Smoking cessation interventions for pregnant women: Review and future directions

Smoking Cessation Interventions for Pregnant Women: Review and Future Directions Patricia O'Campo, Mary V. Davis, and Andrea C. Gielen

A substantial proportion of disease and death in the US could be prevented if tobacco use was curtailed or eliminated. Low birth weight, pregnancy complications, and infant morbidity are but a few of the adverse outcomes experienced by pregnant and postpartum women and infants that result from cigarette smoking. Pregnancy may be an ideal time to intervene with smoking women. On learning of their pregnancy, many women reduce or quit smoking on their own. For those who do not quit, interventions during the childbearing year could provide additional incentive and support for complete cessation. Successful clinic-based interventions share similar characteristics and tailoring cessation messages to client populations may enhance the effectiveness of interventions. Assessing a smoker's degree of addiction and tailoring counseling for cessation according to the patient's readiness might enhance current clinical practices. Even with the most effective individual counseling, it is increasingly evident that additional strategies are needed to achieve population-wide reductions in smoking and its related health conditions. Examples of these efforts are increased taxation on cigarettes, community-based anti-tobacco programs, and increasing the number of smoke-free environments. Thus, in addition to clinic-based efforts, health professionals might take an active role in supporting the broad range of programmatic, legislative, and advocacy efforts.

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substantial p r o p o r t i o n of disease and death in the United States could be p r e v e n t e d if tobacco use were curtailed or eliminated. Although smoking rates in the United States have shown a consistent decline over the last three decades, nearly one third o f the population still smoke cigarettes. Lower social classes are overr e p r e s e n t e d a m o n g smokers because rates o f smoking have declined much faster a m o n g those in mid- and u p p e r socioeconomic positions. More than 3,000 new smokers are recruited daily; the young, particularly young women, are being increasingly targeted by cigarette companies. 1'2 Approximately one in four w o m e n currently smoke. 3 Although historically w o m e n have had lower rates o f smoking than men, w o m e n have recently experienced an increase in smoking-related diseases. For example, in 1987, lung cancer surpassed breast cancer as the leading cause o f cancer deaths a m o n g w o m e n of all ages. Table 1 presents a s u m m a r y o f potentially adverse health outcomes that result f r o m smoking cigarettes.

Health Effects o f S m o k i n g A m o n g Pregnant Women I n f a n t birth weight is one of the most important determinants o f health and survival after birth.

Infants b o r n in the low birth weight category (<2,500 g) are 40 times m o r e likely to die in the neonatal period than normal birth weight infants. 4 In 1992, 16.3% o f A f r i c a n - A m e r i c a n and 6.8% o f white infants were b o r n in the low birth weight category. 5 Low birth weight infants who survive the neonatal period may face further short- and long-term health problems. Shortt e r m complications o f low birth weight include lower respiratory tract infections; long-term difficulties include neurodevelopmental conditions, learning disorders, and behavioral problems. 4 Furthermore, the cost of health care for low birth weight infants is substantially greater, during and after delivery, than that for normal birth weight 4 infants. Approximately 20% o f pregnant women in the United States smoke t h r o u g h o u t their pregnancies.6 Maternal smoking during pregnancy is one

From the Departments of Maternal and Child Health and Health Policy and Management, Johns Hopkins School of Hygiene and Public Health, Baltimore, and Birch and Davis Associates Inc., Silver Spring, MD. Address reprint requests to Patricia O'Campo, PhD, Johns Hopkins University, 624 N Broadway, Room 189, Baltimore, MD 21205. Copyright 9 1995 by W.B. Saunders Company O146-0005/95/1904-0005505.00/0

Seminars in Perinatology, Vol 19, No 4 (August), 1995: pp 279-285

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Table 1. Adverse Health Outcomes caused by Tobacco Use for Pregnancy and Nonpregnant Women, Infants, and Children During the Postpartum Period Pregnant Women Complications during pregnancy: placenta previa, abruptio placenta Low birth weight Delivery Hospitalization Infant mortali W

Postpartum Infants and Children

Nonpregnant Women

Sudden infant death syndrome (SIDS) Colds, lower respiratory tract infections

Colds, flu, other acute respiratory illnesses Heart disease

Asthma

Cancers: lung, oral, esophageal, cervical Emphysema Increased use of the health care system

Developmental disorders Increased use of health care services Hospitalizations

o f the most i m p o r t a n t preventable risk factors o f a low birth weight infant. 7 Maternal smoking decreases infant birth weight on average by 200 g, primarily t h r o u g h retarding fetal growth after the 30th week o f pregnancy. 8 Smoking during the third trimester o f pregnancy compromises fetal growth, p r i m a r i l y t h r o u g h intrauterine hypoxia. As a result o f smoking, c a r b o n monoxide crosses the placenta and binds with b o t h maternal and fetal hemoglobin to p r o d u c e carboxyhemoglobin, reducing the ability o f the blood to carry adequate levels of oxygen to the fetus. 8 Maternal smoking may also indirectly compromise fetal growth and birth weight t h r o u g h affecting maternal nutrition. 8 Some researchers c o n t e n d that p r e g n a n t w o m e n who smoke, eat less, and gain less weight during pregnancy result in deliveries o f smaller infants.8 However, observed differences in weight gain during pregnancy between smokers and nonsmokers are relatively small and inconsistent across studies. Moreover, the relationship between maternal smoking and intrauterine growth retardation (IUGR) remains after adjusting for maternal weight gain during pregnancy. 8

Rationale for Intervening Prenatally W o m e n who quit smoking early in pregnancy can deliver infants c o m p a r a b l e in weight and size to those o f w o m e n who never smoked during pregnancy, s'9 Infants b o r n to w o m e n who quit smoking by the third trimester o f pregnancy have higher birth weights than infants b o r n to w o m e n

Osteoporosis Early menopause

who reduce smoking behavior, or who make no change in smoking during pregnancy. 9"1~Results f r o m observational and experimental studies also indicate that infants b o r n to w o m e n who significantly reduce smoking behavior during pregnancy benefit through increased birth weight. 9 An estimated 17% to 26% o f low birth weight deliveries could be p r e v e n t e d by eliminating smoking altogether during pregnancy. 8 However, u n d e r the best circumstances, a conservative estimate o f quitting is a b o u t 8%. Therefore, applying this estimate nationwide, approximately 1,920 low birth weight deliveries might be prevented, and $20 to $56 million might be saved annually 9, if widespread interventions were implemented. Pregnancy may be an ideal time to intervene with smoking women. Many women, on learning o f their pregnancy, reduce or quit smoking on their own. Most o f those who do not quit reduce their levels of smoking. Interventions during this period could provide additional incentive and support for complete cessation. Unfortunately, after delivery, most w o m e n r e t u r n to their original patterns of smoking. 9'11-1~ Thus, prenatal interventions, especially those c o u p l e d with p o s t p a r t u m reinforcements, may prevent the substantial relapse that often occurs. In addition to the health benefits to the fetus and infant gained by smoking reduction or cessation during pregnancy, cessation also leads to improved long-term health o f the woman. The two leading causes of death for women, heart disease and cancer, occur m o r e frequently and at a younger age for smokers. 14 W o m e n who smoke are at increased risk for complications o f

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oral contraceptive use, early menopause, cervical cancer, osteoporosis, emphysema, and cardiovascular disease. ~'15 W o m e n who quit smoking permanently by middle age substantially reduce their risk of heart disease and lung cancer in their later years. Because most women come into routine contact with the health care system during pregnancy, smoking cessation during pregnancy can potentially play a significant role in improving maternal and child health.

Helping Pregnant Women to Stop Smoking Although 90% o f all smokers would like to quit, permanent smoking cessation is difficult for many smokers to achieve. 16 Over the past 25 years, methodologies for p r o m o t i n g smoking cessation during the prenatal period have undergone great changes.l 7 For example, counseling methods are now coupled with pharmacological agents, such as nicotine gum or the nicotine patch, to increase the likelihood o f p e r m a n e n t cessation in nonpregnant women, is The nicotine patch has not been tested in pregnant women, although is the U.S. F o o d and Drug Administration has asked companies to conduct trials in this area as part o f post-marketing study. Although counsCing all pregnant smokers to quit is r e c o m m e n d e d , the extent to which this counseling takes place is not dear. 4's Studies in other medical care contexts suggest that effective behavioral counseling of smokers by physicians rarely occurs. 19 In some o f our own work, we have f o u n d that, even in the context o f a clinical trial tha~: included provider participation, 20% of pregnap_t women reported that their provider never, or o~.~yonce, mentioned smoking cessation during pregnancy. ~

Effectiveness of S ~ o k i n g Cessation Interventions Over the last few decades, numerous studies have been conducted in the United States on smoking cessation among pregnant women, most of which have been observational. 1~ These studies have identified correlates of cessation which show that women with particular demographic p r o f i l e s - married, young, better educated---are more successful at quitting during pregnancy without the assistance of an intervention, s O t h e r groups who

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are more likely to quit smoking during pregnancy include those who receive care from a private physician, smoke fewer than 10 cigarettes per day, start smoking later in life, have fewer children, and have no other smokers in the household. a Observational studies also suggest that permanent cessation may be most likely a m o n g teen mothers. Most adult smokers began using tobacco by the age o f 18 years. 2~ Within the first years o f smoking, while the individual is adopting the behavior, smoking levels are lower, and addiction to nicotine is less strong. Therefore, adolescent smokers who are pregnant may be most receptive to intervention and may be able to achieve permanent cessation. 21 Because observational studies cannot avoid the problem o f selection bias (ie, those women who are most motivated being either more compliant or selecting to be in the intervention group), they are a weak design for determining the impact o f cessation interventions on smoking behavior. Conversely, findings from randomized clinical trials (RCTs) can provide valuable information for designing future programs and individualizing care to help pregnant women to stop smoking.

Randomized Clinical Trials T h e r e have been 10 US-based r a n d o m i z e d clinical trials o f smoking cessation during pregnancy. 9'11'2227 Overall, most clinic-based interventions rely on self-help materials with counseling from a health educator or counselor. Price et al26 used an educational video, Petersen et a127 used an audiotape, and a more intensive intervention had monthly phone contact and biweekly mail contact with intervention clients. Overall quit rates in the treatment groups ranged from 4.9% to 31.9%; a m o n g control groups quit rates ranged from 1.4% to 17.2%. Quit rates did not appear to vary by the intensity o f the intervention activity, in the Sexton and Hebel RCT, 22 the quit rates were the highest, at 31.9%. For example, in one clinical trial in which the intervention included a mailed self-help manual and audiotape, the quit rate in the treatment g r o u p was 16.3%. In another clinical trial in which the intervention was composed of interaction with a health educator and either an educational videotape plus a self-help pamphlet or a self-help booklet, the quit

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rate was 4.9%. Although not uniformly available for all studies, the socioeconomic status of the client population may have b e e n an important factor in the quitting patterns. For example, health maintenance organization (HMO) p o p u lations a p p e a r to have higher quit rates than do public clinic populations. 2s

Enhancing the Effectiveness o f Smoking Cessation Intervention~ Smoking cessation intervention trials for pregnant w o m e n have d e m o n s t r a t e d that, in the aggregate, participants have been able to reduce smoking significantly and improve on the problem o f low birth weight. Nonetheless, the substantial variation in the effectiveness o f the array o f intervention strategies that have been evaluated suggests that there is no single intervention that can be r e c o m m e n d e d for universal adoption by prenatal care providers. T h e r e are, however, c o m m o n elements of successful interventions that have e m e r g e d f r o m .research. The populations o f p r e g n a n t smokers studied have been h e t e r o g e n e o u s with regard to demographic and cultural background. Given what is known about the predictors of smoking cessation (regardless o f intervention), w o m e n with different backgrounds can be expected to have different reasons for continuing or quitting smoking. In fact, in o u r own research, we f o u n d that Afr i c a n - A m e r i c a n w o m e n f r o m different geographic regions have different predictors of smoking cessation and reduction during pregnancy. 21 Clinical trials of the same self-help intervention (with counseling a n d reinforcement) achieved very different results a m o n g A f r i c a n American w o m e n in Birmingham, Alabama, and Baltimore, Maryland. In Birmingham, the intervention g r o u p quit rates were 1 8.1%, c o m p a r e d with 10.7% in the control g r o u p (P = .03). ~ In the Baltimore study, the intervention g r o u p quit rates were 6.2%, c o m p a r e d with 5.6% in the control group.51 The discrepant findings may be attributable in part to sociodemographic characteristics and smoking patterns between the two samples. 9,11,21 These findings are consistent with health behavior change theory and experience that suggest the effectiveness of interventions depends on the match between the needs o f a specific target audience and the type o f intervention provided. 29'3~

This does not mean that every provider needs to start de novo in planning a smoking cessation p r o g r a m that is unique to the specific target audience, but rather that meaningful needs assessm e n t and formative evaluation should be undertaken before a p r o g r a m is i m p o r t e d or planned. For example, discussion groups or individual interviews with smokers are low-cost strategies that can yield i m p o r t a n t insights into a target audience's concerns about quitting and perceived needs for help, as well as provide feedback on the acceptability and potential effectiveness o f p r o g r a m plans. Professional health educators who are trained in these p r o g r a m - p l a n n i n g skills are useful resource people for clinicians who are considering implementing smoking cessation interventions. Based on the findings o f evaluation studies reviewed in the previous section, certain general features should be included in any intervention. Dolan-Mullen et al's meta-analysis 2s concluded that (1) effectiveness is enhanced by using materials that are specific to pregnant women rather than those written for a m o r e general audience, and (2) multiple methods (eg, counseling, written materials, follow-up) are superior to " o n e - s h o t " approaches. Any smoking cessation p r o g r a m for p r e g n a n t w o m e n should encourage a policy of " n o smoking" in the woman's home. Not only will this eliminate one source o f stimulus to smoke, and thus make cessation easier for the woman, it will also have the added health benefit of reducing exposure to second-hand smoke, which is a significant source of carbon monoxide exposure for m a n y p r e g n a n t w o m e n . 9'21'31 O u r own data show that a woman's cotinine level, after adjusting for the n u m b e r of cigarettes smoked p e r day, is significantly influenced by her exposure to passive smoking resulting f r o m allowing people to smoke in the home. 31 The clinician should assess the patient's degree o f addiction and readiness to quit smoking as a part o f taking a p r e g n a n t woman's medical history. For example, Fagerstr/Sm et al have an instrument which takes a few minutes to administer that could be used to assess degree o f addiction. Table 2 presents some questions f r o m the Fagerstr6m assessment tool. 32 Addiction assessments could also be conducted effectively by a trained health education professional. Based on the answers to Fagerstr6m's test, the

Smoking Cessation Interventions

Table 2. Addiction Assessment Questions 1. How soon after you wake up do you smoke your first cigarette? 2. Which cigarette would most you hate to give up? 3. How many cigarettes do you smoke per day?

patient is rated as having a very low, low, medium, high, or very high degree o f addiction. Once the degree of addition is determined, the appropriate means o f intervention can be" identified. For example, women who have a high or very high degree of addiction to cigarettes--those who either smoke their first cigarette within the first 30 minutes o f waking, would hate to give up their first cigarette o f the day, or smoke more than 10 cigarettes a d a y - - a r e unlikely to be able to quit with self-help methods alone. Rather, considerable reinforcement would be required. Not all patients, especially those with h i g h degrees o f addiction, will be ready to quit when presenting for prenatal care. Clinicians therefore could further assess the patient's readiness to quit smoking in addition to the degree of addiction. The stages o f change (SOC) approach 33 could be used to assess readiness to quit. SOC acknowledges that smokers when presented with an opportunity to quit smoking vary in their willingness and capability to quit. The first column o f Table 3 lists the five stages o f change for addictive behaviors. Certain smokers are "precontemplaters," not even considering quitting, when they enter care. O t h e r smokers are "contemplating" quitting when they are presented with an opportunity. Although they are considering quitting, they have not yet initiated an action plan to quit. Counseling for such individuals may involve discussions about the pros and cons o f stopping smoking. Smokers who are "ready for action" when they enter care are planning to make a quit

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attempt in the immediate future and are most open to clinician counseling on methods to stop smoking. Smokers who are making an active attempt to quit cannot be considered former or ex-smokers because most smokers require several quit attempts before they can be considered quitters. An individual who has remained smoke free for a year, can be considered a f o r m e r smoker, but he or she may relapse and smoke again given certain circumstances. Patients at different stages o f readiness to quit require different kinds of counseling from their physicians. Precontemplaters should be counseled to consider quitting, and contemplators should be counseled to plan to make an active quit attempt. Smokers ready for action should be encouraged to make an action plan for quitting; those smokers who are actively making a quit attempt should be encouraged and supported in their attempt. 33 Tailoring counsel for cessation according to the patient's readiness to quit is an effective m e t h o d to begin the process o f achieving permanent cessation. There have been no interventions designed to specifically take into account a woman's degree o f addiction and readiness to quit. Adoption o f such an approach, however, might enhance the effectiveness o f smoking cessation interventions. In the meantime, screening pregnant smokers for the degree o f addiction and readiness to quit may help identify women who will benefit from specific types o f interventions. For example, a simple, low-cost intervention (eg, brief counseling with printed materials) can be effective among those women identified as light smokers (fewer than 5 to 10 cigarettes per day), women who have thought about or tried quitting since becoming pregnant, and women who express some confi-

Table 3. Stages of Readiness to Quit Smoking

Stage

Definition

Precontemplative

Has not thought of quitting smoking

Contemplative

Has considered quitting but not yet acted

Ready for action Action

Plans to make a quit attempt in near future Has been off cigarettes for several weeks

Maintenance

Has maintained quit status for several months

Intervention Raise level of awareness about the need to quit Elicit feelings--pros, cons, concerns-about quitting Build confidence in commitment to quit Reward successful attempt and reinforce commitment to stay quit Support continued commitment to stay quit

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Table 4. What Health Professionals Can Do to Help Pregnant Women Quit Smoking Clinical Settings

Community Settings

Assess t h e s m o k i n g history o f all female patients, i n c l u d i n g a d o l e s c e n t s C o u n s e l all s m o k i n g p a t i e n t s to quit o r at least to b e g i n the process o f cessation S u p p o r t the cessation efforts o f all patients, especially d u r i n g a n active quit a t t e m p t Use i n t e r v e n t i o n s a n d messages t h a t are appropriate for your patient population

Contact the local medical society and encourage the organization to be active in tobacco control efforts Volunteer to testify in legislative and administrative hearings during which tobacco control measures are being considered Contact the local health department to volunteer for tobacco control activities Contact the local school system to volunteer for presentations to youth on avoiding tobacco use

dence in their ability to quit. Alternatively, a more intensive intervention (eg, additional follow-up counseling) is probably needed for those women who do not share these characteristics.

Environmental Factors Affecting a Pregnant Woman's Ability to Stop Smoking It is important for clinicians to recognize the complex process o f smoking cessation. Factors that substantially affect a woman's ability to achieve cessation include the presence o f other smokers in her household, workplace policies regarding smoking, and living in communities that are targeted by the tobacco companies with prosmoking messages (ie, billboards). Even with the most effective individual counseling, it is increasingly evident that additional strategies are needed to achieve population-wide reductions in smoking and its related health conditions. 1'~~ For example, in Canada during the 1980s, when gove r n m e n t legislation was more vigorous and cigarette taxation was higher in comparison with the United States, rates o f tobacco consumption also declined faster. ~6 In Canada federal and local taxes constituted two thirds of the total price o f a pack o f cigarettes, whereas in the United States combined state and federal taxes constituted 20%. The Canadian government has also passed various legislation that restricts tobacco promotional activities, bans tobacco product advertising, and implements economic programs to help tobacco growers leave the industry. ~6 Similar efforts are beginning in the United States. For example, the California Proposition 99 effort included a multimedia campaign and a $.25/pack cigarette tax increase. This resulted in a tripling o f the rate at which cigarette consumption declined. 3~ American Stop Smoking Intervention

Study for Cancer Prevention (ASSIST), funded by the National Cancer Institute, and Initiative to Mobilize for the Prevention and Control o f Tobacco Use (IMPACT), funded by the Centers for Disease Control and Prevention, are tobacco control efforts designed to change environmental factors that affect tobacco use, such as increasing the n u m b e r o f tobacco-free environments or even targeting community norms about smoking. Health professionals can take an active role in supporting these multifaceted education and advocacy efforts. Table 4 presents a broad range of activities that health professionals may engage in to prevent initiation of smoking or to p r o m o t e smoking cessation. In addition to these activities, health professionals may become active in promoting institutional changes within their own workplaces to p r o m o t e smoking cessation efforts. ~7 As pointed out by Wynder, 35 "professionals need to match the commitment and expertise o f therapeutic medicine with an equal emphasis on health promotion." Because of their high public credibility and potential political impact, it is imperative that health professionals become involved in supporting tobacco control efforts in their communities.

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