- Email: [email protected]
Is smokeless tobacco use becoming more common among U.S. male smokers? Trends in Alaska
Addictive Behaviors 37 (2012) 862–865
Contents lists available at SciVerse ScienceDirect
Addictive Behaviors
Short Communication
Is smokeless tobacco use becoming more common among U.S. male smokers? Trends in Alaska Julie E. Maher a,⁎, Chris J. Bushore a, Kristen Rohde a, Clyde W. Dent a, Erin Peterson b a b
Program Design and Evaluation Services, Oregon Public Health Division and Multnomah County Health Department, United States Tobacco Prevention and Control Program, State of Alaska Department of Health and Social Services, United States
a r t i c l e Keywords: Smokeless tobacco Smoking Dual use Trends United States Men
i n f o
a b s t r a c t Introduction: The tobacco industry has promoted the use of smokeless tobacco (SLT) to smokers as a substitution for cigarettes when smoking is not possible, and some smokers are using SLT this way. However, few publications have examined recent trends in dual cigarette and SLT use (dual use) over time in the U.S. Materials and methods: We examined trends in the use of SLT among current, former and never cigarette smokers using data on adult (aged 18+ years) males (n = 16,590) from the 1996–2008 Alaska Behavioral Risk Factor Surveillance System (BRFSS). We also examined trends from 2004 to 2008 in cigarette consumption among dual users. Results: Between 1996 and 2008, the overall prevalence of current SLT use and prevalence of current smoking among Alaskan men did not significantly change over time (p-value from age-adjusted models p = .63, p = .09, respectively). When we examined trends in SLT use by smoking status, we found that the prevalence of current SLT use remained unchanged between 1996 and 2008 among former and never smokers, but almost doubled among current smokers (age-adjusted p = .004). Between 2004 and 2008, cigarette consumption remained steady among current smokers who did not use SLT, but significantly decreased among dual users (age-adjusted p b .001). Conclusions: Our findings suggest that male smokers in Alaska are increasingly likely to use SLT, but do not appear to be switching to SLT use exclusively. We recommend that other state tobacco control programs examine trends in dual use to confirm our findings, and for programs to continue encouraging cessation of all tobacco products. © 2012 Elsevier Ltd. All rights reserved.
1. Introduction The tobacco control community remains divided about the use of smokeless tobacco (SLT) instead of cigarettes as a harm reduction strategy (Zeller, Hatsukami, & Strategic Dialogue on Tobacco Harm Reduction Group, 2009). Both the effectiveness and feasibility of this strategy remain unclear (Zeller et al., 2009). Sweden is considered a potential example of how people could switch from smoking to SLT (Foulds, Ramstrom, Burke, & Fagerstrom, 2003), but those results have not been replicated in the U.S. (Zhu et al., 2009). Recent examination of tobacco industry documents suggests the industry is marketing SLT products to U.S. smokers. Some industry messages have encouraged smokers to use SLT as a substitution for cigarettes when smoking is not possible, thereby promoting dual
Abbreviations: SLT, Smokeless Tobacco; CDC, Centers for Disease Control and Prevention; BRFSS, Behavioral Risk Factor Surveillance System; CASRO, Council of American Survey Research Organizations. ⁎ Corresponding author at: 827 NE Oregon St, Suite 250, Portland, OR 97232, United States. Tel.: + 1 971 673 0603. E-mail address: [email protected] (J.E. Maher). 0306-4603/$ – see front matter © 2012 Elsevier Ltd. All rights reserved. doi:10.1016/j.addbeh.2012.02.015
cigarette and SLT use (“dual use”) (Carpenter, Connolly, Ayo-Yusuf, & Wayne, 2009; Meija & Ling, 2010). Indeed, a recent U.S. study suggests that many dual users are using SLT in situations when they cannot smoke (McClave-Regan & Berkowitz, 2011). The health implications of dual use compared to smoking only are unclear. The differences in health outcomes based on literature review are under debate (Frost-Pineda, Appleton, Fisher, Fox, & Gaworski, 2010; Frost-Pineda, Appleton, Fisher, Fox, & Gaworski, 2011; Glantz & Ling, 2011). Some have hypothesized that the health risks of cigarettes and SLT may be additive or even synergistic (Wetter, McClure, de Moor, et al., 2002). In addition, others have suggested that dual use could prolong dependence on tobacco products, rather than helping smokers quit (Meija & Ling, 2010; Tomar, Alpert, & Connolly, 2010). Despite this, few publications have examined recent trends over time in dual use in a population-based sample in the U.S. (Mumford, Levy, Gitchell, & Blackman, 2005; Rodu & Cole, 2009). The most recent publication used national data for men from 2000 to 2005 (Rodu & Cole, 2009); it found the prevalence of dual use and of SLT only use stayed stable during this time, while smoking prevalence significantly decreased. Those authors reported that cigarette consumption was lower among dual users than those who only smoked, but did
J.E. Maher et al. / Addictive Behaviors 37 (2012) 862–865
not report temporal trends in cigarette consumption within these groups. The purpose of our study was to examine recent trends in current SLT use among current, former, and never male smokers in the State of Alaska, where SLT use is relatively high (CDC, 2010a), and to examine recent trends in cigarette consumption among dual users. 2. Materials and methods
863
including smoking allowed anywhere, allowed in some areas, and not allowed anywhere. When we created the workplace smoking ban status variable, we considered if a person worked outside or was unemployed. Quit intentions were ascertained by asking about wanting to quit smoking. A quit attempt during the last year was defined as having stopped smoking for one day or longer because of trying to quit smoking. Data were considered missing for a particular question if a participant responded “don't know” or refused to answer.
2.1. Setting 2.4. Statistical analyses Alaska State Department of Health and Social Services has had a tobacco control program since 1994. The program is funded at about 70% of the Centers for Disease Control and Prevention (CDC) recommended level (as of 2007) (CDC, 2010b). Although one program goal is to reduce SLT use, this has not been a major focus. In 2009, the Alaska current SLT use prevalence was the 12th highest in the U.S. (CDC, 2010a). 2.2. Sample We used Alaska Behavioral Risk Factor Surveillance System (BRFSS) data from 1996 to 2008. The Alaska BRFSS is part of the national BRFSS, and is a random-digit-dialed, cross-sectional survey stratified on geographic region. Eligible participants are non-institutionalized, aged 18 years or over, living in Alaska households with a landline telephone, and speak English (Alaska Division of Public Health, 2009). In 1996–2008, the Council of American Survey Research Organizations (CASRO) response rate ranged from 47.7% (year 2000) to 67.5% (year 2005). During 1996–2008, 16,590 men participated in BRFSS and are included in the analyses of SLT use trends. Only men were included in this study because SLT prevalence is low among Alaskan women overall (2.5%) (CDC, 2010a). The sample size per year ranged from 691 (year 1996) to 2142 (year 2008), with the average yearly sample size being about 1400. Trends in cigarette consumption are limited to 2004–2008 because consumption questions were not asked on earlier BRFSS surveys. This project relied on public health surveillance data and did not require institutional review board approval. 2.3. Measures We briefly describe the measures used; specific question wording can be found elsewhere (Alaska Division of Public Health, 2009). We classified participants as never smokers if they had not smoked at least 100 cigarettes in their life. Those who had smoked at least 100 cigarettes and reported now smoking “everyday” or “some days” were classified as current smokers; those who reported now smoking “not at all” were classified as former smokers. We calculated cigarette consumption by multiplying the number of days during the past 30 that the participant smoked by the number of cigarettes smoked per day. The result was converted to packs per month. Participants were classified as current SLT users if they answered “yes” to the following two questions: “Have you ever used or tried any…” and “Do you currently use any smokeless tobacco products such as chewing tobacco, snuff, Iq'mik or Blackbull?” Dual use was defined as currently smoking and using SLT. We used additional measures for descriptive purposes. We used BRFSS data on the participant's age, race, income, education level, and consumption of alcohol. Telephone prefix was used to impute geographic location. Urban (vs. rural) was defined as a Metropolitan Statistical Area or a Micropolitan Statistical Area as defined by the U.S. Census Bureau (U.S. Office of Management and Budget, 2009). We examined smoking ban and quit measures from the Alaska BRFSS. Questions asked about participants' home smoking rules and their workplace's official smoking policy, with response categories
For all analyses, we used the .05 level of significance and procedures in Stata® that took into account complex sampling design. We weighted the data to adjust for differential sampling rates within each telephone bank and for the number of telephones and adults in the household, and to ensure that the age and geographic distribution of male participants matched that for Alaska men based on the Claritas population estimates for a given year (Nielsen Claritas Site Reports). We tested for trends during 1996–2008 in current SLT use overall and current smoking overall with logistic regression. Because the average age of Alaskans increased significantly over this time, we adjusted for age by including it as an independent variable. We used logistic regression to test for trends in current SLT use among current, former, and never smokers. We fitted models stratified by smoking status; each model had current SLT use as the dependent variable, and time and age as independent variables. Positive parameter estimates for time indicated an increase in the odds of current SLT use over time. We also tested for differences in these trends by fitting an overall model (not stratified) with time by smoking status interaction terms. Using a similar approach, we fitted linear regression models to test for trends during 2004–2008 in cigarette consumption among current dual users compared to smokers only. For descriptive purposes, we compared other characteristics of current dual users to smokers only using chi-square tests (during 2004–2008 combined). 3. Results Among Alaskan men in 2008, the prevalence of current SLT use was 8.6% and the prevalence of current smoking was 23.9%; these prevalences had not significantly changed between 1996 and 2008 (p = .63, p = .09 for trend after adjusting for age). The prevalence of current SLT use significantly increased among current smokers during 1996–2008 (p = .004 for trend after adjusting for age). We found that the odds of SLT use among current smokers increased by 6% per year (age-adjusted OR = 1.06, 95% confidence interval: 1.02–1.10). However, the prevalence of current SLT use did not significantly change among former and never smokers (Fig. 1). This trend was significantly different for current smokers than for former (p = .027) and never smokers (p = .004). Cigarette packs per month smoked among current dual users significantly decreased during 2004–2008 (mean per year for 2004 to 2008: 22.9, 16.4, 21.2, 8.5, 9.2; p b .001 for trend after adjusting for age; n = 118), but remained steady among current smokers only (mean per year for 2004 to 2008: 20.6, 18.8, 17.0, 17.8, 19.9; p = .725 for trend after adjusting for age; n = 1234). This trend was significantly different for dual users than for smokers only (p = .002). Overall, 9.5% (95% CI: 7.9%–11.5%) of current smokers during 2004–2008 reported current SLT use. Compared to current smokers only, current dual users were significantly younger, more likely to live in rural areas, and more likely to be heavy drinkers of alcohol (Table 1). They were somewhat more likely to have lower incomes and more likely to report a smoking ban at home, but these differences did not reach statistical significance (p = .088, p = .144, respectively).
864
J.E. Maher et al. / Addictive Behaviors 37 (2012) 862–865
Smokeless Percent
A) Current Smokers (p=.004) 14% 12% 10% 8% 6% 4% 2% 0%
Standard BRFSS Questions, 2004–2008
1996 1997 1998 1999 2000 2001 2002 2003* 2004 2005 2006 2007 2008
Smokeless Percent
B) Former Smokers (p=.901) 14% 12% 10% 8% 6% 4% 2% 0%
Characteristic
Use SLT and smoke (n = 244a)
Only smoke (n = 2284a)
p-value
Age: b 45 years Race White AK Native Otherb Yearly income: b$50,000 Geography: Rural Education: HS diploma or less
82.5%
61.2%
b.001
67.2% 26.8% 6.0% 69.0% 44.6% 67.0%
63.9% 25.1% 10.9% 60.5% 31.7% 61.1%
.346
.088 .006 .270
Alaska-Added BRFSS Questions, 2004–2008c 1996 1997 1998 1999 2000 2001 2002 2003* 2004 2005 2006 2007 2008
C) Never Smokers (p=.218) Smokeless Percent
Table 1 Characteristics of men who use smokeless tobacco (SLT) and smoke compared to men who only smoke, State of Alaska, 2004–2008.
14% 12% 10% 8% 6% 4% 2% 0% 1996 1997 1998 1999 2000 2001 2002 2003* 2004 2005 2006 2007 2008
Fig. 1. Trends in prevalence of current smokeless tobacco use, by smoking status: Males aged 18 years and older, Alaska, 1996–2008. The points represent the percent using smokeless for any given year. The lines are the fitted regression lines. All p-values are calculated using an age-adjusted model. Sample sizes for the models: current smokers (n = 4489), former smokers (n = 5107), never smokers (n = 6866). * Smokeless tobacco questions were not included in the 2003 Alaska BRFSS.
4. Discussion The present study used data on Alaskan men to examine recent trends in SLT use among current, former, and never smokers, and trends in cigarette consumption among current dual users. The prevalence of SLT use among former smokers stayed flat over time, suggesting that there was not an increase in male smokers switching to using SLT exclusively. This finding is consistent with patterns observed in a one-year longitudinal study from 2002 to 2003 in the U.S. (Zhu et al., 2009). However, we found that the proportion of current smokers who are also using SLT significantly increased over time, and evidence that cigarette consumption among dual users is decreasing over time. To our knowledge, we are the first to report such patterns among men in a U.S. sample. Other recent population-based studies in the U.S. offer some insight into the patterns we observed. Tomar et al. (2010) examined patterns of dual use among U.S. men in 2006–2007, around the time major cigarette companies gained control of most of the U.S. SLT market, to serve as a “baseline.” They found that current daily smokers who used snuff on some days, compared to daily smokers who did not use snuff, were more likely to want to quit smoking and to have a quit attempt in the past year. They hypothesized that either these dual users may be partially substituting snuff for smoking thereby delaying successfully quitting smoking, or that smokers with failed quit attempts may then try snuff as a cessation strategy. A more recent U.S. study using 2008 data by McClave-Regan and Berkowitz (2011) suggests that many dual users are partially substituting SLT use for smoking, but not using SLT for cessation. That study found two-thirds of dual users were using SLT when they could not smoke, and three-quarters of the dual users did not believe that SLT could help them quit smoking. Whether such substitution and associated decreases in cigarette consumption might decrease health risks is an important area for further study.
Characteristic
Use SLT and smoke (n = 129a)
Only smoke (n = 1334a)
p-value
Smoking ban at home d Workplace smoking ban status Work inside & no smoking allowed Work inside & smoking allowed Work outside Unemployed Want to quit Quit attempt in last year Alcohol: >2 drinks/day
72.0%
63.2%
.144
30.0%
31.2%
.553
24.3%
18.0%
19.7% 26.0% 76.6% 56.5% 21.2%
17.0% 33.8% 75.9% 54.9% 9.6%
.905 .825 .037
a Data are missing for less than 10% of participants for each of the measures. Information on heavy drinking was only available for 2005–2008, so the sample sizes are smaller (n = 115 dual users and n = 950 smokers only). b Other race category includes: African American (1.4% of the total); Asian (1.4%); Native Hawaiian/Other Pacific Islander (1.1%); and Other race/Refused (6.6%). c During 2004–2008, Alaska asked extra questions of about half of the BRFSS participants; hence, there are responses for the standard BRFSS questions for all male participants and for the Alaska-added BRFSS questions for about half of them. d Smoking ban in the home defined as no smoking allowed anywhere.
The tobacco industry's promotion of SLT to smokers (Carpenter et al., 2009) could be influencing male smokers in Alaska to use SLT, but other factors could be influencing the trends observed as well. For example, the prevalence of home smoking bans in Alaska has increased over time (Alaska DHSS, 2009; Peterson, Fenaughty, & Eberhart-Phillips, 2004), and such bans may be associated with dual use (Mumford et al., 2005). Alaska also had increases in cigarette taxes in 2005, 2006, and 2007 without any increases in SLT taxes since 1997, and there is some evidence that this situation could lead to increased SLT use (Ohsfeldt, Boyle, & Capilouto, 1997), but the evidence is mixed (Mumford et al., 2005). In addition, smoking has become less socially acceptable over time in the U.S. (Gutman, 2011); these social norm changes may be influencing smokers to use SLT in public, instead of smoking. This study has several limitations. First, the BRFSS is limited to adults living in households with landline telephones and who speak English. Second, response rates were less than 70%. Data were weighted to reflect the age and geographic distribution of Alaska men, but non-response might be related to other characteristics that could affect the trends observed. Third, our SLT question did not ask specifically about new types of tobacco products (e.g., lozenges), and we did not ask frequency of SLT use (e.g., someday vs. everyday). Fourth, because we used data from repeat, cross-sectional surveys, we could not examine changes in smoking and SLT use within individuals over time. For example, in trying to interpret the reduction in cigarette consumption among dual users over time, we do not know whether current smokers are increasingly likely to use SLT as a substitution method or if lighter smokers are increasingly more likely to start using SLT; however, the former seems a more plausible
J.E. Maher et al. / Addictive Behaviors 37 (2012) 862–865
explanation. Last, it is possible that trends observed in dual use could be due, in part, to a birth cohort effect. However, we found that the increase in SLT use among smokers was essentially identical among those over 29 years old and among those 18–29 (p = .77; data not shown). 5. Conclusions Our findings suggest that male current smokers in Alaska are increasingly likely to use SLT, but do not appear to be switching to SLT use exclusively. To help understand these trends, future research should examine the reasons more smokers in the U.S. are using SLT and whether it helps smokers reduce their cigarette consumption. We recommend that other state tobacco control programs examine trends in SLT use among former and current smokers to confirm our findings, and for programs to continue encouraging cessation of all tobacco products. Role of funding sources The Alaska Tobacco Prevention and Control Program funded this work and collaborated on this manuscript. Contributors Julie Maher took the lead on interpreting the results and writing the manuscript. Chris Bushore and Clyde Dent conducted the analyses. Kristen Rohde conducted the literature searches and helped summarize previous research. All authors contributed to the design of the study, helped in interpreting results, and edited the manuscript. Conflict of interest The authors do not have any competing interests to declare.
References Alaska Department of Health and Social Services (DHSS) (2009, September). Alaska Tobacco Facts, 2009 Update. Retrieved from. http://hss.state.ak.us/dph/chronic/ tobacco/alaska_tobacco_facts.pdf Alaska Division of Public Health (2009). Behavioral Risk Factor Surveillance System Survey. Retrieved from. http://www.hss.state.ak.us/dph/chronic/hsl/brfss Carpenter, C. M., Connolly, G. N., Ayo-Yusuf, O. A., & Wayne, G. F. (2009). Developing smokeless tobacco products for smokers: An examination of tobacco industry documents. Tobacco Control, 18(1), 54–59, doi:10.1136/tc.2008.026583. Centers for Disease Control and Prevention (2010). State-specific prevalence of cigarette smoking and smokeless tobacco use among adults – United States, 2009. Morbidity and Mortality Weekly Report, 59(43), 1400–1406 Retrieved from. http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5943a2.htm
865
Centers for Disease Control and Prevention (2010). Tobacco Control State Highlights 2010. Retrieved from. http://www.cdc.gov/tobacco/data_statistics/state_data/ state_highlights/2010/pdfs/highlights2010.pdf Foulds, J., Ramstrom, L., Burke, M., & Fagerstrom, K. (2003). Effect of smokeless tobacco (snus) on smoking and public health in Sweden. Tobacco Control, 12(4), 349–359. Frost-Pineda, K., Appleton, S., Fisher, M., Fox, K., & Gaworski, C. L. (2010). Does dual use jeopardize the potential role of smokeless tobacco in harm reduction? Nicotine & Tobacco Research, 12(11), 1055–1067. Frost-Pineda, K., Appleton, S., Fisher, M., Fox, K., & Gaworski, C. L. (2011). Response to Glantz and Ling. Nicotine & Tobacco Research, 13(4), 297. Glantz, S. A., & Ling, P. M. (2011). Misleading conclusions from Altria researchers about population health effects of dual use. Nicotine & Tobacco Research, 13(4), 296. Gutman, M. (2011, April). Social Norms and Attitudes about Smoking: 1991–2010. Center for Public Program Evaluation, Robert Wood Johnson Foundation Retrieved from. http://www.rwjf.org/files/research/72054.trendssocialnorms.041211.pdf McClave-Regan, A. K., & Berkowitz, J. (2011). Smokers who are also using smokeless tobacco products in the US: a national assessment of characteristics, behaviours and beliefs of ‘dual users’. Tobacco Control, 20(3), 239–242. Mejia, A. B., & Ling, P. M. (2010). Tobacco industry consumer research on smokeless tobacco users and product development. American Journal of Public Health, 100(1), 78–87, doi:10.2105/AJPH.2008.152603. Mumford, E. A., Levy, D. T., Gitchell, J. G., & Blackman, K. O. (2005). Tobacco control policies and the concurrent use of smokeless tobacco and cigarettes among men, 1992–2002. Nicotine & Tobacco Research, 7(6), 891–900, doi:10.1080/ 114622200500266098. Nielsen Claritas SiteReports. (n.d.). Retrieved June 25, 2010, from http://www.claritas. com/sitereports/Default.jsp Ohsfeldt, R. L., Boyle, R. G., & Capilouto, E. (1997). Effects of tobacco excise taxes on the use of smokeless tobacco products in the USA. Health Economics, 6(5), 525–531, doi:10.1002/(SICI)1099-1050(199709)6:5b525::AID-HEC300>3.0.CO;2-Y. Peterson, E., Fenaughty, A., & Eberhart-Phillips, J. E. (2004, February). Tobacco in the great land: A portrait of Alaska's leading cause of death. Retrieved from. http:// www.epi.alaska.gov/pubs/tobaccofeb04.pdf Rodu, B., & Cole, P. (2009). Smokeless tobacco use among men in the United States, 2000 and 2005. Journal of Oral Pathology & Medicine, 38(7), 545–550, doi: 10.1111/j.1600-0714.2009.00780x. Tomar, S. L., Alpert, H. R., & Connolly, G. N. (2010). Patterns of dual use of cigarettes and smokeless tobacco among US males: Findings from national surveys. Tobacco Control, 19(2), 104–109, doi:10.1136/tc.2009.031070. U.S. Office of Management and Budget (2009, December 1). OMB Bulletin No. 10–02: Update of statistical area definitions and guidance on their uses. Retrieved from. http://www.whitehouse.gov/omb/assets/bulletins/b10-02.pdf Wetter, D. W., McClure, J. B., de Moor, C., et al. (2002). Concomitant use of cigarettes and smokeless tobacco: Prevalence, correlates, and predictors of tobacco cessation. Preventive Medicine, 34, 638–648. Zeller, M., & Hatsukami, D.Strategic Dialogue on Tobacco Harm Reduction Group. (2009). The strategic dialogue on tobacco harm reduction: A vision and blueprint for action in the US. Tobacco Control, 18(4), 324–332, doi:10.1136/tc.2008.027318. Zhu, S. H., Wang, J. B., Hartman, A., Zhuang, Y., Gamst, A., Gibson, J. T., et al. (2009). Quitting cigarettes completely or switching to smokeless tobacco: Do US data replicate the Swedish results? Tobacco Control, 18(2), 82–87, doi:10.1136/tc.2008. 028209.
Contents lists available at SciVerse ScienceDirect
Addictive Behaviors
Short Communication
Is smokeless tobacco use becoming more common among U.S. male smokers? Trends in Alaska Julie E. Maher a,⁎, Chris J. Bushore a, Kristen Rohde a, Clyde W. Dent a, Erin Peterson b a b
Program Design and Evaluation Services, Oregon Public Health Division and Multnomah County Health Department, United States Tobacco Prevention and Control Program, State of Alaska Department of Health and Social Services, United States
a r t i c l e Keywords: Smokeless tobacco Smoking Dual use Trends United States Men
i n f o
a b s t r a c t Introduction: The tobacco industry has promoted the use of smokeless tobacco (SLT) to smokers as a substitution for cigarettes when smoking is not possible, and some smokers are using SLT this way. However, few publications have examined recent trends in dual cigarette and SLT use (dual use) over time in the U.S. Materials and methods: We examined trends in the use of SLT among current, former and never cigarette smokers using data on adult (aged 18+ years) males (n = 16,590) from the 1996–2008 Alaska Behavioral Risk Factor Surveillance System (BRFSS). We also examined trends from 2004 to 2008 in cigarette consumption among dual users. Results: Between 1996 and 2008, the overall prevalence of current SLT use and prevalence of current smoking among Alaskan men did not significantly change over time (p-value from age-adjusted models p = .63, p = .09, respectively). When we examined trends in SLT use by smoking status, we found that the prevalence of current SLT use remained unchanged between 1996 and 2008 among former and never smokers, but almost doubled among current smokers (age-adjusted p = .004). Between 2004 and 2008, cigarette consumption remained steady among current smokers who did not use SLT, but significantly decreased among dual users (age-adjusted p b .001). Conclusions: Our findings suggest that male smokers in Alaska are increasingly likely to use SLT, but do not appear to be switching to SLT use exclusively. We recommend that other state tobacco control programs examine trends in dual use to confirm our findings, and for programs to continue encouraging cessation of all tobacco products. © 2012 Elsevier Ltd. All rights reserved.
1. Introduction The tobacco control community remains divided about the use of smokeless tobacco (SLT) instead of cigarettes as a harm reduction strategy (Zeller, Hatsukami, & Strategic Dialogue on Tobacco Harm Reduction Group, 2009). Both the effectiveness and feasibility of this strategy remain unclear (Zeller et al., 2009). Sweden is considered a potential example of how people could switch from smoking to SLT (Foulds, Ramstrom, Burke, & Fagerstrom, 2003), but those results have not been replicated in the U.S. (Zhu et al., 2009). Recent examination of tobacco industry documents suggests the industry is marketing SLT products to U.S. smokers. Some industry messages have encouraged smokers to use SLT as a substitution for cigarettes when smoking is not possible, thereby promoting dual
Abbreviations: SLT, Smokeless Tobacco; CDC, Centers for Disease Control and Prevention; BRFSS, Behavioral Risk Factor Surveillance System; CASRO, Council of American Survey Research Organizations. ⁎ Corresponding author at: 827 NE Oregon St, Suite 250, Portland, OR 97232, United States. Tel.: + 1 971 673 0603. E-mail address: [email protected] (J.E. Maher). 0306-4603/$ – see front matter © 2012 Elsevier Ltd. All rights reserved. doi:10.1016/j.addbeh.2012.02.015
cigarette and SLT use (“dual use”) (Carpenter, Connolly, Ayo-Yusuf, & Wayne, 2009; Meija & Ling, 2010). Indeed, a recent U.S. study suggests that many dual users are using SLT in situations when they cannot smoke (McClave-Regan & Berkowitz, 2011). The health implications of dual use compared to smoking only are unclear. The differences in health outcomes based on literature review are under debate (Frost-Pineda, Appleton, Fisher, Fox, & Gaworski, 2010; Frost-Pineda, Appleton, Fisher, Fox, & Gaworski, 2011; Glantz & Ling, 2011). Some have hypothesized that the health risks of cigarettes and SLT may be additive or even synergistic (Wetter, McClure, de Moor, et al., 2002). In addition, others have suggested that dual use could prolong dependence on tobacco products, rather than helping smokers quit (Meija & Ling, 2010; Tomar, Alpert, & Connolly, 2010). Despite this, few publications have examined recent trends over time in dual use in a population-based sample in the U.S. (Mumford, Levy, Gitchell, & Blackman, 2005; Rodu & Cole, 2009). The most recent publication used national data for men from 2000 to 2005 (Rodu & Cole, 2009); it found the prevalence of dual use and of SLT only use stayed stable during this time, while smoking prevalence significantly decreased. Those authors reported that cigarette consumption was lower among dual users than those who only smoked, but did
J.E. Maher et al. / Addictive Behaviors 37 (2012) 862–865
not report temporal trends in cigarette consumption within these groups. The purpose of our study was to examine recent trends in current SLT use among current, former, and never male smokers in the State of Alaska, where SLT use is relatively high (CDC, 2010a), and to examine recent trends in cigarette consumption among dual users. 2. Materials and methods
863
including smoking allowed anywhere, allowed in some areas, and not allowed anywhere. When we created the workplace smoking ban status variable, we considered if a person worked outside or was unemployed. Quit intentions were ascertained by asking about wanting to quit smoking. A quit attempt during the last year was defined as having stopped smoking for one day or longer because of trying to quit smoking. Data were considered missing for a particular question if a participant responded “don't know” or refused to answer.
2.1. Setting 2.4. Statistical analyses Alaska State Department of Health and Social Services has had a tobacco control program since 1994. The program is funded at about 70% of the Centers for Disease Control and Prevention (CDC) recommended level (as of 2007) (CDC, 2010b). Although one program goal is to reduce SLT use, this has not been a major focus. In 2009, the Alaska current SLT use prevalence was the 12th highest in the U.S. (CDC, 2010a). 2.2. Sample We used Alaska Behavioral Risk Factor Surveillance System (BRFSS) data from 1996 to 2008. The Alaska BRFSS is part of the national BRFSS, and is a random-digit-dialed, cross-sectional survey stratified on geographic region. Eligible participants are non-institutionalized, aged 18 years or over, living in Alaska households with a landline telephone, and speak English (Alaska Division of Public Health, 2009). In 1996–2008, the Council of American Survey Research Organizations (CASRO) response rate ranged from 47.7% (year 2000) to 67.5% (year 2005). During 1996–2008, 16,590 men participated in BRFSS and are included in the analyses of SLT use trends. Only men were included in this study because SLT prevalence is low among Alaskan women overall (2.5%) (CDC, 2010a). The sample size per year ranged from 691 (year 1996) to 2142 (year 2008), with the average yearly sample size being about 1400. Trends in cigarette consumption are limited to 2004–2008 because consumption questions were not asked on earlier BRFSS surveys. This project relied on public health surveillance data and did not require institutional review board approval. 2.3. Measures We briefly describe the measures used; specific question wording can be found elsewhere (Alaska Division of Public Health, 2009). We classified participants as never smokers if they had not smoked at least 100 cigarettes in their life. Those who had smoked at least 100 cigarettes and reported now smoking “everyday” or “some days” were classified as current smokers; those who reported now smoking “not at all” were classified as former smokers. We calculated cigarette consumption by multiplying the number of days during the past 30 that the participant smoked by the number of cigarettes smoked per day. The result was converted to packs per month. Participants were classified as current SLT users if they answered “yes” to the following two questions: “Have you ever used or tried any…” and “Do you currently use any smokeless tobacco products such as chewing tobacco, snuff, Iq'mik or Blackbull?” Dual use was defined as currently smoking and using SLT. We used additional measures for descriptive purposes. We used BRFSS data on the participant's age, race, income, education level, and consumption of alcohol. Telephone prefix was used to impute geographic location. Urban (vs. rural) was defined as a Metropolitan Statistical Area or a Micropolitan Statistical Area as defined by the U.S. Census Bureau (U.S. Office of Management and Budget, 2009). We examined smoking ban and quit measures from the Alaska BRFSS. Questions asked about participants' home smoking rules and their workplace's official smoking policy, with response categories
For all analyses, we used the .05 level of significance and procedures in Stata® that took into account complex sampling design. We weighted the data to adjust for differential sampling rates within each telephone bank and for the number of telephones and adults in the household, and to ensure that the age and geographic distribution of male participants matched that for Alaska men based on the Claritas population estimates for a given year (Nielsen Claritas Site Reports). We tested for trends during 1996–2008 in current SLT use overall and current smoking overall with logistic regression. Because the average age of Alaskans increased significantly over this time, we adjusted for age by including it as an independent variable. We used logistic regression to test for trends in current SLT use among current, former, and never smokers. We fitted models stratified by smoking status; each model had current SLT use as the dependent variable, and time and age as independent variables. Positive parameter estimates for time indicated an increase in the odds of current SLT use over time. We also tested for differences in these trends by fitting an overall model (not stratified) with time by smoking status interaction terms. Using a similar approach, we fitted linear regression models to test for trends during 2004–2008 in cigarette consumption among current dual users compared to smokers only. For descriptive purposes, we compared other characteristics of current dual users to smokers only using chi-square tests (during 2004–2008 combined). 3. Results Among Alaskan men in 2008, the prevalence of current SLT use was 8.6% and the prevalence of current smoking was 23.9%; these prevalences had not significantly changed between 1996 and 2008 (p = .63, p = .09 for trend after adjusting for age). The prevalence of current SLT use significantly increased among current smokers during 1996–2008 (p = .004 for trend after adjusting for age). We found that the odds of SLT use among current smokers increased by 6% per year (age-adjusted OR = 1.06, 95% confidence interval: 1.02–1.10). However, the prevalence of current SLT use did not significantly change among former and never smokers (Fig. 1). This trend was significantly different for current smokers than for former (p = .027) and never smokers (p = .004). Cigarette packs per month smoked among current dual users significantly decreased during 2004–2008 (mean per year for 2004 to 2008: 22.9, 16.4, 21.2, 8.5, 9.2; p b .001 for trend after adjusting for age; n = 118), but remained steady among current smokers only (mean per year for 2004 to 2008: 20.6, 18.8, 17.0, 17.8, 19.9; p = .725 for trend after adjusting for age; n = 1234). This trend was significantly different for dual users than for smokers only (p = .002). Overall, 9.5% (95% CI: 7.9%–11.5%) of current smokers during 2004–2008 reported current SLT use. Compared to current smokers only, current dual users were significantly younger, more likely to live in rural areas, and more likely to be heavy drinkers of alcohol (Table 1). They were somewhat more likely to have lower incomes and more likely to report a smoking ban at home, but these differences did not reach statistical significance (p = .088, p = .144, respectively).
864
J.E. Maher et al. / Addictive Behaviors 37 (2012) 862–865
Smokeless Percent
A) Current Smokers (p=.004) 14% 12% 10% 8% 6% 4% 2% 0%
Standard BRFSS Questions, 2004–2008
1996 1997 1998 1999 2000 2001 2002 2003* 2004 2005 2006 2007 2008
Smokeless Percent
B) Former Smokers (p=.901) 14% 12% 10% 8% 6% 4% 2% 0%
Characteristic
Use SLT and smoke (n = 244a)
Only smoke (n = 2284a)
p-value
Age: b 45 years Race White AK Native Otherb Yearly income: b$50,000 Geography: Rural Education: HS diploma or less
82.5%
61.2%
b.001
67.2% 26.8% 6.0% 69.0% 44.6% 67.0%
63.9% 25.1% 10.9% 60.5% 31.7% 61.1%
.346
.088 .006 .270
Alaska-Added BRFSS Questions, 2004–2008c 1996 1997 1998 1999 2000 2001 2002 2003* 2004 2005 2006 2007 2008
C) Never Smokers (p=.218) Smokeless Percent
Table 1 Characteristics of men who use smokeless tobacco (SLT) and smoke compared to men who only smoke, State of Alaska, 2004–2008.
14% 12% 10% 8% 6% 4% 2% 0% 1996 1997 1998 1999 2000 2001 2002 2003* 2004 2005 2006 2007 2008
Fig. 1. Trends in prevalence of current smokeless tobacco use, by smoking status: Males aged 18 years and older, Alaska, 1996–2008. The points represent the percent using smokeless for any given year. The lines are the fitted regression lines. All p-values are calculated using an age-adjusted model. Sample sizes for the models: current smokers (n = 4489), former smokers (n = 5107), never smokers (n = 6866). * Smokeless tobacco questions were not included in the 2003 Alaska BRFSS.
4. Discussion The present study used data on Alaskan men to examine recent trends in SLT use among current, former, and never smokers, and trends in cigarette consumption among current dual users. The prevalence of SLT use among former smokers stayed flat over time, suggesting that there was not an increase in male smokers switching to using SLT exclusively. This finding is consistent with patterns observed in a one-year longitudinal study from 2002 to 2003 in the U.S. (Zhu et al., 2009). However, we found that the proportion of current smokers who are also using SLT significantly increased over time, and evidence that cigarette consumption among dual users is decreasing over time. To our knowledge, we are the first to report such patterns among men in a U.S. sample. Other recent population-based studies in the U.S. offer some insight into the patterns we observed. Tomar et al. (2010) examined patterns of dual use among U.S. men in 2006–2007, around the time major cigarette companies gained control of most of the U.S. SLT market, to serve as a “baseline.” They found that current daily smokers who used snuff on some days, compared to daily smokers who did not use snuff, were more likely to want to quit smoking and to have a quit attempt in the past year. They hypothesized that either these dual users may be partially substituting snuff for smoking thereby delaying successfully quitting smoking, or that smokers with failed quit attempts may then try snuff as a cessation strategy. A more recent U.S. study using 2008 data by McClave-Regan and Berkowitz (2011) suggests that many dual users are partially substituting SLT use for smoking, but not using SLT for cessation. That study found two-thirds of dual users were using SLT when they could not smoke, and three-quarters of the dual users did not believe that SLT could help them quit smoking. Whether such substitution and associated decreases in cigarette consumption might decrease health risks is an important area for further study.
Characteristic
Use SLT and smoke (n = 129a)
Only smoke (n = 1334a)
p-value
Smoking ban at home d Workplace smoking ban status Work inside & no smoking allowed Work inside & smoking allowed Work outside Unemployed Want to quit Quit attempt in last year Alcohol: >2 drinks/day
72.0%
63.2%
.144
30.0%
31.2%
.553
24.3%
18.0%
19.7% 26.0% 76.6% 56.5% 21.2%
17.0% 33.8% 75.9% 54.9% 9.6%
.905 .825 .037
a Data are missing for less than 10% of participants for each of the measures. Information on heavy drinking was only available for 2005–2008, so the sample sizes are smaller (n = 115 dual users and n = 950 smokers only). b Other race category includes: African American (1.4% of the total); Asian (1.4%); Native Hawaiian/Other Pacific Islander (1.1%); and Other race/Refused (6.6%). c During 2004–2008, Alaska asked extra questions of about half of the BRFSS participants; hence, there are responses for the standard BRFSS questions for all male participants and for the Alaska-added BRFSS questions for about half of them. d Smoking ban in the home defined as no smoking allowed anywhere.
The tobacco industry's promotion of SLT to smokers (Carpenter et al., 2009) could be influencing male smokers in Alaska to use SLT, but other factors could be influencing the trends observed as well. For example, the prevalence of home smoking bans in Alaska has increased over time (Alaska DHSS, 2009; Peterson, Fenaughty, & Eberhart-Phillips, 2004), and such bans may be associated with dual use (Mumford et al., 2005). Alaska also had increases in cigarette taxes in 2005, 2006, and 2007 without any increases in SLT taxes since 1997, and there is some evidence that this situation could lead to increased SLT use (Ohsfeldt, Boyle, & Capilouto, 1997), but the evidence is mixed (Mumford et al., 2005). In addition, smoking has become less socially acceptable over time in the U.S. (Gutman, 2011); these social norm changes may be influencing smokers to use SLT in public, instead of smoking. This study has several limitations. First, the BRFSS is limited to adults living in households with landline telephones and who speak English. Second, response rates were less than 70%. Data were weighted to reflect the age and geographic distribution of Alaska men, but non-response might be related to other characteristics that could affect the trends observed. Third, our SLT question did not ask specifically about new types of tobacco products (e.g., lozenges), and we did not ask frequency of SLT use (e.g., someday vs. everyday). Fourth, because we used data from repeat, cross-sectional surveys, we could not examine changes in smoking and SLT use within individuals over time. For example, in trying to interpret the reduction in cigarette consumption among dual users over time, we do not know whether current smokers are increasingly likely to use SLT as a substitution method or if lighter smokers are increasingly more likely to start using SLT; however, the former seems a more plausible
J.E. Maher et al. / Addictive Behaviors 37 (2012) 862–865
explanation. Last, it is possible that trends observed in dual use could be due, in part, to a birth cohort effect. However, we found that the increase in SLT use among smokers was essentially identical among those over 29 years old and among those 18–29 (p = .77; data not shown). 5. Conclusions Our findings suggest that male current smokers in Alaska are increasingly likely to use SLT, but do not appear to be switching to SLT use exclusively. To help understand these trends, future research should examine the reasons more smokers in the U.S. are using SLT and whether it helps smokers reduce their cigarette consumption. We recommend that other state tobacco control programs examine trends in SLT use among former and current smokers to confirm our findings, and for programs to continue encouraging cessation of all tobacco products. Role of funding sources The Alaska Tobacco Prevention and Control Program funded this work and collaborated on this manuscript. Contributors Julie Maher took the lead on interpreting the results and writing the manuscript. Chris Bushore and Clyde Dent conducted the analyses. Kristen Rohde conducted the literature searches and helped summarize previous research. All authors contributed to the design of the study, helped in interpreting results, and edited the manuscript. Conflict of interest The authors do not have any competing interests to declare.
References Alaska Department of Health and Social Services (DHSS) (2009, September). Alaska Tobacco Facts, 2009 Update. Retrieved from. http://hss.state.ak.us/dph/chronic/ tobacco/alaska_tobacco_facts.pdf Alaska Division of Public Health (2009). Behavioral Risk Factor Surveillance System Survey. Retrieved from. http://www.hss.state.ak.us/dph/chronic/hsl/brfss Carpenter, C. M., Connolly, G. N., Ayo-Yusuf, O. A., & Wayne, G. F. (2009). Developing smokeless tobacco products for smokers: An examination of tobacco industry documents. Tobacco Control, 18(1), 54–59, doi:10.1136/tc.2008.026583. Centers for Disease Control and Prevention (2010). State-specific prevalence of cigarette smoking and smokeless tobacco use among adults – United States, 2009. Morbidity and Mortality Weekly Report, 59(43), 1400–1406 Retrieved from. http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5943a2.htm
865
Centers for Disease Control and Prevention (2010). Tobacco Control State Highlights 2010. Retrieved from. http://www.cdc.gov/tobacco/data_statistics/state_data/ state_highlights/2010/pdfs/highlights2010.pdf Foulds, J., Ramstrom, L., Burke, M., & Fagerstrom, K. (2003). Effect of smokeless tobacco (snus) on smoking and public health in Sweden. Tobacco Control, 12(4), 349–359. Frost-Pineda, K., Appleton, S., Fisher, M., Fox, K., & Gaworski, C. L. (2010). Does dual use jeopardize the potential role of smokeless tobacco in harm reduction? Nicotine & Tobacco Research, 12(11), 1055–1067. Frost-Pineda, K., Appleton, S., Fisher, M., Fox, K., & Gaworski, C. L. (2011). Response to Glantz and Ling. Nicotine & Tobacco Research, 13(4), 297. Glantz, S. A., & Ling, P. M. (2011). Misleading conclusions from Altria researchers about population health effects of dual use. Nicotine & Tobacco Research, 13(4), 296. Gutman, M. (2011, April). Social Norms and Attitudes about Smoking: 1991–2010. Center for Public Program Evaluation, Robert Wood Johnson Foundation Retrieved from. http://www.rwjf.org/files/research/72054.trendssocialnorms.041211.pdf McClave-Regan, A. K., & Berkowitz, J. (2011). Smokers who are also using smokeless tobacco products in the US: a national assessment of characteristics, behaviours and beliefs of ‘dual users’. Tobacco Control, 20(3), 239–242. Mejia, A. B., & Ling, P. M. (2010). Tobacco industry consumer research on smokeless tobacco users and product development. American Journal of Public Health, 100(1), 78–87, doi:10.2105/AJPH.2008.152603. Mumford, E. A., Levy, D. T., Gitchell, J. G., & Blackman, K. O. (2005). Tobacco control policies and the concurrent use of smokeless tobacco and cigarettes among men, 1992–2002. Nicotine & Tobacco Research, 7(6), 891–900, doi:10.1080/ 114622200500266098. Nielsen Claritas SiteReports. (n.d.). Retrieved June 25, 2010, from http://www.claritas. com/sitereports/Default.jsp Ohsfeldt, R. L., Boyle, R. G., & Capilouto, E. (1997). Effects of tobacco excise taxes on the use of smokeless tobacco products in the USA. Health Economics, 6(5), 525–531, doi:10.1002/(SICI)1099-1050(199709)6:5b525::AID-HEC300>3.0.CO;2-Y. Peterson, E., Fenaughty, A., & Eberhart-Phillips, J. E. (2004, February). Tobacco in the great land: A portrait of Alaska's leading cause of death. Retrieved from. http:// www.epi.alaska.gov/pubs/tobaccofeb04.pdf Rodu, B., & Cole, P. (2009). Smokeless tobacco use among men in the United States, 2000 and 2005. Journal of Oral Pathology & Medicine, 38(7), 545–550, doi: 10.1111/j.1600-0714.2009.00780x. Tomar, S. L., Alpert, H. R., & Connolly, G. N. (2010). Patterns of dual use of cigarettes and smokeless tobacco among US males: Findings from national surveys. Tobacco Control, 19(2), 104–109, doi:10.1136/tc.2009.031070. U.S. Office of Management and Budget (2009, December 1). OMB Bulletin No. 10–02: Update of statistical area definitions and guidance on their uses. Retrieved from. http://www.whitehouse.gov/omb/assets/bulletins/b10-02.pdf Wetter, D. W., McClure, J. B., de Moor, C., et al. (2002). Concomitant use of cigarettes and smokeless tobacco: Prevalence, correlates, and predictors of tobacco cessation. Preventive Medicine, 34, 638–648. Zeller, M., & Hatsukami, D.Strategic Dialogue on Tobacco Harm Reduction Group. (2009). The strategic dialogue on tobacco harm reduction: A vision and blueprint for action in the US. Tobacco Control, 18(4), 324–332, doi:10.1136/tc.2008.027318. Zhu, S. H., Wang, J. B., Hartman, A., Zhuang, Y., Gamst, A., Gibson, J. T., et al. (2009). Quitting cigarettes completely or switching to smokeless tobacco: Do US data replicate the Swedish results? Tobacco Control, 18(2), 82–87, doi:10.1136/tc.2008. 028209.