Stimulus control of habits: Evidence for both stimulus specificity and devaluation insensitivity in a dual-response task.

Goal-directed and habitual actions are clearly defined by their associative relations. Whereas goal-directed control can be confirmed via tests of outcome devaluation and contingency-degradation sensitivity, a comparable criterion for positively detecting habits has not been established. To confirm habitual responding, a test of control by the stimulus-response association is required while also ruling out goal-directed control. Here we describe an approach to developing such a test in rats using two discriminative stimuli that set the occasion for two different responses that then earn the same outcome. Performance was insensitive to outcome devaluation and showed stimulus-response specificity, indicative of stimulus-controlled behavior. The reliance of stimulus-response associations was further supported by a lack of sensitivity during the single extinction test session used here. These results demonstrate that two concurrently trained responses can come under habitual control when they share a common outcome. By reducing the ability of one stimulus to signal its corresponding response-outcome association, we found evidence for goal-directed control that can be dissociated from habits. Overall, these experiments provide evidence that tests assessing specific stimulus-response associations can be used to investigate habits.

Establishing an SEIR-based framework for local modelling of COVID-19 infections, hospitalisations and deaths.

Without timely assessments of the number of COVID-19 cases requiring hospitalisation, healthcare providers will struggle to ensure an appropriate number of beds are made available. Too few could cause excess deaths while too many could result in additional waits for elective treatment. As well as supporting capacity considerations, reliably projecting future "waves" is important to inform the nature, timing and magnitude of any localised restrictions to reduce transmission. In making the case for locally owned and locally configurable models, this paper details the approach taken by one major healthcare system in founding a multi-disciplinary "Scenario Review Working Group", comprising commissioners, public health officials and academic epidemiologists. The role of this group, which met weekly during the pandemic, was to define and maintain an evolving library of plausible scenarios to underpin projections obtained through an SEIR-based compartmental model. Outputs have informed decision-making at the system's major incident Bronze, Silver and Gold Commands. This paper presents illustrated examples of use and offers practical considerations for other healthcare systems that may benefit from such a framework.

Assessing the potential of upper respiratory tract point-of-care testing: a systematic review of the prognostic significance of upper respiratory tract microbes.

OBJECTIVES: Microbial point-of-care testing (POCT) has potential to revolutionize clinical care. Understanding the prognostic value of microbes identified from the upper respiratory tract (a convenient sampling site) is a necessary first step to understand potential for upper respiratory tract POCTs in assisting antimicrobial treatment decisions for respiratory infections (RTIs). The aim was to investigate the relationship between upper respiratory tract microbial detection and disease prognosis, including effects of antimicrobial use. METHODS: Data sources were the MEDLINE and Embase databases. Study eligibility criteria consisted of quantitative studies reporting microbiological and prognostic data from patients of all age groups presenting with RTI. Patients presenting to healthcare or research settings with RTI participated. Interventions included upper respiratory tract swab. The methods used were systematic review and meta-analysis. RESULTS: Searches identified 5156 articles, of which 754 were duplicates and 4258 excluded on title or abstract. A total of 144 full texts were screened; 21 articles were retained. Studies reported data for 15 microbes and 26 prognostic measures (390 potential associations). One hundred and seven (27%) associations were investigated statistically, of which 38 (36%) were significant. Most studies reported only prognostic value of test positive results. Meta-analyses suggested hospitalization duration was longer for patients with respiratory syncytial virus than adenovirus and influenza, but significant heterogeneity was observed between studies. CONCLUSIONS: A quarter of potential prognostic associations have been investigated. Of these, a third were significant, suggesting considerable potential for POCT. Future research should investigate prognostic value of positive and negative tests, and interactions between test results, use of antimicrobials and microbial resistance.

No effect of prenatal vitamin D deficiency on autism-relevant behaviours in multiple inbred strains of mice.

Autism Spectrum Disorders (ASD) is a group of neurodevelopmental disorders commonly characterised by verbal and non-verbal communication deficits, impaired social interaction and repetitive, stereotypic behaviours. The aetiology of ASD is most likely a combination of genetic and environmental factors. Epidemiological evidence suggests that prenatal vitamin D deficiency is associated with an increased incidence of ASD. The overall aim of this study was to investigate prenatal vitamin D deficiency on ASD-related behavioural phenotypes in multiple inbred strains of mice. We included two commonly used inbred mouse strains (C57BL/6J and BALB/c) as well as inbred BTBR mice, which show ASD-related behaviours, such as excessive self-grooming, hyperlocomotion, social interaction deficits and altered communication. We also studied the effect of prenatal vitamin D deficiency in a fourth strain; an F1 cross of C57BL/6J x BTBR mice, which have a partial BTBR phenotype. To implement prenatal vitamin D deficiency, female mice were placed on vitamin D deplete diets for ten weeks, including mating and gestation, until littering, when all dams were switched to the control diet. Behavioural symptoms related to ASD were measured, including isolation-induced ultrasonic vocalisations to measure communication, the three-chambered social interaction task to observe social interaction, the open field test to examine hyperlocomotion, assessment of grooming and rearing behaviour and finally the active place avoidance task to observe spatial learning and memory in response to a mild foot shock. Prenatal vitamin D deficiency had a negative impact on preference for social novelty in C57BL/6J mice, despite similar vocalisation phenotypes, and prenatal vitamin D-deficient F1 mice were found to be hypolocomotive in the open field test yet performed better on the active place avoidance task. Despite clear differences between strains, there were no other consistent significant main effects of maternal diet on the behaviour of the offspring. Vitamin D deficiency has been implicated as a risk factor for ASD and these data show that there is greater variation between different inbred strains in ASD-related behaviour, suggesting that prenatal vitamin D deficiency is not sufficient to recapitulate an ASD phenotype in multiple inbred strains of mice.

Psychological treatment of depression and anxiety in patients with co-morbid personality disorder: A scoping study of trial evidence.

It is unclear what the best psychological treatment is for depression and anxiety in people with co-morbid personality disorder. Trials of different psychological treatment options for this patient group have been conducted, but this evidence has not previously been systematically reviewed or critically appraised. We set out to conduct a scoping review in order to describe which psychological therapies appear most effective in treating depression and/or anxiety in patients with co-morbid personality disorder. PsycINFO, Cochrane library trials, Medline and Embase databases were searched for studies involving randomized, controlled, experimental, parallel-arm comparisons, examining any well-defined, psychotherapeutic intervention for adults, in an outpatient setting, with a clearly defined diagnosis of depression and/or anxiety, and co-morbid personality disorder. A total of 1662 papers were identified. Fifteen met criteria for inclusion and were reviewed. There was weak evidence to support the use of cognitive behavioural therapy as a psychological treatment for depression in patients with co-morbid personality disorder. However, the literature is characterized by considerable methodological heterogeneity, and further research is needed before there is sufficient evidence to indicate which psychological treatment would be most effective in treating anxiety and/or depression in this patient group. Copyright © 2017 John Wiley & Sons, Ltd.

Midwives and women's views on using UK recommended depression case finding questions in antenatal care.

OBJECTIVE: detecting and treating depression early on in pregnancy can improve health outcomes for women and their children. UK guidelines recommend that Midwives screen for antenatal depression (AND) at the woman's first Midwife appointment using recommended depression case finding questions. This is the first qualitative study to explore Midwives' and women's views of using these questions in the context of antenatal care. DESIGN: Semi-structured interviews with Midwives and pregnant women exploring their views and experiences of screening for AND, conducted alongside a validation study of the depression case finding questions. SETTING: the initial appointment with the Midwife when the woman is 10-12 weeks pregnant. Interviewees were working or living in Bristol, England. PARTICIPANTS: maximum variation samples of 15 Midwives and 20 pregnant women. MEASUREMENTS AND FINDINGS: Midwives and pregnant women viewed the depression case finding questions as a useful way of introducing mental health issues. Midwives often adapted the questions rather than using the phrasing specified in the UK guideline. Sometimes Midwives chose not to use the questions, for example if a partner was present. Both Midwives and women struggled to differentiate symptoms of early pregnancy from antenatal depression; yet thought that detecting depression early on in pregnancy was important. Women were unsure about the kind of help that was available; some women reported this as a reason for withholding their true feelings. There was a general lack of awareness among Midwives about the range of non-drug treatments potentially available to women and referral pathways to access them. KEY CONCLUSION: both Midwives and women regard screening for AND as acceptable and important but reported shortcomings with the recommended depression case finding questions. IMPLICATIONS FOR PRACTICE: providing training for Midwives on how to frame the questions and increase their knowledge and application of the referral pathways suggested by UK guidelines will help address some of the issues raised by Midwives and women in our study.

A pragmatic randomized controlled trial to evaluate the effectiveness of a facilitated exercise intervention as a treatment for postnatal depression: the PAM-PeRS trial.

BACKGROUND: Postnatal depression affects about 10-15% of women in the year after giving birth. Many women and healthcare professionals would like an effective and accessible non-pharmacological treatment for postnatal depression. METHOD: Women who fulfilled the International Classification of Diseases (ICD)-10 criteria for major depression in the first 6 months postnatally were randomized to receive usual care plus a facilitated exercise intervention or usual care only. The intervention involved two face-to-face consultations and two telephone support calls with a physical activity facilitator over 6 months to support participants to engage in regular exercise. The primary outcome was symptoms of depression using the Edinburgh Postnatal Depression Scale (EPDS) at 6 months post-randomization. Secondary outcomes included EPDS score as a binary variable (recovered and improved) at 6 and 12 months post-randomization. RESULTS: A total of 146 women were potentially eligible and 94 were randomized. Of these, 34% reported thoughts of self-harming at baseline. After adjusting for baseline EPDS, analyses revealed a -2.04 mean difference in EPDS score, favouring the exercise group [95% confidence interval (CI) -4.11 to 0.03, p = 0.05]. When also adjusting for pre-specified demographic variables the effect was larger and statistically significant (mean difference = -2.26, 95% CI -4.36 to -0.16, p = 0.03). Based on EPDS score a larger proportion of the intervention group was recovered (46.5% v. 23.8%, p = 0.03) compared with usual care at 6 months follow-up. CONCLUSIONS: This trial shows that an exercise intervention that involved encouragement to exercise and to seek out social support to exercise may be an effective treatment for women with postnatal depression, including those with thoughts of self-harming.

The effect of developmental vitamin D deficiency in male and female Sprague-Dawley rats on decision-making using a rodent gambling task.

Developmental vitamin D (DVD) deficiency is a plausible risk factor for schizophrenia that has been associated with behavioural alterations including disruptions in latent inhibition and response inhibition. The rodent gambling task (rGT) assesses risk-based decision-making, which is a key cognitive deficit observed in schizophrenia patients. The primary aim of this study was to examine risk-based decision-making in DVD-deficient and control rats on the rGT. We also evaluated the performance of female Sprague-Dawley rats on the rGT for the first time. Adult male and female Sprague-Dawley rats from control and vitamin D deficient dams were trained to perform the rGT in standard operant chambers and their performance and choice-preferences were assessed. Female rats were significantly faster to reach rGT training criteria compared with male rats and DVD-deficient rats were faster to reach training criteria than control animals. After reaching stable performance on the rGT DVD-deficient and control rats showed a significant preference for the optimal choice-option in the rGT, but there were no significant effects of sex or diet on these responses. DVD deficiency did not alter the decision-making processes on the rGT because no significant changes in choice-preferences were evident. This is the first study to demonstrate that once established, the performance of females is comparable to male Sprague-Dawley rats on the rGT.

Dairy consumption and insulin sensitivity: a systematic review of short- and long-term intervention studies.

AIM: Evidence from epidemiological studies suggests that higher consumption of dairy products may be inversely associated with risk of type 2 diabetes and other components of the metabolic syndrome, although the evidence is mixed. Intervention studies that increase dairy intake often involve lifestyle changes, including weight loss, which alone will improve insulin sensitivity. The aim of this review was to examine weight stable intervention studies that assess the effect of an increased intake of dairy products or dairy derived supplements on glucose metabolism and insulin sensitivity. DATA SYNTHESIS: An electronic search was conducted using MEDLINE, EMBASE, the Cochrane Database and Web of Science for randomised controlled trials altering only dairy intake in humans with no other lifestyle or dietary change, particularly no weight change, and with measurement of glucose or insulin. Healthy participants and those with features of the metabolic syndrome were included. Chronic whey protein supplementation was also included. Ten studies were included in this systematic review. CONCLUSIONS: In adults, four of the dairy interventions showed a positive effect on insulin sensitivity as assessed by Homeostasis Model Assessment (HOMA); one was negative and five had no effect. As the number of weight stable intervention studies is very limited and participant numbers small, these findings need to be confirmed by larger trials in order to conclusively determine any relationship between dairy intake and insulin sensitivity.

Adolescents' views and experiences of treatments for Type 2 diabetes: a qualitative study.

AIM: To explore adolescents' views and experiences of different treatments for Type 2 diabetes, in order to improve treatment concordance and consider how the current treatment pathway for adolescent Type 2 diabetes could be improved. METHODS: In-depth interviews were held with 12 adolescents who had been diagnosed with Type 2 diabetes. Adolescents were sampled from a UK cohort study. Data were analysed thematically. RESULTS: Interviewees struggled to maintain lifestyle changes. Insulin, metformin and liraglutide were described as effective but, in some cases, as resulting in side effects. Injected treatments were viewed less favourably than oral medications. Weight loss surgery was considered an acceptable treatment for obese adolescents who had tried other treatments for their diabetes. It was apparent that some adolescents had not been surprised by their diagnosis and did not fully appreciate the implications of having diabetes. It was also evident that some individuals had not told peers about their diagnosis due to fearing how they would react. Factors identified as improving treatment concordance included reminders and viewing treatment as effective and easy to take. CONCLUSIONS: Adolescents want treatments that are effective, discrete, easy to take and do not make them different from their peers. As liraglutide was described as effective, and surgery viewed as acceptable in certain circumstances, greater consideration should be given to their potential role in treating adolescent Type 2 diabetes. Practitioners need to ensure that adolescents appreciate the implications of having diabetes and may want to address adolescents' concerns regarding how others view this condition.

Remission of diabetes in patients with long-standing type 2 diabetes following placement of adjustable gastric band: a retrospective case control study.

Rates of remission in obese patients with long-standing type 2 diabetes (>2 years), following an adjustable gastric band are unclear. We conducted a retrospective case-control study of patients (n = 89) matched for age and body mass index with non-surgical controls. Cases had a longer duration of diabetes (99 ± 53 and 80 ± 59 months, p < 0.05) and a lower HbA1c than controls (7.9 ± 1.6 vs. 8.5 ± 1.9%, p < 0.05). At follow-up (median 105 weeks) cases had lost 16.8 ± 13.5 kg and controls 1.7 ± 8.9 kg (p < 0.001) and HbA1c decreased by 0.6-0.8% (p < 0.001 for time) with no difference between cases and controls. Diabetes resolution, defined by HbA1c less than 6.5% and taking no medications, occurred in 14 (16%) cases and 2 controls. This is in contrast to published outcomes of resolution of type 2 diabetes after bariatric surgery. We conclude that there is a clear need for randomized studies of the effect of gastric banding in patients with long-standing type 2 diabetes.

A pragmatic randomised controlled trial to evaluate the cost-effectiveness of a physical activity intervention as a treatment for depression: the treating depression with physical activity (TREAD) trial.

OBJECTIVE: The TREAting Depression with physical activity (TREAD) study investigated the cost-effectiveness of a physical activity intervention, in addition to usual general practitioner care, as a treatment for people with depression. DESIGN: An individually randomised, pragmatic, multicentre randomised controlled trial with follow-up at 4, 8 and 12 months. A subset of participants took part in a qualitative study that investigated the acceptability and perceived benefits of the intervention. SETTING: General practices in the Bristol and Exeter areas. PARTICIPANTS: Aged 18-69 years with an International Statistical Classification of Diseases and Related Health Problems, 10th Edition (ICD-10) diagnosis of depression and scoring ≥ 14 on the Beck Depression Inventory (BDI). Those who were unable to complete self-administered questionnaires in English, with medical contraindications to physical activity or with psychosis, bipolar disorder or serious drug abuse were excluded. INTERVENTIONS: We devised an intervention designed to encourage choice and autonomy in the adoption of physical activity. It consisted of up to three face-to-face and ten telephone contacts delivered by a trained physical activity facilitator over an 8-month period. MAIN OUTCOME MEASURES: The primary outcome was the BDI score measured at 4 months. Secondary outcomes included depressive symptoms over the 12 months and quality of life, antidepressant use and level of physical activity. RESULTS: The study recruited 361 patients, with 182 randomised to the intervention arm and 179 to the usual care arm; there was 80% retention at the 4-month follow-up. The intervention group had a slightly lower BDI score at 4 months [-0.54, 95% confidence interval (CI) -3.06 to 1.99] but there was no evidence that the intervention improved outcome for depression. Neither was there any evidence to suggest a difference in the prescription of or self-reported use of antidepressants. However, the amount of physical activity undertaken by those who had received the intervention was increased (odds ratio 2.3, 95% CI 1.3 to 3.9) and was sustained beyond the end of the intervention. From a health-care perspective, the intervention group was more costly than the usual care group, with the cost of the intervention £220 per person on average. It is therefore extremely unlikely that the intervention is cost-effective as a treatment for depression using current willingness-to-pay thresholds. CONCLUSIONS: This physical activity intervention is very unlikely to lead to any clinical benefit in terms of depressive symptoms or to be a cost-effective treatment for depression. Previous research has reported some benefit and there are three possible reasons for this discrepancy: first, even though the intervention increased self-reported physical activity, the increase in activity was not sufficiently large to lead to a measurable influence; second, only more vigorous activity might be of benefit; and third, previous studies had recruited individuals with a pre-existing commitment to physical activity. Future research is needed to identify and explain the mechanisms by which depression might be effectively treated, including, in particular, specific guidance on the optimum type, intensity and duration of physical activity required to produce a therapeutic effect. TRIAL REGISTRATION: Current Controlled Trials ISRCTN16900744. FUNDING: This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 16, No. 10. See the HTA programme website for further project information.

A pragmatic randomised controlled trial to compare antidepressants with a community-based psychosocial intervention for the treatment of women with postnatal depression: the RESPOND trial.

OBJECTIVES: To evaluate clinical effectiveness at 4 weeks of antidepressant therapy for mothers with postnatal depression (PND) compared with general supportive care; to compare outcome at 18 weeks of those randomised to antidepressant therapy with those randomised to listening visits as the first intervention (both groups were to be allowed to receive the alternative intervention after 4 weeks if the woman or her doctor so decided); and to assess acceptability of antidepressants and listening visits to users and health professionals. DESIGN: A pragmatic two-arm individually randomised controlled trial. SETTING: Participants were recruited from 77 general practices: 21 in Bristol, 21 in south London and 35 in Manchester. PARTICIPANTS: A total of 254 women who fulfilled International Classification of Diseases version 10 criteria for major depression in the first 6 postnatal months were recruited and randomised. INTERVENTIONS: Women were randomised to receive either an antidepressant, usually a selective serotonin reuptake inhibitor prescribed by their general practitioner (GP), or non-directive counselling (listening visits) from a specially trained research health visitor (HV). The trial was designed to compare antidepressants with general supportive care for the first 4 weeks, after which women allocated to listening visits commenced their sessions. It allowed for women to receive the alternative intervention if they had not responded to their allocated intervention or wished to change to, or add in, the alternative intervention at any time after 4 weeks. MAIN OUTCOME MEASURES: The duration of the trial was 18 weeks. Primary outcome, measured at 4 weeks and 18 weeks post randomisation, was the proportion of women improved on the Edinburgh Postnatal Depression Scale (EPDS), that is scoring < 13. Secondary outcomes were the EPDS measured as a continuous variable at 4 and 18 weeks, and scores on various other questionnaires. RESULTS: At 4 weeks, women were more than twice as likely to have improved if they had been randomised to antidepressants compared with listening visits, which started after the 4-week follow-up, i.e. after 4 weeks of general supportive care [primary intention-to-treat (ITT), 45% versus 20%; odds ratio (OR) 3.4, 95% confidence interval (CI) 1.8 to 6.5, p < 0.001]. Explanatory analyses emphasised these findings. At 18 weeks, ITT analysis revealed that the proportion of women improving was 11% greater in the antidepressant group, but logistic regression analysis showed no clear benefit for one group over the other [62% versus 51%, OR 1.5 (95% CI 0.8 to 2.6), p = 0.19]. Overall, there was a difference between the groups in favour of the antidepressant group of about 25 percentage points at 4 weeks, which reduced at 18 weeks. No statistical support existed for a benefit of antidepressants at 18 weeks, but 95% CIs could not rule out a clinically important benefit. It was difficult for GPs not to prescribe antidepressants to women randomised to listening visits after the initial 4 weeks, so many women received both interventions in both groups by 18 weeks and consequently power was reduced. Qualitative interviews with women revealed a preference for listening visits but an acceptance that antidepressants might be necessary. They wished to be reassured that their GP and HV were offering continuity of care focusing on their particular set of circumstances. Interviews with GPs and HVs revealed lack of collaboration in managing care for women with PND; neither professional group was willing to assume responsibility. CONCLUSIONS: At 4 weeks, antidepressants were significantly superior to general supportive care. Trial design meant that by 18 weeks many of the women initially randomised to listening visits were also receiving antidepressants, and more vice versa. The lack of evidence for differences at 18 weeks is likely to reflect a combination of reduced power and the considerable degree of switching across the two interventions. Qualitative study revealed that women found both antidepressants and listening visits effective depending on their circumstances and preferences. The trial indicates that early treatment with antidepressants leads to clinical benefit for women with PND.

Predicting the population impact of chlamydia screening programmes: comparative mathematical modelling study.

BACKGROUND: Published individual-based, dynamic sexual network modelling studies reach different conclusions about the population impact of screening for Chlamydia trachomatis. The objective of this study was to conduct a direct comparison of the effect of organised chlamydia screening in different models. METHODS: Three models simulating population-level sexual behaviour, chlamydia transmission, screening and partner notification were used. Parameters describing a hypothetical annual opportunistic screening program in 16-24 year olds were standardised, whereas other parameters from the three original studies were retained. Model predictions of the change in chlamydia prevalence were compared under a range of scenarios. RESULTS: Initial overall chlamydia prevalence rates were similar in women but not men and there were age and sex-specific differences between models. The number of screening tests carried out was comparable in all models but there were large differences in the predicted impact of screening. After 10 years of screening, the predicted reduction in chlamydia prevalence in women aged 16-44 years ranged from 4% to 85%. Screening men and women had a greater impact than screening women alone in all models. There were marked differences between models in assumptions about treatment seeking and sexual behaviour before the start of the screening intervention. CONCLUSIONS: Future models of chlamydia transmission should be fitted to both incidence and prevalence data. This meta-modelling study provides essential information for explaining differences between published studies and increasing the utility of individual-based chlamydia transmission models for policy making.

Modelling the effectiveness of chlamydia screening in England.

BACKGROUND: Several developed countries have initiated chlamydia screening programmes. Screening for a sexually transmitted infection has both direct individual and indirect population-wide effects. Mathematical models can incorporate these non-linear effects and estimate the likely impact of different screening programmes and identify areas where more data are needed. METHODS: A stochastic, individual based dynamic network model, parameterised from UK screening studies and data on sexual behaviour and chlamydia epidemiology, was used to investigate the likely impact of opportunistic screening on chlamydia prevalence. Three main strategies were considered for <25 year olds: (1) annual offer to women; (2) annual offer to women or if changed partner within last 6 months; (3) annual offer to men and women. Sensitivity analyses were performed for key screening parameters including uptake rate, targeted age range, percentage of partners notified, and screening interval. RESULTS: Under strategy 1, continuous opportunistic screening of women <25 years of age is expected to reduce the population prevalence by over 50% after 5 years. Prevalence is also expected to decrease in unscreened older women and in men. For all three strategies screening those aged over 25 results in small additional reductions in prevalence. Including men led to a faster and greater reduction in overall prevalence, but involved approximately twice as many tests as strategy 1 and 10% more than strategy 2. The frequency of attendance at healthcare sites limits the number of opportunities to screen and the effect of changing the screening interval. CONCLUSIONS: The model suggests that continuous opportunistic screening at high uptake rates could significantly reduced chlamydia prevalence within a few years. Opportunistic programmes depend on regular attendance at healthcare providers, but there is a lack of high quality data on patterns of attendance. Inequalities in coverage may result in a less efficient and less equitable outcome.

Investigating ethnic inequalities in the incidence of sexually transmitted infections: mathematical modelling study.

OBJECTIVES: To investigate ethnic differences in rates of gonorrhoea using empirical sexual behaviour data in a simple mathematical model. To explore the impact of different intervention strategies in this simulated population. METHODS: The findings from cross sectional studies of gonorrhoea rates and sexual behaviour in three ethnic groups in south east London were used to determine the parameters for a deterministic, mathematical model of gonorrhoea transmission dynamics, in a population stratified by sex, sexual activity (rate of partner change), and ethnic group (white, black African, and black Caribbean). We compared predicted and observed rates of infection and simulated the effects of targeted and population-wide intervention strategies. RESULTS: In model simulations the reported sexual behaviours and mixing patterns generated major differences in the rates of gonorrhoea experienced by each subpopulation. The fit of the model to observed data was sensitive to assumptions about the degree of mixing by level of sexual activity, the numbers of sexual partnerships reported by men and women, and the degree to which observed data underestimate female infection rates. Interventions to reduce duration of infection were most effective when targeted at black Caribbeans. CONCLUSIONS: Average measures of sexual behaviour in large populations are inadequate descriptors for the epidemiology of gonorrhoea. The consistency between the model results and empirical data shows that profound differences in gonorrhoea rates between ethnic groups can be explained by modest differences in a limited number of sexual behaviours and mixing patterns. Targeting effective services to particular ethnic groups can have a disproportionate influence on disease reduction in the whole community.

Butt in, butt out: pupils' views on the extent to which staff could and should enforce smoking restrictions.

Schools which enforce a no-smoking policy may experience lower rates of pupil smoking. Little is known, however, about how young people view such restrictions and it has been argued that smoking bans might actually encourage adolescent smoking. This paper presents pupils' views on the extent to which staff could, and should, enforce smoking restrictions. Twenty-five single-sex discussion groups were held with 13-year-old pupils who had been purposively selected from two Scottish secondary schools. Both schools served relatively deprived communities and ostensibly had no-smoking policies, but varied in their pupil smoking rates. The pupils' accounts suggested that staff enforcement could interrupt pupil smoking and discourage smoking on school premises, but did not affect whether or not they actually smoked. Pupils viewed staff efforts as ineffective and felt staff did not always have the authority or status needed to enforce a ban. Differences were found between the schools, but these did not explain the variation in their smoking profiles.

A fresh perspective on a rank issue: pupils' accounts of staff enforcement of smoking restrictions.

Evidence on the effectiveness of school-based smoking restrictions on reducing pupil smoking rates is mixed. So far, the effect of such policies has only been considered using quantitative methods and 'level of enforcement' has primarily been measured according to data collected from staff. This qualitative study is based on data collected during 25 discussion groups held with 13-year-old pupils concerning whether and how staff in their school addressed pupil smoking. Groups were conducted in two schools. Both served relatively deprived communities but varied in their pupil smoking rates. Pupils made reference to members of the Senior Management Team, teaching and non-teaching staff. They mentioned a range of possible staff reactions and discussed what factors they felt influenced how staff responded. It appeared that a more proactive, firm line was being taken in the 'high' than in the 'low' smoking school.

School differences in pupil smoking: a consequence of a trade-off between health and education agendas?

Current policy documents stress that raising standards in education and health are inextricably linked, with schools identified as well placed to advance both agendas. This paper considers these assumptions in the light of data derived from 27 staff interviews conducted in two secondary schools. These schools served relatively disadvantaged communities, but differed in their pupil smoking rates with one school being 'high-smoking', the other 'low-smoking'. It explores whether this difference reflects the differential emphasis placed by each school on education or health. Analysis reveals that the 'low-smoking' school subscribes to holistic values and operates according to a child-centred bottom-up philosophy offering a differentiated programme of pupil support contingent on needs. In contrast, the 'high-smoking' school maintains a narrow focus on educational outcomes, and its high expectations are viewed as running counter to those held by pupils and parents. The contrasting school philosophies bring different unintended consequences. The holistic focus of the low-smoking school is associated with tempered educational expectations, thus conflicting with recommendations in education policies. The singular education focus of the high-smoking school leaves little room for a health agenda, and can overlook and disenfranchise the educationally disinclined. The school systems' impact on pupil engagement may explain their different smoking rates.

Ifs, maybes and butts: factors influencing staff enforcement of pupil smoking restrictions.

Levels of pupil smoking are reported to be associated with the extent to which school staff consistently enforce smoking restrictions. Little is known, however, about factors which might motivate or discourage staff from doing so. Following analysis of interviews conducted with 27 members of school personnel purposively selected from two Scottish secondary schools serving relatively deprived communities, this paper identifies various issues that hinder staff intervention when confronted with pupil smoking. Both schools had no-smoking policies. In each, staff assumed or understood that smoking within the buildings was forbidden, yet were unsure about how far the bans extended. While the risk of fire in the school buildings prompted staff to intervene when smoking was witnessed indoors, where this risk was absent, decisions were largely context dependent or motivated by personal and professional values. Concerns about staff-pupil relationships, attention to pupils' wider welfare, lack of authority and staff levels of discomfort were salient issues inhibiting intervention. Implications for smoking policies and their enforcement are discussed. The concept of the Health Promoting School is considered in the light of the findings and inherent tensions highlighted.