7. Tobacco Exposure

INTRODUCTION

This section of the Guidelines provides recommendations to pediatric care providers on limiting tobacco exposure in their child and adolescent patients. The section begins with background information on the importance of tobacco dependence as a risk factor for cardiovascular disease (CVD). This is followed by the Expert Panel's summary of the evidence review relative to tobacco exposure. The evidence review and the development process for the Guidelines are outlined in Section I. Introduction and are described in detail in Appendix A. Methodology. As described, the evidence review augments a standard systematic review where the findings from the studies reviewed constitute the only basis for recommendations with each study described in detail. This evidence review combines a systematic review with an Expert Panel consensus process that incorporates and grades the quality of all relevant data based on preidentified criteria. Because of the large volume of included studies and the diverse nature of the evidence, the Expert Panel also provides a critical overview of the studies reviewed for each risk factor, highlighting those that, in its judgment, provide the most important information. Detailed information from each study has been extracted into the evidence tables. The complete evidence tables will be available online at http://www.nhlbi.nih.gov/guidelines/cvd_ped/index.htm. The conclusions of the Expert Panel's review of the evidence are then summarized and graded, and the section ends with age-based recommendations to prevent tobacco exposure. References are listed sequentially at the end of the section, with references from the evidence review identified by unique PubMed identifier (PMID) numbers in bold text. Additional references do not include the PMID number.

BACKGROUND

Tobacco dependence is responsible for approximately 4 million annual deaths worldwide. Moreover, in utero exposure to tobacco products, involuntary tobacco smoke exposure (secondhand smoke), and tobacco use directly impair the health of fetuses, infants, children, and adolescents. Based on an analysis of published causes of death, tobacco use is the leading actual cause of death in the United States.^[1]  The evidence that tobacco use is harmful and addictive is unequivocal.^{[2],[3],[4],[5],[6]}  In childhood, nicotine is highly addicting, with symptoms of tobacco dependence demonstrated after only brief intermittent use.^[7]  Current cigarette use among high school students declined from 1997 to 2003, but rates have been stable since, through 2007.^[8]  From a public health standpoint, the need to reduce tobacco exposure is sufficiently compelling that a role for pediatric health care providers is essential.

A clinical practice guideline update from the U.S. Public Health Service published in May 2008 systematically reviewed almost 9,000 publications and concluded that smoking prevention and cessation interventions are effective in adults.^[9],[10]  However, different approaches may be needed for children and adolescents. Physicians who care for children are well-positioned to provide tobacco use prevention and treatment interventions for their patients. Youth interventions should target parents as well as their children, since parental smoking is both a risk factor for child smoking and a source of secondhand smoke exposure.

OVERVIEW OF THE EVIDENCE FOR PREVENTION OF TOBACCO EXPOSURE

From the evidence review relative to environmental smoke exposure, a moderate number of studies address the efficacy of physician-based interventions to alter parental smoking habits.^[11]  A 2003 systematic review included 19 studies published through October 2001 that tested interventions to reduce tobacco smoke exposure in children; 6 of these were part of the evidence review for these Guidelines.^[12]  Only four interventions were judged to be effective:  Three involved intensive counseling in a clinical setting, and one used a curricular approach in a school setting. The reviewers concluded that there was good evidence that brief informational interventions were ineffective and found limited support for intensive counseling in primary care. The evidence review for these Guidelines identified eight randomized controlled trials (RCTs), three of which showed a significant decrease in children's smoke exposure.^{[13],[14],[15],[16],[17],[18],[19],[20]}  An intervention in low-income families in a primary care setting used motivational interviewing with informational materials supplied to controls; at 6-month followup, household nicotine levels were significantly lower in the intervention group.^[17]  In low-income families, seven counseling sessions delivered over 3 months were effective in significantly decreasing maternal smoking rates by self-report and children's urine cotinine concentrations.^[18]  In a pediatric clinic setting, a brief motivational interview followed by up to three telephone counseling calls in the following 3 months showed significantly higher maternal abstinence rates at 3- and 12-month followups.^[16]  Studies with unsuccessful interventions used tobacco exposure demonstrations,^[13] a home-based intervention by lay community health advisors,^[15] and a physician-delivered report of infant urine cotinine results, with mailed information on decreasing smoke exposure.^[13]  The Special Turku Coronary Risk Factor Intervention Project, a Finnish study that successfully reduced saturated fat intake beginning in infancy, with followup for more than a decade, showed no differences in parental smoking between the intervention and control groups despite repeated lifestyle counseling that included an antitobacco message.^[14]  Two pediatric care provider studies specifically addressed smoking cessation in mothers following the birth of a child.^[16],[19]  As in the obstetrical literature, these were effective in achieving smoking cessation during pregnancy, but after 6–12 months, there was no evidence for postnatal effect. Overall, interventions to decrease environmental smoke exposure carried out in pediatric care settings have shown mixed results, with some evidence that intensive counseling can be effective.

Office-based counseling directed at children and adolescents for prevention of tobacco use has been a mainstay in pediatric preventive care. Although contact with preadolescents and adolescents in primary care is sporadic, pediatricians and family physicians retain a critical voice in conveying health information to children and their parents. Counseling with regard to the adverse effects of tobacco products does improve patient knowledge.^[2],[3],[5]  The evidence review identified two major systematic reviews for consideration. A 2003 systematic review of smoking prevention interventions delivered by health care providers included four studies, of which only one showed a significant effect on prevention of smoking initiation.^[21]  A 2007 systematic review of family-based programs for smoking prevention identified 14 RCTs for review.^[22]  Four of the nine that tested a family intervention against a control group had significant positive effects, whereas only one of the five that tested a family intervention against a school-based intervention had a significant positive outcome. None of the six that compared the incremental effects of a family plus a school program with a school program alone had significant positive effects. Overall, a significantly lower rate of smoking initiation was achieved in approximately 40 percent of interventions. The amount of implementer training and the quality of the implementation were related to positive outcomes, but the number of sessions was not. Use of biomarkers of tobacco exposure in addition to self-report of tobacco use provided no consistent benefit. In an RCT, a pediatric practice-based smoking prevention and cessation program that used a combined provider- and peer-delivered intervention was effective in preventing initiation of smoking at 1-year evaluation.^[23]

Studies of the benefits of office-based counseling on smoking reduction have yielded conflicting results. A 2006 Cochrane Collaboration review of the effectiveness of strategies to achieve smoking cessation in adolescents identified 15 trials for inclusion. The review found that interventions that used pharmacologic aids were ineffective, but those that used the stages of change approach and/or motivational interviewing did achieve statistically significant positive results at 6-month followup.^[24]  A randomized trial of more than 2,500 adolescents, both smokers and nonsmokers, in 7 large pediatric and family practice departments of a group health maintenance organization combined 30-second clinician advice, a 10-minute interactive computer program, a 5-minute motivational interview, and telephone booster sessions. At followup more than 6 months later, the abstinence rate was significantly higher in the intervention group compared to the control group.^[25]  In adolescent smokers, brief counseling by providers in an emergency department was associated with an increase in quit attempts by adolescent smokers.^[26]  A recent combined provider- and peer-delivered intervention set in pediatric practice settings increased abstinence rates among smokers at 6-month but not at 12-month followup.^[23]

School-based smoking prevention programs have achieved modest success, although there, too, results have been inconsistent, and evidence of long-term benefits is often unavailable.^{[27],[28],[29],[30],[31]}  Two systematic reviews provide important perspectives. A 2006 Cochrane review identified 23 high-quality RCTs of school-based programs to prevent smoking initiation.^[32]  The interventions included providing information, social influence approaches, social skills training, and community approaches. Information alone was ineffective, but the combined social influences and social skills interventions were moderately effective in approximately half of the trials. A 2005 systematic review focused on long-term followup of school-based smoking prevention. Of eight studies that were reviewed, only one showed decreased smoking prevalence in the intervention group at longer than 1-year followup.^[33]

Pharmacotherapies (i.e., nicotine replacement and medication) have been proven to aid in smoking cessation in adults. Some RCTs have demonstrated the safety of the nicotine patch and nicotine gum, as well as bupropion in adolescent smokers, but cessation results are inconsistent.^[34],[35]  Overall, such studies performed in young smokers have shown that pharmacotherapies were not successful.^[24],[36]

Public health measures have been the most effective methods to prevent and limit tobacco use. Successful strategies include taxation of tobacco products, clean indoor air legislation, and counteradvertising against tobacco products.^[2]  Regulatory efforts and activities as well as efforts to promote clean indoor air in homes, automobiles, and schools all have been shown to have positive effects on tobacco smoke exposure and tobacco use.^[33],[37]

CONCLUSIONS AND GRADING OF THE EVIDENCE REVIEW ON PREVENTION OF TOBACCO EXPOSURE

Among all the known risk factors for CVD, the dichotomy between known benefits of risk elimination and the paucity of evidence for effective interventions to achieve risk reduction in pediatric care provider settings is greatest for tobacco exposure. The quality of the evidence regarding the harm of smoking and the benefits of passive smoke exposure avoidance, smoking prevention, and smoking cessation is uniformly Grade A. The reason that evidence grades in the recommendations are less than Grade A reflects the lack of existing evidence on interventions impacting smoking behaviors in specific pediatric age groups as opposed to the collective evidence.

• Good-quality interventions in pediatric care settings to decrease children's environmental smoke exposure have shown mixed results (Grade B).
• Intervention studies to prevent smoking initiation have had moderate success, although long-term results are limited (Grade B).
• Practice-based interventions to achieve smoking cessation in adolescents have had moderate success with limited long-term followup (Grade B).
• School-based smoking prevention programs have been moderately successful, with limited long-term followup (Grade B).

Although the evidence base in support of an office-based approach to tobacco intervention is moderate and at times mixed, the evidence that cigarette use is harmful and addictive is unequivocal. From a public health standpoint, the need to reduce tobacco exposure is sufficiently compelling that a role for pediatric health care providers is essential. The lack of harm associated with such interventions and the importance of communicating the message of risk associated with tobacco provide the rationale for supporting "Strongly recommend," despite the lack of conclusive evidence that office-based interventions reliably reduce tobacco initiation or smoking cessation. Physicians and nurses who care for children are well-positioned to provide intervention to patients who smoke. The Expert Panel believes that such providers should routinely identify patients who smoke using the medical history. Patients should be explicitly informed about the addictive and adverse health effects of tobacco use. By using the 5A questions (Ask, Advise, Assess, Assist, Arrange), providers can assess their patients' readiness to quit and assist in providing resources to support smoking cessation efforts. Information about telephone quit lines (e.g., 1–800–QUIT–NOW), community cessation programs, and pharmacotherapy should also be made available.

As described, practice-based interventions to decrease environmental smoke exposure have shown mixed results. Nonetheless, the Expert Panel believes that pediatric care providers should identify parents and other caregivers who smoke and explicitly recommend that children not be exposed to tobacco smoke in the home, in automobiles, and in any other space where exposure can occur. For the parent who smokes, information provided should include statements about health benefits to the individual, child, and/or fetus, as well as referral to smoking cessation care providers.

Prenatal tobacco exposure is addressed separately in Section XIII. Perinatal Factors. Pediatric care providers should identify mothers who use tobacco and should deliver explicit counseling to these mothers to quit smoking before pregnancy, not smoke during pregnancy, and remain smoke free after the baby's birth. Such counseling has been shown to be effective during pregnancy, but postpregnancy recidivism is high.

The Expert Panel strongly recommends that pediatric care providers deliver a clear and repeated antismoking and smoking cessation message. When possible, primary care providers should attempt to integrate more intensive approaches to tobacco use prevention and cessation in their practices. Only a small number of studies have demonstrated that pharmacotherapies (i.e., nicotine replacement and medication) have been effective in supporting smoking cessation efforts in adolescents. Nonetheless, pediatricians may wish to acquire experience using these therapies or identify another health care professional with such experience for referral.

Tobacco use is considered in risk stratification algorithms in individuals with hypercholesterolemia, hypertension, and diabetes mellitus. Treatment thresholds for pharmacologic treatment of elevated cholesterol and hypertension are lower with tobacco use, and treatment goals may be more aggressively pursued in active smokers.

Public health measures have been effective in preventing and limiting tobacco use. Pediatricians need to be involved in advocacy for such regulatory efforts, as well as in school- and community-based efforts to prevent the initiation of smoking and to promote effective cessation strategies.

Table 7–1. Evidence-Based Recommendations to Prevent Tobacco Exposure

Grades reflect the findings of the evidence review.
Recommendation levels reflect the consensus opinion of the Expert Panel.
Supportive actions represent expert consensus suggestions from the Expert Panel provided to support implementation of the recommendations

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