Thank you for the opportunity to express our views on the USPSTF draft research plan regarding interventions for tobacco cessation in adults. The National Center for Health Research is a nonprofit think tank that conducts, analyzes, and scrutinizes research, policies, and programs on a range of issues related to health and safety. We do not accept funding from companies that make products that are the subject of our work, so we have no conflicts of interest.
It is estimated that cigarette use and exposure claim about 480,000 lives every year in the United States. In 2016, about 15.5%, of U.S. adults identified as a “current” smoker, which, over the last decade, represented a 5% reduction in prevalence. Unfortunately, according to the National Health Interview Survey (NHIS), the Nation’s progress has plateaued at around that level in recent years.
We strongly support the efforts of the USPSTF to draft a research plan to identify benefits and harms of tobacco cessation interventions in broad populations, including pregnant women. We have several recommendations that would strengthen the USPSTF research plan:
- A key question to be answered is: What evidence is needed to establish the short-term and long-term benefits of tobacco cessation on an individual and population level?
According to the U.S. Surgeon General, smoking contributes significantly to the development of cancer of the mouth and throat, esophagus, trachea/bronchus/lung, stomach, liver, pancreas, kidney, cervix, bladder, and colon and rectum. Smoking is also linked to many other serious chronic diseases including heart disease, stroke, chronic obstructive lung disease and asthma, diabetes, rheumatoid arthritis, blindness, reproductive defects, ectopic pregnancy, and immune dysfunction. Given the magnitude of harms, there is no doubt that tobacco cessation interventions are beneficial for both individual and population health.
Retrospective and modeling analysis demonstrate the potential for significant gains associated with tobacco cessation. A retrospective analysis of real world data indicates that a national reduction in smoking from 1964 to 2012 averted about 8 million premature smoking-related deaths. However, a key question that does not have a clear answer is: what are the relative contributions of tobacco cessation efforts vs. prevention efforts in averting smoking-related deaths? With respect to smoking cessation, research shows that smoking cessation has significant benefits on the individual level and population level. For the individual who quits smoking, he/she can expect to see excess cardiovascular risk drop by about 50% within the first 2 years after the quit date.
These individual-level gains are magnified on the population level. A population level model demonstrates significant cardiovascular benefit associated with a 1% absolute decrease in smoking prevalence per year. In the first year, the model shows 1000 fewer heart attacks and about 500 fewer strokes in the first year. If cessation results in a 1% absolute decrease in smoking prevalence every year, this will result in 63,000 fewer heart attacks and 34,000 fewer strokes over a 7 year period. These reductions have significant impact on morbidity and mortality since heart attacks are the leading cause of death and strokes cause substantial disability.
The more difficult research task involves the assessment of the impact of smoking cessation on smoking-related cancers for the individual and for the population. For the individual who quits smoking, he/she can expect to see excess lung cancer risk drop by about 50% within about 10 years after the quit date. Since the medical community has only recently recognized the contribution of smoking to other cancers, there is limited data on tobacco cessation and excess risk reduction with respect to those other cancers. We know that generally there is a substantial lag in the cumulative effect of tobacco exposure and development of cancers. It will likely take decades to see the full health benefits of tobacco reduction and/or cessation. Prospective studies which are likely to rely on surrogate markers of disease, are limited in their feasibility and usefulness for answering the questions at hand.
- We appreciate the USPSTF inclusion of pregnant women as part of the target population.
In the consideration of potential benefits and harms, we encourage the USPSTF to examine potential fetal outcomes, including developmental and birth-related outcomes. We also encourage the USPSTF to review evidence for or against pharmacotherapy interventions for tobacco cessation in pregnant women or women who could become pregnant. A UK epidemiological reported that in-utero nicotine exposure accounts for about 3 cases of respiratory abnormalities in 1,000 live births, which is a small, but significant absolute risk.[6,7] Such a risk must be considered when counseling women of childbearing age about tobacco cessation.
- In relation to KQ3 (What harms are associated with tobacco cessation interventions in adults, including pregnant women?), we encourage the USPSTF to review the harms associated with electronic nicotine delivery systems, as these products have been touted as safer alternatives that may also serve as quit aids.
We agree with the 2015 USPSTF conclusion that the “current evidence is insufficient to recommend electronic nicotine delivery systems (ENDS) for tobacco cessation in adults, including pregnant women.” However, recent evidence has established biological plausibility for their potential health harms. The report by Reidel, et al. entitled “E-Cigarette Use Causes a Unique Innate Immune Response in the Lung, Involving Increased Neutrophilic Activation and Altered Mucin Secretion” challenges the notion that e-cigarettes are a better alternative to their combustible counterparts. Through sputum analysis, the researchers uncovered that much like combustible cigarettes, e-cigarettes cause a cascade of destructive cellular and molecular mechanisms that lead to inflammation and tissue damage, with the potential to cause chronic lung disease. Given the claims that e-cigarettes can be used for smoking cessation, we strongly urge the USPSTF to consider this new evidence and other available evidence as part of the assessment of potential benefits and harms of tobacco cessation interventions.
In conclusion, we generally support the USPSTF draft research plan regarding interventions for tobacco cessation, but recommend additional issues be addressed as noted above.
- Jamal A, Phillips E, Gentzke AS, et al. Current Cigarette Smoking Among Adults United States, 2016. MMWR Morb Mortal Wkly Rep 2018;67:53–59. DOI: http://dx.doi.org/10.15585/mmwr.mm6702a1
- U.S. Surgeon General. The Health Consequences of Smoking—50 Years of Progress. 2014. Available online: www.surgeongeneral.gov/library/reports.
- Honey K. Advances in Tobacco Control. CANCER RESEARCH Catalyst: The Official Blog of the American Association for Cancer Research. November 2017. Available online: http://blog.aacr.org/advances-in-tobacco-control/
- James M. Lightwood and Stanton A. Glantz. Short-term Economic and Health Benefits of Smoking Cessation. Circulation. 1997;96:1089-1096, originally published August 19, 1997 https://doi.org/10.1161/01.CIR.96.4.1089
- Fry JS, et al. How rapidly does the excess risk of lung cancer decline following quitting smoking? A quantitative review using the negative exponential model. Regulatory Toxicology and Pharmacology. 2013; 67(1):13-26. https://doi.org/10.1016/j.yrtph.2013.06.001
- Lee, P.N. & Fariss, M.W. A systematic review of possible serious adverse health effects of nicotine replacement therapy. Arch Toxicol. 2017;91: 1565. https://doi.org/10.1007/s00204-016-1856-y
- Dhalwani NN. et al. Nicotine replacement therapy in pregnancy and major congenital anomalies in offspring. Pediatrics. 2015;135(5):859-67. doi: 10.1542/peds.2014-2560.
- Reidel B. et al. E-Cigarette Use Causes a Unique Innate Immune Response in the Lung, Involving Increased Neutrophilic Activation and Altered Mucin Secretion. Am J Respir Crit Care Med. 2018;197(4):492-501. doi: 10.1164/rccm.201708-1590OC.