摘要：Objectives. To compare potential population-wide benefits and risks, we examined the potential impact of increased nicotine replacement therapy (NRT) use for smoking cessation on future US mortality. Methods. We developed a simulation model incorporating a Monte Carlo uncertainty analysis, with data from the 2005 National Health Interview Survey and Cancer Prevention Study II. We estimated the number of avoided premature deaths from smoking attributable to increased NRT use, before and after incorporating assumptions about NRT harm. Results. We estimate that a gradual increase in the proportion of NRT-aided quit attempts to 100% by 2025 would lead to 40 000 (95% credible interval = 31 000, 50 000) premature deaths avoided over a 20-year period. Most avoided deaths would be attributable to lung cancer and cardiovascular disease. After we incorporated assumptions about potential risk from long-term NRT, the estimate of avoided premature deaths from all causes declined to 32 000. Conclusions. Even after we assumed some harm from long-term NRT use, the benefits from increased cessation success far outweigh the risks. However, the projected reduction in premature mortality still reflects a small portion of the tobacco-related deaths expected over a 20-year period. Cigarette smoking is one of the leading modifiable causes of death in the United States, accounting for more than 400 000 deaths 1 and 5.5 million years of life lost annually. 2 It has been estimated that up to half of persistent smokers will be killed by their habit, and lifelong smokers lose, on average, 10 years of life compared with nonsmokers. 3 Despite a decline in smoking prevalence in the United States, there were still approximately 36 million daily smokers in 2005. 4 Further, although the majority of smokers express a desire to quit, 5 the average smoker makes several quit attempts before succeeding. 6 The use of pharmacotherapy, including nicotine replacement therapy (NRT), has been shown to increase the likelihood of a successful quit attempt. 7 Smoking cessation has numerous health benefits, 6 including an increase in longevity, even among smokers who quit later in life. 3 Effective smoking cessation policies, including increased NRT availability and use, would be expected to reduce smoking-attributable deaths in the United States. Some concerns have arisen about the safety of long-term NRT use, which could reduce the cessation-related benefits of NRT-aided quit attempts. Hemodynamic effects of nicotine intake have been described, which may have implications for cardiovascular disease risk. 8 – 10 However, tobacco smoke contains many toxic compounds that can damage the cardiovascular system, including combustion products such as carbon monoxide and nitrogen oxides 8 , 11 , 12 ; thus, it is not clear what fraction of smoking-related cardiovascular risk may be attributable to nicotine intake. Further, clinical trials have generally shown NRT use to be safe. 13 , 14 Concerns have also been raised about increased risk for cancer on the basis of evidence from in vitro and in vivo studies showing that nicotine can result in tumor promotion through increased cell proliferation, inhibition of apoptosis, and angiogenesis. 15 – 17 To quantitatively compare the risks and benefits of NRT use, we developed a Monte Carlo simulation model to estimate future mortality patterns associated with changing patterns of NRT use and subsequent success in smoking cessation. We also incorporated assumptions about long-term NRT use and its potential harms to weigh the risks and benefits of NRT use for smoking cessation.
