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Biomedical subjects

M J Jarvis

Publications and source records attributed to M J Jarvis.

At least 19 recordsLinked to original sources
PubMed2006

Prevalence, diagnosis and relation to tobacco dependence of chronic obstructive pulmonary disease in a nationally representative population sample.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is the fourth most common cause of death worldwide. It is caused primarily by cigarette smoking. Given its importance, it is remarkable that reliable national prevalence data are lacking for most countries. This study provides estimates of the national prevalence of COPD in England, the extent of under-detection of the disorder, and patterns of cigarette smoking, dependence, and motivation to stop smoking in those with the disease. METHODS: Data from 8215 adults over the age of 35 who participated in the Health Survey for England were analysed. Information was obtained on self-reported and cotinine validated smoking status, cigarette dependence, motivation to stop smoking, COPD defined by spirometry using joint American Thoracic Society and European Respiratory Society criteria, and self-reports of diagnosis with respiratory disorders. RESULTS: Spirometry-defined COPD was present in 13.3% (95% CI 12.6 to 14.0) of participants, over 80% of whom reported no respiratory diagnosis. Even among people with severe or very severe COPD by spirometric assessment, only 46.8% (95% CI 39.1 to 54.6) reported any diagnosed respiratory disease. A total of 34.9% (95% CI 32.1 to 37.8) of people with spirometry-defined COPD were smokers compared with 22.4% (95% CI 21.4 to 23.4) of those without, and smoking prevalence increased with disease severity. Smokers with spirometry-defined COPD were more cigarette dependent but had no greater desire to quit than other smokers. CONCLUSION: COPD is common among adults in England and is predominantly undiagnosed. In smokers it is associated with higher degrees of cigarette dependence but not with a greater motivation to stop smoking.

Adult↗
PubMed2006

A photometric redshift of z = 6.39 +/- 0.12 for GRB 050904.

Gamma-ray bursts (GRBs) and their afterglows are the most brilliant transient events in the Universe. Both the bursts themselves and their afterglows have been predicted to be visible out to redshifts of z approximately 20, and therefore to be powerful probes of the early Universe. The burst GRB 000131, at z = 4.50, was hitherto the most distant such event identified. Here we report the discovery of the bright near-infrared afterglow of GRB 050904 (ref. 4). From our measurements of the near-infrared afterglow, and our failure to detect the optical afterglow, we determine the photometric redshift of the burst to be z = 6.39 - 0.12 + 0.11 (refs 5-7). Subsequently, it was measured spectroscopically to be z = 6.29 +/- 0.01, in agreement with our photometric estimate. These results demonstrate that GRBs can be used to trace the star formation, metallicity, and reionization histories of the early Universe.

Journal Article↗
PubMed2006

Vulnerability to smoking after trying a single cigarette can lie dormant for three years or more.

OBJECTIVE: To examine the development of smoking behaviour among adolescents who, at age 11, had tried cigarettes just once. DESIGN: A five-year prospective study. SETTING: 36 schools in South London, England. SUBJECTS: A socioeconomically and ethnically diverse sample of students completed questionnaires annually from age 11-16. A total of 5863 students took part, with an annual response rate ranging from 74-85%. 2041 (35%) provided smoking status data every year. MAIN OUTCOME MEASURES: Current smoking (smoking sometimes or more often) for the first time. Cotinine assays provided biochemical verification of smoking status. RESULTS: Students who at age 11 reported having tried smoking cigarettes just once (n = 260), but were not smoking at the time, were more likely to take-up smoking at a later age than those that had not tried smoking (n = 1719), even after a gap of up to three years of not smoking. The odds of starting to smoke at age 14 were 2.1 times greater (95% confidence interval 1.2 to 3.5) in the age 11 "one time triers" than the "non-triers", even once sex, ethnicity, deprivation, parental smoking and conduct disorder were adjusted for. CONCLUSIONS: This is the first clear demonstration of a "sleeper effect" or period of dormant vulnerability. Our findings have implications for understanding the development of cigarette use and for policies to reduce smoking in young people. Preventing children from trying even one cigarette may be important, and the design of interventions should recognise adolescents who have smoked just once, several years previously, as potentially vulnerable to later smoking uptake.

Adolescent↗
PubMed2005

Toward a comprehensive long term nicotine policy.

Global tobacco deaths are high and rising. Tobacco use is primarily driven by nicotine addiction. Overall tobacco control policy is relatively well agreed upon but a long term nicotine policy has been less well considered and requires further debate. Reaching consensus is important because a nicotine policy is integral to the target of reducing tobacco caused disease, and the contentious issues need to be resolved before the necessary political changes can be sought. A long term and comprehensive nicotine policy is proposed here. It envisages both reducing the attractiveness and addictiveness of existing tobacco based nicotine delivery systems as well as providing alternative sources of acceptable clean nicotine as competition for tobacco. Clean nicotine is defined as nicotine free enough of tobacco toxicants to pass regulatory approval. A three phase policy is proposed. The initial phase requires regulatory capture of cigarette and smoke constituents liberalising the market for clean nicotine; regulating all nicotine sources from the same agency; and research into nicotine absorption and the role of tobacco additives in this process. The second phase anticipates clean nicotine overtaking tobacco as the primary source of the drug (facilitated by use of regulatory and taxation measures); simplification of tobacco products by limitation of additives which make tobacco attractive and easier to smoke (but tobacco would still be able to provide a satisfying dose of nicotine). The third phase includes a progressive reduction in the nicotine content of cigarettes, with clean nicotine freely available to take the place of tobacco as society's main nicotine source.

Health Policy↗
PubMed2004

[Alphabet of stopping smoking--why people smoke?].

This paper describes the principle of tobacco dependence--psychosocial and physical (drug) dependence, reasons for starting, maintaining or stopping smoking, including treatment barriers. It deals with individual needs of nicotine doses and socio-economic relations.

Humans↗
PubMed2003

Socioeconomic disparities in cancer-risk behaviors in adolescence: baseline results from the Health and Behaviour in Teenagers Study (HABITS).

BACKGROUND: This study explores the association between socioeconomic deprivation and five factors associated with long-term risk of cancer, in adolescents. METHODS: BMI, fat intake, fruit and vegetable intake, smoking, and exercise were assessed in 4320 students ages 11 to 12, from 36 schools, in the first year of a 5-year longitudinal study of the development of health behaviors (HABITS study). Neighborhood socioeconomic deprivation for each student's area of residence was matched to their postcode (zip code). We used multiple logistic regression analyses to investigate the relationship between risky behaviors and socioeconomic circumstances. RESULTS: Univariate analyses showed boys and girls from more deprived neighborhoods were more likely to have tried smoking, to eat a high fat diet, and to be overweight. Girls living in more deprived areas were also less likely to eat five servings of fruit and vegetables or to exercise at the weekend. Most differences persisted after controlling for ethnicity. A clear deprivation gradient emerged for each risk factor, indicating the linear nature of the relationship. CONCLUSIONS: This study demonstrates the influence of deprivation on engaging in cancer-risk health behaviors. These patterns may set young people from more socioeconomically deprived social environments on a trajectory leading to increased cancer mortality in adult life.

Adolescent↗
PubMed2003

Examining the relationship between pubertal stage, adolescent health behaviours and stress.

BACKGROUND: This paper examines the associations between puberty and three important health behaviours (smoking, food intake and exercise) and explores whether these associations are mediated by puberty's relationship to stress and psychological difficulties. METHOD: Data were taken from the first year of the ongoing, 5-year, Health and Behaviours in Teenagers Study (HABITS). This is a school-based study set in 36 schools in London. In the first year of the study, 4320 students (2578 boys, 1742 girls) in their first year of secondary education took part. RESULTS: Among girls, being more pubertally advanced was associated with a greater likelihood of having tried smoking. Among boys, being more pubertally advanced was associated with a greater likelihood of having tried smoking, a higher intake of high-fat food and higher levels of exercise. More pubertally advanced girls experienced more stress but not more psychological difficulties. There were no associations between puberty and either stress or psychological difficulties in boys. Stress and psychological difficulties were associated with health behaviours in girls and boys, but neither of these factors mediated the relationship between pubertal stage and health behaviours found in girls. CONCLUSIONS: These results suggest that the onset of puberty has a marked effect on the development of health behaviours. Puberty was related to an acceleration of the development of unhealthy behaviours, except for exercise behaviour in boys, where advanced puberty was associated with more exercise. These changes were unrelated to adolescent issues of stress and a causal explanation for these associations must be sought elsewhere.

Adolescent↗
PubMed2003

Oral tobacco cessation with UK resident Bangladeshi women: a community pilot investigation.

Our objective was to establish the short-term outcomes for successful tobacco cessation of a programme offering UK resident Bangladeshi women chewing paan with tobacco nicotine replacement therapy (NRT) in addition to brief advice and encouragement alone. We used a short-term longitudinal, quasi-experimental study design, in the setting of two local authority housing estates in Tower Hamlets, London. Bangladeshi women volunteers were recruited following presentations to community groups. The volunteers were assigned, after matching for age, number of paan with tobacco chewed daily and medical screening, to receive one of two tobacco cessation interventions (NRT with brief encouragement and advice, and brief advice and encouragement alone). The main outcome measures were changes in tobacco use and nicotine dependence, assessed by questionnaire and intake measures, adverse effects, and withdrawal symptoms. In total, 130 volunteers were recruited. Their mean age was 42.5 years (SD = 11.3). Mean number of paan quid with tobacco chewed daily was 10.7 (SD = 9.3) and the average age of starting to add tobacco to paan was 24 years (SD = 12). Ninety-one percent completed the 4-week trial. We found that 19.5% had stopped tobacco use, of whom 22% had received NRT, and 17% brief advice and encouragement alone. The successful members of the NRT group made a significantly greater reduction in their salivary cotinine scores at final review compared to baseline. Oral pain was reported as a barrier to successful oral tobacco cessation by 62% of the volunteers at final review. We conclude that methods identified as helping tobacco smokers successfully stop smoking can be used with Bangladeshi women chewing paan with tobacco. More research is needed to investigate these short-term outcomes and to explore the particular barriers to successful cessation for this group such as oral pain.

Adult↗
PubMed2003

European Union policy on smokeless tobacco: a statement in favour of evidence based regulation for public health.

RATIONALE: This statement is an updated version of one released by the same authors in February 2003. The statement was produced to follow up the Royal College of Physicians (RCP) Tobacco Advisory Group report "Protecting smokers, saving lives: the case for a tobacco and nicotine regulatory authority", which argued for an evidence based regulatory approach to smokeless tobacco and harm reduction and posed a series of questions that regulators must address in relation to smokeless tobacco. The purpose of this statement is to provide arguments of fact and principle to follow the RCP's report and to outline the public health case for changing existing European Union (EU) regulation in this area. A review of regulation in relation to harm reduction and regulation of tobacco products other than cigarettes is required in Article 11 of EU directive 2001/37/EC, and this is a contribution towards forming a consensus in the European public health community about what policy the EU should adopt in the light of this review, or following ongoing legal action that may potentially strike out the existing regulation altogether. PUBLIC HEALTH CASE: We believe that the partial ban applied to some forms of smokeless tobacco in the EU should be replaced by regulation of the toxicity of all smokeless tobacco. We hold this view for public health reasons: smokeless tobacco is substantially less harmful than smoking and evidence from Sweden suggests it is used as a substitute for smoking and for smoking cessation. To the extent there is a "gateway" it appears not to lead to smoking, but away from it and is an important reason why Sweden has the lowest rates of tobacco related disease in Europe. We think it is wrong to deny other Europeans this option for risk reduction and that the current ban violates rights of smokers to control their own risks. For smokers that are addicted to nicotine and cannot or will not stop, it is important that they can take advantage of much less hazardous forms of nicotine and tobacco-the alternative being to "quit or die". and many die. While nicotine replacement therapies (NRT) may have a role in harm reduction, tobacco based harm reduction options may reach more smokers and in a different, market based, way. Chewing tobacco is not banned or regulated in the EU but is often highly toxic, and our proposal could remove more products from the market than it permitted. REGULATORY OPTIONS: We believe that the EU policy on smokeless tobacco should adapt to new scientific knowledge and that the European Commission should bring forward proposals to amend or replace Article 8 of directive 2001/37/EC with a new regulatory framework. Canada has developed testing regimens for tobacco constituents and these could be readily adapted to the European situation. A review of EU policy in this area is required no later than December 2004, and we believe the Commission should expedite the part of its review that deals with harm reduction and regulation of tobacco products other than cigarettes so as to reconsider its policy on smokeless tobacco. We held this view before Swedish Match brought its legal proceedings to challenge EU legislation and we will continue to hold these views if its action fails.

European Union↗
PubMed2001

Nicotine yield from machine-smoked cigarettes and nicotine intakes in smokers: evidence from a representative population survey.

BACKGROUND: The relevance of nicotine yields from machine-smoked cigarettes for quantifying smokers' nicotine intakes and exposure to cigarette toxins has been called into question. However, most studies of the relationship between nicotine yield and nicotine intake have been on relatively small and unrepresentative samples and have included few smokers of "ultra-low" brands (i.e., those yielding around 1 mg of tar and 0.1 mg of nicotine). METHODS: We examined the relationship between salivary cotinine (a major metabolite of nicotine) concentrations and nicotine yields of machine-smoked cigarettes in a nationally representative sample of 2031 adult smokers of manufactured cigarettes surveyed in the 1998 Health Survey for England. We used standard linear regression techniques to examine associations and two-sided tests of statistical significance. RESULTS: Cotinine concentrations varied widely between smokers at any level of nominal brand nicotine yield. On average, cotinine levels were slightly lower in smokers of lower nicotine-yielding brands, but these smokers differed in terms of sex, socioeconomic profile, and cigarette consumption. After we controlled for potential confounders, nicotine yield from the brand smoked accounted for only 0.79% of the variation in saliva cotinine concentrations. Nicotine intake per cigarette smoked, as estimated from salivary cotinine level, did not correspond with machine-smoked yields at any level of nicotine yield. Nicotine intake per cigarette was about eight times greater than machine-smoked yields at the lowest deliveries (1.17 mg estimated nicotine intake per cigarette from brands averaging 0.14-mg delivery from machine smoking) and 1.4 times greater for the highest yield cigarettes (1.31-mg estimated nicotine intake per cigarette from brands averaging 0.91 mg from machine smoking). CONCLUSIONS: Smokers' tendency to regulate nicotine intake vitiates potential health gains from lower tar and nicotine cigarettes. Current approaches to characterizing tar and nicotine yields of cigarettes provide a simplistic guide to smokers' exposure that is misleading to consumers and regulators alike and should be abandoned.

Adolescent↗
PubMed2001

Public awareness of warning signs for cancer in Britain.

BACKGROUND: The objective of this study was to establish the level of public awareness of warning signs for cancer in Britain. METHODS: An interview-based survey of a representative sample of the UK population was undertaken; 3693 men and women completed the interview (69% response rate). The data from this survey included demographic characteristics as well as recognition of the 'seven warning signs for cancer'. FINDINGS: Results revealed that recognition of signs ranged from 81% ('thickening or lump'; n = 2994) to 37% ('indigestion/difficulty swallowing'; n = 1356). On average participants identified 4.2 of the signs, with only 1.6% (n = 58) identifying all seven. There were strong associations with demographic characteristics, with better recognition being associated with being female, married, higher socioeconomic status (SES), higher income, a homeowner and having more years of education. INTERPRETATION: From these results we conclude that fewer than one in ten of the UK population can recognize seven warning signs for cancer, but the mean number recognized (4.2 signs) suggests that there is a reasonable level of public awareness. It must be cause for concern that most markers of lower SES are independently associated with poorer recognition, suggesting that public education needs to do more to narrow the inequalities in health knowledge.

Adolescent↗
PubMed2001

Awareness of risk factors for cancer among British adults.

Awareness of risk factors for five common cancers was assessed in a representative sample of 3 693 adults in the UK. Respondents were presented with a risk of 14 factors comprising 10 which have established links with various cancers (older age, many sexual partners, low fibre diet, smoking, a relative with the cancer, low fruit and vegetable diet, taking HRT/the contraceptive pill, being overweight, viruses or infection, and a high fat diet) and four so-called "mythic" causes (food additives, overhead power lines, pollution, stress). Out of 15 well-established associations between risk factors and cancers, the average number correctly identified was 5. Women and those with higher levels of education got more correct. Endorsement of mythic causes was comparatively low (less than 5% for most cancers), but were higher in men and those with less education. These results are somewhat reassuring in relation to the prevalence of erroneous beliefs, but raise considerable concern about public understanding of well established causes. Better health education will be needed to maximise public awareness of cancer prevention.

Adult↗
PubMed2001

Passive smoking in the home: plasma cotinine concentrations in non-smokers with smoking partners.

BACKGROUND: Risks of lung cancer and of heart disease attributable to passive smoking have been evaluated mainly in non-smokers married to smokers, but there has been little quantitative assessment of the extent of exposure in marriage partners as indicated by markers of inhaled smoke dose. OBJECTIVE: To relate plasma cotinine concentrations in non-smoking English adults to the smoking behaviour of their partners and to demographic and other factors. DATA: Population survey. Data from two years (1994 and 1996) of the Health Survey for England. MAIN OUTCOME MEASURES: Plasma cotinine concentrations in non-smoking adults married to or cohabiting with a partner. RESULTS: There was a strong dose-response relation between cotinine concentrations in non-smoking adults and the smoking behaviour of their partners, rising from a geometric mean of 0.31 ng/ml in those with non-smoking partners to 1.99 ng/ml in those whose partners smoked 30 or more cigarettes per day. In addition, exposure was greater in men, in the autumn and winter, and in those living in more disadvantaged circumstances, and there was an increasing gradient of exposure from the south to the north of the country. On average, cotinine concentrations in non-smokers with a smoking partner were 0.6-0.7% of those in cigarette smokers. CONCLUSIONS: If cotinine is taken as a measure of risk relevant dose, the implied increase in risk of lung cancer in non-smokers with smoking partners is consistent with the risk observed in epidemiological studies. Smoking by partners in the home is a major source of non-smoking adults' exposure to passive smoking.

Adult↗
PubMed2001

Trends in sales weighted tar, nicotine, and carbon monoxide yields of UK cigarettes.

BACKGROUND: Reducing tar yields of manufactured cigarettes has been an important plank of government policy on tobacco, but sale weighted yields are not routinely published. METHODS: Tar, nicotine, and carbon monoxide yields measured by the Laboratory of the Government Chemist were combined with cigarette brand market shares from national surveys of smoking behaviour to generate sales weighted yield estimates for the period 1972-99. RESULTS: Sales weighted mean tar yields have declined steadily and in 1999 were 9.6 mg per cigarette, less than half their level in 1972. Over the same period nicotine yields have come down from 1.33 mg to 0.79 mg per cigarette. Carbon monoxide yields have shown smaller declines. At the same time as absolute yields have declined, there have also been changes in tar to nicotine ratios. Smokers in 1999 were exposed to 22% less tar per unit of nicotine than in 1973, and smokers of low tar brands have consistently been exposed to less tar per unit of nicotine than smokers of other brands. CONCLUSIONS: The value of reducing cigarette tar and nicotine yields has been questioned, since the tendency of smokers to compensate for reductions in nicotine delivery undermines the policy. The favourable trends in tar to nicotine ratios suggest that, despite this, there may have been some modest public health benefit. It cannot be assumed that future reductions from present levels would necessarily result in further improvement in tar to nicotine ratios. An explicit focus on the ratio of tar to nicotine may provide a metric of greater relevance for public health than the present emphasis on absolute tar yields.

Carbon Monoxide↗
PubMed2000

Children's exposure to passive smoking in England since the 1980s: cotinine evidence from population surveys.

OBJECTIVE: To determine whether children's exposure to passive smoking has changed since the late 1980s. DESIGN: Cross sectional surveys of nationally representative samples of secondary school children carried out between 1988 and 1998 by Office for National Statistics. SETTING: England. SUBJECTS: Secondary school children aged 11-15. MAIN OUTCOME MEASURES: Salivary cotinine concentrations in non-smoking children. RESULTS: Cotinine concentrations in all non-smoking children almost halved between 1988 and 1998, from a geometric mean of 0.96 (95% confidence interval 0.83 to 1.11) ng/ml in 1988 to 0.52 (0.43 to 0.62) ng/ml in 1998. This reduction was largely due to reductions in exposure in children from non-smoking households and to decreases in the percentage of parents who smoked. Children living with mothers or fathers who smoked experienced little reduction in exposure. CONCLUSIONS: Exposure to passive smoking among children in England has approximately halved since the late 1980s. This reduction is partly explained by the fall in the percentage of both mothers and fathers who smoke and is also likely to reflect reductions of smoking in public places. However, there is only limited evidence that children from smoking households have experienced a reduction in exposure through parents' avoidance of smoking in their presence.

Adolescent↗