Cigarette Smoking and Smoking Cessation Among Persons With Chronic Obstructive Pulmonary Disease

T H E SC I E N C E O F H E A L T H P R O M O T I O N Applied Research Brief: Smoking Control Cigarette Smoking and Smoking Cessation Among Persons With Chronic Obstructive Pulmonary Disease Jeannine S. Schiller, MPH; Hanyu Ni, MPH, PhD Abstract Purpose. To identify factors predictive of smoking cessation among adults with chronic obstructive pulmonary disease (COPD). Data from the 1997 to 2002 National Health Interview Surveys were analyzed for adults at least 25 years of age with COPD using logistic regression. Results. Of the adults with COPD, 36.2% were current smokers. Of the current smokers and former smokers who had quit smoking during the past year, 22.9% reported not receiving cessation advice from a health care professional during the past year. Although half of smokers with COPD had attempted to quit during the past year, only 14.6% were successful. Attempting to quit was negatively associated with heavy drinking but positively associated with being younger and having cardiovascular diseases, lung cancer, and activity limitation due to lung problems. Factors predictive of successful cessation included being at least 65 years old, not being poor, and activity limitation due to lung problems. Conclusion. This study underscores the importance of continuing to develop smoking cessation strategies for COPD patients and implementing clinical guidelines on smoking cessation among health care providers. (Am J Health Promot 2006;20[5]:319 323.) Key Words: Lung Diseases, Tobacco, Health Surveys, Smoking Cessation, Health Promotion, Prevention Research. Manuscript format: research; Research purpose: modeling/relationship testing; Study design: nonexperimental; Outcome measure: behavioral; Setting: state/national; Health focus: smoking control; Strategy: skill building/behavior change; Target population: adults; Target population circumstances: education/income level, race/ethnicity Jeannine S. Schiller, MPH, is with the Division of Health Interview Statistics, National Center for Health Statistics, Centers for Disease Control and Prevention, Hyattsville, Maryland. Hanyu Ni, MPH, PhD, is with the Division of Epidemiology and Clinical Application, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland. Send reprint requests to Jeannine S. Schiller, MPH, Division of Health Interview Statistics, National Center for Health Statistics, Centers for Disease Control and Prevention, 3311 Toledo Road, Room 2334, Hyattsville, MD 20782; jdv2@cdc.gov. This manuscript was submitted January 3, 2005; revisions were requested April 7, 2005, and June 9, 2005; the manuscript was accepted for publication June 20, 2005. Copyright 2006 by American Journal of Health Promotion, Inc. 0890-1171/06/$5.00 0 PURPOSE Cigarette smoking is the primary cause of chronic obstructive pulmonary disease (COPD) as well as a major risk factor associated with the progression of COPD. 1 The current clinical guidelines on COPD treatment recommend that health care providers help their COPD patients to stop smoking by providing counseling and pharmacotherapy. 2 However, few population-based data are available on smoking behaviors among persons with COPD and whether they receive cessation advice from health providers. Additionally, it remains unclear what factors are associated with attempted and successful smoking cessation among smokers after they are diagnosed with COPD. The availability of this information is essential for initiating effective strategies to help COPD patients stop smoking. The objectives of this study, therefore, were to identify cigarette smoking patterns and explore factors predictive of smoking cessation among persons aged 25 years and over who had COPD. METHODS Design The National Health Interview Survey (NHIS) is conducted annually by the National Center for Health Statistics of the Centers for Disease Control and Prevention, covering the civilian, noninstitutionalized household population of the United States. Information on demographics, health status, and health care services is collected for every member of the family in a sample household. Additional information is collected on one randomly selected adult aged 18 years and over from each family using the Sample Adult Questionnaire. Sample Data from the 1997 to 2002 Sample Adult components (the source of smoking information on the NHIS) May/June 2006, Vol. 20, No. 5 319

Table 1 Percent Distributions of Selected Smoking Patterns Among Adults Aged 25 Years and Over, by Chronic Obstructive Pulmonary Disease (COPD) Status, and by Sex for Adults With COPD: 1997 2002 National Health Interview Surveys* Adults With COPD Adults Without COPD Characteristic Men Women Total Total p Percent (Standard Error) Total 100.0 (0.00) 100.0 (0.00) 100.0 (0.00) 100.0 (0.00) Ever smoked at least 100 cigarettes in entire life# Yes 79.0 (0.77) 61.3 (0.69) 67.9 (0.52) 46.4 (0.18) No 21.0 (0.77) 38.7 (0.69) 32.1 (0.52) 53.6 (0.18) Smoking status# Current 36.3 (0.85) 36.1 (0.69) 36.2 (0.54) 22.0 (0.17) Former 42.7 (0.90) 25.2 (0.58) 31.7 (0.52) 24.4 (0.15) Never 21.0 (0.77) 38.8 (0.69) 32.2 (0.52) 53.6 (0.18) Age first started smoking regularly (y)#,** 6 15 51.0 (1.61) 34.0 (1.11) 40.3 (0.93) 28.7 (0.29) 16 17 20.4 (1.16) 22.6 (0.97) 21.8 (0.74) 23.5 (0.25) 18 20 18.2 (1.19) 23.8 (1.06) 21.7 (0.80) 27.7 (0.27) 21 85 10.4 (0.95) 19.7 (0.82) 16.2 (0.63) 20.1 (0.25) Average number of cigarettes smoked per d#, 1 14 27.6 (1.31) 36.9 (1.10) 33.4 (0.85) 43.2 (0.34) 15 24 38.5 (1.52) 41.8 (1.10) 40.6 (0.87) 39.9 (0.30) 25 34 15.5 (1.19) 11.6 (0.71) 13.0 (0.61) 9.6 (0.20) 35 94 18.5 (1.32) 9.7 (0.66) 13.0 (0.65) 7.3 (0.16) Attempted to quit smoking during the past y Yes 52.8 (1.51) 51.1 (1.03) 51.7 (0.89) 44.9 (0.32) No 47.2 (1.51) 48.9 (1.03) 48.3 (0.89) 55.1 (0.32) Successfully quit smoking during the past y Yes 15.8 (1.44) 13.8 (1.14) 14.6 (0.89) 15.9 (0.32) No 84.2 (1.44) 86.2 (1.14) 85.4 (0.89) 84.1 (0.32) Advised to quit smoking by a health professional during the past y Yes 73.3 (3.39) 79.2 (2.05) 77.1 (1.85) 51.0 (0.90) No 26.7 (3.39) 20.8 (2.05) 22.9 (1.85) 49.0 (0.90) Used stopping all at once ( cold turkey ) as a method to attempt/quit smoking Yes 81.9 (2.19) 73.9 (2.16) 77.5 (1.57) 82.6 (0.47) No 18.1 (2.19) 26.1 (2.16) 22.5 (1.57) 17.4 (0.47) Used medications as a method to attempt/quit smoking Yes 2.9 (0.84) 7.3 (1.21) 5.3 (0.78) 3.0 (0.21) No 97.1 (0.84) 92.7 (1.21) 94.7 (0.78) 97.0 (0.21) Used the nicotine patch as a method to attempt/quit smoking Yes 11.1 (1.83) 16.6 (1.97) 14.2 (1.38) 7.7 (0.32) No 88.9 (1.83) 83.4 (1.97) 85.8 (1.38) 92.3 (0.32) * Data from: 1997 to 2002 National Health Interview Surveys. Based on 2 test of independence between smoking pattern and COPD status. Sample size 3725. Sample size 7513. Sample size 11,238. Sample size 164,273. # Excludes persons with unknown responses for the smoking variable. ** Denominator for these estimates is adults aged 25 years and over who ever smoked 100 cigarettes in their lifetime. Denominator for these estimates is adults aged 25 years and over who smoked every day or some days. Average number of cigarettes smoked per day is based only on the days that the respondent smoked. 0.1623 0.0022 0.0041 320 American Journal of Health Promotion

were combined to provide a larger sample size and improve the precision of subgroup estimates. The overall response rate was 89.5% for the Household components and 84.2% for the Sample Adult components. The percent of unknowns for demographic and health characteristics is generally less than 1%. Because COPD is relatively rare in persons under age 25, this study was restricted to persons aged 25 years and over (sample size 175,631). Measures Adults who had been told by a health professional that they had either emphysema, chronic bronchitis, or both conditions were considered to have COPD. Information on other health characteristics was also analyzed. Adults were asked several questions about smoking, including current smoking status and time since quitting, if they were former smokers. Current smokers were asked whether they ever stopped smoking for 1 day or longer during the past year because they were trying to quit. Two aspects of smoking cessation were investigated: (1) any attempt to quit smoking for 1 day or longer during the past year among past-year smokers (i.e., current smokers and former smokers who had quit smoking during the past year), and (2) success in stopping smoking during the past year among those who had attempted to quit. This study also analyzed data from the Cancer Control Module of the 2000 NHIS. The supplemental questions regarding methods used for smoking cessation were completed by current and former smokers. Current smokers were also asked questions that assessed their intent and plans to quit smoking and about receiving smoking cessation advice from a health professional. Data from the Cancer Control Module are presented in Table 1 but were not included in the logistic regression because of the small sample sizes. Analysis Estimates were calculated using NHIS weights, which were calibrated to census totals for sex, age, and race/ethnicity of the U.S. population. The rate of quit attempts was estimated by dividing the number of COPD smokers who attempted to quit during the past year by the total number of past-year smokers. The rate for successful cessation was estimated by dividing the number of COPD smokers who successfully stopped smoking during the past year by the total number of COPD smokers who attempted to quit during the past year. Differences between rates or percents were evaluated using 2 tests at the.05 level. Logistic regression was used to identify factors predictive of attempting to quit smoking and successful cessation during the past year. Because the objective of this study was to explore factors predictive of smoking cessation among people with COPD, backward selection was used to measure the intercorrelations of the influential factors and determine the best-fit model. Both models started with the same set of potential predictive factors, which included demographic characteristics, activity limitations, chronic conditions, mental health indicators, and other health characteristics. These factors were selected based on their association with smoking cessation behaviors through either bivariate analyses or a literature review in this area. Analyses were performed using SAS-callable SU- DAAN software and accounting for the complex sample design of the NHIS. RESULTS A total of 11,238 adults aged 25 years and over were classified as having COPD in the 1997 to 2002 NHISs. This translates into a prevalence rate of 6.1% or approximately 10.7 million civilian, noninstitutionalized adults aged 25 years and over in the United States with COPD. Table 1 shows smoking patterns among adults by COPD status. Overall, approximately two thirds of adults with COPD had smoked at least 100 cigarettes in their lifetime, and nearly half of them had stopped smoking. The prevalence of current smoking was much higher among adults with COPD than those without (36.2% vs. 22.0%, p.001). Nearly 90% of smokers with COPD smoked every day (data not shown). Compared with smokers without COPD, those with COPD were more likely to have started smoking regularly before age 16 years and to smoke more heavily. Among adults with COPD who had smoked in the past year, half had attempted to quit for at least 1 day in the past year. This is significantly higher than for persons without COPD (51.7% vs. 44.9%, p.001). For those who attempted to quit smoking, there was no difference in the rate of success in quitting between smokers with and without COPD. Only 14.6% of smokers with COPD who attempted to quit were successful in stopping smoking. No difference was found between male and female smokers in terms of quit attempts and successful smoking cessation. Based on data from the Cancer Control Module of the 2000 NHIS, more than 20% of past-year smokers with COPD reported not receiving cessation advice while visiting a health professional during the past year. Stopping smoking all at once, or cold turkey, was the method Denominator for these estimates is adults aged 25 years and over who were either current smokers or past-year smokers. Denominator for these estimates is adults aged 25 years and over who attempted to quit smoking during the past year. Estimates are based only on data from the 2000 NHIS. Denominator for these estimates is adults aged 25 years and over who were either current smokers or past-year smokers and visited or spoke with a health professional about their health within the past year. Estimates are based only on data from the 2000 NHIS. Denominator for these estimates is adults aged 25 years and over who were either former smokers or current smokers who had ever stopped smoking for one day or longer because they were trying to quit smoking. May/June 2006, Vol. 20, No. 5 321

Table 2 Factors Associated With Attempt to Quit Smoking or Successful Smoking Cessation During the Past Year Among Adults Aged 25 Years and Over With Chronic Obstructive Pulmonary Disease: Logistic Regression Results* Model 1: Attempted to Quit Smoking During the Past Year Characteristic Odds Ratio (95% Confidence Interval) Model 2: Successfully Quit Smoking During the Past Year Characteristic Odds Ratio (95% Confidence Interval) Age (y) Age (y) 25 34 1.49 (1.15 1.93) 25 34 0.45 (0.28 0.70) 35 44 1.08 (0.86 1.35) 35 44 0.39 (0.25 0.60) 45 64 1.15 (0.94 1.40) 45 64 0.39 (0.28 0.56) 65 and over Reference 65 and over Reference Alcohol status Difficulty climbing steps Abstainers/former drinkers Reference No difficulty Reference Infrequent/light/moderate drinkers 1.06 (0.90 1.24) Some difficulty 0.89 (0.62 1.30) Heavy drinkers 0.66 (0.52 0.85) A lot of difficulty 1.50 (1.06 1.12) Activity limitation due to lung or breathing problem Activity limitation due to lung or breathing problem Yes 1.56 (1.28 1.89) Yes 1.67 (1.17 2.38) No Reference No Reference Lung cancer Poverty status Yes 2.41 (1.15 5.04) Poor Reference No Reference Near poor 1.27 (0.83 1.94) Cardiovascular diseases Not poor 2.13 (1.38 3.30) Yes 1.34 (1.14 1.56) Unknown 2.12 (1.33 3.40) No Reference Hopeless All/most of the time 0.52 (0.30 0.90) Some of the time 0.49 (0.31 0.77) A little/none of the time Reference * Data from: 1997 to 2002 National Health Interview Surveys. Models exclude persons with unknown responses for any of the selected characteristics. Respondents were asked how difficult it is to walk up 10 steps without resting and without the use of any special equipment. Poverty status is based on family income and family size using the U.S. Census Bureau s poverty thresholds for the previous calendar year. Poor persons are defined as below the poverty threshold. Near poor persons have incomes of 100% to less than 200% of the poverty threshold. Not poor persons have incomes that are 200% of the poverty threshold or greater. most commonly used to quit smoking. Approximately 5% and 14% of persons with COPD used medications or the nicotine patch, respectively, to either attempt to quit or successfully stop smoking. The results from logistic regression analyses, shown in Table 2, revealed that predictive factors for attempting to quit smoking were being younger (25 to 34 years old), having cardiovascular diseases, having lung cancer, and having activity limitation as a result of lung problems. Heavy drinking was negatively associated with attempting to quit smoking. The predictive factors for successful smoking cessation among those attempting to quit were being aged 65 years or over, not being poor, having activity limitation due to lung problems, and having a lot of difficulty climbing steps. Feeling hopeless was negatively associated with successful smoking cessation. DISCUSSION Summary Despite evidence of the benefits of smoking cessation, this study revealed that only half of past-year smokers with COPD attempted to quit during the past year, and most (85%) were unsuccessful. Consistent with findings from studies conducted among all smokers, 3,4 we found that younger smokers with COPD were more likely to attempt quitting, but older smokers with COPD were more likely to succeed in quitting. Our study indicated that factors predictive of unsuccessful cessation were feelings of hopelessness and being poor. Lack of health insurance may contribute to low cessation rates among poor persons, because they may lack access to cessation strategies. Persons who feel hopeless may feel that attempts to change their disease status are useless. 5 Certain activity limitations were predictive of successful smoking cessation; smokers may quit in hopes of reducing these limitations. Although clinical guidelines on smoking cessation recommend that health care providers provide smoking cessation advice during patient visits, 6 NHIS data show that about 20% of smokers with COPD did not receive cessation advice during visits in the past year. However, it is possible that brief counseling was provided but not reported or recalled by the patient. A combination of patient counseling and pharmacological therapies has been found to be most effective in helping patients stop smoking, 322 American Journal of Health Promotion

and a combination of nicotine replacement therapy with bupropion can help increase cessation rates. 2,7 Despite these findings, this study found that none of the smokers with COPD who successfully stopped smoking in the past year reported using both counseling and medications to quit smoking. The most common cessation method used by smokers with COPD was stopping cold turkey (all at once). The second most commonly used method was the nicotine patch. However, the patch was used by only 14% of smokers with COPD. Use of the nicotine patch to successfully stop smoking among persons with COPD was more likely among those with health insurance compared to those who were uninsured (data not shown). Limitations The NHIS does not examine medical records to confirm self-reported conditions; therefore, there is a possibility of misclassification of COPD. However, based on a study conducted to evaluate diagnostic reporting in the NHIS, chronic conditions that require physician diagnosis and ongoing medical care, such as emphysema and chronic bronchitis, showed the highest level of agreement of all types of chronic conditions between interviews and medical records. 8 A relatively high agreement (78% to 86%) between self-reporting and medical records was also found by a study that specifically examined the validity of self-reported COPD among selected participants in the Nurses Health Study. 9 Implications The findings from this study underscore the importance of continuing efforts in developing effective smoking cessation strategies for COPD patients and in implementing clinical guidelines on smoking cessation among health care providers. Acknowledgments Both authors are employees of the federal government and performed the research presented in this manuscript within the scope of their employment with their agencies. References 1. US Department of Health and Human Services. The Health Benefits of Smoking Cessation. A Report of the Surgeon General, 1990. Rockville, Md: Centers for Disease Control and Prevention, Office on Smoking and Health; 1990. 2. The Tobacco Use and Dependence Clinical Practice Guideline Panel, Staff, and Consortium Representatives. A clinical practice guideline for treating tobacco use and dependence: A US Public Health Service report. JAMA. 2000;283:3244 3254. 3. Hennrikus DJ, Jeffery RW, Lando HA. The smoking cessation process: longitudinal observations in a working population. Prev Med. 1995;24:235 244. 4. Gorecka D, Bednarek M, Nowinski A, et al. [Predictors of success in smoking cessation among participants of spirometric screening for COPD]. Pneumonol Alergol Pol. 2001; 69(11 12):611 616. 5. Morgan MD, Britton JR. Chronic obstructive pulmonary disease 8: non-pharmacological management of COPD. Thorax. 2003;58:453 457. 6. Fiore MC. AHCPR smoking cessation guideline: a fundamental review. Tob Control. 1997; 6(suppl 1):S4 S8. 7. Jorenby DE, Leischow SJ, Nides MA, et al. A controlled trial of sustained-release bupropion, a nicotine patch, or both for smoking cessation. N Engl J Med. 1999;340:685 691. 8. Edwards W, Winn D, Kurlantzick V. Evaluation of National Health Interview Survey diagnostic reporting. Vital Health Stat. 1994;2: 22 32. 9. Barr RG, Herbstman J, Speizer FE, Camargo CA Jr. Validation of self-reported chronic obstructive pulmonary disease in a cohort study of nurses. Am J Epidemiol. 2002;155:965 971. May/June 2006, Vol. 20, No. 5 323