In our study in remote Indigenous communities in Arnhem Land we have now interviewed 305 smokers. Of these, 181 had quit intentions and 37 were trying to quit at the time of interview. The effectiveness of more intensive support compared with brief advice has not been evaluated in these populations. However, the need for more intensive support is highlighted in smokers’ own words, for example:

“I’m trying to find a way.” and “I can’t do it on my own.”

In our survey, smokers and non-smokers alike called for more intensive community-based support for smokers to quit, for example:

“… form support groups ….. away from the clinic because they are too busy doing other djama [work].” and “… we need house to house education, every house, clan by clan …”

Our research is trialing interventions that are not limited to quit support. We agree with Thomas and Johnston that population-level interventions have been associated with the steepest declines in smoking prevalence in Australia generally. For Indigenous Australians, especially those living in remote communities, it is not yet known if such smoking reduction initiatives can work. High smoking rates that have not changed in 20 years is evidence that impacts of wider initiatives have not been felt in remote communities.

If we understand him correctly, Ramstrom considered our findings on what has happened in the U.S. too obvious to be interesting. It is obvious because, for over 50 years, Sweden has had a particular smokeless tobacco product, snus, that the US did not have [1]. He apparently considered the history of U.S smokeless tobacco use (which is over 100 years) of no significance and he was confident that the U.S. smokeless tobacco products cannot possibly work to help American smokers quit cigarettes. We did not approach the problem with that perspective. That is why we conducted the study. In our paper, we have considered product difference as part of the explanation in the discussion section [2]. But logic requires us not to attribute the different results between the U.S and Sweden to a single factor when there are so many other contributing factors, including significant cultural differences between the two countries. The way that Ramstrom placed all his confidence in a single factor explanation without making an effort to rule out other strong alternative explanations strikes us as rather unscientific.

Ramstrom also did not like our caution that a significant increase in population smoking cessation may not come from promoting smokeless tobacco in places like the U.S. We believe that the results found in our study justify caution in prediction. The results do not suggest that it will be impossible to increase population smoking cessation rates by promoting smokeless tobacco use. They do suggest that it would require a much more aggressive marketing campaign to get more Americans to use smokeless tobacco than simply getting rid of misinformation about the relative risks of smokeless tobacco and cigarettes. An aggressive promotion of smokeless tobacco products, especially if it comes from both the public health community and the tobacco industry, could change the landscape of tobacco control in a rather unpredictable manner. In many countries nowadays, the tobacco control activities and people’s attitude toward tobacco use are very different from those of Sweden’s in the 1970’s, when snus started to be used by more Swedish men. In fact, we do not even know whether the observed effects of snus on smoking cessation in Sweden were mainly due to the large price differential between cigarettes and snus, which had nothing to with snus being perceived as safer [2]. Again, Ramstrom’s confidence in predicting the future with such limited information seems unfounded.

We welcome Ramstrom’s attempt to present empirical data to compare quitting among current smokers in Sweden and the U.S. It is difficult to find two surveys from two countries that are directly comparable, so some estimation is necessary at this point. However, we have difficulty following his method of analysis because he switched between quit ratio and annual quit rate in his comments. The former is an accumulative rate of former smokers among ever smokers, typically obtained in cross- sectional surveys and not adjusted for population change over time when they are reported from different surveys (for example, if there is a sudden influx of young smokers from year 1 to year 2, the quit ratio of the population can actually go down if analyzed using cross-sectional surveys). The latter is confined to the same cohort of smokers for a particular year, and in our case is followed up longitudinally in 12 months. Ramstrom computed the quit ratio using two cross-sectional surveys and he believed that he has proved the annual quit rates for Swedish men are higher than those of their American counterparts and that this is attributable to the fact that Swedish men used snus. This really doesn’t work. One cannot directly deduce an annual quit rate from the quit ratio in this manner. Since this issue is technically subtle it would be preferable if Ramstrom could present his detailed calculations with a description of the data sets used for calculation as a regular research article. The e-letters format, which does not use a regular peer review process, is not conducive to careful examination of the methodology used. We have tried, but we cannot judge from Ramstrom's comments how he decided that the annual quit rate for the time period considered was higher for Swedish than for U.S male smokers. Our statement that U.S. smokers appear to have higher quit rate is based on the fact that the 6-month abstinence rates are 7.6% and 6.6% for U.S. males and females, respectively, which compared favorably to Rodu et al.’s report of 6.0% and 4.1% for Swedish male and female smokers. These results were reported on page 85 in Zhu et al.’s study [2]. The rates reported in the Rodu et al. study included those who had quit for a long time as well as those who had just quit at the time of the survey [3]. Given that the relapse rate between 6 and 12 months is low, it seems reasonable that the 12-month abstinence rate in the U.S. would not be too much lower than those reported. In any case, we would certainly welcome any empirical analysis that can shed light on this issue. It would be a nice change from continuing this route of debate based on preference of how optimistic or pessimistic one is in predicting the future.

Conflict of Interest: None declared.

Reference:

1. Ramstrom LM. Potential utility of switching to smokeless tobacco. Tob Control eLetter published online June 18, 2009 http://tobaccocontrol.bmj.com/cgi/eletters/18/2/82#2899

2. Zhu S-H, Wang JB, Hartman A, Zhuang Y, Gamst A, Gibson T, et al. Quitting cigarettes completely or switching to smokeless: Do U.S. data replicate the Swedish results? Tob Control. 2009;18:82-87. doi:10.1136/tc.2008.028209 http://tobaccocontrol.bmj.com/cgi/content/full/18/2/82

3. Rodu B, Stegmayr B, Nasic S, et al.. Evolving patterns of tobacco use in northern Sweden. J Intern Med 2003;253:660–665

The study by Zhu et al. "Quitting Cigarettes Completely or Switching to Smokeless Tobacco:Do U.S. Data Replicate the Swedish Results?" has raised a number interesting questions. [1] However, the conclusions of the study need further scrutiny in addition to the previously published comments.

The main conclusion “The Swedish results are not replicated in the U.S.” is certainly true, but not very interesting since it just lays down something very obvious. Sweden’s last 50 years’ development of increasing snus use is built on quite old Swedish traditions and could not possibly have been replicated in a country where Swedish type moist oral smokeless tobacco has not until recently been available altogether and misleading pieces of discouraging information have dominated over evidence-based statements regarding the characteristics of the product.[2]

The statement “Both male and female U.S. smokers appear to have higher quit rates for smoking than have their Swedish counterparts, despite greater use of smokeless tobacco in Sweden.” has very little support in the study, at the same time as there is evidence of the opposite in other scientific sources. The Zhu et al. study reports that 11.6 % of the men who were smoking at baseline declared that they were not smoking at the end of the observation period. But this does not mean that there has been a 11.6 % rate of sustained smoking cessation. It just means that 11.6 % of the initial smokers have started quit attempts that have remained successful up till the end of the observation period. But, it must be assumed that a number of these attempters will relapse, particularly those who started their quit attempt in the later part of the observation period. This assumption is further supported by the observation that a 11.6 % decrease of smoking from 2002 to 2003 appears to deviate from the actual US pattern. The nationwide Behavioural Risk Factor Surveillance Survey, BRFSS, reports a decrease in male prevalence of smoking of just 4.6 % from 2002 to 2003.[3] Further, none of these figures tell us anything about quit rate (ratio between Former Smokers and Ever Smokers). However, from BRFSS data it can also be calculated that in 2003 quit rates in the U.S. population were 0.53 for men and 0.51 for women. Swedish data representing variables defined exactly as these BRFSS data are not available in published sources but present in the more comprehensive database of FSI, The Research Group for Societal and Information Studies. From these data it can be calculated that corresponding Swedish quit rates are 0.63 for men and 0.54 for women. So, Swedish quit rates are markedly higher than those in the U.S. as far as men are concerned and slightly higher for women. Further, the pattern of differences in quit rates between countries and genders is consistent with the corresponding patterns of differences in snus use. A large population study in Sweden has demonstrated that: 1) the gender difference is absent both in the subgroup with snus use and in the subgroup without snus use, and 2) in each gender the quit rates are substantially higher in those with than in those without snus use. [4] These observations, and findings from other Swedish population-based studies, [5, 6, 7] do suggest that the inter-country differences in quit rates may be associated with the use of snus in Sweden. The above statement by Zhu et al. is not consistent with actual evidence.

The statement “Promoting smokeless tobacco for harm reduction in countries with ongoing tobacco control programs may not result in any positive population effect on smoking cessation.” would be true if promotion of smokeless tobacco were seen as a priori unable to achieve actual use of smokeless tobacco for smoking cessation purposes. But, the relevant question is whether or not actual use of smokeless tobacco for smoking cessation purposes can yield a positive population effect on smoking cessation. As pointed out above, Swedish population studies have consistently found a positive association between snus use and increased smoking cessation, particularly in men. These findings are also recognized by various international expert reviews. [8, 9 (p. 109), 10] Similar patterns have been demonstrated in Norwegian population studies. [11,12] A recent US population study suggests that also in the U.S. there are signs that use of smokeless tobacco for smoking cessation purposes are emerging and have higher success rates than those using NRT, just as found in Sweden and Norway. [13] All of these findings come from population-based studies and do then apply to the population level. They also come from countries with ongoing tobacco control programs. These programs do then appear to have taken advantage by being supplemented by the use of smokeless tobacco. Consequently, the above statement by Zhu et al is severely weakened by relevant evidence that is actually available.

After noticing that that the Swedish results have not yet been replicated in the U.S., it is natural to look into a possible future. In that respect Zhu et al. appear to be too pessimistic. Norway has already come quite a bit and, as mentioned above, there are emerging signs of progress in the U.S. as well, and this development may be accelerated if evidence-based public information is strengthened. It should thereby be kept in mind that, according to the Swedish experience, snus can both be an effective temporary aid towards total freedom from nicotine, and, a low -toxicity form for continued nicotine intake for the largely neglected group of smokers who can’t quit using nicotine. Their situation has recently been discussed in a British expert report. [14] For these smokers, quitting nicotine completely is no option. Why not then promote the other option, switching to low-toxicity smokeless tobacco. From health point of view this may be almost as beneficial as quitting completely. [15, 16] This potential utility of switching to smokeless tobacco may eventually, if promoted in a responsible manner, save lives in the U.S. just as in Sweden.

Lars Ramstrom PhD Director Institute for Tobacco Studies Stockholm, Sweden

Email: lars.ramstrom@tobaccostudies.com

Conflict of interest. Owner of shares in Pfizer Inc. Never any funding from tobacco industry sources.

References

1. Zhu S-H et al. Quitting cigarettes completely or switching to smokeless tobacco: Do U.S. data replicate the Swedish results. Tob. Control published online 23 Jan 2009; doi:10.1136/tc.2008.028209.

2. Phillips CV et al. You might as well smoke; the misleading and harmful public message about smokeless tobacco. BMC Public Health. 2005 Apr 5;5:31.

3.National Center for Chronic Disease Prevention and Health Promotion, Behavioral Risk Factor Surveillance System. Prevalence and Trends Data, Nationwide (States and DC) – 2003. (Available at: http://apps.nccd.cdc.gov/brfss/page.asp?cat=&yr=2003&state=UB# accessed June 13, 2009.)

4. Ramström L et al. Role of snus in initiation and cessation of tobacco smoking in Sweden. Tob. Control, 2006 Jun;15(3):210-4.

5. Furberg H et al. Cigarettes and oral snuff use in Sweden: Prevalence and transitions. Addiction 2006:101;1509-1515.

6. Rodu B et al. Evolving patterns of tobacco use in northern Sweden. Journal of Internal Medicine 2003;253:660-665.

7. Furberg H et al. Is Swedish snus associated with smoking initiation or smoking cessation? Tob. Control, 2005 Dec;14(6):422-4.

8. Tobacco Advisory Group of the Royal College of Physicians. Ending tobacco smoking in Britain: Radical strategies for prevention and harm reduction in nicotine addiction. Royal College of Physicians, London, 2008.

9. SCENIHR, Scientific Committee on Emerging and Newly Identified Health Risks. Health Effects of Smokeless Tobacco Products. Brussels: European Commission; 2008. (Available at: http://ec.europa.eu/health/ph_risk/committees/04_scenihr/docs/scenihr_o_013.pdf, accessed June 13, 2009).

10.The European Respiratory Society. Tobacco Smoking: Harm Reduction Strategies - An ERS Research Seminar. Brussels, 2006.

11. Lund K E. The role of snus in the decline of smoking in Norway. Presentation at the 14th World Conference on Tobacco or Health, Mumbai, India, 2009.

12. Scheffels J. Snus as a strategy for smoking cessation. Presentation at the 14th World Conference on Tobacco or Health, Mumbai, India, 2009.

13. Rodu B et al. Switching to smokeless tobacco as a smoking cessation method: evidence from the 2000 National Health Interview Survey. Harm Reduction Journal 2008, 5:18 doi:10.1186/1477-7517-5-18.

14. Tobacco Advisory Group of the Royal College of Physicians. Harm reduction in nicotine addiction: Helping people who can't quit. Royal College of Physicians, London, 2007.

15. Levy DT et al. The relative risks of a low-nitrosamine smokeless tobacco product compared with smoking cigarettes: estimates of a panel of experts. Cancer Epidemiol Biomarkers Prev 2004; 13: 2035-42.

16. Gartner CE et al. Assessment of Swedish snus for tobacco harm reduction: an epidemiological modelling study. Lancet, 2007; 369: 2010- 2014.

We appreciate Dr. Nitzkin’s desire to improve the current FDA bill. Our paper clearly stated that smokers are generally uninformed about the relative risk of various tobacco products and that is an issue that the public health community still must address (1). However, it is important not to equate providing accurate risk information with promoting the use of specific tobacco products. Nitzkin does not seem to make this distinction very clearly (2, 3).

The chief aim of our paper is to provide empirical analysis of available data to increase understanding of what has happened in the U.S. People differ in their predictions of what the overall population effect on smoking cessation will be if smokeless tobacco products are promoted for harm reduction. We believe results reported in Zhu et al. justify the cautionary note in our conclusion (1).

1. Zhu S-H, Wang JB, Hartman A, Zhuang Y, Gamst A, Gibson T, et al. Quitting cigarettes completely or switching to smokeless: Do U.S. data replicate the Swedish results? Tob Control. 2009;18:82-87. doi:10.1136/tc.2008.028209 http://tobaccocontrol.bmj.com/cgi/content/full/18/2/82

2. Nitzkin JL, Rodu B. Promoting snus will save lives in the USA. Tob Control eLetter published online February 6, 2009.

3. Nitzkin JL. Response to Zhu February 24 e-letter. Tob Control, eLetter published online March 24, 2009 http://tobaccocontrol.bmj.com/cgi/eletters/18/2/82#2891