K K Cheng

The importance of social sources of cigarettes to school students

Objective: To discover the importance of social sources of tobacco to young people as opposed to commercial sources; to describe the peer market for cigarettes in schools and the consequences for young people of their involvement in it. Study design: Cross sectional questionnaire survey, one-to-one interviews, and focus groups. Setting: Seven schools in Birmingham, UK. Subjects: All students in two randomly selected classes from each school completed the questionnaire, and never smokers, occasional smokers, and regular smokers were interviewed. Results: Two thirds of occasional smokers and one quarter of regular smokers obtained cigarettes socially, mostly for free. A few smokers regularly bought their cigarettes from others. Among friendship groups, both smokers and non-smokers were involved in the exchange of cigarettes, often for money, which is a common activity. A few young people use the selling of cigarettes to fund their own smoking. Some young people, smokers and non-smokers, are involved in semi-commercial selling of cigarettes. All school students are aware of where to purchase cigarettes from non-friends, which is only used “in emergency” because of the high price. One school had a strong punishment policy for students caught with cigarettes. In this school, more people bought singles from the peer market and the price was higher. Conclusions: The passing and selling of cigarettes in school is a common activity, which from the young persons perspective, ensures that all share cross counter purchases. A few people are prepared to use the peer market for monetary gain and it appears to be responsive to external conditions. The peer market might mean that efforts to control illegal sales of cigarettes are not as effective as hoped.

Does smoking status influence the prognosis of bladder cancer? A systematic review.

Objectivesu2002To summarize, in a systematic review, the evidence for the effect of stopping smoking on recurrence, cancer‐specific and all cause‐mortality among smokers with newly diagnosed bladder cancer.

A cluster randomised controlled trial of smoking cessation in pregnant women comparing interventions based on the transtheoretical (stages of change) model to standard care.

Objectives: To evaluate the effectiveness in helping pregnant women stop smoking of two interventions (Pro-Change for a healthy pregnancy) based on the transtheoretical model of behaviour change (TTM) compared to current standard care. Design: Cluster randomised trial. Setting: Antenatal clinics in West Midlands, UK general practices. Participants: 918 pregnant smokers Interventions: 100 general practices were randomised into the three trial arms. Midwives in these practices delivered three interventions: A (standard care), B (TTM based self help manuals), and C (TTM based self help manuals plus sessions with an interactive computer program giving individualised smoking cessation advice). Main outcome measures: Biochemically confirmed smoking cessation for 10 weeks previously, and point prevalence abstinence, both measured at 30 weeks of pregnancy and 10 days after delivery. Results: There were small differences between the TTM arms. Combining the two arms, the odds ratios at 30 weeks were 2.09 (95% confidence interval (CI) 0.90 to 4.85) for 10 week sustained abstinence and 2.92 (95% CI 1.42 to 6.03) for point prevalence abstinence relative to controls. At 10 days after delivery, the odds ratios were 2.81 (95% CI 1.11 to 7.13) and 1.85 (95% CI 1.00 to 3.41) for 10 week and point prevalence abstinence respectively. Conclusions: While there is a small borderline significant increase in quitting in the combined intervention arms compared with the controls, the effect of the intervention is small. At 30 weeks gestation and at 10 days postnatal, only about 3% of the intervention groups achieved sustained cessation, with numbers needed to treat of 67 (30 weeks of gestation) and 53 (10 weeks postnatal) for one additional woman to achieve sustained confirmed cessation. Given also that the intervention was resource intensive, it is of doubtful benefit.

The risk of preterm delivery in women from different ethnic groups

Objective To examine whether routinely measured variables explained the increased risk of preterm delivery in some UK ethnic groups.

The influence of school culture on smoking among pupils

School factors and not solely pupil composition probably cause variation in smoking prevalence amongst schools, but there are no theoretical models to explain why. In this paper we propose a hypothesis to explain schools influence on pupils smoking and test this using an existing cross-sectional survey of 23,282 pupils from 166 secondary schools in the West Midlands, UK. We hypothesise that school-level educational achievement scores would not be associated with smoking prevalence, but schools providing value-added education given the social background of pupils (authoritative schools) would provide effective support and control, have a relatively strong influence on pupils lives and be associated with lower than average smoking prevalence. Schools providing value-denuded education (laissez-faire schools) would have a relatively weak influence on pupils lives and be associated with higher than average smoking prevalence. The school achievement measures were the proportion of pupils achieving 5A-C General Certificates of Secondary Education (5A-Cs) grades and the proportion of half days lost to truancy. Value-added/denuded terms were created by regressing 5A-Cs and truancy on five markers of the social profile of pupils at the school. Authoritative schools achieved better than expected rates on both measures. Laissez-faire schools achieved worse than expected rates on both measures. All other schools were classed as indeterminate. Multilevel logistic regression was used to relate the risk of regular smoking to school culture in both achievement and authoritative/laissez-faire terms, both with and without adjustment for pupil-level risk factors for smoking. As predicted, schools achievement measures were unrelated to pupils smoking. The odds ratios (95% confidence intervals) for smoking in authoritative and laissez-faire schools relative to indeterminate schools were 0.80 (0.70-0.91) and 1.16 (1.07-1.27), respectively. Adjustment for pupil-level smoking risk factors had little effect. School culture is an independent risk factor for adolescent smoking. Schools providing effective support and control might protect pupils from smoking.

Adding fluoride to water supplies.

Adding fluoride to water supplies to prevent dental caries is controversial. K K Cheng, Iain Chalmers, and Trevor A Sheldon identify the issues it raises in the hope of furthering constructive public consultation and debate

The risk of smoking in relation to engagement with a school-based smoking intervention

Health promotion interventions cannot work if people do not engage with them. The aim of this study was to examine whether disengagement from an adolescent smoking prevention and cessation intervention was an independent risk factor for regular smoking 1 and 2 years later. The data were taken from a cluster randomised controlled trial, in the West Midlands, UK, based on the transtheoretical or stages of change model. In this trial, 8,352 13-14-year old school pupils enrolled, and the data in this report were based on the 7,413 and 6,782 pupils present at 1 and 2 years follow-ups, respectively. The intervention group undertook three sessions using an interactive computer programme. At the end of the programme, pupils recorded their responses to it. Pupils were classed as engaged if they thought the intervention was both useful and interesting; all others were classed as disengaged. Random effects logistic regression related the number of times engaged to regular smoking at 1 and 2 years follow-up, adjusted for school absences and 11 potential confounders. The majority of pupils were engaged by the intervention. For participants using the intervention three times but not engaging once, the odds ratios (95% confidence intervals) for smoking at 1 and 2 years relative to the controls were 1.83 (1.41-2.39) and 1.70 (1.38-2.11). For those engaging three times, they were 0.79 (0.60-1.03) and 0.96 (0.75-1.21). There was no interaction with baseline intention to smoke, classified by stage of change, but there was a borderline significant interaction with baseline smoking status, with disengagement acting as a stronger risk factor among baseline never-smokers. We conclude that disengagement from interventions is a risk factor for smoking independently of experimentation with cigarettes. The best explanation is that disengagement from school, an established risk factor for smoking, generalises to disengagement from didactic school-based health promotion programmes.