Re-treatment with varenicline is a cost-effective aid for smoking cessation

Identifying best modelling practices for tobacco control policy simulations: a systematic review and a novel quality assessment framework

BACKGROUND

Policy simulation models (PSMs) have been used extensively to shape health policies before real-world implementation and evaluate post-implementation impact. This systematic review aimed to examine best practices, identify common pitfalls in tobacco control PSMs and propose a modelling quality assessment framework.

METHODS

We searched five databases to identify eligible publications from July 2013 to August 2019. We additionally included papers from Feirman et al for studies before July 2013. Tobacco control PSMs that project tobacco use and tobacco-related outcomes from smoking policies were included. We extracted model inputs, structure and outputs data for models used in two or more included papers. Using our proposed quality assessment framework, we scored these models on population representativeness, policy effectiveness evidence, simulated smoking histories, included smoking-related diseases, exposure-outcome lag time, transparency, sensitivity analysis, validation and equity.

FINDINGS

We found 146 eligible papers and 25 distinct models. Most models used population data from public or administrative registries, and all performed sensitivity analysis. However, smoking behaviour was commonly modelled into crude categories of smoking status. Eight models only presented overall changes in mortality rather than explicitly considering smoking-related diseases. Only four models reported impacts on health inequalities, and none offered the source code. Overall, the higher scored models achieved higher citation rates.

CONCLUSIONS

While fragments of good practices were widespread across the reviewed PSMs, only a few included a 'critical mass' of the good practices specified in our quality assessment framework. This framework might, therefore, potentially serve as a benchmark and support sharing of good modelling practices.

Motivational support intervention to reduce smoking and increase physical activity in smokers not ready to quit: the TARS RCT

Background

Physical activity can support smoking cessation for smokers wanting to quit, but there have been no studies on supporting smokers wanting only to reduce. More broadly, the effect of motivational support for such smokers is unclear.

Objectives

The objectives were to determine if motivational support to increase physical activity and reduce smoking for smokers not wanting to immediately quit helps reduce smoking and increase abstinence and physical activity, and to determine if this intervention is cost-effective.

Design

This was a multicentred, two-arm, parallel-group, randomised (1 : 1) controlled superiority trial with accompanying trial-based and model-based economic evaluations, and a process evaluation.

Setting and participants

Participants from health and other community settings in four English cities received either the intervention (n = 457) or usual support (n = 458).

Intervention

The intervention consisted of up to eight face-to-face or telephone behavioural support sessions to reduce smoking and increase physical activity.

Main outcome measures

The main outcome measures were carbon monoxide-verified 6- and 12-month floating prolonged abstinence (primary outcome), self-reported number of cigarettes smoked per day, number of quit attempts and carbon monoxide-verified abstinence at 3 and 9 months. Furthermore, self-reported (3 and 9 months) and accelerometer-recorded (3 months) physical activity data were gathered. Process items, intervention costs and cost-effectiveness were also assessed.

Results

The average age of the sample was 49.8 years, and participants were predominantly from areas with socioeconomic deprivation and were moderately heavy smokers. The intervention was delivered with good fidelity. Few participants achieved carbon monoxide-verified 6-month prolonged abstinence [nine (2.0%) in the intervention group and four (0.9%) in the control group; adjusted odds ratio 2.30 (95% confidence interval 0.70 to 7.56)] or 12-month prolonged abstinence [six (1.3%) in the intervention group and one (0.2%) in the control group; adjusted odds ratio 6.33 (95% confidence interval 0.76 to 53.10)]. At 3 months, the intervention participants smoked fewer cigarettes than the control participants (21.1 vs. 26.8 per day). Intervention participants were more likely to reduce cigarettes by ≥ 50% by 3 months [18.9% vs. 10.5%; adjusted odds ratio 1.98 (95% confidence interval 1.35 to 2.90] and 9 months [14.4% vs. 10.0%; adjusted odds ratio 1.52 (95% confidence interval 1.01 to 2.29)], and reported more moderate-to-vigorous physical activity at 3 months [adjusted weekly mean difference of 81.61 minutes (95% confidence interval 28.75 to 134.47 minutes)], but not at 9 months. Increased physical activity did not mediate intervention effects on smoking. The intervention positively influenced most smoking and physical activity beliefs, with some intervention effects mediating changes in smoking and physical activity outcomes. The average intervention cost was estimated to be £239.18 per person, with an overall additional cost of £173.50 (95% confidence interval -£353.82 to £513.77) when considering intervention and health-care costs. The 1.1% absolute between-group difference in carbon monoxide-verified 6-month prolonged abstinence provided a small gain in lifetime quality-adjusted life-years (0.006), and a minimal saving in lifetime health-care costs (net saving £236).

Conclusions

There was no evidence that behavioural support for smoking reduction and increased physical activity led to meaningful increases in prolonged abstinence among smokers with no immediate plans to quit smoking. The intervention is not cost-effective.

Limitations

Prolonged abstinence rates were much lower than expected, meaning that the trial was underpowered to provide confidence that the intervention doubled prolonged abstinence.

Future work

Further research should explore the effects of the present intervention to support smokers who want to reduce prior to quitting, and/or extend the support available for prolonged reduction and abstinence.

Trial registration

This trial is registered as ISRCTN47776579.

Funding

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 27, No. 4. See the NIHR Journals Library website for further project information.

Comparison between success rates for smokers re-treated by a smokers' clinic and success rates for smokers treated for the first time

AIMS

To compare success rates and characteristics of smokers treated a second time by a smokers' clinic with success rates of their first treatment.

DESIGN

Retrospective cohort study.

SETTING

Tobacco Dependence Treatment clinic in Prague, Czech Republic, between 2005 and 2017.

PARTICIPANTS

A total of 5225 smokers treated either once (n = 5006, single treatment sample, SS) or also second time (n = 219, re-treated sample, RS), on average 4.47 years after the first visit.

INTERVENTION

Smokers received intensive treatment of tobacco dependence with pharmacotherapy options. Outcomes were evaluated after 1 year. In case of failure or relapse, participants could undergo re-treatment in the same setting at least 1 year after the start of the first treatment.

MEASUREMENTS

Twelve-month self-reported continuous abstinence; CO-validated (≤ 6 parts per million); number of visits; type of pharmacotherapy; mental health history; Fagerström Test for Cigarette Dependence; time between first and second treatment.

RESULTS

The abstinence rate in the SS was 34.8% [95% confidence interval (CI) = 33.4%, 36.1%] and in the RS was 37% (95% CI = 30.6%, 43.8%) and 39.7% (95% CI = 33.2%, 45.5%) for their first and second treatments, respectively. The samples were comparable on smoking and socio-demographic characteristics and pharmacotherapy used, but the RS in the second treatment had a higher prevalence of diagnosed mental health disorder at 39.3% (95% CI = 32.8%; 46.1%) compared with 23.7% (95% CI = 22.5%; 24.9%) in the SS. Participants who initiated their second quit attempt 1 to 2 years after the first one were less successful than those who initiated their second quit attempt later (25 versus 43%; P < 0.05). The results of the first treatment cycle were not found to be a reliable predictor for outcomes of the second cycle of treatment in univariate or multivariate logistic regression (odds ratio = 1.35, 95% CI = 0.70-2.63, P = 0.373).

CONCLUSION

In Prague, Czech Republic, smokers re-attending stop-smoking treatment more than 2 years after their previous quit attempt appear to achieve similar success rates to those being treated for the first time.

Initiating Pharmacologic Treatment in Tobacco-Dependent Adults. An Official American Thoracic Society Clinical Practice Guideline

Background: Current tobacco treatment guidelines have established the efficacy of available interventions, but they do not provide detailed guidance for common implementation questions frequently faced in the clinic. An evidence-based guideline was created that addresses several pharmacotherapy-initiation questions that routinely confront treatment teams.Methods: Individuals with diverse expertise related to smoking cessation were empaneled to prioritize questions and outcomes important to clinicians. An evidence-synthesis team conducted systematic reviews, which informed recommendations to answer the questions. The GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach was used to rate the certainty in the estimated effects and the strength of recommendations.Results: The guideline panel formulated five strong recommendations and two conditional recommendations regarding pharmacotherapy choices. Strong recommendations include using varenicline rather than a nicotine patch, using varenicline rather than bupropion, using varenicline rather than a nicotine patch in adults with a comorbid psychiatric condition, initiating varenicline in adults even if they are unready to quit, and using controller therapy for an extended treatment duration greater than 12 weeks. Conditional recommendations include combining a nicotine patch with varenicline rather than using varenicline alone and using varenicline rather than electronic cigarettes.Conclusions: Seven recommendations are provided, which represent simple practice changes that are likely to increase the effectiveness of tobacco-dependence pharmacotherapy.

Simulating future public health benefits of tobacco control interventions: a systematic review of models

BACKGROUND

To prioritise tobacco control interventions, simulating their health impacts is valuable. We undertook a systematic review of tobacco intervention simulation models to assess model structure and input variations that may render model outputs non-comparable.

METHODS

We applied a Medline search with keywords intersecting modelling and tobacco. Papers were limited to those modelling health outputs (eg, mortality, health-adjusted life years), and at least two of cancer, cardiovascular and respiratory diseases. Data were extracted for each simulation model with ≥3 arising papers, including: model type, untimed or with time steps and trends in business-as-usual (BAU) tobacco prevalence and epidemiology.

RESULTS

Of 1911 papers, 186 met the inclusion criteria, including 13 eligible simulation models. The SimSmoke model had the largest number of publications (n=46), followed by Benefits of Smoking Cessation on Outcomes (n=12) and Tobacco Policy Model (n=10). Two of 13 models only estimated deaths averted, 1 had no time steps, 5 had no future trends in BAU tobacco prevalence, 9 had no future trends in BAU disease epidemiology and 7 had no time lags from quitting tobacco to reversal of health harm.

CONCLUSIONS

Considerable heterogeneity exists in simulation models, making outputs substantively non-comparable between models. Ranking of interventions by one model may be valid. However, this may not be true if, for example, interventions that differentially affect age groups (eg, a tobacco-free generation policy vs increased cessation among adults) do not account for plausible future trends. Greater standardisation of model structures and outputs will allow comparison across models and countries, and for comparisons of the impact of tobacco control interventions with other preventive interventions.

Can the use of varenicline improve the efficacy of pharmacotherapy for nicotine addiction?

Introduction: Smoking is a huge medical and social problem in Poland, with as many as about 24% of Poles being addicted to nicotine. Approximately 6 million people worldwide die every year from conditions that are closely related to tobacco addiction, such as cancer and cardiovascular, metabolic or lung diseases. The difficulty in combatting nicotine dependence is largely due to the complex mechanism of this addiction. The motivation of a patient to quit smoking is of great importance in the difficult withdrawal process. Strengthening this motivation is one of the most important tasks of physicians and addiction therapists.

Overview of literature: Nicotine replacement therapy (NRT) has been the most widely known way to break away from smoking addiction for many years now. It involves delivering nicotine to the body in ways that are less harmful than through tobacco smoke. As a consequence, the cravings for nicotine are reduced, making it easier for the patient to break with the addiction. Clinical trials have shown that the use of NRT is associated with a 50-70% increased chance of maintaining abstinence from smoking compared to placebo. There are many NRT products, including nicotine chewing gum, nicotine patches, lozenges, dissolvable nicotine sticks, or inhalers. Bupropion is a selective dopamine–noradrenaline reuptake inhibitor. This drug is one of the most commonly used in the pharmacotherapy of depression in the United States. At the same time, it has been found to have a positive effect on people trying to break up with the habit of smoking cigarettes. The mechanism of action remains unknown in this case, but studies clearly indicate the efficacy of bupropion, which is comparable to the efficacy of NRT. Varenicline is a partial agonist selective for α4β2 nicotinic acetylcholine receptors. It has a higher affinity for these receptors than nicotine. By stimulating them, it causes an increase in dopamine secretion (but to a lesser extent than cigarette smoking), helping in this way ease withdrawal symptoms.

Conclusions: Varenicline has higher efficacy than bupropion and NRTs. Simultaneous use of two NRT forms increases the effectiveness of this method to a level comparable to varenicline. Contrary to previous reports, it seems that varenicline does not increase self-aggressive behaviour and the risk of suicide. The effectiveness of antinicotinic drugs depends on the sex of the patient. For both sexes, the most effective drug is varenicline. It is slightly more effective in women than in men. By contrast, NRT and bupropion show greater therapeutic potential in men.