- Email: [email protected]
Risk factors for adolescent smoking in urban and rural China: Findings from the China seven cities study
Addictive Behaviors 33 (2008) 1081–1085
Contents lists available at ScienceDirect
Addictive Behaviors
Short communication
Risk factors for adolescent smoking in urban and rural China: Findings from the China seven cities study Huiyan Ma a,⁎, Jennifer B. Unger a, Chih-Ping Chou a, Ping Sun a, Paula H. Palmer a, Yan Zhou a, Jie Yao a, Bin Xie b, Peggy E. Gallaher a, Qian Guo a, Yonglan Wei c, Bin Chen d, Zhanju Wang e, Xu Wang f, Haiping Duan g, Yu Song h, Jie Gong i, Stanley P. Azen a, Liming Lee j, C. Anderson Johnson a a
Keck School of Medicine, University of Southern California, United States School of Social Work, University of Southern California, United States Chengdu Center for Disease Control and Prevention, China d Hangzhou Center of Disease Prevention and Control, China e Harbin Center for Disease Control and Prevention, China f Kunming Health Education Institute, China g Qingdao Municipal Centers for Disease Control and Prevention, China h Shenyang Center for Disease Control and Prevention, China i Wuhan Center for Disease Control and Prevention, China j Peking Union Medical College, China b c
a r t i c l e Keywords: Smoking Risk factor Adolescent China
i n f o
a b s t r a c t Cigarette smoking is rising among urban Chinese adolescents and poses a significant public health concern. The majority of Chinese youth live in rural areas, but most research on the risk factors for smoking has been conducted in urban areas of China. This study examined the associations between parental smoking, peer smoking, and low refusal self-efficacy and smoking among urban and rural Chinese youth. This analysis used a cross-sectional sample of 3412 ninth grade students in urban and rural areas under the administrative jurisdiction of seven large cities in China. Multilevel logistic regression models were used to associate the risk factors with lifetime and current smoking, separately in boys and girls. Adolescent smoking was not strongly associated with parental smoking. However it was strongly associated with peer smoking and low refusal self-efficacy across both the urban and rural samples. Students with lower refusal self-efficacy were approximately 5–17 times more likely to be lifetime or current smokers than those with higher refusal self-efficacy. Smoking prevention interventions in China may need to focus on raising adolescents' refusal self-efficacy. © 2008 Elsevier Ltd. All rights reserved.
1. Introduction Cigarette smoking is rising among urban Chinese adolescents and poses a significant public health concern. While the majority of Chinese youth live in rural areas, there have been no studies that address whether risk and protective factors for smoking are similar or different between urban and rural adolescents in China. Clarification of this question is crucial to
⁎ Corresponding author. Institute for Health Promotion and Diseases Prevention Research, Keck School of Medicine, University of Southern California, 1000 S. Fremont, Box 8, Alhambra, CA 91803, United States. Tel.: +1 626 457 6627; fax: +1 626 457 4012. E-mail address: [email protected] (H. Ma). 0306-4603/$ – see front matter © 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.addbeh.2008.04.004
1082
H. Ma et al. / Addictive Behaviors 33 (2008) 1081–1085
inform the development of smoking prevention programs appropriate for both groups. Therefore, the primary focus of this study is to assess whether risk factors for smoking that have been identified in Western studies (Hoffman, Sussman, Unger, & Valente, 2006) are also risk factors for smoking in urban and rural areas of China. Such factors include parental smoking, peer smoking, and low refusal self-efficacy. This study also compares and contrasts the strength of these risk factors in urban and rural areas. 2. Methods 2.1. Data sources and sample selection Cross-sectional data for the current study were obtained during the third-year survey (in 2004) of the China Seven Cities Study (CSCS). The CSCS is a longitudinal, school-based cohort study of health-related behaviors conducted by a consortium of researchers and public health officials in each of the seven cities and at the University of Southern California (USC). The seven participating cities are located in four regions across China: Northeast (Harbin, Shenyang), Center (Wuhan), Southwest (Chengdu, Kunming), and Coastal (Hangzhou, Qingdao). The CSCS conducted surveys in 2002, 2003, and 2004. In 2002 and 2003, surveys were conducted only in the urban areas of the seven cities, whereas the third-year survey was expanded to middle schools in the rural areas governed by these seven cities. Therefore, the third-year survey collected data from both urban and rural ninth grade students. All data collection methods, procedures and questionnaires were consistent across the urban and rural sites. Detailed information about the CSCS sampling procedures for the urban areas is reported elsewhere (Johnson et al., 2006). Briefly, 2444 urban and 968 rural ninth graders provided complete data for this analysis. 2.2. Data collection Parental consent forms were distributed to students in their schools. Students with parental consent completed the questionnaire during class, and parents completed the questionnaire at home. Consent procedures and survey instruments were approved by the Institutional Review Boards of the University of Southern California and the seven cities.
Table 1 List of the variables included in the statistical models
Dependent variables Lifetime Experimental smoking A whole cigarette smoking Current smoking (past month)
Interested potential risk factors Parental smoking Peer influence Good friend smoking Perceived smoking
Low refusal self-efficacy
Covariates City Age
Questions
Coding for the analysis
Have you ever tried smoking, even a few puffs? How old were you when you smoked a whole cigarette for the first time? During the past 30 days, on how many days did you smoke cigarettes?
0= 1= 0= 1= 0= 1=
Have you smoked at least 100 cigarettes in your entire life? (by asking parents)
0 = no 1 = yes for mother or/and father
How many of your good friends smoke cigarettes at least once a month? Out of every 100 adolescents of your gender and your age, how many do you think smoke cigarettes once a month or more?
If one of your best friends offered you a cigarette, would you smoke it?
0 = none 1 = from a few to all 0 = none 1 = about 10 2 = about 20 3 = about 30 4 = about 40 5 = about 50 6 = about 60 7 = about 70 8 = about 80 9 = about 90 10 = about 100 0 = maybe/definitely not (high refusal self-efficacy) 1 = maybe/definitely yes (low refusal self-efficacy)
Cities where students lived during the survey How old are you?
Dummy coding for 7 cities Full age
no yes I have never smoked a whole cigarette specific age was reported 0 days 1-30 days
H. Ma et al. / Addictive Behaviors 33 (2008) 1081–1085
1083
2.3. Measures The questionnaires were developed collaboratively by a team of researchers in the US and China (Johnson et al., 2006). All questionnaire items were translated from English to Mandarin Chinese and then back-translated from Chinese to English. The measures used as dependent variables, potential predictors, and covariates are listed in Table 1. 2.4. Data analysis We conducted all analyses separately for male and female ninth grade students. The characteristics of the participants were compared between urban and rural areas using chi-square tests for differences in frequency distributions and student's t-test for differences in means. Two-level multiple random-intercept logistic regression models were used to test the influence of the common risk factors. Level-1 models (student level) included parental smoking, friends' smoking, perceived smoking, low refusal self-efficacy, and age. Level-2 models (school level) were developed to account for the clustering of students within schools, and to adjust for variation across cities by including a dummy code for cities as a fixed effect. The models were fitted separately for urban boys, rural boys, urban girls, and rural girls to obtain separate odds ratios (ORs) and 95% confidence intervals (CIs) for each group. Furthermore, we explored whether the effects of these factors differed across urban and rural areas by pooling the urban and rural samples for boys and girls and fitting two-level multiple random-intercept logistic regression models including the main effect terms and interaction terms simultaneously. If the two-sided P-value of the interaction term from the Wald test was less than 0.05, the association differed between urban and rural areas. 3. Results 3.1. Comparison of demographics and predictors between urban and rural areas Parental smoking rates were similar in urban (63.01%) and rural (63.43%) areas (Table 2). Compared to urban boys, rural boys were more likely to report that their friend(s) smoked at least one cigarette per month (P b 0.0001), perceived a higher percentage of smoking prevalence among their same gendered best friends (P = 0.03), and were more likely to have low smoking refusal selfefficacy (P b 0.0001). In comparison to urban girls, rural girls perceived a lower percentage of smoking among their same gender best friends (P b 0.0001), but there were no statistically significant differences in friends' smoking and refusal self-efficacy between urban and rural girls. 3.2. Comparison of smoking prevalence between urban and rural areas Lifetime and current smoking prevalence were higher among rural boys than among urban boys (All P b 0.001) (Table 2). Lifetime experimental and whole cigarette smoking prevalence was higher among urban girls than among rural girls (All P b 0.05). 3.3. Association of youth smoking behavior with parental smoking Parental smoking was associated with a higher risk of lifetime experimental smoking among urban boys (OR = 1.34, 95% CI = 1.01–1.79), but not among other groups (Table 3). No significant relationships were found between youth and parent smoking on other smoking measures.
Table 2 Characteristics of urban and rural ninth grade students, China Characteristics
Male Urban (n = 1187)
Mean age (SDc) Potential risk factor Parental smoking Peer influence Good friend smoking Mean perceived smoking prevalence (SDc) Low refusal self-efficacy Smoking measures Lifetime experimental smoking Lifetime whole cigarette smoking Past month smoking a
Female Rural (n = 457)
14.81 (0.74)
15.20 (0.81)
62.85%
63.68%
34.20% 18.80% (23.50%) 10.95%
52.08% 21.64% (25.01%) 20.57%
35.89% 20.81% 13.56%
55.14% 39.17% 21.01%
Rural (n = 511)
P-valuea
14.64 (0.71)
14.94 (0.78)
b0.0001b
0.76
63.17%
63.21%
b 0.0001 0.03b
20.74% 4.46% (9.98%) 3.13%
0.82 b0.0001b
b 0.0001
21.24% 8.79% (13.96%) 4.38%
b 0.0001 b 0.0001 0.0002
23.87% 9.86% 7.56%
17.42% 6.46% 5.09%
0.003 0.02 0.06
P-value
a
b 0.0001b
Urban (n = 1257)
P-value ascertained from χ2 test, except where otherwise noted. bP-value ascertained from student's t test. cSD = standard deviation.
0.99
0.23
1084
H. Ma et al. / Addictive Behaviors 33 (2008) 1081–1085
Table 3 The association between potential risk factors and smoking behaviors among urban and rural ninth grade students, China
Lifetime experimental smoking Parental smoking Peer influence Good friend smoking Perceived smoking prevalence (per 10%↑) Low refusal self-efficacy Lifetime whole cigarette smoking Parental smoking Peer influence Good friend smoking Perceived smoking prevalence (per 10%↑) Low refusal self-efficacy Past month smoking Parental smoking Peer influence Good friend smoking Perceived smoking prevalence (per 10%↑) Low refusal self-efficacy a
Adjusted a OR (95% CI) for boys
Adjusted a OR (95% CI) for girls
Urban
Rural
Urban
Rural
(n = 1187)
(n = 457)
(n =1257)
(n = 511)
1.34 (1.01–1.79)
0.94 (0.60–1.49)
1.24 (0.93–1.67)
1.15 (0.68–1.94)
2.34 (1.73–3.16) 1.10 (1.03–1.18) 14.79 (7.88–27.78)
4.13 (2.53–6.74) 1.10 (0.99–1.23) 9.56 (4.14–22.06)
2.25 (1.61–3.15) 1.17 (1.06–1.29) 7.24 (3.73–14.07)
2.30 (1.32–4.02) 1.17 (0.93–1.46) 4.69 (1.51–14.53)
1.31 (0.90–1.91)
1.15 (0.70–1.89)
1.05 (0.68–1.64)
2.20 (0.89–5.44)
2.53 (1.73–3.70) 1.12 (1.04–1.20) 16.87 (10.05–28.33)
2.73 (1.62–4.62) 1.14 (1.02–1.26) 11.99 (6.05–23.80)
2.69 (1.68–4.30) 1.18 (1.04–1.34) 15.06 (7.72–29.37)
3.03 (1.37–6.71) 1.28 (0.95–1.72) 10.92 (3.11–38.37)
1.02 (0.68–1.53)
0.80 (0.47–1.38)
1.25 (0.79–1.97)
0.66 (0.29–1.50)
1.85 (1.20–2.83) 1.15 (1.07–1.25) 9.38 (5.95–14.81)
3.42 (1.79–6.55) 1.09 (0.97–1.21) 5.27 (3.04–9.16)
1.35 (0.80–2.28) 1.13 (0.98–1.29) 4.68 (2.30–9.55)
1.24 (0.47–3.25) 1.19 (0.87–1.63) 1.25 (0.14–10.94)
Two-level multiple regression models include parental smoking, good friend smoking, perceived smoking, lack of refusal self-efficacy, age, and city.
3.4. Association of smoking behavior with peer smoking 3.4.1. Good friend smoking In both urban and rural areas, compared to students who did not have friends who smoked, those who did were about 2–4 times more likely to have ever tried smoking, 2–3 times more likely to have ever smoked a whole cigarette, and 2–3 times more likely to be current smokers (boys only) (Table 3). 3.4.2. Perceived smoking Perceived smoking was associated with a higher risk of lifetime smoking and past month smoking among both urban and rural participants (Table 3). However, the association reached statistical significance only for urban boys', rural boys' and urban girls' lifetime smoking. Each 10% perceived smoking prevalence increased the risk by approximately10–17% for lifetime experimental smoking, 12–28% for lifetime a whole cigarette smoking, and 9–19% for past month smoking. 3.5. Association of smoking behavior with low refusal self-efficacy In both urban and rural areas, those who had lower refusal self-efficacy were approximately 5–15 times more likely to ever have tried smoking, 11–17 times more likely to ever have smoked a whole cigarette, 5–9 times more likely to be current smokers (restricted to boys) (Table 3). There was a 25% non-statistically significant increase in risk among rural girls' current smoking. 3.6. Interaction Contrary to the hypotheses, the strength of the association between risk factors and smoking behavior did not differ significantly between urban and rural areas (all P N 0.05). 4. Discussion Overall, the influence of parental smoking on the smoking behavior of ninth grade students was relatively weak in both urban and rural areas of China. Parental influences on adolescent smoking were similarly weak in studies in urban Guangzhou, China (Wen et al., 2007), and in Western countries (Hoffman et al., 2006). Friends' smoking and perceived smoking prevalence were risk factors for adolescent smoking in both urban and rural areas of China. These effects are similar in direction and magnitude to those found in previous studies in China (Grenard et al., 2006; Li, Fang, & Stanton, 1999; Yang et al., 2004; Zhu, Liu, Shelton, Liu, & Giovino, 1996; Zhu et al., 1992). More importantly, we found that low refusal self-efficacy was strongly associated with adolescent smoking in China, where offering a cigarette is a gesture of good will (Davis, 2000; Pan, 2004), a “wedding cigarette” is a necessity for guests at typical Chinese wedding ceremonies, and cigarette offerings are as common as shaking hands among men. Smoking has a long cultural tradition in China. However, as China moves through significant cultural change, prevention interventions for Chinese youth might include instruction on how to refuse a cigarette without seeming rude or disrespectful.
H. Ma et al. / Addictive Behaviors 33 (2008) 1081–1085
1085
The results of this study suggest that increasing cigarette refusal self-efficacy should be a major goal in smoking prevention programs for Chinese youth in both urban and rural areas. Public messages that focus on changing prevailing cultural norms about tobacco and emphasize refusal skill efficacy will contribute to changing this deep engrained cultural norm. Acknowledgment This research was supported by the USC Pacific Rim Transdisciplinary Tobacco and Alcohol Use Research Center (NIH grant 1 P50 CA84735-01) and the Sidney R. Garfield Endowment. The authors are deeply grateful to the CSCS steering committee and team members. References Davis, D. S. (2000). The consumer revolution in urban China. Los Angeles, California: University of California Press. Grenard, J. L., Guo, Q., Jasuja, G. K., Unger, J. B., Chou, C. -P., Gallaher, P. E., et al. (2006). Influences affecting adolescent smoking behavior in China. Nicotine & Tobacco Research, 8(2), 245−255. Hoffman, B. R., Sussman, S., Unger, J. B., & Valente, T. W. (2006). Peer influences on adolescent cigarette smoking: a theoretical review of the literature. Substance Use & Misuse, 41(1), 103−155. Johnson, A. C., Palmer, P. H., Chou, C. -P., Pang, Z., Zhou, D., Dong, L., et al. (2006). Tobacco use among youth and adults in Mainland China: The China seven cities study. Public Health, 120(12), 1156−1169. Li, X., Fang, X., & Stanton, B. (1999). Cigarette smoking among schoolboys in Beijing, China. Journal of Adolescence, 22(5), 621−625. Pan, Z. (2004). Socioeconomic predictors of smoking and smoking frequency in urban China: Evidence of smoking as a social function. Health Promotion International, 19(3), 309−315. Wen, X., Chen, W., Muscat, J. E., Qian, Z., Lu, C., Zhang, C., et al. (2007). Modifiable family and school environmental factors associated with smoking status among adolescents in Guangzhou, China. Preventive Medicine, 45(2−3), 189−197. Yang, G., Ma, J., Chen, A. P., Brown, S., Taylor, C. E., & Samet, J. M. (2004). Smoking among adolescents in China: 1998 survey findings. International Journal of Epidemiology, 33(5), 1103−1110. Zhu, B. P., Liu, M., Shelton, D., Liu, S., & Giovino, G. A. (1996). Cigarette smoking and its risk factors among elementary school students in Beijing. American Journal of Public Health, 86(3), 368−375. Zhu, B. P., Liu, M., Wang, S. Q., He, G. Q., Chen, D. H., Shi, J. H., et al. (1992). Cigarette smoking among junior high school students in Beijing, China, 1988. International Journal of Epidemiology, 21(5), 854−861.
Contents lists available at ScienceDirect
Addictive Behaviors
Short communication
Risk factors for adolescent smoking in urban and rural China: Findings from the China seven cities study Huiyan Ma a,⁎, Jennifer B. Unger a, Chih-Ping Chou a, Ping Sun a, Paula H. Palmer a, Yan Zhou a, Jie Yao a, Bin Xie b, Peggy E. Gallaher a, Qian Guo a, Yonglan Wei c, Bin Chen d, Zhanju Wang e, Xu Wang f, Haiping Duan g, Yu Song h, Jie Gong i, Stanley P. Azen a, Liming Lee j, C. Anderson Johnson a a
Keck School of Medicine, University of Southern California, United States School of Social Work, University of Southern California, United States Chengdu Center for Disease Control and Prevention, China d Hangzhou Center of Disease Prevention and Control, China e Harbin Center for Disease Control and Prevention, China f Kunming Health Education Institute, China g Qingdao Municipal Centers for Disease Control and Prevention, China h Shenyang Center for Disease Control and Prevention, China i Wuhan Center for Disease Control and Prevention, China j Peking Union Medical College, China b c
a r t i c l e Keywords: Smoking Risk factor Adolescent China
i n f o
a b s t r a c t Cigarette smoking is rising among urban Chinese adolescents and poses a significant public health concern. The majority of Chinese youth live in rural areas, but most research on the risk factors for smoking has been conducted in urban areas of China. This study examined the associations between parental smoking, peer smoking, and low refusal self-efficacy and smoking among urban and rural Chinese youth. This analysis used a cross-sectional sample of 3412 ninth grade students in urban and rural areas under the administrative jurisdiction of seven large cities in China. Multilevel logistic regression models were used to associate the risk factors with lifetime and current smoking, separately in boys and girls. Adolescent smoking was not strongly associated with parental smoking. However it was strongly associated with peer smoking and low refusal self-efficacy across both the urban and rural samples. Students with lower refusal self-efficacy were approximately 5–17 times more likely to be lifetime or current smokers than those with higher refusal self-efficacy. Smoking prevention interventions in China may need to focus on raising adolescents' refusal self-efficacy. © 2008 Elsevier Ltd. All rights reserved.
1. Introduction Cigarette smoking is rising among urban Chinese adolescents and poses a significant public health concern. While the majority of Chinese youth live in rural areas, there have been no studies that address whether risk and protective factors for smoking are similar or different between urban and rural adolescents in China. Clarification of this question is crucial to
⁎ Corresponding author. Institute for Health Promotion and Diseases Prevention Research, Keck School of Medicine, University of Southern California, 1000 S. Fremont, Box 8, Alhambra, CA 91803, United States. Tel.: +1 626 457 6627; fax: +1 626 457 4012. E-mail address: [email protected] (H. Ma). 0306-4603/$ – see front matter © 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.addbeh.2008.04.004
1082
H. Ma et al. / Addictive Behaviors 33 (2008) 1081–1085
inform the development of smoking prevention programs appropriate for both groups. Therefore, the primary focus of this study is to assess whether risk factors for smoking that have been identified in Western studies (Hoffman, Sussman, Unger, & Valente, 2006) are also risk factors for smoking in urban and rural areas of China. Such factors include parental smoking, peer smoking, and low refusal self-efficacy. This study also compares and contrasts the strength of these risk factors in urban and rural areas. 2. Methods 2.1. Data sources and sample selection Cross-sectional data for the current study were obtained during the third-year survey (in 2004) of the China Seven Cities Study (CSCS). The CSCS is a longitudinal, school-based cohort study of health-related behaviors conducted by a consortium of researchers and public health officials in each of the seven cities and at the University of Southern California (USC). The seven participating cities are located in four regions across China: Northeast (Harbin, Shenyang), Center (Wuhan), Southwest (Chengdu, Kunming), and Coastal (Hangzhou, Qingdao). The CSCS conducted surveys in 2002, 2003, and 2004. In 2002 and 2003, surveys were conducted only in the urban areas of the seven cities, whereas the third-year survey was expanded to middle schools in the rural areas governed by these seven cities. Therefore, the third-year survey collected data from both urban and rural ninth grade students. All data collection methods, procedures and questionnaires were consistent across the urban and rural sites. Detailed information about the CSCS sampling procedures for the urban areas is reported elsewhere (Johnson et al., 2006). Briefly, 2444 urban and 968 rural ninth graders provided complete data for this analysis. 2.2. Data collection Parental consent forms were distributed to students in their schools. Students with parental consent completed the questionnaire during class, and parents completed the questionnaire at home. Consent procedures and survey instruments were approved by the Institutional Review Boards of the University of Southern California and the seven cities.
Table 1 List of the variables included in the statistical models
Dependent variables Lifetime Experimental smoking A whole cigarette smoking Current smoking (past month)
Interested potential risk factors Parental smoking Peer influence Good friend smoking Perceived smoking
Low refusal self-efficacy
Covariates City Age
Questions
Coding for the analysis
Have you ever tried smoking, even a few puffs? How old were you when you smoked a whole cigarette for the first time? During the past 30 days, on how many days did you smoke cigarettes?
0= 1= 0= 1= 0= 1=
Have you smoked at least 100 cigarettes in your entire life? (by asking parents)
0 = no 1 = yes for mother or/and father
How many of your good friends smoke cigarettes at least once a month? Out of every 100 adolescents of your gender and your age, how many do you think smoke cigarettes once a month or more?
If one of your best friends offered you a cigarette, would you smoke it?
0 = none 1 = from a few to all 0 = none 1 = about 10 2 = about 20 3 = about 30 4 = about 40 5 = about 50 6 = about 60 7 = about 70 8 = about 80 9 = about 90 10 = about 100 0 = maybe/definitely not (high refusal self-efficacy) 1 = maybe/definitely yes (low refusal self-efficacy)
Cities where students lived during the survey How old are you?
Dummy coding for 7 cities Full age
no yes I have never smoked a whole cigarette specific age was reported 0 days 1-30 days
H. Ma et al. / Addictive Behaviors 33 (2008) 1081–1085
1083
2.3. Measures The questionnaires were developed collaboratively by a team of researchers in the US and China (Johnson et al., 2006). All questionnaire items were translated from English to Mandarin Chinese and then back-translated from Chinese to English. The measures used as dependent variables, potential predictors, and covariates are listed in Table 1. 2.4. Data analysis We conducted all analyses separately for male and female ninth grade students. The characteristics of the participants were compared between urban and rural areas using chi-square tests for differences in frequency distributions and student's t-test for differences in means. Two-level multiple random-intercept logistic regression models were used to test the influence of the common risk factors. Level-1 models (student level) included parental smoking, friends' smoking, perceived smoking, low refusal self-efficacy, and age. Level-2 models (school level) were developed to account for the clustering of students within schools, and to adjust for variation across cities by including a dummy code for cities as a fixed effect. The models were fitted separately for urban boys, rural boys, urban girls, and rural girls to obtain separate odds ratios (ORs) and 95% confidence intervals (CIs) for each group. Furthermore, we explored whether the effects of these factors differed across urban and rural areas by pooling the urban and rural samples for boys and girls and fitting two-level multiple random-intercept logistic regression models including the main effect terms and interaction terms simultaneously. If the two-sided P-value of the interaction term from the Wald test was less than 0.05, the association differed between urban and rural areas. 3. Results 3.1. Comparison of demographics and predictors between urban and rural areas Parental smoking rates were similar in urban (63.01%) and rural (63.43%) areas (Table 2). Compared to urban boys, rural boys were more likely to report that their friend(s) smoked at least one cigarette per month (P b 0.0001), perceived a higher percentage of smoking prevalence among their same gendered best friends (P = 0.03), and were more likely to have low smoking refusal selfefficacy (P b 0.0001). In comparison to urban girls, rural girls perceived a lower percentage of smoking among their same gender best friends (P b 0.0001), but there were no statistically significant differences in friends' smoking and refusal self-efficacy between urban and rural girls. 3.2. Comparison of smoking prevalence between urban and rural areas Lifetime and current smoking prevalence were higher among rural boys than among urban boys (All P b 0.001) (Table 2). Lifetime experimental and whole cigarette smoking prevalence was higher among urban girls than among rural girls (All P b 0.05). 3.3. Association of youth smoking behavior with parental smoking Parental smoking was associated with a higher risk of lifetime experimental smoking among urban boys (OR = 1.34, 95% CI = 1.01–1.79), but not among other groups (Table 3). No significant relationships were found between youth and parent smoking on other smoking measures.
Table 2 Characteristics of urban and rural ninth grade students, China Characteristics
Male Urban (n = 1187)
Mean age (SDc) Potential risk factor Parental smoking Peer influence Good friend smoking Mean perceived smoking prevalence (SDc) Low refusal self-efficacy Smoking measures Lifetime experimental smoking Lifetime whole cigarette smoking Past month smoking a
Female Rural (n = 457)
14.81 (0.74)
15.20 (0.81)
62.85%
63.68%
34.20% 18.80% (23.50%) 10.95%
52.08% 21.64% (25.01%) 20.57%
35.89% 20.81% 13.56%
55.14% 39.17% 21.01%
Rural (n = 511)
P-valuea
14.64 (0.71)
14.94 (0.78)
b0.0001b
0.76
63.17%
63.21%
b 0.0001 0.03b
20.74% 4.46% (9.98%) 3.13%
0.82 b0.0001b
b 0.0001
21.24% 8.79% (13.96%) 4.38%
b 0.0001 b 0.0001 0.0002
23.87% 9.86% 7.56%
17.42% 6.46% 5.09%
0.003 0.02 0.06
P-value
a
b 0.0001b
Urban (n = 1257)
P-value ascertained from χ2 test, except where otherwise noted. bP-value ascertained from student's t test. cSD = standard deviation.
0.99
0.23
1084
H. Ma et al. / Addictive Behaviors 33 (2008) 1081–1085
Table 3 The association between potential risk factors and smoking behaviors among urban and rural ninth grade students, China
Lifetime experimental smoking Parental smoking Peer influence Good friend smoking Perceived smoking prevalence (per 10%↑) Low refusal self-efficacy Lifetime whole cigarette smoking Parental smoking Peer influence Good friend smoking Perceived smoking prevalence (per 10%↑) Low refusal self-efficacy Past month smoking Parental smoking Peer influence Good friend smoking Perceived smoking prevalence (per 10%↑) Low refusal self-efficacy a
Adjusted a OR (95% CI) for boys
Adjusted a OR (95% CI) for girls
Urban
Rural
Urban
Rural
(n = 1187)
(n = 457)
(n =1257)
(n = 511)
1.34 (1.01–1.79)
0.94 (0.60–1.49)
1.24 (0.93–1.67)
1.15 (0.68–1.94)
2.34 (1.73–3.16) 1.10 (1.03–1.18) 14.79 (7.88–27.78)
4.13 (2.53–6.74) 1.10 (0.99–1.23) 9.56 (4.14–22.06)
2.25 (1.61–3.15) 1.17 (1.06–1.29) 7.24 (3.73–14.07)
2.30 (1.32–4.02) 1.17 (0.93–1.46) 4.69 (1.51–14.53)
1.31 (0.90–1.91)
1.15 (0.70–1.89)
1.05 (0.68–1.64)
2.20 (0.89–5.44)
2.53 (1.73–3.70) 1.12 (1.04–1.20) 16.87 (10.05–28.33)
2.73 (1.62–4.62) 1.14 (1.02–1.26) 11.99 (6.05–23.80)
2.69 (1.68–4.30) 1.18 (1.04–1.34) 15.06 (7.72–29.37)
3.03 (1.37–6.71) 1.28 (0.95–1.72) 10.92 (3.11–38.37)
1.02 (0.68–1.53)
0.80 (0.47–1.38)
1.25 (0.79–1.97)
0.66 (0.29–1.50)
1.85 (1.20–2.83) 1.15 (1.07–1.25) 9.38 (5.95–14.81)
3.42 (1.79–6.55) 1.09 (0.97–1.21) 5.27 (3.04–9.16)
1.35 (0.80–2.28) 1.13 (0.98–1.29) 4.68 (2.30–9.55)
1.24 (0.47–3.25) 1.19 (0.87–1.63) 1.25 (0.14–10.94)
Two-level multiple regression models include parental smoking, good friend smoking, perceived smoking, lack of refusal self-efficacy, age, and city.
3.4. Association of smoking behavior with peer smoking 3.4.1. Good friend smoking In both urban and rural areas, compared to students who did not have friends who smoked, those who did were about 2–4 times more likely to have ever tried smoking, 2–3 times more likely to have ever smoked a whole cigarette, and 2–3 times more likely to be current smokers (boys only) (Table 3). 3.4.2. Perceived smoking Perceived smoking was associated with a higher risk of lifetime smoking and past month smoking among both urban and rural participants (Table 3). However, the association reached statistical significance only for urban boys', rural boys' and urban girls' lifetime smoking. Each 10% perceived smoking prevalence increased the risk by approximately10–17% for lifetime experimental smoking, 12–28% for lifetime a whole cigarette smoking, and 9–19% for past month smoking. 3.5. Association of smoking behavior with low refusal self-efficacy In both urban and rural areas, those who had lower refusal self-efficacy were approximately 5–15 times more likely to ever have tried smoking, 11–17 times more likely to ever have smoked a whole cigarette, 5–9 times more likely to be current smokers (restricted to boys) (Table 3). There was a 25% non-statistically significant increase in risk among rural girls' current smoking. 3.6. Interaction Contrary to the hypotheses, the strength of the association between risk factors and smoking behavior did not differ significantly between urban and rural areas (all P N 0.05). 4. Discussion Overall, the influence of parental smoking on the smoking behavior of ninth grade students was relatively weak in both urban and rural areas of China. Parental influences on adolescent smoking were similarly weak in studies in urban Guangzhou, China (Wen et al., 2007), and in Western countries (Hoffman et al., 2006). Friends' smoking and perceived smoking prevalence were risk factors for adolescent smoking in both urban and rural areas of China. These effects are similar in direction and magnitude to those found in previous studies in China (Grenard et al., 2006; Li, Fang, & Stanton, 1999; Yang et al., 2004; Zhu, Liu, Shelton, Liu, & Giovino, 1996; Zhu et al., 1992). More importantly, we found that low refusal self-efficacy was strongly associated with adolescent smoking in China, where offering a cigarette is a gesture of good will (Davis, 2000; Pan, 2004), a “wedding cigarette” is a necessity for guests at typical Chinese wedding ceremonies, and cigarette offerings are as common as shaking hands among men. Smoking has a long cultural tradition in China. However, as China moves through significant cultural change, prevention interventions for Chinese youth might include instruction on how to refuse a cigarette without seeming rude or disrespectful.
H. Ma et al. / Addictive Behaviors 33 (2008) 1081–1085
1085
The results of this study suggest that increasing cigarette refusal self-efficacy should be a major goal in smoking prevention programs for Chinese youth in both urban and rural areas. Public messages that focus on changing prevailing cultural norms about tobacco and emphasize refusal skill efficacy will contribute to changing this deep engrained cultural norm. Acknowledgment This research was supported by the USC Pacific Rim Transdisciplinary Tobacco and Alcohol Use Research Center (NIH grant 1 P50 CA84735-01) and the Sidney R. Garfield Endowment. The authors are deeply grateful to the CSCS steering committee and team members. References Davis, D. S. (2000). The consumer revolution in urban China. Los Angeles, California: University of California Press. Grenard, J. L., Guo, Q., Jasuja, G. K., Unger, J. B., Chou, C. -P., Gallaher, P. E., et al. (2006). Influences affecting adolescent smoking behavior in China. Nicotine & Tobacco Research, 8(2), 245−255. Hoffman, B. R., Sussman, S., Unger, J. B., & Valente, T. W. (2006). Peer influences on adolescent cigarette smoking: a theoretical review of the literature. Substance Use & Misuse, 41(1), 103−155. Johnson, A. C., Palmer, P. H., Chou, C. -P., Pang, Z., Zhou, D., Dong, L., et al. (2006). Tobacco use among youth and adults in Mainland China: The China seven cities study. Public Health, 120(12), 1156−1169. Li, X., Fang, X., & Stanton, B. (1999). Cigarette smoking among schoolboys in Beijing, China. Journal of Adolescence, 22(5), 621−625. Pan, Z. (2004). Socioeconomic predictors of smoking and smoking frequency in urban China: Evidence of smoking as a social function. Health Promotion International, 19(3), 309−315. Wen, X., Chen, W., Muscat, J. E., Qian, Z., Lu, C., Zhang, C., et al. (2007). Modifiable family and school environmental factors associated with smoking status among adolescents in Guangzhou, China. Preventive Medicine, 45(2−3), 189−197. Yang, G., Ma, J., Chen, A. P., Brown, S., Taylor, C. E., & Samet, J. M. (2004). Smoking among adolescents in China: 1998 survey findings. International Journal of Epidemiology, 33(5), 1103−1110. Zhu, B. P., Liu, M., Shelton, D., Liu, S., & Giovino, G. A. (1996). Cigarette smoking and its risk factors among elementary school students in Beijing. American Journal of Public Health, 86(3), 368−375. Zhu, B. P., Liu, M., Wang, S. Q., He, G. Q., Chen, D. H., Shi, J. H., et al. (1992). Cigarette smoking among junior high school students in Beijing, China, 1988. International Journal of Epidemiology, 21(5), 854−861.