pregnancies, drunkenness, or cannabis use. Some results suggested an adverse effect. Although methodological limitations may at least partly explain these findings, any further implementation of such interventions in the UK should be only within randomised trials.

The Quality of Young People's Heterosexual Relationships: A Longitudinal Analysis of Characteristics Shaping Subjective Experience

CONTEXT Research on young peoples sexual relationships often overlooks subjective experiences and enjoyment. Perceived quality of sexual relationships may be related to gender, background characteristics, circumstances of first intercourse and subsequent sexual history. METHODS Longitudinal data from 13-16-year-olds who participated in randomized trials of school sex education in either Scotland (N=5,356) or England (N=6,269) were used to examine young peoples subjective experiences of heterosexual relationships. Logistic regression models tested for associations between selected variables and pressure and regret at first intercourse, pressure and enjoyment at most recent intercourse, and three measures of relationship quality. RESULTS Of the 42% of youth who reported having had sex by follow-up, most assessed their first and most recent sexual relationships positively. Greater proportions of females than of males felt pressure at first sexual intercourse (19% vs. 10%), regretted their first time (38% vs. 20%) and did not enjoy their most recent sex (12% vs. 5%). Younger age at first sex was an important correlate of partner pressure and regret at first intercourse (odds ratios, 2.0 each, for those 13 or younger vs. 15-16-year-olds). Negative experiences were associated with less control (e.g., feeling pressure, being drunk or stoned, and not planning sex) and with less intimacy (e.g., sex with a casual partner and less frequent sex). Background social characteristics had limited influence compared with circumstances of first intercourse and subsequent sexual history. CONCLUSION Most young people evaluated their early sexual experiences positively. The quality of relationships was enhanced by better communication and greater physical intimacy. For a vulnerable minority, however, early sexual experiences were negative. They could be protected by delaying first intercourse, restricting sexual activity to established relationships and learning skills to improve control in sexual encounters.

Using random allocation to evaluate social interventions: Three recent UK examples

Although widely accepted in medicine and health services research, randomized controlled trials (RCTs) are often viewed with hostility by social scientists, who cite a variety of reasons as to why this approach to evaluation cannot be used to research social interventions. This article discusses the three central themes in these debates, which are those of science, ethics, and feasibility. The article uses three recent U.K. trials of social interventions (day care for preschool children, social support for disadvantaged families, and peer-led sex education for young people) to consider issues relating to the use of random allocation for social intervention evaluation and to suggest some practical strategies for the successful implementation of “social” RCTs. The article argues that the criteria of science, ethics, and feasibility can and should apply to social intervention trials in just the same way as they do to clinical trials.

Effect of social exclusion on the risk of teenage pregnancy: development of hypotheses using baseline data from a randomised trial of sex education

Study objective: The UK government argues that “social exclusion” increases risk of teenage pregnancy and that educational factors may be dimensions of such exclusion. The evidence cited by the government is limited to reporting that socioeconomic disadvantage and educational attainment influence risk. Evidence regarding young people’s attitude to school is not cited, and there is a lack of research concerning the UK. This paper develops hypotheses on the relation between socioeconomic and educational dimensions of social exclusion, and risk of teenage pregnancy, by examining whether dislike of school and socioeconomic disadvantage are associated with cognitive/behavioural risk measures among 13/14 year olds in English schools. Design: Analysis of data from the baseline survey of a study of sex education. Setting and participants: 13/14 year old school students from south east England. Main results: The results indicate that socioeconomic disadvantage and dislike of school are associated with various risk factors, each with a different pattern. Those disliking school, despite having comparable knowledge to those liking school, were more likely to have sexual intercourse, expect sexual intercourse by age 16, and expect to be parents by the age of 20. For most associations, the crude odds ratios (ORs) and the ORs adjusted for the other exposure were similar, suggesting that inter-confounding between exposures was limited. Conclusions: It is hypothesised that in determining risk of teenage pregnancy, the two exposures are independent. Those disliking school might be at greater risk of teenage pregnancy because they are more likely to see teenage pregnancy as inevitable or positive.

Contraceptive method at first sexual intercourse and subsequent pregnancy risk: findings from a secondary analysis of 16-year-old girls from the RIPPLE and SHARE studies.

Purpose Existing failure rate studies indicate that typical use of oral contraception (OC) results in fewer unplanned pregnancies than condom use, even among teenagers. However, comparative data on pregnancy risk associated with different contraceptive methods are lacking for younger teenagers starting their first sexual relationship. This study examined associations between contraceptive method at first intercourse and subsequent pregnancy in 16-year-old girls. Methods Six thousand three hundred forty-eight female pupils from 51 secondary schools completed a questionnaire at mean age 16 years; 2,501 girls reported sexual intercourse. Logistic regression (N = 1952) was used to model the association of contraceptive method at first intercourse with pregnancy. Results At first intercourse (median age 15 years) 54% reported using condoms only, 11% dual OC and condoms, 4% OC only, 4% emergency contraception, and 21% no effective method. Method used was associated with a similar method at a most recent intercourse. One in 10 girls reported a pregnancy. When compared to use of condoms only, greater pregnancy risk was found with no effective method (odds ratio [OR] 2.97, 95% confidence interval [CI] 2.12–4.15) or OC only (OR 2.44, 95% CI 1.29–4.60). Pregnancy risk for dual use and emergency contraception did not differ from that for condoms only. Both significant effects were partially attenuated by adjusting for user characteristics and sexual activity. Conclusions Young teenagers may use OC less efficiently than condoms for pregnancy prevention. The characteristics of those using OC-only confirm vulnerability to unintended pregnancy, and suggest that alternative contraceptive strategies should be considered for these young women.

Promoting critical consciousness and social mobilization in HIV/AIDS programmes: lessons and curricular tools from a South African intervention

The development of critical consciousness is seen as a key stage in communities increasing levels of dialogue about priority problems and effecting structural change for health. However, relatively little research identifies concrete methods for programmes to build critical consciousness. We examined how a South African structural intervention used critical consciousness as a tool for prevention of intimate partner violence and HIV infection. We collected qualitative data in the form of in-depth interviews with managers, trainers, and participants of the Intervention with Microfinance for AIDS and Gender Equity intervention (IMAGE) in rural South Africa. The data were analysed through a coding structure developed in QSR NVivo. We draw practical lessons from IMAGE to guide other HIV programmes aiming to promoting critical consciousness and social mobilization. This research suggests that specific curricular tools can work towards critical consciousness and that mobilization efforts in future programmes can be strengthened by including individual and collective efforts by participants.