Exploring views of members of the public and policymakers on the acceptability of population level dietary and active-travel policies: a qualitative study.

BACKGROUND: There is limited evidence on what shapes the acceptability of population level dietary and active-travel policies in England. This information would be useful in the decision-making process about which policies should be implemented and how to increase their effectiveness and sustainability. To fill this gap, we explored public and policymakers' views about factors that influence public acceptability of dietary and active-travel policies and how to increase public acceptability for these policies. METHODS: We conducted online, semi-structured interviews with 20 members of the public and 20 policymakers in England. A purposive sampling frame was used to recruit members of the public via a recruitment agency, based on age, sex, socioeconomic status and ethnicity. Policymakers were recruited from existing contacts within our research collaborations and via snowball sampling. We explored different dietary and active-travel policies that varied in their scope and focus. Interviews were transcribed verbatim and analysed using thematic reflexive analysis with both inductive and deductive coding. RESULTS: We identified four themes that informed public acceptability of dietary and active-travel policies: (1) perceived policy effectiveness, i.e., policies that included believable mechanisms of action, addressed valued co-benefits and barriers to engage in the behaviour; (2) perceived policy fairness, i.e., policies that provided everyone with an opportunity to benefit (mentioned only by the public), equally considered the needs of various population subgroups and rewarded 'healthy' behaviours rather than only penalising 'unhealthy' behaviours; (3) communication of policies, i.e., policies that were visible and had consistent and positive messages from the media (mentioned only by policymakers) and (4) how to improve policy support, with the main suggestion being an integrated strategy addressing multiple aspects of these behaviours, inclusive policies that consider everyone's needs and use of appropriate channels and messages in policy communication. CONCLUSIONS: Our findings highlight that members' of the public and policymakers' support for dietary and active-travel policies can be shaped by the perceived effectiveness, fairness and communication of policies and provide suggestions on how to improve policy support. This information can inform the design of acceptable policies but can also be used to help communicate existing and future policies to maximise their adoption and sustainability.

Whole-school interventions promoting student commitment to school to prevent substance use and violence: a systematic review.

OBJECTIVES: Whole-school interventions that promote student commitment to school are a promising modality to reduce health inequalities through school-level change; however, evidence for the effectiveness of these interventions in improving policy-relevant health outcomes, such as substance use and violence, has not been comprehensively synthesised. STUDY DESIGN: This was a systematic review and meta-analysis. METHODS: We searched 20 databases and a range of other sources to identify randomised trials meeting our intervention definition and reporting substance use and violence outcomes. Extracted effect estimates were meta-analysed using robust variance estimation with random effects, separating effects <1 year from baseline and effects at or more than 1 year from baseline. RESULTS: We included 18 evaluations with varying risk of bias. Pooled effects suggested significant impacts on short-term (odds ratio [OR] = 0.85, 95% confidence interval [CI] 0.76, 0.96) and long-term (OR = 0.79, 95% CI 0.65, 0.98) violence perpetration, short-term (OR = 0.84, 95% CI 0.72, 0.98) and long-term (OR = 0.85, 95% CI 0.73, 0.99) violence victimisation, and short-term (OR = 0.83, 95% CI 0.70, 0.97) and long-term (OR = 0.79, 95% CI 0.62, 0.998) substance use outcomes, with effects relatively stable between short-term and long-term analyses. Stratifying substance use meta-analyses by type (e.g. smoking, alcohol) did not impact results. All meta-analyses had substantial heterogeneity. CONCLUSION: Although diverse in content, interventions appear effective with respect to the review outcomes and as a form of universal prevention. Future research should consider contextual contingencies in intervention effectiveness, given considerable policy and practice interest in these interventions and the need to support schools in effective decision-making as to intervention choice.

Statistical and agent-based modelling of the transmissibility of different SARS-CoV-2 variants in England and impact of different interventions.

The English SARS-CoV-2 epidemic has been affected by the emergence of new viral variants such as B.1.177, Alpha and Delta, and changing restrictions. We used statistical models and the agent-based model Covasim, in June 2021, to estimate B.1.177 to be 20% more transmissible than the wild type, Alpha to be 50-80% more transmissible than B.1.177 and Delta to be 65-90% more transmissible than Alpha. Using these estimates in Covasim (calibrated 1 September 2020 to 20 June 2021), in June 2021, we found that due to the high transmissibility of Delta, resurgence in infections driven by the Delta variant would not be prevented, but would be strongly reduced by delaying the relaxation of restrictions by one month and with continued vaccination. This article is part of the theme issue 'Technical challenges of modelling real-life epidemics and examples of overcoming these'.

Is being a victim of bullying or cyberbullying in secondary school associated with subsequent risk-taking behavior in adolescence? A longitudinal study in secondary schools.

INTRODUCTION: Neurobiological and social changes in adolescence can make victims of bullying more susceptible to subsequent impulsive behavior. With the high prevalence of bullying in schools and rise in cyberbullying in the United Kingdom, it is important that the health impacts of bullying victimization, including on risk-taking, are understood. Our study aims to investigate whether bullying/cyberbullying victimization is associated with subsequent health risk-taking behavior in adolescence. Risk-taking behavior includes electronic cigarette and cigarette smoking, alcohol consumption, illicit drug use, early sexual debut, weapon carrying, damaging property, and setting fire. METHODS: A secondary quantitative analysis of data from 3337, English, secondary school students in the control arm of the INCLUSIVE trial, constituting an observational cohort. Bullying victimization was measured at baseline (age 11/12 years) using the gatehouse bullying scale and a separate question on cyberbullying victimization. Logistic regression was used to test for an association between bullying/cyberbullying victimization at baseline and risk-taking behavior at 36 months, adjusting for baseline risk-taking behavior and other potential confounders, and accounting for school clustering. RESULTS: There was strong evidence (p ≤ .02) for a positive dose-responsive association between being bullied at baseline and nearly all risk-taking behavior at follow-up. Although there was no evidence for an association between being bullied at baseline and weapon carrying (p = .102), there was evidence for a positive association between being cyberbullied at baseline and weapon carrying (p = .036). CONCLUSIONS: It is plausible that bullying/cyberbullying victimization increases the likelihood of subsequent risk-taking behavior in adolescence. Policy options should focus on implementing evidence-based antibullying school interventions.

HIV self-testing intervention experiences and kit usability: results from a qualitative study among men who have sex with men in the SELPHI (Self-Testing Public Health Intervention) randomized controlled trial in England and Wales.

OBJECTIVES: SELPHI (HIV Self-Testing Public Health Intervention) is the largest randomized controlled trial (RCT) of HIV self-testing (HIVST) in a high-income setting to date, and has recruited 10 000 men who have sex with men (cis- and transgender) and transgender women who have sex with men. This qualitative substudy aimed to explore how those utilizing self-tests experience HIVST and the implications for further intervention development and scale-up. This is the first qualitative study in Europe investigating experiences of HIVST among intervention users, and the first globally examining the experience of using blood-based HIVST. METHODS: Thirty-seven cisgender MSM SELPHI participants from across England and Wales were purposively recruited to the substudy, in which semi-structured interviews were used to explore testing history, HIVST experiences and intervention preferences. Interviews were audio-recorded, transcribed and analysed through a framework analysis. RESULTS: Men accessed the intervention because HIVST reduced barriers related to convenience, stigma and privacy concerns. Emotional responses had direct links to acceptability. Supportive intervention components increased engagement with testing and addressed supportive concerns. HIVST facilitated more frequent testing, with the potential to reduce sexually transmitted infection (STI) screening frequency. Substudy participants with an HIV-positive result (n = 2) linked to care promptly and reported very high acceptability. Minor adverse outcomes (n = 2; relationship discord and fainting) did not reduce acceptability. Ease of use difficulties were with the lancet and the test processing stage. CONCLUSIONS: Intervention components shaped acceptability, particularly in relation to overcoming a perceived lack of support. The intervention was broadly acceptable and usable; participants expressed an unexpected degree of enthusiasm for HIVST, including those with HIV-positive results and individuals with minor adverse outcomes.

Does integrated academic and health education prevent substance use? Systematic review and meta-analyses.

BACKGROUND: Prevention of substance (alcohol, tobacco, illegal/legal drug) use in adolescents is a public health priority. As the scope for school-based health education is constrained in school timetables, interventions integrating academic and health education have gained traction in the UK and elsewhere, though evidence for their effectiveness remains unclear. We sought to synthesize the effectiveness of interventions integrating academic and health education for the prevention of substance use. METHODS: We searched 19 databases between November and December 2015, among other methods. We included randomized trials of interventions integrating academic and health education targeting school students aged 4-18 and reporting substance use outcomes. We excluded interventions for specific health-related subpopulations (e.g., children with behavioural difficulties). Data were extracted independently in duplicate. Outcomes were synthesized by school key stage (KS) using multilevel meta-analyses, for substance use, overall and by type. RESULTS: We identified 7 trials reporting substance use. Interventions reduced substance use generally in years 7-9 (KS3) based on 5 evaluations (d = -0.09, 95% CI [-0.17, -0.01], I2  = 35%), as well as in years 10-11 (KS4) based on 3 evaluations (-0.06, [-0.09, -0.02]; I2  = 0%). Interventions were broadly effective for reducing specific alcohol, tobacco, and drug use in both KS groups. CONCLUSIONS: Evidence quality was highly variable. Findings for years 3-6 and 12-13 could not be meta-analysed, and we could not assess publication bias. Interventions appear to have a small but significant effect reducing substance use. Specific methods of integrating academic and health education remain poorly understood.

Conceptualizing Sexual Wellbeing: A Qualitative Investigation to Inform Development of a Measure (Natsal-SW).

Despite increasing scientific and policy interest in sexual wellbeing, it remains poorly conceptualized. Many studies purporting to measure it instead measure related but distinct concepts, such as sexual satisfaction. This lack of conceptual clarity impedes understanding, measuring, and improving sexual wellbeing. We present qualitative research from multi-stage, mixed-methods work to develop a new measure of sexual wellbeing (Natsal-SW) for the fourth British National Survey of Sexual Attitudes & Lifestyles. Literature review and discussion generated a conceptual framework with seven proposed domains: respect, self-esteem, comfort, self-determination, safety and security, forgiveness, and resilience. Semi-structured interviews with 40 adults aged 18-64 then explored whether and how these domains aligned with participants' own understandings, experiences, and language of sexual wellbeing. Data were analyzed thematically. Participants conceptualized sexual wellbeing as distinct from sexual satisfaction and sexual health and as multidimensional, dynamic, and socially and structurally influenced. All seven proposed domains resonated with accounts of sexual wellbeing as a general construct. The personal salience of different domains and their dimensions varied between individuals (especially by gender and sexual orientation) and fluctuated individually over time. This study clarifies dimensions of domains that participants considered important, providing an empirical basis to inform development of a new measure of sexual wellbeing.

Modelling the impact of reopening schools in the UK in early 2021 in the presence of the alpha variant and with roll-out of vaccination against SARS-CoV-2.

Following the resurgence of the COVID-19 epidemic in the UK in late 2020 and the emergence of the alpha (also known as B117) variant of the SARS-CoV-2 virus, a third national lockdown was imposed from January 4, 2021. Following the decline of COVID-19 cases over the remainder of January 2021, the question of when and how to reopen schools became an increasingly pressing one in early 2021. This study models the impact of a partial national lockdown with social distancing measures enacted in communities and workplaces under different strategies of reopening schools from March 8, 2021 and compares it to the impact of continual full national lockdown remaining until April 19, 2021. We used our previously published agent-based model, Covasim, to model the emergence of the alpha variant over September 1, 2020 to January 31, 2021 in presence of Test, Trace and Isolate (TTI) strategies. We extended the model to incorporate the impacts of the roll-out of a two-dose vaccine against COVID-19, with 200,000 daily vaccine doses prioritised by age starting with people 75 years or older, assuming vaccination offers a 95% reduction in disease acquisition risk and a 30% reduction in transmission risk. We used the model, calibrated until January 25, 2021, to simulate the impact of a full national lockdown (FNL) with schools closed until April 19, 2021 versus four different partial national lockdown (PNL) scenarios with different elements of schooling open: 1) staggered PNL with primary schools and exam-entry years (years 11 and 13) returning on March 8, 2021 and the rest of the schools years on March 15, 2020; 2) full-return PNL with both primary and secondary schools returning on March 8, 2021; 3) primary-only PNL with primary schools and exam critical years (years 11 and 13) going back only on March 8, 2021 with the rest of the secondary schools back on April 19, 2021 and 4) part-rota PNL with both primary and secondary schools returning on March 8, 2021 with primary schools remaining open continuously but secondary schools on a two-weekly rota-system with years alternating between a fortnight of face-to-face and remote learning until April 19, 2021. Across all scenarios, we projected the number of new daily cases, cumulative deaths and effective reproduction number R until April 30, 2021. Our calibration across different scenarios is consistent with alpha variant being around 60% more transmissible than the wild type. We find that strict social distancing measures, i.e. national lockdowns, were essential in containing the spread of the virus and controlling hospitalisations and deaths during January and February 2021. We estimated that a national lockdown over January and February 2021 would reduce the number of cases by early March to levels similar to those seen in October 2020, with R also falling and remaining below 1 over this period. We estimated that infections would start to increase when schools reopened, but found that if other parts of society remain closed, this resurgence would not be sufficient to bring R above 1. Reopening primary schools and exam critical years only or having primary schools open continuously with secondary schools on rotas was estimated to lead to lower increases in cases and R than if all schools opened. Without an increase in vaccination above the levels seen in January and February, we estimate that R could have increased above 1 following the reopening of society, simulated here from April 19, 2021. Our findings suggest that stringent measures were integral in mitigating the increase in cases and bringing R below 1 over January and February 2021. We found that it was plausible that a PNL with schools partially open from March 8, 2021 and the rest of the society remaining closed until April 19, 2021 would keep R below 1, with some increase evident in infections compared to continual FNL until April 19, 2021. Reopening society in mid-April, without an increase in vaccination levels, could push R above 1 and induce a surge in infections, but the effect of vaccination may be able to control this in future depending on the transmission blocking properties of the vaccines.

Feasibility and acceptability of a whole-school social-marketing intervention to prevent unintended teenage pregnancies and promote sexual health: evidence for progression from a pilot to a phase III randomised trial in English secondary schools.

BACKGROUND: Reducing unintended teenage pregnancy and promoting adolescent sexual health remains a priority in England. Both whole-school and social-marketing interventions are promising approaches to addressing these aims. However, such interventions have not been rigorously trialled in the UK and it is unclear if they are appropriate for delivery in English secondary schools. We developed and pilot trialled Positive Choices, a new whole-school social marketing intervention to address unintended teenage pregnancy and promote sexual health. Our aim was to assess the feasibility and acceptability of the intervention and trial methods in English secondary schools against pre-defined progression criteria (relating to randomisation, survey follow-up, intervention fidelity and acceptability and linkage to birth/abortion records) prior to carrying out a phase III trial of effectiveness and cost-effectiveness. METHODS: Pilot RCT with integral process evaluation involving four intervention and two control schools in south-east England. The intervention comprised a student needs survey; a student/staff-led school health promotion council; a classroom curriculum for year-9 students (aged 13-14); whole-school student-led social-marketing activities; parent information; and a review of local and school-based sexual health services. Baseline surveys were conducted with year 8 (aged 12-13) in June 2018. Follow-up surveys were completed 12 months later. Process evaluation data included audio recording of staff training, surveys of trained staff, staff log books and researcher observations of intervention activities. Survey data from female students were linked to records of births and abortions to assess the feasibility of these constituting a phase III primary outcome. RESULTS: All six schools were successfully randomised and retained in the trial. Response rates to the survey were above 80% in both arms at both baseline and follow-up. With the exception of the parent materials, the fidelity target for implementation of essential elements in three out of four schools was achieved. Student surveys indicated 80% acceptability among those who reported awareness of the programme and interviews with staff suggested strong acceptability. Linkage to birth/abortion records was feasible although none occurred among participants. CONCLUSIONS: The criteria for progression to a phase III trial were met. Our data suggest that a whole-school social-marketing approach may be appropriate for topics that are clearly prioritised by schools. A phase III trial of this intervention is now warranted to establish effectiveness and cost-effectiveness. Births and terminations are not an appropriate primary outcome measure for such a trial. TRIAL REGISTRATION: ISRCTN65324176.

Modelling the potential impact of mask use in schools and society on COVID-19 control in the UK.

As the UK reopened after the first wave of the COVID-19 epidemic, crucial questions emerged around the role for ongoing interventions, including test-trace-isolate (TTI) strategies and mandatory masks. Here we assess the importance of masks in secondary schools by evaluating their impact over September 1-October 23, 2020. We show that, assuming TTI levels from August 2020 and no fundamental changes in the virus's transmissibility, adoption of masks in secondary schools would have reduced the predicted size of a second wave, but preventing it would have required 68% or 46% of those with symptoms to seek testing (assuming masks' effective coverage 15% or 30% respectively). With masks in community settings but not secondary schools, the required testing rates increase to 76% and 57%.

Sexually transmitted infection risk exposure among black and minority ethnic youth in northwest London: findings from a study translating a sexually transmitted infection risk-reduction intervention to the UK setting.

OBJECTIVES: Young black women are disproportionately affected by sexually transmitted infections (STI) in the UK, but effective interventions to address this are lacking. The Young Brent Project explored the nature and context of sexual risk-taking in young people to inform the translation of an effective clinic-based STI reduction intervention (Project SAFE) from the USA to the UK. METHODS: One-to-one in-depth interviews (n = 37) and group discussions (n = 10) were conducted among men and women aged 15-27 years from different ethnic backgrounds recruited from youth and genitourinary medicine clinic settings in Brent, London. The interviews explored the context within which STI-related risks were assessed, experienced and avoided, the skills needed to recognise risk and the barriers to behaviour change. RESULTS: Concurrent sexual partnerships, mismatched perceptions and expectations, and barriers to condom use contributed to STI risk exposure and difficulties in implementing risk-reduction strategies. Women attempted to achieve monogamy, but experienced complex and fluid sexual relationships. Low risk awareness, flawed partner risk assessments, negative perceptions of condoms and lack of control hindered condom use. Whereas men made conscious decisions, women experienced persuasion, deceit and difficulty in requesting condom use, particularly with older partners. CONCLUSIONS: Knowledge of STI and condom use skills is not enough to equip young people with the means to reduce STI risk. Interventions with young women need to place greater emphasis on: entering and maintaining healthy relationships; awareness of risks attached to different forms of concurrency and how concurrency arises; skills to redress power imbalances and building self-esteem.

Measuring risk of HIV and HCV among injecting drug users in the Russian Federation.

BACKGROUND: The aim of the study was to measure risk of HIV and HCV infection among injecting drug users (IDUs) through force of infection (FOI) models in three cities of the Russian Federation and assess the value of behavioural data and FOI in predicting risk of infection as a method of second-generation surveillance. METHODS: FOI models were fitted to prevalence data collected through an anonymous, cross-sectional community-recruited survey of IDUs with oral fluid sample collection for antibodies to HIV and HCV. Risk of infection was estimated from FOI estimates obtained by fitting a model to prevalence data by length of injecting career for each city and then overall. Risk behaviours were examined by injecting career length. RESULTS: A total of 1473 IDUs were recruited. Prevalence of HIV was 8.1% (95% CI 6.7-9.6%) and HCV 63.4% (95% CI 60.9-65.9%). A higher FOI in new initiates to injecting (injecting career length <1 year) was found for both HIV and HCV compared with experienced IDUs (injecting career length <5 years). Increased risk of infection was not corroborated by injecting risk behaviours among new initiates into injecting (n = 38). Only 5.7% (n = 2) reported receptive sharing in the last 4 weeks, 57.9% (n = 22) sharing any injecting paraphernalia, 2.6% (n = 1) frontloading and 8.5% (n = 3) ever injecting with used needles/syringes. However, 29% of new initiates reported exchanging sex in the last 4 weeks (29%) compared with 11% long term IDUs. CONCLUSIONS: FOI models can play an important role in surveillance of HIV but caution is needed in the interpretation of behavioural data for predicting current or future risk of HIV.

Cervical screening: Perceptions and barriers to uptake among Somali women in Camden.

OBJECTIVES: To explore barriers to, and ways to improve, uptake of cervical screening among Somali women in Camden, London. STUDY DESIGN: A qualitative research study using focus group discussions and in-depth interviews. METHODS: A qualitative study (comprising seven focus groups and eight in-depth interviews) was conducted with 50 first-generation Somali women aged 25-64 years. Both the groups and the interviews explored participants' understanding of the purpose of cervical screening, and the various risk factors for cervical cancer, as well as their opinions on barriers to screening and suggestions for overcoming those barriers. RESULTS: Knowledge about the purpose of cervical screening was limited among Somali women. There was also a lack of understanding of risk factors for cervical cancer, and many of the women held fatalistic attitudes, associated with the idea of 'God's will', about this cancer and other aspects of health. Another culturally specific barrier was embarrassment associated with female circumcision, i.e. female genital mutilation. Other barriers suggested by the participants were: lack of knowledge about the need for cervical screening, practical problems such as appointment times and childcare needs, language difficulties, fear of the test and negative past experiences. Possible solutions suggested by the participants included the provision of education and information about cervical screening in the Somali language by Somali community workers. They also suggested that healthcare staff should be trained about Somali culture, particularly regarding female circumcision, and that general practitioners should more proactively encourage Somali women to attend screening. CONCLUSIONS: Language difficulties and specific cultural issues are key barriers to first-generation Somali women attending cervical screening. Providing education and information orally, as well as improving access to a more culturally appropriate screening service, could lead to improved uptake among this group.

Does the UK government's teenage pregnancy strategy deal with the correct risk factors? Findings from a secondary analysis of data from a randomised trial of sex education and their implications for policy.

BACKGROUND: Much of the UK government's 1999 report on teenage pregnancy was by necessity based on rather old or non-longitudinal research. AIM: To examine the associations between risk factors identified in the report and pregnancy at or before age 16 years among young women and partners of young men using the more recent data. RESULTS: Socioeconomic disadvantage, being born to a teenage mother, expectation of being a teenage parent, low educational expectations and various other behaviours are potential risk factors for teenage pregnancy, as suggested by unadjusted analyses. Those who cited school as providing information on sex had a reduced risk of pregnancy at or before age 16 years, as did girls reporting easy communication with parent or guardian at baseline. Various measures of low sexual health knowledge were not associated, in either adjusted or unadjusted analyses, with increased risk of pregnancy at or before age 16 years among boys or girls. CONCLUSIONS: A focus on many of the risk factors identified in the 1999 report is supported herein. It is suggested that knowledge may not be an important determinant, but that relationships with parents and school, as well as expectations for the future, may have important influences on teenage pregnancy. The analysis also provides new insights into risk factors for pregnancies among the partners of young men.

Influence of family type and parenting behaviours on teenage sexual behaviour and conceptions.

BACKGROUND: Longitudinal data were used to explore relations between teenage pregnancy, sexual behaviour, and family type. The study examined whether students from lone parent and/or teenage mother initiated families more commonly report sex, lack of contraception at first sex, and/or conceptions by age 15/16, and whether such associations can be explained by low parental strictness, difficult parent-child communication, and/or low parental input into sex education. Up to date longitudinal UK research on family influences on conceptions is lacking, as is longitudinal research on family influences on sexual behaviour. No previous studies have comprehensively examined effects of parenting behaviours. Unlike previous research, this study tested theories suggesting that parenting deficits among lone parent and teenage initiated families increase risk of teenage pregnancy among their children. METHODS: Secondary analysis of data from a trial of sex education. RESULTS: Girls and boys from lone parent families or having mothers who were teenagers when they were born were more likely to report sex but not lack of contraception at first sex by age 15/16. Girls and boys with mothers having them as teenagers, and boys but not girls from lone parent families, were more likely to report being involved in conceptions by age 15/16. Only the association between teenage mother family and girls' conceptions was reduced by adjusting for a parenting behaviour measure. CONCLUSIONS: Students from lone parent families or having mothers who were teenagers when they were born are more likely to report early sexual debut and conceptions by age 15/16, but this is not generally explained by parenting style.

Intraclass correlation values for adolescent health outcomes in secondary schools in 21 European countries.

BACKGROUND: Cluster randomised controlled trials (CRCTs) are increasingly used to evaluate the effectiveness of interventions for improving health. A key feature of CRCTs is that individuals in clusters are often more alike than individuals in different clusters, irrespective of treatment. This similarity within clusters needs to be taken into account when planning CRCTs to obtain adequate sample sizes, and when analysing clustered data to obtain correct estimates. METHODS: Nationally representative data from 15 to 16 year olds were analysed, from 21 of the 35 countries that participated in the 2007 European School Survey Project on Alcohol and Other Drugs. Within country school level intra-class correlation coefficients (ICCs) were calculated for substance use (self-reported alcohol use, regular alcohol use, binge drinking, any smoking, regular smoking, and illicit drug use) and psychosocial health (depressive mood and self-esteem). Unadjusted and adjusted ICCs are presented. ICCs are adjusted for student sex and socioeconomic status. RESULTS: ICCs ranged from 0.01 to 0.21, with the highest (0.21) reported for regular smoking. Within country school level ICCs varied substantially across health outcomes, and among countries for the same health outcomes. Estimated ICCs were consistently higher for substance use (range 0.01-0.21), than for psychosocial health (range 0.01-0.07). Within country ICCs for health outcomes varied by changes in the measurement of particular health outcomes, for example the ICCs for regular smoking (range 0.06-0.21) were higher than those for having smoked at all in the last month (range 0.03-0.17). CONCLUSIONS: For school level ICCs to be effectively utilised in informing sample size requirements for CRCTs and adjusting estimates from meta-analyses, the school level ICCs need to be both country and outcome specific.

The effect of dislike of school on risk of teenage pregnancy: testing of hypotheses using longitudinal data from a randomised trial of sex education.

STUDY OBJECTIVE: To examine whether attitude to school is associated with subsequent risk of teenage pregnancy. To test two hypotheses that attitude to school is linked to pregnancy via pathways involving young people having "alternative" expectations or deficits in sexual health knowledge and confidence. DESIGN: Analysis of longitudinal data arising from a trial of sex education. Examination of associations between attitude to school and protected first sex, unprotected first sex, unprotected and protected last sex, and pregnancy, both crude and adjusting in turn for expectation of parenting by age 20, lack of expectation of education/training at age 20, and sexual health knowledge and confidence. SETTING: Schools in central and southern England. PARTICIPANTS: Girls of median age 13.7 years at baseline, 14.7 years at follow up 1, and 16.0 years at follow up 2. MAIN RESULTS: In unadjusted analysis, attitude to school was significantly associated with protected and unprotected first sex by follow up 1, protected first sex between follow up 1 and 2, unprotected last sex, and pregnancy. Dislike of school was more strongly associated with increased risk of these outcomes than was ambivalence to school. These associations remained after adjusting for socioeconomic status and for expectation of parenting, lack of expectation of education/training, and various indicators of knowledge and confidence about sexual health. CONCLUSIONS: Dislike of school is associated with subsequent increased risk of teenage pregnancy but the mechanism underlying any possible causal link is unlikely to involve "alternative" expectations or deficits in sexual health knowledge or confidence.

[Factors that affect the Hoffmann reflex as a tool used in neurophysiological examination]. / Factores que afectan el reflejo de Hoffmann en su uso como herramienta de exploración neurofisiológica.

INTRODUCTION: The Hoffmann reflex, or H-reflex, which is the electrical equivalent of the myotatic reflex, is a very valuable tool for evaluating the reflex pathway and for investigating the mechanisms that regulate the intensity of its response. Yet, the complex interaction of the H-reflex circuit with other neural components requires a tight-fit recording protocol. DEVELOPMENT: In this paper we present a review of the main technical, physiological and methodological factors that affect the recording of the H-reflex when used as an instrument for neurophysiological exploration. The paper reviews aspects concerning the method of stimulation, recording and analysing the reflex response. The physiological mechanisms that interact to modulate the amplitude of the H-reflex, such as pre-synaptic inhibition, post-activation depression and the excitability of the motoneurons, are described and the different methods used to control the variations that arise in each case are also outlined. Lastly, a summary of the main points to be borne in mind when recording the H-reflex is presented. CONCLUSIONS: Due to the large number of variables and the non-linear way they interact with one another, we must proceed with care when drawing conclusions from the discussion of the results obtained under such strict protocols. Progress also has to be made in the development and application of new mathematical, statistical and modelling tools in order to achieve a more accurate interpretation of the findings that are observed.

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.