Pharmacologic-based strategies for smoking cessation: clinical and cost-effectiveness analyses.

Abstract

Tobacco smoking is a risk factor for cancer, respiratory disease, and cardiovascular disease. It is estimated that 19% of Canadians (approximately 5.2 million) aged 15 years and older were smokers in 2007.1 Each year, approximately 45,000 Canadians die from smoking.2 Significantly, one-third of Canadian smokers aged 15 years or older express an intention to quit in the next 30 days.3 Nicotine, the addictive chemical component of tobacco products that attracts smokers, has consequences for personal and community health. Smoking is an addiction. Although many smokers report that they quit unaided, most smokers who try to quit without smoking cessation aids are unsuccessful in the long term. In the US and UK, 70% of smokers intend to quit every year, 45% try to quit, and less than 5% are successful.4,5 The rate of relapse is high among smokers who quit without treatment. The proportion of smokers who can achieve abstinence for at least one week is 25% to 51%, 10% to 20% for those able to do it for at least three months, and only 3% to 5% for those able to abstain for six months.6 There are many prescribed pharmacotherapies for smoking cessation, including nicotine replacement products, bupropion, and varenicline. Smoking cessation programs often combine drug treatment and behavioural support (such as psychological interventions, telephone support, and self-help). Objective The objective of the report was to: Compare the pharmacological agents (drug-based smoking cessation aids) to determine which of these works best (clinical effectiveness) at six months and 12 months after patients attempt to quit smoking. Perform an economic analysis to determine which smoking cessation therapy was the most cost-effective for patients, drug plans, and the Canadian health care system. Methods To compare pharmacological agents with or without behavioural support programs for smoking cessation in adults, a systematic review with meta-analyses and an economic evaluation were carried out. A budget impact analysis and an examination of current public funding and planning issues were also performed. For the clinical review, a total of 155 articles (from August 1982 to June 2009) describing 143 trials were selected for inclusion in the clinical analyses. To meet the inclusion criteria, randomized controlled trials (RCTs) must have reported biochemically validated measures of smoking abstinence from the study start date or from the target quit date of at least six months. Analyses were conducted using a Bayesian random effects model for mixed treatment comparisons meta-analysis. Continuous abstinence rates (patients have not smoked at all since quitting) and point prevalence abstinence rates (patients have not smoked in the past seven days) were analyzed separately. For the economic analysis, a decision-analytic model was constructed to assess the cost-effectiveness (cost per additional quitter and cost per life-year gained; cost per quality-adjusted life-year [QALY] gained) of nicotine replacement therapy (NRT), bupropion, and varenicline compared with no pharmacologic treatment, from the perspective of a publicly funded health care system. For the base case, the general population (stratified by age and gender) motivated to quit smoking was considered. Treatment strategies included one-time cessation interventions of NRT, bupropion, varenicline, and no pharmacologic treatment; it was assumed that all patients received the same level of behavioural support. Budget impact analyses were conducted by comparing current utilization patterns of NRT, bupropion, and varenicline, with alternative scenarios reflecting the prescription patterns of these therapies.