INTRODUCTION

China is the world’s largest producer, manufacturer, and consumer of tobacco^1,2. Chinese men consume over one-third of the world’s cigarettes^3,4. The prevalence of smoking in China among people 15 years or older was 28.1% in 2010, including 52.9% of men and 2.4% of women². Although the quit rate has increased from 3% in 1991 to 9% in 2006, one-third of male smokers will eventually die from tobacco-related disease³.

Each year, exposure to secondhand smoke (SHS) causes over 435 000 adult and 165 000 childhood deaths globally⁵. Worldwide, 40% of children, 35% of women, and 33% of men are exposed to SHS indoors⁵. Adverse health outcomes including ischemic heart disease, lower respiratory infections, asthma, and lung cancer may be reduced with interventions limiting SHS exposure⁵.

Belief that SHS causes serious illness, and that it is associated with smoking behavior, has been studied extensively in Western nations^6,7. The belief that SHS causes illness, particularly in children, is positively associated with quit attempts among smokers^6,7. In Australia, one in five smokers attempted to quit due to concerns that their behavior was causing problems among friends and family⁶.

There is less information in China about the associations between adults’ belief that SHS causes serious illness, and behavioral intention to quit, attempts to quit, and quitting smoking. Approximately 70% of adults are exposed to SHS each week and 100 000 people die from SHS every year in China⁸. Of all Chinese adults, 54.3% reported being exposed to SHS at work, 76.3% at restaurants, and 16.4% on public transportation⁹. Lower levels of income and education are associated with higher exposure to SHS in China¹⁰.

Positive associations were demonstrated between the awareness of personal health risks of smoking, and quit-smoking behavior^11,12. Results from China’s International Tobacco Control survey indicate pressure from friends and family motivate Chinese adults to attempt to quit smoking^11,12. Health concerns for oneself and one’s family were also cited as a primary reason for attempting to quit smoking in a study of male smokers in Hangzhou¹³. It is unclear, however, whether personal health concerns or SHS were the primary motivator for attempting to quit. It remains to be determined whether knowledge that SHS can harm friends and family has an impact on successfully quitting smoking. Described herein is a cross-sectional study of current Chinese smokers, age 15 years and older, surveyed in 2010, to evaluate the associations between the belief that SHS causes serious illness and intention to quit, attempts to quit, and quitting smoking tobacco.

METHODS

RESULTS

Of the nationally representative sample of 13 354 men and women in China in 2010, current smokers were 4010 and former smokers were 856. After accounting for cluster, strata, and weight factors, this represents 28.1% as current smokers and 5.4% as former smokers (Table 1). Correlation matrices revealed no highly correlated interrelationships among any of the covariates examined, the tolerance values were well above 0.10, and the CN=3.36 was far below the rule-of-thumb of 30 (not tabulated)¹⁸. Therefore, there was no evidence of collinearity.

DISCUSSION

The results of this study demonstrate that current smokers’ attitudes about exposure to SHS could play an important role in the overall strategy to reduce tobacco use in China. The aim of this study was to ascertain whether the belief that SHS causes serious illness was associated with intention to quit, attempts to quit, and quitting smoking among Chinese adult smokers. After adjusting for covariates, there was a significant association between the belief that SHS causes serious illness and intention to quit and quitting smoking. But the association between the belief that SHS causes serious illness and attempting to quit smoking did not reach statistical significance. Analyses also indicated significant associations with several covariates: rules about smoking at home, noticed information on billboards about the dangers of smoking, noticed signs promoting cigarettes, visited a doctor within the past year, and the belief that smoking causes lung cancer. The belief that exposure to SHS causes serious illness is an additional element to include in a comprehensive tobacco-control strategy.

The finding that smokers who believe SHS exposure causes serious illness were more likely to intend to quit smoking or quit smoking is consistent with other studies^6,19. Concern about exposing others, particularly children, to SHS has been cited as one of the strongest indicators for quitting smoking^19,20. Increasing knowledge of the dangers of SHS also decreases tolerance for smoking at home^6,19,20. This finding may in part be explained by Chinese culture, which values responsibility to one’s family and filial piety respect for one’s parents and ancestors^11,13. China has a highly collectivistic culture in which the needs of the group come before the needs of the individual²¹. If smoking is perceived as a threat to the health of one’s family, collectivism may explain a willingness among Chinese smokers to quit smoking in order to protect members of their in-group^21,22. Social disapproval of smoking is a more significant predictor of regretting smoking in China than in Western countries, which may induce quitting smoking behavior^22,23. Strong family relationships are also associated with abstaining from smoking in China²⁵. Future anti-tobacco campaigns should focus on education about the dangers of exposures to SHS in the context of one’s in-group and family^25,26.

Although only 2.4% of women smoke in China, 72.4% are exposed to SHS, with 38.0% exposed on a daily basis, many of whom do not recognize the dangers of SHS exposure²⁷. Consequently, women bear nearly 80% of the burden of disease due to SHS exposure²⁸. Children in China with chronic exposure to SHS have respiratory problems that continue into adulthood, including impaired lung function, coughing, sneezing, and phlegm²⁹. Smoke-free laws that are strictly enforced have resulted in a significant reduction in SHS exposure in the public places of Guangzhou, Harbin, Shanghai, Shenzhen, and Tiajin³⁰. Greater efforts are required to promote smoke-free environments that weaken smoking customs³⁰.

After adjusting for covariates, the belief that SHS causes serious illness did not reach statistical significance for attempting to quit smoking. Previous research has demonstrated that health concerns for friends and family are among the primary reasons Chinese adult smokers attempt to quit smoking^11,12. However, quit attempts are less successful in China among smokers without firsthand experiences of the adverse health effects of smoking tobacco, personally or within the family^11,12. Education must also include outreach to smokers living alone and who may not feel the onus of protecting family and friends.

The finding that adult smokers who did not allow smoking at home were 2.46 times more likely to quit smoking is in accord with published data^31,32. Home-smoking bans have proven to be powerful smoking interventions: they reduce the likelihood of being a current smoker, reduce the number of cigarettes consumed per day, and increase the number of quit attempts³¹. In China, concern regarding the health effects of SHS exposure was the greatest reason for not allowing smoking at home, but most families still allow smoking in at least one room^2,32. Current laws in China ban smoking in selected outdoor locations and all indoor public places, including gymnasiums, libraries, museums, trains, classrooms, dorms, and schools². There is a paucity of information about penalties for violations of these regulations however, and there is no national ban on smoking in the workplace in China².

The result that smokers who noticed information about the dangers of smoking on billboards were more likely to have attempted to quit also aligns with the literature, which demonstrates that mass media campaigns are effective tobacco-control methods^33,34. Of the media analyzed that displayed smoking, only billboards reached statistical significance for attempted to quit. Visually explicit advertisements are particularly successful for increasing quit attempts³⁴. Billboards displaying adverse health outcomes of smoking increase public awareness of smoking dangers and decrease smoking prevalence³³. Billboards may also include Quitline service information, which has shown promise as a smoking cessation service in Hong Kong³⁵.

The results further suggest that adult smokers who believe smoking causes serious illness were more likely to have intended or attempted to quit, which is in accord with other studies^25,26. Most former smokers cite health concerns as the primary motivation for quitting smoking, but the perceived risks and harms of smoking are low in China compared to other countries^25,26. Among Chinese smokers, the greatest factor for attempting and intending to quit is knowledge of the adverse health effects of smoking, but misconceptions regarding health consequences of smoking remain pervasive among Chinese smokers^11,12. Educational campaigns to improve public perceptions of smoking risks, combined with social support and accessible smoking cessation clinics, are effective strategies to increase quit attempts^11,12,36.

Noticing signs promoting cigarettes was not significantly associated in this study with quitting smoking behavior, and numerous studies have demonstrated that tobacco advertisements foster positive attitudes about tobacco use^37,38. At the time GATS was conducted in 2010, China did not have laws or regulations for restricting the advertising or promoting of tobacco products^2,38. Since GATS was conducted, a subsequent law banned the use of signs and mass media to advertise or promote cigarettes². The challenge is to ensure that these new regulations are enforced².

Smokers who attempted to quit smoking were more likely to have visited a doctor within the past year, which also agrees with the literature^20,39. Simple advice or brief interventions from nonsmoking physicians have been shown to be a cost-effective means to increase quit attempts and quit rates^20,39. Larger interventions and pharmacotherapy are even more successful for smokers with high nicotine dependence in China^39,40. However, this message may be muted by virtue of the fact that 46.7% of male physicians in China have been reported as active smokers⁴¹.

CONCLUSIONS

The results of this study contribute an additional significant tenet to a comprehensive tobacco-control strategy, namely, the belief that exposure to SHS causes serious illness. This message can be incorporated into the other, established control methods like explicit warning labels, high taxes, physician advice, and mass media campaigns, to help decrease the overall burden of tobacco use.