Muon spin relaxation study of LaTiO(3) and YTiO(3)

We report muon spin relaxation (μSR) measurements on two Ti(3+) containing perovskites, LaTiO(3) and YTiO(3), which display long-range magnetic order at low temperature. For both materials, oscillations in the time dependence of the muon polarization are observed which are consistent with three-dimensional magnetic order. From our data we identify two magnetically inequivalent muon stopping sites. The μSR results are compared with the magnetic structures of these compounds previously derived from neutron diffraction and μSR studies on structurally similar compounds.

Coexistence of magnetic fluctuations and superconductivity in the pnictide high temperature superconductor SmFeAsO1-xFx measured by muon spin rotation

Muon spin rotation experiments were performed on the pnictide high temperature superconductor SmFeAsO1-xFx with x=0.18 and 0.3. We observed an unusual enhancement of slow spin fluctuations in the vicinity of the superconducting transition which suggests that the spin fluctuations contribute to the formation of an unconventional superconducting state. An estimate of the in-plane penetration depth lambda ab(0)=190(5) nm was obtained, which confirms that the pnictide superconductors obey an Uemura-style relationship between Tc and lambda ab(0);(-2).

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. Date of the most recent search: September 2007.

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 measure was abstinence from smoking after at least six months follow up. We also considered the effect of advice on mortality where long-term follow-up data were available. 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. Effects were expressed as relative risks. Where possible, meta-analysis was performed using a Mantel-Haenszel fixed effect model.

MAIN RESULTS

We identified 41 trials, conducted between 1972 and 2007, 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) detected a significant increase in the rate of quitting (relative risk (RR) 1.66, 95% confidence interval (CI) 1.42 to 1.94). Amongst 11 trials where the intervention was judged to be more intensive the estimated effect was higher (RR 1.84, 95% CI 1.60 to 2.13) but there was no statistical difference between the intensive and minimal subgroups. Direct comparison of intensive versus minimal advice showed a small advantage of intensive advice (RR 1.37, 95% CI 1.20 to 1.56). Direct comparison also suggested a small benefit of follow-up visits. Only one study determined the effect of smoking advice on mortality. This study found no statistically significant differences in death rates at 20 years follow up.

AUTHORS' CONCLUSIONS

Simple advice has a small effect on cessation rates. Assuming an unassisted quit rate of 2 to 3%, a brief advice intervention can increase quitting by a further 1 to 3%. Additional components appear to have only a small effect, though there is a small additional benefit of more intensive interventions compared to very brief interventions.

Nicotine replacement therapy for smoking cessation

BACKGROUND

The aim of nicotine replacement therapy (NRT) is temporarily to replace much of the nicotine from cigarettes to reduce motivation to smoke and nicotine withdrawal symptoms, thus easing the transition from cigarette smoking to complete abstinence.

OBJECTIVES

The aims of this review were:To determine the effect of NRT compared to placebo in aiding smoking cessation, and to consider whether there is a difference in effect for the different forms of NRT (chewing gum, transdermal patches, nasal spray, inhalers and tablets/lozenges) in achieving abstinence from cigarettes. To determine whether the effect is influenced by the dosage, form and timing of use of NRT; the intensity of additional advice and support offered to the smoker; or the clinical setting in which the smoker is recruited and treated. To determine whether combinations of NRT are more likely to lead to successful quitting than one type alone. To determine whether NRT is more or less likely to lead to successful quitting compared to other pharmacotherapies.

SEARCH STRATEGY

We searched the Cochrane Tobacco Addiction Group trials register for papers with 'nicotine' or 'NRT' in the title, abstract or keywords. Date of most recent search July 2007.

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. We calculated the risk ratio (RR) for each study. Where appropriate, we performed meta-analysis using a Mantel-Haenszel fixed-effect model.

MAIN RESULTS

We identified 132 trials; 111 with over 40,000 participants contributed to the primary comparison between any type of NRT and a placebo or non-NRT control group. The RR of abstinence for any form of NRT relative to control was 1.58 (95% confidence interval [CI]: 1.50 to 1.66). The pooled RR for each type were 1.43 (95% CI: 1.33 to 1.53, 53 trials) for nicotine gum; 1.66 (95% CI: 1.53 to 1.81, 41 trials) for nicotine patch; 1.90 (95% CI: 1.36 to 2.67, 4 trials) for nicotine inhaler; 2.00 (95% CI: 1.63 to 2.45, 6 trials) for oral tablets/lozenges; and 2.02 (95% CI: 1.49 to 3.73, 4 trials) for nicotine nasal spray. The effects were largely independent of the duration of therapy, the intensity of additional support provided or the setting in which the NRT was offered. The effect was similar in a small group of studies that aimed to assess use of NRT obtained without a prescription. In highly dependent smokers there was a significant benefit of 4 mg gum compared with 2 mg gum, but weaker evidence of a benefit from higher doses of patch. There was evidence that combining a nicotine patch with a rapid delivery form of NRT was more effective than a single type of NRT. Only one study directly compared NRT to another pharmacotherapy. In this study quit rates with nicotine patch were lower than with the antidepressant bupropion.

AUTHORS' CONCLUSIONS

All of the commercially available forms of NRT (gum, transdermal patch, nasal spray, inhaler and sublingual tablets/lozenges) can help people who make a quit attempt to increase their chances of successfully stopping smoking. NRTs increase the rate of quitting by 50-70%, regardless of setting. The effectiveness of NRT appears to be largely independent of the intensity of additional support provided to the individual. Provision of more intense levels of support, although beneficial in facilitating the likelihood of quitting, is not essential to the success of NRT.

Anomalous temperature evolution of the internal magnetic field distribution in the charge-ordered triangular antiferromagnet AgNiO2

Zero-field muon-spin relaxation measurements of the frustrated triangular quantum magnet AgNiO2 are consistent with a model of charge disproportionation that has been advanced to explain the structural and magnetic properties of this compound. Below an ordering temperature of TN=19.9(2) K we observe six distinct muon precession frequencies, due to the magnetic order, which can be accounted for with a model describing the probable muon sites. The precession frequencies show an unusual temperature evolution which is suggestive of the separate evolution of two opposing magnetic sublattices.

Muon-fluorine entangled states in molecular magnets

The information accessible from a muon-spin relaxation experiment can be limited due to a lack of knowledge of the precise muon stopping site. We demonstrate here the possibility of localizing a spin polarized muon in a known stopping state in a molecular material containing fluorine. The muon-spin precession that results from the entangled nature of the muon spin and surrounding nuclear spins is sensitive to the nature of the stopping site. We use this property to identify three classes of sites that occur in molecular magnets and describe the extent to which the muon distorts its surroundings.

Interventions to reduce harm from continued tobacco use

BACKGROUND

It may be reasonable to try to reduce the harm from continued smoking amongst smokers unable or unwilling to quit. Possible approaches to reduce the exposure to toxins from smoking include reducing the amount of tobacco used, and using less toxic products. The interventions evaluated in controlled trials have predominantly attempted to reduce the number of cigarettes smoked.

OBJECTIVES

To assess the effect of interventions intended to reduce the harm from smoking on the following: biomarkers of damage caused by tobacco, biomarkers of tobacco exposure, number of cigarettes smoked, quitting, and long-term health status.

SEARCH STRATEGY

We searched the Cochrane Tobacco Addiction Group Specialised Register using free text and MeSH terms for harm reduction, smoking reduction and cigarette reduction. The initial search was in March 2006, updated in March 2007.

SELECTION CRITERIA

Randomized or quasi-randomized controlled trials of interventions in tobacco users to reduce amount smoked, or to reduce harm from smoking by means other than cessation. Outcomes were change in cigarette consumption, markers of cigarette exposure and any markers of damage or benefit to health, measured at least six months from the start of the intervention.

DATA COLLECTION AND ANALYSIS

We pooled trials with similar interventions and outcomes using a fixed-effect model. Other studies were summarised narratively.

MAIN RESULTS

The 13 included trials all evaluated interventions to help smokers cut down the amount smoked. Self-reported reduction in cigarettes per day (CPD) was validated by reduction in carbon monoxide (CO) levels. Most trials tested nicotine replacement therapy (NRT) to assist reduction. No eligible studies evaluated the use of potentially reduced-exposure products. In a pooled analysis of eight trials, NRT significantly increased the odds of reducing CPD by 50% or more for people using nicotine gum or inhaler or a choice of product compared to placebo (n=3273, odds ratio [OR] 2.02, 95% confidence interval [CI] 1.55 to 2.62). Where average changes from baseline were compared for different measures, CO and cotinine consistently showed smaller reductions than CPD. Whilst the effect for NRT was significant, small numbers of people in either treatment or control group successfully sustained a reduction of 50% or more. Use of NRT also significantly increased the odds of quitting (OR 1.90, 95% CI 1.46 to 2.47). One trial of bupropion failed to detect an effect on reduction or cessation. Four trials of different types of advice and instructions on reducing CPD did not provide clear evidence.

AUTHORS' CONCLUSIONS

There is insufficient evidence about long-term benefit to give firm support the use of interventions intended to help smokers reduce but not quit tobacco use. Some people who do not wish to quit can be helped to cut down the number of cigarettes smoked and reduce their carbon monoxide levels by using nicotine gum or nicotine inhaler. Because the long-term health benefit of a reduction in smoking rate is unclear this application of NRT is more appropriately used as a precursor to quitting.

Chiral-like critical behavior in the antiferromagnet cobalt glycerolate

Critical exponents closely matching those of the N=2 chiral universality class have been obtained for the layered magnetic system cobalt glycerolate using muon spin relaxation. This class was originally introduced to represent geometrically frustrated triangular stacked-layer XY magnets with chiral noncollinear spin structures. Since the present magnetic system is a canted XY system without geometrical frustration or chiral degeneracy, the results indicate that the order parameter for canting in this system plays a similar role to the chiral order parameter in the geometrically frustrated systems, strongly suggesting that both types of noncollinear system share the same universality class.

Magnetism in geometrically frustrated YMnO3 under hydrostatic pressure studied with muon spin relaxation

The ferroelectromagnet YMnO3 consists of weakly coupled triangular layers of S=2 spins. Below T(N) approximately equal to 70 K muon-spin relaxation data show two oscillatory relaxing signals due to magnetic order, with no purely relaxing signals resolvable (which would require different coexisting spin distributions). The transition temperature T(N) increases with applied hydrostatic pressure, even though the ordered moment decreases. These results suggest that pressure increases both the exchange coupling between the layers and the frustration within the layers.

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, (e.g. blocking nicotine receptors) 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 September 2006.

SELECTION CRITERIA

We considered randomized trials comparing antidepressant medications to placebo or an alternative pharmacotherapy for smoking cessation. We also included trials comparing different doses, using pharmacotherapy to prevent relapse or re-initiate smoking cessation or 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 available in each trial, and biochemically validated rates if available. Where appropriate, we performed meta-analysis using a fixed-effect model.

MAIN RESULTS

Seventeen new trials were identified since the last update in 2004 bringing the total number of included trials to 53. There were 40 trials of bupropion and eight trials of nortriptyline. When used as the sole pharmacotherapy, bupropion (31 trials, odds ratio [OR] 1.94, 95% confidence interval [CI] 1.72 to 2.19) and nortriptyline (four trials, OR 2.34, 95% CI 1.61 to 3.41) both doubled the odds of cessation. There is insufficient evidence that adding bupropion or nortriptyline to nicotine replacement therapy provides an additional long-term benefit. Three trials of extended therapy with bupropion to prevent relapse after initial cessation did not find evidence of a significant long-term benefit. From the available data bupropion and nortriptyline appear to be equally effective and of similar efficacy to nicotine replacement therapy. Pooling three trials comparing bupropion to varenicline showed a lower odds of quitting with bupropion (OR 0.60, 95% CI 0.46 to 0.78). 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. Nortriptyline has the potential for serious side-effects, but none have been seen in the few small trials for smoking cessation. There were six trials of selective serotonin reuptake inhibitors; four of fluoxetine, one of sertraline and one of paroxetine. None of these detected significant long-term effects, and there was no evidence of a significant benefit when results were pooled. 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.

AUTHORS' CONCLUSIONS

The antidepressants bupropion and nortriptyline aid long-term smoking cessation but selective serotonin reuptake inhibitors (e.g. fluoxetine) do not. Evidence suggests that the mode of action of bupropion and nortriptyline is independent of their antidepressant effect and that they are of similar efficacy to nicotine replacement. Adverse events with both medications are rarely serious or lead to stopping medication.

Nicotine receptor partial agonists for smoking cessation

BACKGROUND

Nicotine receptor partial agonists may help smokers to quit by a combination of maintaining moderate levels of dopamine to counteract withdrawal symptoms (acting as an agonist) and reducing smoking satisfaction (acting as an antagonist). Varenicline was developed as a nicotine receptor partial agonist from cytisine, a drug widely used in central and eastern Europe for smoking cessation. The first trial reports of varenicline were released in 2006, and further trials are underway.

OBJECTIVES

The primary objective of this review is to assess the efficacy and tolerability of nicotine receptor partial agonists, including varenicline and cytisine, for smoking cessation.

SEARCH STRATEGY

We searched the Cochrane Tobacco Addiction Group's specialised register for trials, using the terms ('varenicline' or 'cytisine' or 'Tabex' or 'nicotine receptor partial agonist') and 'smoking' in the title or abstract, or as keywords. We also searched MEDLINE, EMBASE, PsycINFO and CINAHL using MeSH terms and free text, and we contacted authors of trial reports for additional information where necessary. The last search was in October 2006.

SELECTION CRITERIA

We included randomized controlled trials which compared the treatment drug with placebo. We also included comparisons with bupropion where available. We excluded trials which did not report a minimum follow-up period of six months from start of treatment.

DATA COLLECTION AND ANALYSIS

We extracted data in duplicate on the type of participants, the dose and duration of treatment, the outcome measures, the randomization procedure, concealment of allocation, and completeness of follow up. The main outcome measured was abstinence from smoking after at least six months from the beginning of treatment. We used the most rigorous definition of abstinence, and preferred biochemically validated rates where they were reported. Where appropriate we performed meta-analysis using the Mantel-Haenszel fixed-effect model.

MAIN RESULTS

We found five trials of varenicline compared with placebo for smoking cessation; three of these also included a bupropion experimental arm. We also found one relapse prevention trial, comparing varenicline with placebo. The six trials covered 4924 participants, 2451 of whom used varenicline. We identified one trial of cytisine (Tabex) for inclusion. The pooled odds ratio (OR) for continuous abstinence at 12 months for varenicline versus placebo was 3.22 (95% confidence interval [CI] 2.43 to 4.27). The pooled OR for varenicline versus bupropion was 1.66 (95% CI 1.28 to 2.16). The main adverse effect of varenicline was nausea, which was mostly at mild to moderate levels and usually subsided over time. The two trials which tested the use of varenicline beyond the 12-week standard regimen found the drug to be well-tolerated and effective during long-term use. The one cytisine trial included in this review found that more participants taking cytisine stopped smoking compared with placebo at two-year follow up, with an OR of 1.77 (95% CI 1.30 to 2.40).

AUTHORS' CONCLUSIONS

Varenicline increased the odds of successful long-term smoking cessation approximately threefold compared with pharmacologically unassisted quit attempts. In trials reported so far, more participants quit successfully with varenicline than with bupropion. The effectiveness of varenicline as an aid to relapse prevention has not been clearly established. The main adverse effect of varenciline is nausea, but this is mostly at mild to moderate levels and tends to reduce with habituation. There is a need for independent trials of varenicline versus placebo, to test the early findings. There is also a need for direct comparisons with nicotine replacement therapy, and for further trials with bupropion, to establish the relative efficacy of the treatments.Cytisine may also increase the chances of quitting, but the evidence at present is inconclusive.

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, (e.g. blocking nicotine receptors) 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 September 2006.

SELECTION CRITERIA

We considered randomized trials comparing antidepressant medications to placebo or an alternative pharmacotherapy for smoking cessation. We also included trials comparing different doses, using pharmacotherapy to prevent relapse or re-initiate smoking cessation or 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 available in each trial, and biochemically validated rates if available. Where appropriate, we performed meta-analysis using a fixed-effect model.

MAIN RESULTS

Seventeen new trials were identified since the last update in 2004 bringing the total number of included trials to 53. There were 40 trials of bupropion and eight trials of nortriptyline. When used as the sole pharmacotherapy, bupropion (31 trials, odds ratio [OR] 1.94, 95% confidence interval [CI] 1.72 to 2.19) and nortriptyline (four trials, OR 2.34, 95% CI 1.61 to 3.41) both doubled the odds of cessation. There is insufficient evidence that adding bupropion or nortriptyline to nicotine replacement therapy provides an additional long-term benefit. Three trials of extended therapy with bupropion to prevent relapse after initial cessation did not find evidence of a significant long-term benefit. From the available data bupropion and nortriptyline appear to be equally effective and of similar efficacy to nicotine replacement therapy. Pooling three trials comparing bupropion to varenicline showed a lower odds of quitting with bupropion (OR 0.60, 95% CI 0.46 to 0.78). 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. Nortriptyline has the potential for serious side-effects, but none have been seen in the few small trials for smoking cessation. There were six trials of selective serotonin reuptake inhibitors; four of fluoxetine, one of sertraline and one of paroxetine. None of these detected significant long-term effects, and there was no evidence of a significant benefit when results were pooled. 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.

AUTHORS' CONCLUSIONS

The antidepressants bupropion and nortriptyline aid long-term smoking cessation but selective serotonin reuptake inhibitors (e.g. fluoxetine) do not. Evidence suggests that the mode of action of bupropion and nortriptyline is independent of their antidepressant effect and that they are of similar efficacy to nicotine replacement. Adverse events with both medications are rarely serious or lead to stopping medication.

Characterization of the Crystal and Magnetic Structures of the Mixed-Anion Coordination Polymer Cu(HCO2)(NO3)(pyz) {pyz = Pyrazine} by X-ray Diffraction, ac Magnetic Susceptibility, dc Magnetization, Muon-Spin Relaxation, and Spin Dimer Analysis

The mixed-anion coordination polymer Cu(HCO2)(NO3)(pyz) was synthesized, its crystal structure was determined by X-ray diffraction, and its magnetic structure was characterized by ac susceptibility, dc magnetization, muon-spin relaxation, and spin dimer analysis. The crystal structure consists of five-coordinate Cu2+ ions that are connected through syn-anti bridging mu-HCO2- and mu-pyz ligands to form a highly corrugated two-dimensional layered network. Bulk magnetic measurements show a broad maximum in chi(T) at 6.6 K. The HCO2- and pyz ligands mediate ferromagnetic and antiferromagnetic spin exchange interactions between adjacent Cu2+ ions with the spin exchange parameters J/kB = 8.17 and -5.4 K, respectively (H = -JSigmaSi x Sj). The muon-spin relaxation data show a transition to a long-range magnetic ordering below TN = 3.66(3) K. For T < TN, the M(H) and chi'ac measurements provide evidence for a field-induced spin-flop transition at 15.2 kOe. That Cu(HCO2)(NO3)(pyz) undergoes a long-range magnetic ordering is an unexpected result because the one-dimensional Cu(NO3)2(pyz) and three-dimensional Cu(HCO2)2(pyz) compounds display linear chain antiferromagnetism with no long-range magnetic ordering down to 2 K.

Opioid antagonists for smoking cessation

BACKGROUND

The reinforcing properties of nicotine may be mediated through release of various neurotransmitters both centrally and systemically. Smokers report positive effects such as pleasure, arousal, and relaxation as well as relief of negative affect, tension, and anxiety. Opioid (narcotic) antagonists are of particular interest to investigators as potential agents to attenuate the rewarding effects of cigarette smoking.

OBJECTIVES

To evaluate the efficacy of opioid antagonists in promoting long-term smoking cessation. The drugs include naloxone and the longer-acting opioid antagonist naltrexone.

SEARCH STRATEGY

We searched the Cochrane Tobacco Addiction Group specialized register for trials of naloxone, naltrexone and other opioid antagonists and conducted an additional search of MEDLINE using 'Narcotic antagonists' and smoking terms in March 2006. We also contacted investigators, when possible, for information on unpublished studies.

SELECTION CRITERIA

We considered randomized controlled trials comparing opioid antagonists to placebo or an alternative therapeutic control for smoking cessation. We included in the meta-analysis only those trials which reported data on abstinence for a minimum of six months. We also reviewed, for descriptive purposes, results from short-term laboratory-based studies of opioid antagonists designed to evaluate psycho-biological mediating variables associated with nicotine dependence.

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 cotinine- or carbon monoxide-verified abstinence from smoking after at least six months follow up in patients smoking at baseline. Where appropriate, we performed meta-analysis using a fixed-effect model (Mantel-Haenszel odds ratios).

MAIN RESULTS

Four trials of naltrexone met inclusion criteria for meta-analyses for long-term cessation. All four trials failed to detect a significant difference in quit rates between naltrexone and placebo. In a pooled analysis there was no significant effect of naltrexone on long-term abstinence, and confidence intervals were wide (odds ratio 1.26, 95% confidence interval 0.80 to 2.01). No trials of naloxone or buprenorphine reported long-term follow up.

AUTHORS' CONCLUSIONS

Based on limited data from four trials it is not possible to confirm or refute whether naltrexone helps smokers quit. The confidence intervals are compatible with both clinically significant benefit and possible negative effects of naltrexone in promoting abstinence. Data from larger trials of naltrexone are needed to settle the question of efficacy for smoking cessation.

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: January 2006.

SELECTION CRITERIA

Randomized or quasi-randomized 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 (LS) and checked by a second (TL). The main outcome measure was the odds ratio for abstinence from smoking after at least six months follow up. We selected the strictest measure of abstinence, using biochemically validated rates where available. We considered participants lost to follow-up to be continuing smokers. Where trials had more than one arm with a less intensive intervention we used only the most similar intervention without the telephone component as the control group in the primary analysis. We assessed statistical heterogeneity amongst sub groups of clinically comparable studies using the I(2) statistic. Where appropriate, we pooled studies using a fixed-effect model. A meta-regression was used to investigate the effect of differences in planned number of calls.

MAIN RESULTS

Forty-eight trials met the inclusion criteria. Among smokers who contacted helplines, quit rates were higher for groups randomised to receive multiple sessions of call-back counselling (eight studies, >18,000 participants, odds ratio (OR) for long term cessation 1.41, 95% confidence interval (CI) 1.27 to 1.57). Two of these studies showed a significant benefit of more intensive compared to less intensive intervention. Telephone counselling not initiated by calls to helplines also increased quitting (29 studies, >17,000 participants, OR 1.33, 95% CI 1.21 to 1.47). A meta-regression detected a significant association between the maximum number of planned calls and the effect size. There was clearer evidence of benefit in the subgroup of trials recruiting smokers motivated to quit. Of two studies that provided access to a hotline one showed a significant benefit and one did not. Two studies comparing different counselling approaches during a single session did not detect significant differences. A further seven studies were too diverse to contribute to meta-analyses and are discussed separately.

AUTHORS' CONCLUSIONS

Proactive telephone counselling helps smokers interested in quitting. There is evidence of a dose response; one or two brief calls are less likely to provide a measurable benefit. Three or more calls increases the odds of quitting compared to a minimal intervention such as providing standard self-help materials, brief advice, or compared to pharmacotherapy alone. Telephone quitlines provide an important route of access to support for smokers, and call-back counselling enhances their usefulness.

Low-temperature spin diffusion in a highly ideal S=1/2 Heisenberg antiferromagnetic chain studied by muon spin relaxation

The organic radical-ion salt DEOCC-TCNQF4 contains linear chains of stacked molecules with significant Heisenberg antiferromagnet interactions along the chain and extremely weak interactions between the chains. Zero-field muSR has confirmed the absence of long-range magnetic order down to 20 mK and field-dependent muSR is found to be consistent with diffusive motion of the spin excitations. The anisotropic spin dynamics and the upper boundary for magnetic ordering temperature both indicate interchain magnetic coupling /J'/<7 mK. As the intrachain coupling J is 110 K, /J'/J/ is significantly less than 10(-4). This system therefore provides one of the most ideal examples of the one-dimensional S=1/2 Heisenberg antiferromagnet yet discovered.

Nicobrevin for smoking cessation

BACKGROUND

Nicobrevin is a proprietary product marketed as an aid to smoking cessation. It contains quinine, menthyl valerate, camphor and eucalyptus oil.

OBJECTIVES

The objective of this review was to assess the effects of Nicobrevin on long term smoking cessation

SEARCH STRATEGY

We searched the Cochrane Tobacco Addiction Group trials register.

SELECTION CRITERIA

Randomized trials comparing Nicobrevin to placebo or an alternative therapeutic control, which reported smoking cessation with at least six months follow up.

DATA COLLECTION AND ANALYSIS

Data were sought on the outcome, method of randomization, and completeness of follow up.

MAIN RESULTS

We identified no trials meeting the full inclusion criteria including long-term follow up.

AUTHORS' CONCLUSIONS

There is no evidence available from long-term trials that Nicobrevin can aid smoking cessation.

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 April 2005.

SELECTION CRITERIA

We included randomized 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 participants, the nature of the self-help materials, the amount of face-to-face contact given to intervention and to control conditions, 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 people 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-effect model.

MAIN RESULTS

We identified sixty trials. Thirty-three compared self-help materials to no intervention or tested materials used in addition to advice. In 11 trials in which self help was compared to no intervention there was a pooled effect that just reached statistical significance (N = 13,733; odds ratio [OR] 1.24, 95% confidence interval [CI] 1.07 to 1.45). This analysis excluded two trials with strongly positive outcomes 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 were seventeen trials using materials tailored for the characteristics of individual smokers, where meta-analysis supported a small benefit of tailored materials (N = 20,414; OR 1.42, 95% CI 1.26 to 1.61). The evidence is strongest for tailored materials compared to no intervention, but also supports tailored materials as more helpful than standard materials. Part of this effect could be due to the additional contact or assessment required to obtain individual data. A small number of other trials failed to detect benefits from using additional materials or targeted materials, or to find differences between different self-help programmes.

AUTHORS' 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 healthcare professional, or nicotine replacement therapy. There is evidence that materials that are tailored for individual smokers are effective, and are more effective than untailored materials, although the absolute size of effect is still small.

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 to 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 MEDLINE and PsycINFO, including the terms behavior therapy, cognitive therapy, psychotherapy or group therapy, in January 2005.

SELECTION CRITERIA

We considered randomized 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 programme. 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 participants, the interventions provided to the groups and the controls, including programme length, intensity and main components, 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. We used the most rigorous definition of abstinence in each trial, and biochemically validated rates where available. Subjects lost to follow up were analyzed as continuing smokers. Where possible, we performed meta-analysis using a fixed-effects (Mantel-Haenszel) model.

MAIN RESULTS

A total of 55 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 = 4395, odds ratio (OR) 2.04, 95% confidence interval (CI) 1.60 to 2.60). Group programmes were more effective than no intervention controls (seven trials, N = 815, OR 2.17, 95% CI 1.37 to 3.45). 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. We did not find an effect of manipulating the social interactions between participants in a group programme on outcome.

AUTHORS' CONCLUSIONS

Group therapy is better for helping people stop smoking than self help, and other less intensive interventions. There is not enough evidence to evaluate whether groups are more effective, or cost-effective, than intensive individual counselling. There is not enough evidence to support the use of particular psychological components in a programme beyond the support and skills training normally included.

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 categorize 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 Cochrane Tobacco Addiction Group Specialized Register in October 2004, MEDLINE (1966 - October 2004), EMBASE (1985 - October 2004) and PsycINFO (to October 2004). We searched abstracts from international conferences on tobacco and we checked the bibliographies of identified studies and reviews for additional references.

SELECTION CRITERIA

We categorized 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 randomized 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 author 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 ten studies of group therapy, seven studies of individual counselling, nine studies of self-help materials and five 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 14 studies of tobacco bans, two studies of social support, four studies of environmental support, five studies of incentives, and eight studies of comprehensive (multi-component) programmes. 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.

AUTHORS' 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 organized 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.

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 Specialized Register for studies with counsel* in any field. Date of the most recent search: December 2004.

SELECTION CRITERIA

Randomized or quasi-randomized trials with at least one treatment arm consisting of face-to-face individual counselling from a healthcare 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 authors extracted data. The intervention and population, method of randomization and completeness of follow up were recorded.

MAIN RESULTS

We identified 21 trials with over 7000 participants. Eighteen trials compared individual counselling to a minimal behavioural intervention, four compared different types or intensities of counselling. Individual counselling was more effective than control. The odds ratio for successful smoking cessation was 1.56 (95% confidence interval 1.32 to 1.84). In a subgroup of three trials where all participants received nicotine replacement therapy the point estimate of effect was smaller and did not reach significance (odds ratio 1.34, 95% confidence interval 0.98 to 1.83). 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).

AUTHORS' CONCLUSIONS

Smoking cessation counselling can assist smokers to quit.

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: September 2004.

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

One reviewer prescreened studies for relevance, and both reviewers independently assessed the studies for inclusion. One reviewer extracted data from included studies and the second checked them. Study designs and types of intervention were heterogeneous so results were synthesized narratively, with greater weight given to controlled studies.

MAIN RESULTS

We identified 34 studies of which 14 had data from a control group for at least one outcome. Giving retailers information was less effective in reducing illegal sales than active enforcement or multicomponent educational strategies, or both. 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.

AUTHORS' 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.