Cu(HCO2)2(pym) (pym = pyrimidine): Low-Dimensional Magnetic Behavior and Long-Range Ordering in a Quantum-Spin Lattice

We synthesized and structurally and magnetically characterized the novel 3D coordination polymer Cu(HCO2)2(pym) (pym = pyrimidine). The compound crystallizes in the monoclinic space group C2/c with a = 14.4639(8) A, b = 7.7209(4) A, c = 8.5172(5) A, beta = 126.076(2) degrees, and V= 768.76(7) A3. In the structure buckled layers of Cu(HCO2)2 are interconnected by pym ligands to afford 1D Cu-pym-Cu chains. Bulk magnetic susceptibility measurements show a broad maximum at 25 K that is indicative of short-range magnetic ordering. Between 12 and 300 K a least-squares fit of the chi(T) data to a mean-field-corrected antiferromagnetic chain model yielded excellent agreement for g = 2.224(3), J/kB = -26.9(2) K, and zJ'/kB = -1.1(3) K. Below approximately 3 K a transition to long-range magnetic ordering is observed, as suggested by a sharp and sudden decrease in chi(T). This result is corroborated by muon spin relaxation measurements that show oscillations in the muon asymmetry below T(N) = 2.802(1) K and rapidly fluctuating moments above T(N).

Antidepressants for smoking cessation

BACKGROUND

There are at least two theoretical reasons to believe antidepressants might help in smoking cessation. Nicotine withdrawal may produce depressive symptoms or precipitate a major depressive episode and antidepressants may relieve these. Nicotine may have antidepressant effects that maintain smoking, and antidepressants may substitute for this effect. Alternatively, some antidepressants may have a specific effect on neural pathways underlying nicotine addiction, independent of their antidepressant effects.

OBJECTIVES

The aim of this review is to assess the effect of antidepressant medications in aiding long-term smoking cessation. The medications include bupropion; doxepin; fluoxetine; imipramine; moclobemide; nortriptyline; paroxetine; sertraline, tryptophan and venlafaxine.

SEARCH STRATEGY

We searched the Cochrane Tobacco Addiction Group trials register which includes trials indexed in MEDLINE, EMBASE, SciSearch and PsycINFO, and other reviews and meeting abstracts, in March 2004.

SELECTION CRITERIA

We considered randomized trials comparing antidepressant medications to placebo or an alternative therapy for smoking cessation. We also included trials comparing different doses, using pharmacotherapy to prevent relapse or re-initiate smoking cessation and using pharmacotherapy to help smokers reduce cigarette consumption. We excluded trials with less than six months follow up.

DATA COLLECTION AND ANALYSIS

We extracted data in duplicate on the type of study population, the nature of the pharmacotherapy, the outcome measures, method of randomization, and completeness of follow up. The main outcome measure was abstinence from smoking after at least six months follow up in patients smoking at baseline, expressed as an odds ratio (OR). We used the most rigorous definition of abstinence for each trial, and biochemically validated rates if available. Where appropriate, we performed meta-analysis using a fixed effect model.

MAIN RESULTS

There was one trial of the monoamine oxidase inhibitor moclobemide, and one of the atypical antidepressant venlafaxine. Neither of these detected a significant long-term benefit. There were five trials of selective serotonin reuptake inhibitors; three of fluoxetine, one of sertraline and one of paroxetine. None of these detected significant effects, and there was no evidence of a significant benefit when results were pooled. There were 24 trials of bupropion and six trials of nortriptyline. When used as the sole pharmacotherapy, bupropion (19 trials, OR 2.06, 95% confidence intervals [CI] 1.77 to 2.40) and nortriptyline (four trials, OR 2.79, 95% CI 1.70 to 4.59) both doubled the odds of cessation. In one trial the combination of bupropion and nicotine patch produced slightly higher quit rates than patch alone, but this was not replicated in a second study. Two trials of extended therapy with bupropion to prevent relapse after initial cessation did not show a significant long-term benefit. There is a risk of about 1 in 1000 of seizures associated with bupropion use. Concerns that bupropion may increase suicide risk are currently unproven.

REVIEWERS' CONCLUSIONS

The antidepressants bupropion and nortriptyline aid long term smoking cessation but selective serotonin reuptake inhibitors (e.g. fluoxetine) do not. The fact that only some forms of antidepressants aid cessation and that they do so regardless of depressive symptoms strongly suggests that their mode of action is independent of their antidepressant effect.

Physician advice for smoking cessation

BACKGROUND

Healthcare professionals frequently advise patients to improve their health by stopping smoking. Such advice may be brief, or part of more intensive interventions.

OBJECTIVES

The aims of this review were to assess the effectiveness of advice from physicians in promoting smoking cessation; to compare minimal interventions by physicians with more intensive interventions; to assess the effectiveness of various aids to advice in promoting smoking cessation and to determine the effect of anti-smoking advice on disease-specific and all-cause mortality.

SEARCH STRATEGY

We searched the Cochrane Tobacco Addiction Group trials register and the Cochrane Central Register of Controlled Trials (CENTRAL). Date of the most recent searches: March 2004.

SELECTION CRITERIA

Randomized trials of smoking cessation advice from a medical practitioner in which abstinence was assessed at least six months after advice was first provided.

DATA COLLECTION AND ANALYSIS

We extracted data in duplicate on the setting in which advice was given, type of advice given (minimal or intensive), and whether aids to advice were used, the outcome measures, method of randomization and completeness of follow up. The main outcome measures were abstinence from smoking after at least six months follow up and mortality. We used the most rigorous definition of abstinence in each trial, and biochemically validated rates where available. Subjects lost to follow up were counted as smokers. Where possible, meta-analysis was performed using a Mantel-Haenszel fixed effect model.

MAIN RESULTS

We identified 39 trials, conducted between 1972 and 2003, including over 31,000 smokers. In some trials, subjects were at risk of specified diseases (chest disease, diabetes, ischaemic heart disease), but most were from unselected populations. The most common setting for delivery of advice was primary care. Other settings included hospital wards and outpatient clinics, and industrial clinics. Pooled data from 17 trials of brief advice versus no advice (or usual care) revealed a small but significant increase in the odds of quitting (odds ratio 1.74, 95% confidence interval 1.48 to 2.05). This equates to an absolute difference in the cessation rate of about 2.5%. There was insufficient evidence, from indirect comparisons, to establish a significant difference in the effectiveness of physician advice according to the intensity of the intervention, the amount of follow up provided, and whether or not various aids were used at the time of the consultation in addition to providing advice. Direct comparison of intensive versus minimal advice showed a small advantage of intensive advice (odds ratio 1.44, 95% confidence interval 1.24 to 1.67). Direct comparison also suggested a small benefit of follow-up visits. Only one study determined the effect of smoking advice on mortality. It found no statistically significant differences in death rates at 20 years follow up.

REVIEWERS' CONCLUSIONS

Simple advice has a small effect on cessation rates. Additional manoeuvres appear to have only a small effect, though more intensive interventions are marginally more effective than minimal interventions.

Physician advice for smoking cessation

BACKGROUND

Healthcare professionals frequently advise patients to improve their health by stopping smoking. Such advice may be brief, or part of more intensive interventions.

OBJECTIVES

The aims of this review were to assess the effectiveness of advice from physicians in promoting smoking cessation; to compare minimal interventions by physicians with more intensive interventions; to assess the effectiveness of various aids to advice in promoting smoking cessation and to determine the effect of anti-smoking advice on disease-specific and all-cause mortality.

SEARCH STRATEGY

We searched the Cochrane Tobacco Addiction Group trials register and the Cochrane Central Register of Controlled Trials (CENTRAL). Date of the most recent searches: March 2004.

SELECTION CRITERIA

Randomized trials of smoking cessation advice from a medical practitioner in which abstinence was assessed at least six months after advice was first provided.

DATA COLLECTION AND ANALYSIS

We extracted data in duplicate on the setting in which advice was given, type of advice given (minimal or intensive), and whether aids to advice were used, the outcome measures, method of randomization and completeness of follow up. The main outcome measures were abstinence from smoking after at least six months follow up and mortality. We used the most rigorous definition of abstinence in each trial, and biochemically validated rates where available. Subjects lost to follow up were counted as smokers. Where possible, meta-analysis was performed using a Mantel-Haenszel fixed effect model.

MAIN RESULTS

We identified 39 trials, conducted between 1972 and 2003, including over 31,000 smokers. In some trials, subjects were at risk of specified diseases (chest disease, diabetes, ischaemic heart disease), but most were from unselected populations. The most common setting for delivery of advice was primary care. Other settings included hospital wards and outpatient clinics, and industrial clinics. Pooled data from 17 trials of brief advice versus no advice (or usual care) revealed a small but significant increase in the odds of quitting (odds ratio 1.74, 95% confidence interval 1.48 to 2.05). This equates to an absolute difference in the cessation rate of about 2.5%. There was insufficient evidence, from indirect comparisons, to establish a significant difference in the effectiveness of physician advice according to the intensity of the intervention, the amount of follow up provided, and whether or not various aids were used at the time of the consultation in addition to providing advice. Direct comparison of intensive versus minimal advice showed a small advantage of intensive advice (odds ratio 1.44, 95% confidence interval 1.24 to 1.67). Direct comparison also suggested a small benefit of follow-up visits. Only one study determined the effect of smoking advice on mortality. It found no statistically significant differences in death rates at 20 years follow up.

REVIEWERS' CONCLUSIONS

Simple advice has a small effect on cessation rates. Additional manoeuvres appear to have only a small effect, though more intensive interventions are marginally more effective than minimal interventions.

Assessment in undergraduate dermatology

Assessment should be considered at an early stage in curriculum planning and must strive for the best balance between validity (testing what is important) and reliability (providing inferences about the student's competence). The primary purpose of summative assessment in clinical medicine is to determine whether the candidate is competent. Dermatologists should use a range of summative assessment techniques that are appropriate for testing the curricular outcomes. These will include tests of application of knowledge and of clinical skills. All students should also receive regular formative assessment to allow them to measure their progress, but this is not used for summative decisions. We review the key issues surrounding assessment and some specific techniques that might be appropriate for testing learning outcomes in undergraduate dermatology, either in the context of a clinical placement or in an integrated assessment involving a number of specialties or systems.

Nicotine replacement therapy for smoking cessation

BACKGROUND

The aim of nicotine replacement therapy (NRT) is to replace nicotine from cigarettes. This reduces withdrawal symptoms associated with smoking cessation thus helping resist the urge to smoke cigarettes.

OBJECTIVES

The aims of this review were:to determine the effectiveness of the different forms of NRT (chewing gum, transdermal patches, nasal spray, inhalers and tablets) in achieving abstinence from cigarettes, or a sustained reduction in amount smoked; to determine whether the effect is influenced by the clinical setting in which the smoker is recruited and treated, the dosage and form of the NRT used, or the intensity of additional advice and support offered to the smoker; to determine whether combinations of NRT are more effective than one type alone; to determine its effectiveness compared to other pharmacotherapies.

SEARCH STRATEGY

We searched the Cochrane Tobacco Addiction Group trials register in March 2004.

SELECTION CRITERIA

Randomized trials in which NRT was compared to placebo or to no treatment, or where different doses of NRT were compared. We excluded trials which did not report cessation rates, and those with follow up of less than six months.

DATA COLLECTION AND ANALYSIS

We extracted data in duplicate on the type of participants, the dose, duration and form of nicotine therapy, the outcome measures, method of randomization, and completeness of follow up. The main outcome measure was abstinence from smoking after at least six months of follow up. We used the most rigorous definition of abstinence for each trial, and biochemically validated rates if available. For each study we calculated summary odds ratios. Where appropriate, we performed meta-analysis using a Mantel-Haenszel fixed effect model.

MAIN RESULTS

We identified 123 trials; 103 contributing to the primary comparison between NRT and a placebo or non-NRT control group. The odds ratio (OR) for abstinence with NRT compared to control was 1.77 (95% confidence intervals (CI): 1.66 to 1.88). The ORs for the different forms of NRT were 1.66 (95% CI: 1.52 to 1.81) for gum, 1.81 (95% CI: 1.63 to 2.02) for patches, 2.35 (95% CI: 1.63 to 3.38) for nasal spray, 2.14 (95% CI: 1.44 to 3.18) for inhaled nicotine and 2.05 (95% CI: 1.62 to 2.59) for nicotine sublingual tablet/lozenge. These odds were largely independent of the duration of therapy, the intensity of additional support provided or the setting in which the NRT was offered. In highly dependent smokers there was a significant benefit of 4 mg gum compared with 2 mg gum (OR 2.20, 95% CI: 1.85 to 3.25). There was weak evidence that combinations of forms of NRT are more effective. Higher doses of nicotine patch may produce small increases in quit rates. Only one study directly compared NRT to another pharmacotherapy. In this study quit rates with bupropion were higher than with nicotine patch or placebo.

REVIEWERS' CONCLUSIONS

All of the commercially available forms of NRT (gum, transdermal patch, nasal spray, inhaler and sublingual tablets/lozenges) are effective as part of a strategy to promote smoking cessation. They increase the odds of quitting approximately 1.5 to 2 fold regardless of setting. The effectiveness of NRT appears to be largely independent of the intensity of additional support provided to the smoker. Provision of more intense levels of support, although beneficial in facilitating the likelihood of quitting, is not essential to the success of NRT.

Workplace interventions for smoking cessation

BACKGROUND

The workplace has potential as a setting through which large groups of people can be reached to encourage smoking cessation.

OBJECTIVES

To categorise workplace interventions for smoking cessation tested in controlled studies and to determine the extent to which they help workers to stop smoking or to reduce tobacco consumption.

SEARCH STRATEGY

We searched the Tobacco Addiction Review Group trials register in November 2002, Medline (1966 - November 2002), EMBASE (1985 - November 2002) and PsycINFO (to November 2002). We searched abstracts from international conferences on tobacco and we checked the bibliographies of identified studies and reviews for additional references.

SELECTION CRITERIA

We categorised interventions into two groups: a) Interventions aimed at the individual to promote smoking cessation and b) interventions aimed at the workplace as a whole. We applied different inclusion criteria for the different types of study. For interventions aimed at helping individuals to stop smoking, we included only randomised controlled trials allocating individuals, workplaces or companies to intervention or control conditions. For studies of smoking restrictions and bans in the workplace, we also included controlled trials with baseline and post-intervention outcomes and interrupted times series studies.

DATA COLLECTION AND ANALYSIS

Information relating to the characteristics and content of all kinds of interventions, participants, outcomes and methods of the study was abstracted by one reviewer and checked by two others. Because of heterogeneity in the design and content of the included studies, we did not attempt formal meta-analysis, and evaluated the studies using qualitative narrative synthesis.

MAIN RESULTS

Workplace interventions aimed at helping individuals to stop smoking included nine studies of group therapy, three studies of individual counselling, eight studies of self-help materials and four studies of nicotine replacement therapy. The results were consistent with those found in other settings. Group programmes, individual counselling and nicotine replacement therapy increased cessation rates in comparison to no treatment or minimal intervention controls. Self-help materials were less effective. Workplace interventions aimed at the workforce as a whole included 13 studies of tobacco bans, two studies of social support, four studies of environmental support, four studies of incentives, six studies of comprehensive (multi-component) programmes and two studies of competitions and recruitment. Tobacco bans decreased cigarette consumption during the working day but their effect on total consumption was less certain. We failed to detect an increase in quit rates from adding social and environmental support to these programmes. There was a lack of evidence that comprehensive programmes reduced the prevalence of smoking. Competitions and incentives increased attempts to stop smoking, though there was less evidence that they increased the rate of actual quitting.

REVIEWER'S CONCLUSIONS

We found 1. Strong evidence that interventions directed towards individual smokers increase the likelihood of quitting smoking. These include advice from a health professional, individual and group counselling and pharmacological treatment to overcome nicotine addiction. Self-help interventions are less effective. All these interventions are effective whether offered in the workplace or elsewhere. Although people taking up these interventions are more likely to stop, the absolute numbers who quit are low. 2. Limited evidence that participation in programmes can be increased by competitions and incentives organised by the employer. 3. Consistent evidence that workplace tobacco policies and bans can decrease cigarette consumption during the working day by smokers and exposure of non-smoking employees to environmental tobacco smoke at work, but conflicting evidence about whether they decrease prevalence of smoking or overall consumption of tobacco by smokers. 4. A lack of evidence that comprehensive approaches reduce the prevalence of smoking, despite the strong theoretical rationale for their use. 5. A lack of evidence about the cost-effectiveness of workplace programmes.

Antidepressants for smoking cessation

BACKGROUND

There at least two reasons to believe antidepressants might help in smoking cessation. Depression may be a symptom of nicotine withdrawal, and smoking cessation sometimes precipitates depression. In some individuals, nicotine may have antidepressant effects that maintain smoking. Antidepressants may substitute for this effect.

OBJECTIVES

The aim of this review is to assess the effect of antidepressant medications in aiding long-term smoking cessation. The drugs include bupropion; doxepin; fluoxetine; imipramine; moclobemide; nortriptyline; paroxetine; selegiline; sertraline, tryptophan and venlafaxine.

SEARCH STRATEGY

We searched the Cochrane Tobacco Addiction Group trials register which includes trials indexed in MEDLINE, EMBASE, SciSearch and PsycINFO, and other reviews and meeting abstracts, in December 2002.

SELECTION CRITERIA

We considered randomized trials comparing antidepressant drugs to placebo or an alternative therapeutic control for smoking cessation. For the meta-analysis, we excluded trials with less than six months follow-up.

DATA COLLECTION AND ANALYSIS

We extracted data in duplicate on the type of study population, the nature of the drug therapy, the outcome measures, method of randomization, and completeness of follow-up. The main outcome measure was abstinence from smoking after at least six months follow-up in patients smoking at baseline, expressed as an odds ratio (OR). We used the most rigorous definition of abstinence for each trial, and biochemically validated rates if available. Where appropriate, we performed meta-analysis using a fixed effects model.

MAIN RESULTS

There was one trial each of moclobemide, sertraline and venlafaxine, two of fluoxetine, five of nortriptyline, and twenty trials of bupropion. In the bupropion trials, 18 had a placebo arm, two of which tested long-term use to prevent relapse. Nine of the bupropion trials have been published in full. Nortriptyline (five trials, OR 2.80, 95% CI 1.81 - 4.32) and bupropion (16 trials, OR 1.97, 95% CI 1.67 - 2.34) both increased the odds of cessation. In one trial the combination of bupropion and nicotine patch produced slightly higher quit rates than patch alone, but this was not replicated in a second study. Two trials of extended therapy with bupropion to prevent relapse after initial cessation have failed to detect a long-term benefit.

REVIEWER'S CONCLUSIONS

The antidepressants bupropion and nortriptyline can aid smoking cessation but selective serotonin reuptake inhibitors (e.g. fluoxetine) do not.

Telephone counselling for smoking cessation

BACKGROUND

Telephone services can provide information and support for smokers. Counselling may be provided proactively or offered reactively to callers to smoking cessation helplines.

OBJECTIVES

To evaluate the effect of proactive and reactive telephone support to help smokers quit.

SEARCH STRATEGY

We searched the Cochrane Tobacco Addiction Group trials register for studies using free text term 'telephone*' or the keywords 'telephone counselling' or 'Hotlines' or 'Telephone'. Date of the most recent search: September 2002.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials in which proactive or reactive telephone counselling to assist smoking cessation was offered to smokers or recent quitters.

DATA COLLECTION AND ANALYSIS

Trials were identified and data extracted by one person and checked by a second. The main outcome measure was abstinence from smoking after at least six months follow-up. We used the most rigorous definition of abstinence in each trial, and biochemically validated rates where available. Participants lost to follow-up were considered to be continuing smokers. Where trials had more than one arm with a less intensive intervention we used only the most similar intervention as the control group in the primary analysis. Where interventions were similar, we performed meta-analysis using a fixed effects model (Peto method) to give an odds ratio.

MAIN RESULTS

Twenty seven trials met inclusion criteria. Thirteen trials compared proactive counselling to a minimal intervention control. There was statistical heterogeneity, with five trials showing a significant benefit, and eight showing non significant differences. The heterogeneity was associated with trials that provided tailored self-help materials to the control group. Meta-analysis using all less intensive intervention arms as the control removed the heterogeneity and suggests that telephone counselling compared to less intensive intervention increases quit rates (OR 1.56, 1.38 - 1.77). Four trials adding telephone support to a face to face intervention control failed to detect a significant effect on long term quit rates. Four trials failed to detect an additional effect of telephone support in users of nicotine replacement therapy. Providing access to a hotline showed a significant benefit in one trial and no significant difference in two. No differences in outcome were detected in trials that compared different types of telephone counselling.

REVIEWER'S CONCLUSIONS

Proactive telephone counselling can be effective compared to an intervention without personal contact. Successful interventions generally involve multiple contacts timed around a quit attempt. The available evidence neither confirms nor rules out a benefit of telephone counselling as an adjunct to face to face counselling or pharmacotherapy. Further trials randomising access to helplines are unlikely to be done but indirect evidence suggests they can be a useful part of a smoking cessation service.

Changes in the motility of B16F10 melanoma cells induced by alterations in resting calcium influx

Alterations in the extracellular Ca(2+) or K(+) concentration had significant influences on the motility of B16F10 melanoma cells measured in the absence of exogenous integrins using a conventional Boyden chamber assay. At normal K(+) concentrations, motility increased slightly when the concentration of Ca(2+) was increased 10-fold. At normal Ca(2+) concentrations, motility increased by 290% when the extracellular K(+) concentration was reduced 10-fold (from control of 5.4 mM to 0.54 mM), and increased to 250% of control levels when the K(+) concentration was increased between 30 and 54 mM, but was relatively uninfluenced at K(+) concentrations between 5 and 30 mM. Simultaneous application of low concentrations (20 microM) of GdCl(3) completely prevented the effects of low and high K(+) on motility. Exposure to Gd(3+) or Tb(3+) also produced a flattening of the cells and enhanced cell attachment. Although the steady state intracellular Ca(2+) concentration was not significantly influenced by the K(+) concentration, the resting permeability to divalent cations, determined from Mn(2+) quench rates in fura-loaded cells, was significantly increased by a reduction in the K(+) concentration. These results indicate that resting Ca(2+) influx is critical to the movement of B16F10 melanoma cells, and demonstrate that lanthanides, which block resting Ca(2+) influx pathways, are potent antimotility agents.

Individual behavioural counselling for smoking cessation

BACKGROUND

Individual counselling from a smoking cessation specialist may help smokers to make a successful attempt to stop smoking.

OBJECTIVES

The objective of the review is to determine the effects of individual counselling.

SEARCH STRATEGY

We searched the Cochrane Tobacco Addiction Group trials register for studies with counsel* in any field. Date of the most recent search: February 2002.

SELECTION CRITERIA

Randomised or quasi-randomised trials with at least one treatment arm consisting of face to face individual counselling from a health care worker not involved in routine clinical care. The outcome was smoking cessation at follow-up at least six months after the start of counselling.

DATA COLLECTION AND ANALYSIS

Both reviewers extracted data. The intervention and population, method of randomisation and completeness of follow-up were recorded.

MAIN RESULTS

We identified eighteen trials. Fifteen compared individual counselling to a minimal intervention, four compared different types or intensities of counselling. Individual counselling was more effective than control. The odds ratio for successful smoking cessation was 1.62 (95% confidence interval 1.35 to 1.94). We failed to detect a greater effect of intensive counselling compared to brief counselling (odds ratio 0.98, 95% confidence interval 0.61 to 1.56).

REVIEWER'S CONCLUSIONS

Smoking cessation counselling can assist smokers to quit.

Self-help interventions for smoking cessation

BACKGROUND

Many smokers give up smoking on their own, but materials giving advice and information may help them and increase the number who quit successfully.

OBJECTIVES

The aims of this review were to determine the effectiveness of different forms of self-help materials, compared with no treatment and with other minimal contact strategies; the effectiveness of adjuncts to self-help, such as computer generated feedback, telephone hotlines and pharmacotherapy; and the effectiveness of approaches tailored to the individual compared with non-tailored materials.

SEARCH STRATEGY

We searched the Cochrane Tobacco Addiction Group trials register using the terms 'self-help', 'manual*' or 'booklet*'. Date of the most recent search March 2002.

SELECTION CRITERIA

We included randomised trials of smoking cessation with follow-up of at least six months, where at least one arm tested a self-help intervention. We defined self-help as structured programming for smokers trying to quit without intensive contact with a therapist.

DATA COLLECTION AND ANALYSIS

We extracted data in duplicate on the type of subjects, the nature of the self-help materials, the amount of face to face contact given to subjects and to controls, outcome measures, method of randomisation, and completeness of follow-up. The main outcome measure was abstinence from smoking after at least six months follow-up in patients smoking at baseline. We used the most rigorous definition of abstinence in each trial, and biochemically validated rates when available. Where appropriate, we performed meta-analysis using a fixed effects model.

MAIN RESULTS

We identified fifty-one trials. Thirty two compared self-help materials to no intervention or tested materials used in addition to advice. In eleven trials in which self-help was compared to no intervention there was a pooled effect that just reached statistical significance (odds ratio 1.24, 95% confidence interval 1.07 to 1.45) This analysis excluded one trial with a strongly positive outcome that introduced significant heterogeneity. Four further trials in which the control group received alternative written materials did not show evidence for an effect of the smoking self-help materials. We failed to find evidence of benefit from adding self-help materials to face to face advice, or to nicotine replacement therapy. There was evidence from fourteen trials using materials tailored for the characteristics of individual smokers that such personalised materials were more effective than standard manuals (ten trials, odds ratio 1.36, 95% confidence interval 1.13 to 1.64) or no materials (three trials, odds ratio 1.80, 95% confidence interval 1.46 to 2.23). A small numbers of trials failed to detect benefit from using additional materials or targetted materials.

REVIEWER'S CONCLUSIONS

Standard self-help materials may increase quit rates compared to no intervention, but the effect is likely to be small. We failed to find evidence that they have an additional benefit when used alongside other interventions such as advice from a health care professional, or nicotine replacement therapy. There is evidence that materials that are tailored for individual smokers are more effective.

Community interventions for reducing smoking among adults

BACKGROUND

Since smoking behaviour is determined by social context, the best way to reduce the prevalence of smoking may be to use community-wide programmes which use multiple channels to provide reinforcement, support and norms for not smoking.

OBJECTIVES

To assess the effectiveness of community interventions for reducing the prevalence of smoking.

SEARCH STRATEGY

We searched the Cochrane Tobacco Addiction Group specialised register, MEDLINE (1966-August 2001) and EMBASE (1980-August 2001) and reference lists of articles.

SELECTION CRITERIA

Controlled trials of community interventions for reducing smoking prevalence in adult smokers. The primary outcome was smoking behaviour.

DATA COLLECTION AND ANALYSIS

Data were extracted by one person and checked by a second.

MAIN RESULTS

Thirty two studies were included, of which seventeen included only one intervention and one comparison community. Only four studies used random assignment of communities to either the intervention or comparison group. The population size of the communities ranged from a few thousand to over 100,000 people. Change in smoking prevalence was measured using cross-sectional follow-up data in 27 studies. The estimated net decline ranged from -1.0% to 3.0% for men and women combined (10 studies). For women, the decline ranged from -0.2% to + 3.5% per year (n=11), and for men the decline ranged from -0.4% to +1.6% per year (n=12). Cigarette consumption and quit rates were only reported in a small number of studies. The two most rigorous studies showed limited evidence of an effect on prevalence. In the US COMMIT study there was no differential decline in prevalence between intervention and control communities, and there was no significant difference in the quit rates of heavier smokers who were the target intervention group. In the Australian CART study there was a significantly greater quit rate for men but not women.

REVIEWER'S CONCLUSIONS

The failure of the largest and best conducted studies to detect an effect on prevalence of smoking is disappointing. A community approach will remain an important part of health promotion activities, but designers of future programmes will need to take account of this limited effect in determining the scale of projects and the resources devoted to them.

Interventions for preventing tobacco sales to minors

BACKGROUND

Laws restricting sales of tobacco products to minors exist in many countries, but young people may still purchase cigarettes easily.

OBJECTIVES

The review assesses the effects of interventions to reduce underage access to tobacco by deterring shopkeepers from making illegal sales.

SEARCH STRATEGY

We searched the Cochrane Tobacco Addiction group trials register, MEDLINE and EMBASE. Date of the most recent searches: October 2001.

SELECTION CRITERIA

We included controlled trials and uncontrolled studies with pre- and post intervention assessment of interventions to change retailers' behaviour. The outcomes were changes in retailer compliance with legislation (assessed by test purchasing), changes in young people's smoking behaviour, and perceived ease of access to tobacco products.

DATA COLLECTION AND ANALYSIS

Studies were prescreened for relevance by one person and assessed for inclusion by two people independently. Data from included studies were extracted by one person and checked by a second. Study designs and types of intervention were heterogeneous so results were synthesised narratively, with greater weight given to controlled studies.

MAIN RESULTS

We identified 30 studies of which 13 were controlled. Giving retailers information was less effective in reducing illegal sales than active enforcement and/or multicomponent educational strategies. No strategy achieved complete, sustained compliance. In three controlled trials, there was little effect of intervention on youth perceptions of access or prevalence of smoking.

REVIEWER'S CONCLUSIONS

Interventions with retailers can lead to large decreases in the number of outlets selling tobacco to youths. However, few of the communities studied in this review achieved sustained levels of high compliance. This may explain why there is limited evidence for an effect of intervention on youth perception of ease of access to tobacco, and on smoking behaviour.

Nicotine replacement therapy for smoking cessation

BACKGROUND

The aim of nicotine replacement therapy (NRT) is to replace nicotine from cigarettes. This reduces withdrawal symptoms associated with smoking cessation thus helping resist the urge to smoke cigarettes.

OBJECTIVES

The aims of this review were to determine the effectiveness of the different forms of nicotine replacement therapy (chewing gum, transdermal patches, nasal spray, inhalers and tablets) in achieving abstinence from cigarettes, or a sustained reduction in amount smoked; to determine whether the effect is influenced by the clinical setting in which the smoker is recruited and treated, the dosage and form of the NRT used, or the intensity of additional advice and support offered to the smoker; to determine whether combinations of NRT are more effective than one type alone; and to determine its effectiveness compared to other pharmacotherapies.

SEARCH STRATEGY

We searched the Cochrane Tobacco Addiction Group trials register in July 2002.

SELECTION CRITERIA

Randomized trials in which NRT was compared to placebo or no treatment, or where different doses of NRT were compared. We excluded trials which did not report cessation rates, and those with follow-up of less than six months.

DATA COLLECTION AND ANALYSIS

We extracted data in duplicate on the type of subjects, the dose and duration and form of nicotine therapy, the outcome measures, method of randomization, and completeness of follow-up. The main outcome measure was abstinence from smoking after at least six months of follow-up. We used the most rigorous definition of abstinence for each trial, and biochemically validated rates if available. Where appropriate, we performed meta-analysis using a fixed effects model (Peto).

MAIN RESULTS

We identified 110 trials; 96 with a non NRT control group. The odds ratio for abstinence with NRT compared to control was 1.74 (95% confidence interval 1.64 - 1.86), The odds ratios for the different forms of NRT were 1.66 for gum, 1.74 for patches, 2.27 for nasal spray, 2.08 for inhaled nicotine and 2.08 for nicotine sublingual tablet/lozenge. These odds were largely independent of the duration of therapy, the intensity of additional support provided or the setting in which the NRT was offered. In highly dependent smokers there was a significant benefit of 4 mg gum compared with 2mg gum (odds ratio 2.67, 95% confidence interval 1.69 - 4.22). There was weak evidence that combinations of forms of NRT are more effective. Higher doses of nicotine patch may produce small increases in quit rates. Only one study directly compared NRT to another pharmacotherapy, in which bupropion was significantly more effective than nicotine patch or placebo.

REVIEWER'S CONCLUSIONS

All of the commercially available forms of NRT (nicotine gum, transdermal patch, the nicotine nasal spray, nicotine inhaler and nicotine sublingual tablets/lozenges) are effective as part of a strategy to promote smoking cessation. They increase quit rates approximately 1.5 to 2 fold regardless of setting. The effectiveness of NRT appears to be largely independent of the intensity of additional support provided to the smoker. Provision of more intense levels of support, although beneficial in facilitating the likelihood of quitting, is not essential to the success of NRT. There is promising evidence that bupropion may be more effective than NRT (either alone or in combination). However, its most appropriate place in the therapeutic armamentarium requires further study and consideration.

Quantitative and functional differences in CD8+ lymphocyte responses in resolved acute and chronic hepatitis C virus infection

CD8+ T lymphocyte responses are important in the clearance of viral infections. In chronic infections they may contribute to pathogenesis. To investigate the role of CD8+ T lymphocyte responses in viral clearance and chronic hepatitis C we have compared hepatitis C virus (HCV) specific cytotoxicity and interferon-gamma (IFN-gamma) production in patients with resolved-acute, and chronic HCV infection. CD8+ T cell responses to a panel of 13 HCV T cell peptide epitopes were studied using Elispot assays of IFN-gamma production and chromium release cytotoxicity assays. Responses of seven patients with resolved acute HCV infection were compared with those of 14 chronically infected patients. HCV-specific cytotoxicity differentiated the two populations of patients. The majority (71%) of patients with resolved acute infection tested positive to 42% of relevant peptides compared with the minority (28%) of patients with chronic hepatitis C (P=0.03) who responded to only 8% of relevant peptides (P=0.0009). In contrast, HCV-specific IFN-gamma production was detected in 86% of patients with either resolved or chronic infection in response to 42% and 35%, respectively, of relevant peptides tested (not significant). In patients with chronic infection the magnitude of the HCV-specific IFN-gamma production was inversely correlated to viral load (R2=0.52; P=0.042). Failure to clear HCV infection may be attributable to the presence of noncytolytic IFN-gamma producing CD8+ T lymphocytes in chronically infected patients. However these CD8+ T cells may play a beneficial role in contributing to the control of viral load in chronic hepatitis C.

Group behaviour therapy programmes for smoking cessation

BACKGROUND

Group therapy offers individuals the opportunity to learn behavioural techniques for smoking cessation, and to provide each other with mutual support.

OBJECTIVES

We aimed to determine the effects of smoking cessation programmes delivered in a group format compared to self-help materials, or to no intervention; to compare the effectiveness of group therapy and individual counselling; and to determine the effect of adding group therapy to advice from a health professional or nicotine replacement. We also aimed to determine whether specific components increased the effectiveness of group therapy. We aimed to determine the rate at which offers of group therapy are taken up.

SEARCH STRATEGY

We searched the Cochrane Tobacco Addiction Group trials register, with additional searches of PsycInfo and MEDLINE, including the terms behavior therapy, cognitive therapy, psychotherapy or group therapy, in December 2001.

SELECTION CRITERIA

We considered randomised trials that compared group therapy with self-help, individual counselling, another intervention or no intervention (including usual care or a waiting list control). We also considered trials that compared more than one group programmes. We included those trials with a minimum of two group meetings, and follow-up of smoking status at least six months after the start of the programme. We excluded trials in which group therapy was provided to both active therapy and placebo arms of trials of pharmacotherapies, unless they had a factorial design.

DATA COLLECTION AND ANALYSIS

We extracted data in duplicate on the people recruited, the interventions provided to the groups and the controls, including programme length, intensity and main components, the outcome measures, method of randomisation, and completeness of follow-up. The main outcome measure was abstinence from smoking after at least six months follow-up in patients smoking at baseline. We used the most rigorous definition of abstinence in each trial, and biochemically validated rates where available. Subjects lost to follow-up were counted as smokers. Where possible, we performed meta-analysis using a fixed effects (Peto) model.

MAIN RESULTS

A total of fifty two trials met inclusion criteria for one or more of the comparisons in the review. Sixteen studies compared a group programme with a self-help programme. There was an increase in cessation with the use of a group programme (N=4,395, odds ratio 1.97, 95% confidence interval 1.57 to 2.48). Group programmes were more effective than no intervention controls (six trials, N=775, odds ratio 2.19, 95% confidence interval 1.42 to 3.37). There was no evidence that group therapy was more effective than a similar intensity of individual counselling. There was limited evidence that the addition of group therapy to other forms of treatment, such as advice from a health professional or nicotine replacement produced extra benefit. There was variation in the extent to which those offered group therapy accepted the treatment. There was limited evidence that programmes which included components for increasing cognitive and behavioural skills and avoiding relapse were more effective than same length or shorter programmes without these components. This analysis was sensitive to the way in which one study with multiple conditions was included. There was no evidence that manipulating the social interactions between participants in a group programme had an effect on outcome.

REVIEWER'S CONCLUSIONS

Groups are better than self-help, and other less intensive interventions. There is not enough evidence on their effectiveness, or cost-effectiveness, compared to intensive individual counselling. The inclusion of skills training to help smokers avoid relapse appears to be useful although the evidence is limited. There is not enough evidence to support the use of particular components in a programme beyond the support and skills training normally included.

Use of systematic reviews in clinical practice guidelines: case study of smoking cessation

OBJECTIVE

To examine the extent to which recommendations in the national guidelines for the cessation of smoking are based on evidence from systematic reviews of controlled trials.

DESIGN

Retrospective analysis of recommendations for the national guidelines for the cessation of smoking.

MATERIALS

National guidelines in clinical practice on smoking cessation published in English.

MAIN OUTCOME MEASURES

The type of evidence (systematic review of controlled trials, individual trials, other studies, expert opinion) used to support each recommendation. We also assessed whether a Cochrane systematic review was available and could have been used in formulating the recommendation.

RESULTS

Four national smoking cessation guidelines (from Canada, New Zealand, the United Kingdom, and the United States) covering 105 recommendations were identified. An explicit evidence base for 100%, 89%, 68%, and 98% of recommendations, respectively, was detected, of which 60%, 56%, 59%, and 47% were based on systematic reviews of controlled studies. Cochrane systematic reviews could have been used to develop between 39% and 73% of recommendations but were actually used in 0% to 36% of recommendations. The UK guidelines had the highest proportion of recommendations based on Cochrane systematic reviews.

CONCLUSIONS

Use of systematic reviews in guidelines is a measure of the "payback" on investment in research synthesis. Systematic reviews commonly underpinned recommendations in guidelines on smoking cessation. The extent to which they were used varied by country and there was evidence of duplication of effort in some areas. Greater international collaboration in developing and maintaining an evidence base of systematic reviews can improve the efficiency of use of research resources.