Trends in the Average Age of Quitting Among U.S. Adult Cigarette Smokers

Development of Dependence in Smokers and Rodents With Voluntary Nicotine Intake: Similarities and Differences

INTRODUCTION

Smoking and vaping throughout adolescence and early adulthood lead to nicotine dependence. Nicotine withdrawal is associated with somatic and affective withdrawal symptoms that contribute to smoking and relapse. Affective nicotine withdrawal symptoms in humans include craving for cigarettes, depression, anxiety, trouble sleeping, and cognitive deficits.

METHODS

Herein, we review clinical studies that investigated nicotine dependence in people who smoke or vape. We also discuss studies that investigated the development of dependence in animals with oral nicotine intake, nicotine aerosol self-administration, and intravenous nicotine self-administration.

RESULTS

Clinical studies report that adolescents who smoke daily develop nicotine dependence before those who smoke infrequently, but ultimately all smokers become dependent in adulthood. Preclinical studies indicate that rats that self-administer nicotine also become dependent. Rats that self-administer nicotine display somatic withdrawal signs and affective withdrawal signs, including increased anxiety and depressive-like behavior, cognitive deficits, and allodynia. Most nicotine withdrawal signs were observed in rodents with daily (7 days/week) or intermittent long access (23-hour) to nicotine. Clinical smoking studies report symptoms of nicotine dependence in adolescents of both sexes, but virtually all preclinical nicotine self-administration studies have been done with adult male rats.

CONCLUSIONS

The role of sex and age in the development of dependence in nicotine self-administration studies remains under-investigated. However, the role of sex and age in nicotine withdrawal has been thoroughly evaluated in studies in which nicotine was administered noncontingently. We discuss the need for volitional nicotine self-administration studies that explore the gradual development of dependence during adolescence and adulthood in rodents of both sexes.

IMPLICATIONS

The reviewed clinical studies investigated the development of nicotine dependence in male and female adolescent and young adult smokers and vapers. These studies indicate that most adolescent smokers and vapers gradually become nicotine dependent. Preclinical studies with rodents show that nicotine intake in widely used self-administration models also leads to dependence. However, almost all animal studies that investigated the development of nicotine dependence have been conducted with adult male rats. To better model smoking and vaping, it is important that nicotine intake in rats or mice starts during adolescence and that both sexes are included.

Smokers have increased risk of soft-tissue complications following primary elective TKA

INTRODUCTION

Smoking has been associated with numerous adverse outcomes following surgical procedures. The purpose of this study was to investigate, whether smoking status at time of surgery influences the outcome of primary TKA.

MATERIALS AND METHODS

Six hundred and eighty-one patients who underwent primary TKA between 2003 and 2006 were included in the study. Smoking status was defined as current, former, and never smoker. Complications leading to revisions were assessed until 17 years of follow-up. Functional outcome was evaluated using clinical scores: Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Visual Analogue Scale (VAS) for pain, Short Form-12 Physical and Mental Component Summaries (SF-12PCS/MCS), and Knee Society Function and Knee Score (KSFS and KSKS).

RESULTS

At a mean follow-up of 95 months (± 47 months), 124 complications led to revision surgery. Soft-tissue complications (OR, 2.35 [95% CI 1.08-5.11]; p = 0.032), hematoma formation (OR, 5.37 [95% CI 1.01-28.49]; p = 0.048), and restricted movement (OR, 3.51 [95% CI 1.25-9.84]; p = 0.017) were more likely to occur in current smokers than never smokers. Current smokers were more likely to score higher at KSFS (p < 0.001) and SF-12PCS (p = 0.0197) compared to never smokers. For overall revision, differences were noted.

CONCLUSION

Current smoking increases risk of soft-tissue complications and revision after primary TKA, especially due to hematoma and restricted movement. Smoking cessation programs could reduce the risk of revision surgery.

Active Smokers Are at Higher Risk of COVID-19 Death: A Systematic Review and Meta-analysis

INTRODUCTION

Current evidence indicates that smoking worsens COVID-19 outcomes. However, when studies restricted their analyses to current smokers, the risks for COVID-19 severity and death are inconsistent.

AIMS AND METHODS

This meta-analysis explored the association between current smoking and the risk for mortality based on the studies that reported all three categories of smoking (current, former, and never smokers) to overcome the limitation of the previous meta-analyses which former smokers might have been classified as nonsmokers. We searched PubMed and Embase up to January 1, 2021. We included studies reporting all three categories of smoking behaviors of COVID-19 patients and mortality outcomes. A random-effects meta-analysis and meta-regression were used to examine relationships in the data.

RESULTS

A total of 34 articles with 35 193 COVID-19 patients was included. The meta-analysis confirmed the association between current smoking (odds ratio [OR] 1.26, 95% confidence interval [CI]: 1.01-1.58) and former smoking (OR 1.76, 95% CI: 1.53-2.03) with COVID-19 mortality. We also found that the risk for COVID-19 death in current smokers does not vary by age, but significantly drops by age in former smokers. Moreover, current smokers in non-high-income countries have higher risks of COVID-19 death compared with high-income countries (OR 3.11, 95% CI: 2.04-4.72 vs. OR 1.14, 95% CI: 0.91-1.43; p = .015).

CONCLUSIONS

Current and former smokers are at higher risk of dying from COVID-19. Tobacco control should be strengthened to encourage current smokers to quit and prevent the initiation of smoking. Public health professionals should take the COVID-19 pandemic as an opportunity to promote smoking prevention and cession.

IMPLICATIONS

This study makes an important contribution to the existing literature by distinguishing between current and former smoking and their separate effects on COVID-19 mortality. We also explore the effects by age of patients and country income level. Findings from this study provide empirical evidence against misinformation about the relationship between smoking and COVID-19 mortality.

Trends in Prevalence of Cigarette Smoking Among US Adults With Major Depression or Substance Use Disorders, 2006-2019

IMPORTANCE

Tobacco use is highly concentrated in persons with mental illness.

OBJECTIVES

To assess trends in past-month prevalence of cigarette smoking among adults with vs without past-year depression, substance use disorders (SUDs), or both, using nationally representative data.

DESIGN, SETTING, AND PARTICIPANTS

Exploratory, serial, cross-sectional study based on data from 558 960 individuals aged 18 years or older who participated in the 2006-2019 US National Surveys on Drug Use and Health.

EXPOSURE

Past-year major depressive episode (MDE) and SUD using Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition, Text Revision) criteria.

MAIN OUTCOMES AND MEASURES

Past-month self-reported cigarette use, adjusted for sociodemographic characteristics.

RESULTS

Of the sampled 558 960 adults, 41.4% (unweighted) were aged 18 to 25 years, 29.8% (unweighted) were aged 26 to 49 years, and 53.4% (unweighted) were women. From 2006 to 2019, the past-month self-reported cigarette smoking prevalence declined significantly among adults with MDE from 37.3% to 24.2% for an average annual percent change of -3.2 (95% CI, -3.5 to -2.8; P < .001), adults with SUD from 46.5% to 35.8% for an average annual percent change of -1.7 (95% CI, -2.8 to -0.6; P = .002), and adults with co-occurring MDE and SUD from 50.7% to 37.0% for an annual average annual percent change of -2.1 (95% CI, -3.1 to -1.2; P < .001). The prevalence declined significantly for each examined age, sex, and racial and ethnic subgroup with MDE and with SUD (all P < .05), except for no significant changes in American Indian or Alaska Native adults with MDE (P = .98) or with SUD (P = .46). Differences in prevalence of cigarette smoking between adults with vs without MDE declined significantly for adults overall from 11.5% to 6.6%, for an average annual percent change of -3.4 (95% CI, -4.1 to -2.7; P < .001); significant average annual percent change declines were also seen for men (-5.1 [95% CI, -7.2 to -2.9]; P < .001); for women (-2.7 [95% CI, -3.9 to -1.5]; P < .001); for those aged 18 through 25 years (-5.2 [95% CI, -7.6 to -2.8]; P < .001); for those aged 50 years or older (-4.7 [95% CI, -8.0 to -1.2]; P = .01); for Hispanic individuals (-4.4 [95% CI, -8.0 to -0.5]; P = .03), and for White individuals (-3.6 [95% CI, -4.5 to -2.7]; P < .001). For American Indian or Alaska Native adults, prevalence did not significantly differ between those with vs without MDE during 2006-2012 but was significantly higher for those with MDE during 2013-2019 (difference, 11.3%; 95% CI, 0.9 to 21.7; P = .04). Differences among those with vs without SUD declined for women for an average annual percent change of -1.8 (95% CI, -2.8 to -0.9; P = .001).

CONCLUSIONS AND RELEVANCE

In this exploratory, serial, cross-sectional study, there were significant reductions in the prevalence of self-reported cigarette smoking among US adults with major depressive episode, substance use disorder, or both, between 2006 and 2019. However, continued efforts are needed to reduce the prevalence further.

Effect of Electronic Portal Messaging With Embedded Asynchronous Care on Physician-Assisted Smoking Cessation Attempts: A Randomized Clinical Trial

IMPORTANCE

Despite the substantial health and financial burdens of smoking and the availability of effective, evidence-based interventions in primary care settings, few smokers and physicians use these strategies for smoking cessation.

OBJECTIVE

To evaluate whether electronic outreach to smokers with embedded asynchronous care increases the number of quit attempts and explore the roles of the message sender (ie, primary care physician [PCP] vs health care system) and patient-related characteristics.

DESIGN, SETTING, AND PARTICIPANTS

This quality improvement randomized clinical trial was designed to measure 2 factors: (1) electronic outreach messaging with and without a survey link to asynchronous care and (2) messaging by a personal PCP or health system. The study was conducted within the electronic health record and portal messaging platform of a large health system in the South Central US. Participants were adult patients 18 years or older who were designated as smokers in their electronic health records. Data were collected from January 13 to February 24, 2020, with participating PCPs surveyed in July 2020.

INTERVENTIONS

Portal messages encouraging a quit attempt and offering physician assistance were sent to smokers who were randomly selected and assigned to 1 of 4 conditions (message with or without embedded asynchronous care and PCP or system as sender). Half of the messages contained an invitation to come to clinics and the other half contained a link to access asynchronous care.

MAIN OUTCOMES AND MEASURES

The primary outcome was electronic health record-documented quit attempts (1 indicates quit attempt; 0, no quit attempt), which were tracked 30 days after the electronic outreach. Secondary outcomes included physician perceptions of the electronic outreach intervention, using a 5-point scale to assess perceptions of workload, comfort with providing medication from survey information, and further interest in the program 6 months after the intervention.

RESULTS

A total of 188 participants (99 women [52.4%] and 89 men [47.3%]) with mean (SD) age of 55.2 (13.9) years were randomized to 1 of 4 conditions. Group 1 (n = 46) received a message from the PCP without a link to the survey; group 2 (n = 48) received a message from the PCP with a link to asynchronous care in the form of the survey. Group 3 (n = 47) received a message from the health system without a link to the survey; group 4 (n = 47) received a message from the health system with a link to the survey. No statistically significant difference in documented quite attempts was found among the 4 study groups. There was also no statistically significant difference in quit attempts between the group that received the asynchronous care survey link and the group that did not (odds ratio, 2.50 [95% CI, 0.72-8.72]). However, the quit attempt rate for those with asynchronous care offered (9 of 95 [9.5%]) was more than double the quit attempt rate for those with in-person care offered (4 of 93 [4.3%]).

CONCLUSIONS AND RELEVANCE

This quality improvement randomized clinical trial did not find a statistically significant difference in physician-assisted quit attempts among patients who received electronic with asynchronous care vs those who received outreach alone, regardless of whether the message source was a PCP or a health system. However, the program engaged patients in difficult-to-reach rural areas as well as younger patients.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT05172219.

The role of electronic cigarette use for quitting or reducing combustible cigarette use in the 30s: Longitudinal changes and moderated relationships

BACKGROUND

Evidence for use of electronic cigarettes (e-cigs) as a potential aid in quitting or reducing combustible cigarette (c-cig) use is mixed. This study examined the extent to which e-cig initiation among smokers in their 30 s predicted quitting or reducing smoking or nicotine dependence symptoms by age 39, and whether the role of e-cigs in quitting differed by prospectively assessed moderators.

METHODS

Data were from the Seattle Social Development Project (SSDP), a panel study of 808 diverse participants with high retention. A subsample of 221 smokers at age 33 was selected for analysis. Self-reports of c-cig use and dependence were assessed longitudinally at ages 33 and 39. Sixteen potential moderators were examined, including social demographics, smoking attitudes and desire to quit, other health behaviors and status, and adolescent and early adult assessments of smoking history.

RESULTS

The use of e-cigs was consistently associated with a lower likelihood of quitting c-cigs by age 39, after accounting for frequency of prior c-cig use at age 33. This negative association persisted across all moderators examined, although it was nonsignificant among those with a definite desire to cut down. Among those who did not quit smoking, e-cig use had no association with decreases in either quantity of c-cigs used or dependence symptoms.

CONCLUSIONS

Results indicate that e-cigarette use was not helpful for quitting or reducing combustible cigarette use in the 30 s. Rather, across extensive tests of moderation, e-cig initiation consistently predicted less quitting during this important age period for successful cessation.

Adult Social Environments and the Use of Combustible and Electronic Cigarettes: Opportunities for Reducing Smoking in the 30s

INTRODUCTION

Reducing cigarette use is a major public health goal in the United States. Questions remain, however, about the potential for the social environment in the adult years-particularly in the 30s and beyond-to influence cigarette use. This study tested pathways hypothesized by the social development model to understand the extent to which social environmental factors at age 33 (eg, involvement with smokers or with physically active people) contribute to changes in cigarette use from age 30 to age 39. Both combustible and electronic cigarette use were investigated.

METHODS

Data were from the Seattle Social Development Project, a longitudinal study of 808 diverse participants with high retention. Self-reports assessed social developmental constructs, combustible and electronic cigarette use, and demographic measures across survey waves.

RESULTS

At age 30, 32% of the sample reported past-month cigarette use. Using structural equation modeling, results showed high stability in cigarette use from age 30 to 39. After accounting for this stability, cigarette-using social environments at age 33 predicted personal beliefs or norms about smoking (eg, acceptability and social costs), which in turn predicted combustible cigarette use at age 39. Cigarette-using environments, however, directly predicted electronic cigarette use at age 39, with no significant role for beliefs about smoking.

CONCLUSIONS

Cigarette use was highly stable across the 30s, but social environmental factors provided significant partial mediation of this stability. Pathways were different for combustible and electronic cigarette use, however, with personal smoking norms playing an important role for the former but not the latter.

IMPLICATIONS

This study addresses the need for longitudinal investigation of social mechanisms and cigarette use in the 30s. Findings reinforce efforts to prevent the uptake of cigarettes prior to the 30s because, once started, smoking is highly stable. But social environmental factors remain viable intervention targets in the 30s to disrupt this stability. Addressing personal norms about smoking's acceptability and social costs is likely a promising approach for combustible cigarette use. Electronic cigarettes, however, present a new challenge in that many perceived social costs of cigarette use do not readily translate to this relatively recent technology.

The OaSiS trial: A hybrid type II, national cluster randomized trial to implement smoking cessation during CT screening for lung cancer

INTRODUCTION

When the Centers for Medicare and Medicaid Services announced coverage for low dose CT lung cancer screening, they also mandated that imaging centers offer smoking cessation services. We designed the Optimizing Lung Screening (OaSiS) trial to evaluate strategies to implement the Public Health Service Guidelines for Treating Tobacco Use and Dependence during CT screening for lung cancer.

METHODS AND DESIGN

OaSiS was implemented using a pragmatic effectiveness-implementation hybrid design in 26 imaging clinics across the United States affiliated with the National Cancer Institute's National Community Oncology Research Program (NCORP). The 26 sites selected for participation in the OaSiS trial were randomized to receive either a compendium of implementation strategies to add or enhance smoking cessation services during lung screening or to usual care. Usual care sites were given the option to receive the full compendium of implementation strategies at the conclusion of data collection. We have evaluated both the effectiveness of the implementation strategies to improve smoking cessation at six months among patients undergoing LDCT screening as well as the adoption and sustainability of evidence-based tobacco cessation strategies in imaging clinics.

DISCUSSION

The OaSiS trial was designed to identify opportunities for implementing evidence-based smoking cessation into LDCT lung cancer screening imaging facilities and to establish the effectiveness of these services. We report our study design and evaluation, including strengths of the pragmatic design and the inclusion of a diverse range of screening programs. Establishing these tobacco cessation services will be critical to reducing smoking related morbidity and mortality.

Characteristics of us adults attempting tobacco use cessation using e-cigarettes

BACKGROUND

Use of e-cigarettes for tobacco cessation efforts is a growing trend in the United States. However, little is known about the factors that determine the use of e-cigarettes for this specific purpose.

METHODS

This study examined current and former cigarette smokers that reported ever using e-cigarettes. Data were obtained from a 2018 Texas population health assessment survey (n = 569) and weighted to be representative to Texas. A multivariable logistic regression was used to assess the socio-demographic and behavioral correlates of using e-cigarettes for tobacco cessation.

RESULTS

Overall, 41.3% of e-cigarette users reported using them for tobacco cessation. Among ever e-cigarette users, Non-Hispanic blacks (aOR: 0.21; 95% CI, 0.07-0.64), males (aOR: 0.40; 95% CI, 0.20-0.80), and individuals not confident in obtaining health information (aOR: 0.38; 95% CI, 0.15-0.96) were less likely to use e-cigarettes for tobacco use cessation. Conversely, among ever e-cigarette users, odds of using e-cigarettes for tobacco cessation were higher among those who were 35-44 years old (aOR: 3.68, 95% CI: 1.26-10.71), those who received advice to quit smoking from a healthcare professional (aOR: 2.77, 95% CI, 1.36-5.64), and those with more than 5 years since their last routine checkup (aOR: 3.91; 95% CI, 1.23-12.45).

CONCLUSION

Findings from this study suggest that both health behaviors and sociodemographic factors predict use of e-cigarettes for the purpose of tobacco cessation. Furthermore, the relationship between use of e-cigarettes as a cessation device and being advised to quit tobacco use by a healthcare professional calls for additional investigation.

Differential expression of nicotine withdrawal as a function of developmental age in the rat

Cigarette smoking and resultant nicotine dependence remain major public health problems. Most smokers begin before the age of 18, yet preclinical models have insufficiently characterized the development of nicotine dependence in adolescence. To categorize the short-term effects of chronic nicotine administration throughout adolescence and adulthood, we exposed male Sprague Dawley rats to 14 days of continuously delivered nicotine (0, 1.2 or 4.8 mg/kg/d) using a subcutaneous osmotic minipump, starting between postnatal day 33 (p33) and p96. Next, to explore the effects of extended exposure to chronic nicotine, we exposed male Sprague Dawley rats to 42 days of continuous nicotine starting in adolescence (p33) or early adulthood (p68). Somatic and affective signs of precipitated withdrawal (PW) were observed after a mecamylamine (1.5 mg/kg, i.p.) challenge as compared to a saline injection. Short term nicotine exposure starting at p96, well within the adult period, elicited a significant increase in somatic PW as measured by a composite behavioral score. In contrast, adolescent exposure to nicotine elicited a unique behavioral profile, dependent on the starting age of exposure. Late adolescence exposure was characterized by scratching while adult exposure was characterized by facial tremors and yawns. Extended exposure to nicotine resulted in age specific characteristic nicotine withdrawal behaviors, including scratches, ptosis and locomotion, distinct from the short-term exposure. Thus, nicotine dependence severity, based on the expression of total somatic PW behaviors, is not observed until the adult period, and differences between adolescents and adults are observed using a more nuanced behavioral scoring approach. We conclude that age of nicotine initiation affects somatic withdrawal signs and their magnitude. These data serve as a foundation for understanding the underlying brain mechanisms of nicotine dependence and their development over adolescence and early adulthood.

Limited self-control and longevity

This paper proposes a new framework to discuss self-control problems in the context of life-cycle health and longevity. Individual decisions are conceptualized as the partial control of impulsive desires of a short-run self by a rationally forward-looking long-run self. The short-run self strives for immediate gratification through consumption of health-neutral and unhealthy goods. The long-run self reflects the long-term consequences of unhealthy behavior on health outcomes and longevity and invests time and money to improve current and future health. The model is calibrated with data from the United States and used to provide an assessment of the impact of imperfect self-control on unhealthy consumption, health investments, lifetime health, and the age at death.

Neurobiological Considerations for Tobacco Use Disorder

PURPOSE OF REVIEW

Neurobiological studies of tobacco/nicotine use examining genetic, molecular, functional, and behavioral correlates have improved our understanding of nicotine/tobacco dependence and have informed treatment. Recent work extending previously established findings and reporting novel methodologies and discoveries in preclinical and human studies are reviewed.

RECENT FINDINGS

Recent work in preclinical models has focused on the differential roles of nicotinic receptor subtypes and nicotine's effects on neural systems beyond cortico-striatal dopaminergic pathways, and utilizing advanced methodologies such as pharmacogenetics, optogenetics and rodent fMRI to identify targets for treatment. Likewise, human neuroimaging studies have identified molecular and functional dynamic shifts associated with tobacco/nicotine use that further inform treatment.

SUMMARY

Nicotine/tobacco use is associated with widespread neural adaptations that are persistent and function to maintain addiction. The continued identification of genetic, molecular, neural, and behavioral endophenotypes related to nicotine/tobacco use, dependence, and addiction will facilitate the development and delivery of personalized treatment.

Smoking kills: An economic theory of addiction, health deficit accumulation, and longevity

In this paper I unify the economic theories of addiction and health deficit accumulation and develop a life cycle theory in which individuals take into account the fact that the consumption of addictive goods reduces their health and longevity. I distinguish two types of addiction: sophisticated and naive. Individuals with sophisticated addiction perfectly control their addiction. Individuals with naive addiction, though otherwise rational and forward looking, fail to fully understand how their addiction develops. I argue that the life cycle consumption pattern predicted for naive addiction is more suitable for motivating empirically observable patterns of addictive goods consumption. I take the case of smoking as unhealthy behavior, calibrate the model with U.S. data, and apply it in order to investigate the life cycle patterns of smoking and quitting smoking and the socioeconomic gradients of unhealthy consumption and longevity.