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C Anderson Johnson

Publications and source records attributed to C Anderson Johnson.

At least 19 recordsLinked to original sources
PubMed2006

Socio-demographic and cultural comparison of overweight and obesity risk and prevalence in adolescents in Southern California and Wuhan, China.

PURPOSE: This study performed parallel analyses on two large samples of seventh graders living in Los Angeles, California and in Wuhan, China to make direct comparisons of overweight and obesity risks in Western and Eastern cultural environments. METHODS: Two representative samples of 1772 and 1896 seventh grade students were randomly selected from the public or parochial middle schools in the greater Los Angeles area of Southern California in the United States, and public schools in Wuhan city of China. Two body mass index (BMI) references recently established by the U.S. National Center for Health Statistics (NCHS) and the International Obesity Task Force (IOTF), respectively, were used to define overweight (85th < or = BMI < 95th percentile) and obesity (BMI > or = 95th percentile). Logistic regressions were conducted to examine relationships between socioeconomic status (SES) and obesity risk. RESULTS: The prevalence rates of combined overweight and obesity in Los Angeles and in Wuhan were 43.1% and 12.1%, respectively, by the US-NCHS reference, and 45.8% and 11.9%, respectively, by the IOTF reference. Chinese-American adolescents had higher prevalence rates for overweight and obesity than those from China. SES was positively related to the risk of overweight and obesity in the Chinese sample, whereas a negative association was found in Southern California adolescents. Urbanicity was significantly positively related to higher overweight and obesity prevalence. CONCLUSION: Different overweight and obesity prevalence estimates and SES effects were observed for American and Chinese adolescent samples. Research on the underlying mechanisms is needed to help us to set up a tailored program for obesity prevention in Eastern and Western cultural environments.

Adolescent↗
PubMed2006

Tobacco use among youth and adults in Mainland China: the China Seven Cities Study.

OBJECTIVE: The China Seven Cities Study (CSCS) monitors geographic and temporal trends in tobacco use among adolescents and adults in seven cities throughout Mainland China: Harbin, Shenyang, Wuhan, Chengdu, Kunming, Hangzhou, and Qingdao. This article presents the methodology and prevalence data from the baseline survey of the CSCS, conducted in 2002. METHODS: Stratified random samples of middle schools, high schools, and colleges were selected within each city. Students and their parents completed self-report surveys of their tobacco use. Data were obtained from 6138 middle school students, 5848 academic high school students, 2448 vocational high school students, 2556 college students, and 25 697 parents. RESULTS: Smoking prevalence varied across age groups, school types, genders, and cities. Past-month smoking prevalence was 9% among middle school students, 8% among academic high school students, 26% among vocational high school students, 21% among college students, and 40% among parents. Smoking prevalence was higher among males than among females, with larger gender disparities among adults than among youth. Smoking also varied across cities, with higher smoking prevalence in southwestern cities and lower prevalence in coastal cities. Intraclass correlations of students within schools are presented to inform statistical power estimates for further research in China. CONCLUSIONS: These results provide a baseline for future longitudinal studies of smoking in these cities and identify demographic groups at risk for tobacco-related disease. Effective smoking prevention programmes for youth and smoking cessation programmes for adults are needed in China, especially in the lower-income southwestern cities and in vocational high schools throughout the country.

Adolescent↗
PubMed2006

Utility of the theory of reasoned action and theory of planned behavior for predicting Chinese adolescent smoking.

One third of smokers worldwide live in China. Identifying predictors of smoking is important for prevention program development. This study explored whether the Theory of Reasoned Action (TRA) and Theory of Planned Behavior (TPB) predict adolescent smoking in China. Data were obtained from 14,434 middle and high school students (48.6% boys, 51.4% girls) in seven geographically varied cities in China. TRA and TPB were tested by multilevel mediation modeling, and compared by multilevel analyses and likelihood ratio tests. Perceived behavioral control was tested as a main effect in TPB and a moderation effect in TRA. The mediation effects of smoking intention were supported in both models (p<0.001). TPB accounted for significantly more variance than TRA (p<0.001). Perceived behavioral control significantly interacted with attitudes and social norms in TRA (p<0.001). Therefore, TRA and TPB are applicable to China to predict adolescent smoking. TPB is superior to TRA for the prediction and TRA can better predict smoking among students with lower than higher perceived behavioral control.

Adolescent↗
PubMed2006

Heritability of cigarette smoking and alcohol use in Chinese male twins: the Qingdao twin registry.

BACKGROUND: China has the world's largest concentration of smokers (350 million) and rising alcohol consumption, yet little is known about tobacco and alcohol use aetiology. In 2000, the Chinese National Twin Registry was established to provide a genetically informative resource for investigation of health behaviour including tobacco and alcohol use. METHODS: Using standard twin methodology, this study aimed to examine the relative contribution of genetic and environmental influences on cigarette smoking and alcohol drinking in a sample of adult Chinese twins (n = 1010 individual twins). More than half of the male twins were smokers (58%), and 32.5% reported alcohol consumption. Among male smokers, 46.4% smoked 20 or more cigarettes per day (heavy smokers) and among drinkers, 32.8% consumed one or more drinks per day. Nearly all female twins were non-smokers (99.2%) and non-drinkers (98.7%); therefore, genetic analysis was limited to male data. RESULTS: In men, current smoking was significantly heritable [75.1%, 95% confidence interval (CI) 56.7-87.5] with no evidence for a significant contribution of shared environmental effects. Heavy smoking was more strongly influenced by genes (66.2%, 95% CI 0-88.4) than shared environment (8.7%, 95% CI 0-71.0). Similarly, current drinking was more strongly influenced by genetic effects (59.5%, 95% CI 0-87.8) than by shared environmental effects (15.3%, 95% CI 0-72.1). Amount of alcohol consumed was influenced to a similar degree by genetic (42.4%, 95% CI 0-91.8) and shared environmental factors (39.2%, 95% CI 0-82.7). CONCLUSIONS: These results support findings from twins of Western origin on the aetiology of tobacco and alcohol use and encourage further work in Chinese twins.

Adult↗
PubMed2006

Age-related smoking progression among adolescents in China.

PURPOSE: This study examined the differences in smoking progression between middle and upper school students. METHODS: The China Seven Cities Study (CSCS) is a longitudinal cohort study. The current sample consists of subjects with both baseline and one-year follow-up measures collected between October 2002 and December 2003. There were 4842 students from 62 middle schools and 5806 students from 83 upper schools. Multilevel random-coefficient modeling techniques were applied. RESULTS: Among male never or lifetime ever smokers, middle school students were susceptible to transitioning more rapidly than upper school students (never--RR: 1.272, 95% confidence interval [CI]: .985-1.642; lifetime ever--RR: 1.497, 95% CI: .979-2.290). Among female lifetime ever smokers, middle school students were more likely to progress than upper school students (RR: 1.353, 95% CI: 1.038-1.763). CONCLUSION: This longitudinal study is the first to explore differences in smoking progression among adolescents in China. The results revealed that over a one-year interval, there was greater progression across smoking trajectories during early adolescence (corresponding to middle school) than later adolescence (upper school). This is consistent with the neurological development hypothesis, but does not rule out alternative explanations. These findings are important to consider relative to the content and timing of prevention interventions in China where smoking rates approach 70% in adult males and are increasing rapidly in women.

Adolescent↗
PubMed2006

The interaction of curriculum type and implementation method on 1-year smoking outcomes in a school-based prevention program.

Studies have shown that the effectiveness of programs or curricula may depend in part on who delivers the material. In adolescent health education programs, peer leaders are often recruited to implement programs because they are more persuasive to other adolescents than adults. Teachers also systematically vary how groups are constructed in school-based health education programs. This study compared the effects of three leader and group selection methods within the context of two tobacco prevention programs. Eight schools received a social influences program (Chips) and eight received a program with a multicultural emphasis (Flavor). Within these 16 schools 84 classrooms consisting of 1486 students were randomly assigned to one of three leader and group creation conditions: (i) leaders defined as those who received the most nominations by students and groups created randomly (random group), (ii) same as (i) but groups created by assigning students to the leaders they nominated (network), and (iii) leaders and groups created by teachers (teacher). One year follow-up data showed that main effects of the curriculum and network assignments were non-significant on smoking initiation when entered alone. Interaction terms of curriculum and assignment methods, however, were significant such that the network and teacher conditions were less effective than the random group condition with Chips, and more effective than random group condition with Flavor. These data show that school-based prevention programs should be evaluated in light of who implements the program. Even a peer-led program will be differentially effective based on how leaders are selected and how groups are formed, and this effect may be curriculum dependent.

Child↗
PubMed2006

A randomized intervention of smoking for adolescents in urban Wuhan, China.

BACKGROUND: Tobacco use is a significant public health problem in China. Culturally specific smoking prevention programs are needed for Chinese adolescents. This study evaluated a school-based smoking prevention curriculum with a social normative approach developed in the United States for adolescents in urban Wuhan, China. METHODS: As a randomized trial, the intervention was implemented in 1998 with 7th grade students in seven schools with seven matched control schools. Multilevel logistic regression models were used to compare ever and recent (past-month) smoking behaviors for the control and program conditions. RESULTS: At the 1-year follow-up, smoking had increased more rapidly in the control schools than in the program schools. The odds of baseline nonsmokers initiating smoking did not differ between the program and control groups (OR=1.08 with 95% CI=0.71, 1.64). The program prevented progression to recent smoking among boys who were baseline ever smokers. Among boys who were recent smokers at baseline, the prevention program significantly reduced risk of remaining recent smokers at follow-up (OR=0.45 with 95% CI=0.23, 0.88). CONCLUSIONS: This social normative smoking prevention curriculum did not demonstrate a significant primary prevention effect but showed potential for secondary prevention. Culturally specific smoking prevention programs are needed for Chinese adolescents.

Adolescent↗
PubMed2006

Weight perception and weight-related sociocultural and behavioral factors in Chinese adolescents.

BACKGROUND: Rapid economic development accompanied by imported Western media, advertising, fashion, and lifestyle in mainland China has resulted in shifts in cultural beliefs and beauty ideals in adolescents. The present study focused on understanding relationships among weight perception and weight-related sociocultural and behavioral factors in Chinese adolescents. METHODS: Data collected in 2002 from 6863 middle and high school students and their parents from four large cities in mainland China were used. Weight status was determined by measured weight and height. Weight perception, media exposure, attitudes, and health behaviors were assessed by a structured questionnaire survey. RESULTS: Boys were more likely to describe themselves as either too thin or relatively thin than girls (37.32% vs. 18.79%), while girls more often considered themselves either relatively heavy or too heavy than boys (50.83% vs. 26.54%). Girls who were actually normal or underweight were more likely than boys to describe themselves as either relatively heavy or very heavy (41.6% vs. 11.6%), while boys who were actually normal or overweight were more likely than girls to believe themselves as underweight (30.9% vs. 15.7%). Girls who were frequently exposed to media from Japan, Korea, Hong Kong, and Taiwan, and placed high value on their physical appearance, were more likely to be dissatisfied with their body weight, which in turn were more likely to restrict consumption of certain foods, smoke cigarettes, and drink alcohol. Similar results were not observed in boys. CONCLUSIONS: Weight dissatisfaction was prevalent in Chinese adolescents and was significantly related to media exposure, attitudes towards physical appearance, and adoption of certain health-risk behaviors in girls. Our findings underscore the importance of sociocultural influences in shaping realistic body image and have implications for prevention and early intervention for establishing health behavioral practices during adolescence.

Adolescent↗
PubMed2006

Resting blood pressure and bone mineral content are inversely related in overweight and obese Hispanic women.

BACKGROUND: Previous studies have shown that hypertension is related to abnormalities of calcium metabolism such as increased calcium losses from kidney and secondary activation of parathyroid glands. In animal studies, high blood pressure (BP) has been shown to increase the risk of bone mineral loss; however whether hypertension is associated with reduced bone mineral content (BMC) in human beings is inconclusive. The relationship between BP and BMC has not been previously studied in Hispanic individuals. METHODS: Total body BMC of 33 overweight and obese (mean BMI= 31.1 kg/m(2)) premenopausal Hispanic women 22 to 51 years of age from Los Angeles, CA, was measured using dual-energy x-ray absorptiometry. Seated systolic BP (SBP) and diastolic BP (DBP) were measured using a standard mercury sphygmomanometer. RESULTS: Partial correlations revealed an inverse relationship among BMC and SBP (r = -0.61, P < .001), DBP (r = -0.52, P < .01), and hypertension (r = -0.69, P < .0001). In multiple linear regressions, SBP was negatively related (beta = -0.31, P = .001) to BMC and explained 10% of the variance. The DBP did not make a significant contribution to the variance. When fat mass and fat-free mass were controlled for, hypertensive women (n = 9) had significantly lower BMC (2119 g v 2441 g; P < .0001) than normotensive women (n = 23). CONCLUSIONS: These results reveal that BMC is partially and inversely correlated with resting SBP and DBP in premenopausal Hispanic women; in addition hypertensive women have lower adjusted means of BMC than normotensive women. Sustained hypercalciuria and ensuing hyperparathyroidism as consequences of high BP may be the mechanisms that explain the pathophysiology of increased bone mineral loss in hypertension.

Adult↗
PubMed2006

Influences affecting adolescent smoking behavior in China.

This study examined multiple influences on the use of tobacco by adolescents in China. Using the theory of triadic influences as a guide, we selected interpersonal, attitudinal/cultural, and intrapersonal constructs from baseline data to predict adolescent smoking 1 year later. We used prospective data from middle and high school students (N = 11,583) and their parents from the China Seven Cities Study, a longitudinal study that is evaluating the effects of changing economic and social factors on health behaviors including tobacco use. A multilevel regression analysis provided some support that each of the influences in the theory of triadic influences affects adolescent smoking in China. After adjusting for important confounders including age, gender, socioeconomic status, and smoking behaviors (lifetime and past 30-day) at baseline, we found significant risk factors within each of the three categories, including interpersonal influences (parental monitoring, good friend smoking, and peer smoking), attitudinal/cultural influences (school academic ranking, initial liking of smoking, and the meaning of smoking), and intrapersonal influences (susceptibility to smoking, and low self-confidence to quit smoking). Results suggest that the etiology of smoking among adolescents in China might be similar to that observed in western countries and that some of the techniques used successfully in prevention programs in those countries might be useful guides when developing prevention programs in China.

Adolescent↗
PubMed2006

Longitudinal effects of pro-tobacco and anti-tobacco messages on adolescent smoking susceptibility.

We examined the longitudinal impact of self-reported exposure to pro- and anti-tobacco media on adolescents' susceptibility to smoking, using in-school surveys from a culturally diverse sample. Ethnicity and acculturation also were examined as potential moderators. Middle-school students (N = 2,292) completed self-report questionnaires during the 6th, 7th, and 8th grades. Chi-square analyses were conducted to determine whether reported exposure to pro- and anti-tobacco media varied according to ethnicity, acculturation, and immigration status. Logistic regression models were used to examine whether pro- and anti-tobacco media exposure in 6th grade was associated with susceptibility to smoking by later grades. Recall of people smoking in television programs and pro-tobacco advertisements in stores was associated with adolescent smoking susceptibility. Exposure to anti-tobacco advertisements on television protected against susceptibility. No significant interaction effects between pro- and anti-tobacco media exposure on smoking susceptibility were found. Ethnicity and acculturation did not moderate these associations. Our longitudinal study provides evidence that pro-tobacco media and advertising increases susceptibility to smoking over time. More important, anti-tobacco advertisements are not sufficient to reduce the harmful effects of adolescent exposure to pro-tobacco media. Policy-level interventions such as restrictions in tobacco advertising may be necessary to prevent adolescent smoking.

Adolescent↗
PubMed2006

Cultural/interpersonal values and smoking in an ethnically diverse sample of Southern California adolescents.

In ethnically diverse school contexts, values from multiple cultures might influence adolescents' attitudes and behaviors. This study developed scales to assess cultural values among Southern California 6'-grade adolescents (N=2281) and evaluated the associations between values and smoking. The scales assessed values salient in many Hispanic and Asian cultures: Respect for Adults (e.g., filial piety, respeto), Interpersonal Harmony (e.g., saving face, simpatia), and Differentiated Gender Roles (e.g., machismo). In cross-sectional and one-year longitudinal models, Respect for Adults and Interpersonal Harmony were associated with a lower risk of lifetime smoking. The associations were significant even after controlling for demographic characteristics, friends' smoking, and parents' smoking, indicating that values influence adolescents' behavior over and above the effects of modeling and peer influence. Increased understanding of adolescents' values could inform the creation of smoking prevention programs for ethnically diverse adolescents.

Adolescent↗
PubMed2005

Hostility, depressive symptoms, and smoking in early adolescence.

Using logistic and multiple regression, we examined the association between hostility, level of depressive symptoms, and smoking in a sample of 1699 ethnically diverse students in California. Self-reports were collected twice from each student, at the beginning of the 6th and 7th grade years. Among 6th graders who had not smoked, depressive symptoms and hostility were associated with smoking initiation by the 7th grade. Among those students who had already tried smoking, increases in depressive symptoms and hostility were associated with more frequent smoking. The association between hostility and smoking was stronger for students reporting higher levels of depressive symptoms.

Adolescent↗
PubMed2005

Do popular students smoke? The association between popularity and smoking among middle school students.

BACKGROUND: Several studies have shown an association between popularity and behavior, indicating that popular people tend to reflect the norms of their group. Among adolescents, it has been hypothesized that popular students are more likely to smoke, especially in schools with high smoking prevalence. METHODS: Data were collected on friendship patterns and smoking from 1,486 sixth and seventh graders in 16 middle schools in southern California. Susceptibility to smoke was measured as not stating a commitment not to smoke in the future, and smoking as ever taken a puff or smoked a whole cigarette. We measured popularity as the number of times a student was chosen as a friend. Multivariate logistic regression was used to correlate popularity with susceptibility to smoke and smoking at follow-up controlling for baseline outcomes, demographic characteristics, and clustering within schools. RESULTS: Popularity was associated with increased susceptibility to smoke (Adjusted Odds Ratio [AOR] = 5.64, p < .001) and smoking (AOR = 5.09, p < .05) over the 1-year interval between surveys. Although the association was strongest for non-White boys, we did not find evidence of interactions between popularity and gender or ethnicity. CONCLUSIONS: Popular middle school students were more likely to become smokers compared to their less popular peers. Although there seems some difference in the association by gender and ethnicity, the evidence does not suggest subgroup effects in this population. Implications for the study of adolescent smoking and prevention programming are discussed.

Adolescent↗
PubMed2005

Family characteristics and smoking among urban and rural adolescents living in China.

BACKGROUND: Adolescent smoking is a public health concern in China. Although the family is an important social influence in China, few associations among family characteristics and adolescent smoking have been examined using Chinese samples. METHODS: Survey data on psychosocial variables and smoking were collected from a sample of 3629 7th grade adolescents (46% female; 54% male; mean age 12.7 years) in Wuhan, China. For adolescents, past 30-day smoking, family relationships, parents' negative sanctioning of smoking, parents' agreement with smoking, and parents' smoking behaviors are assessed. To account for the clustered data structure, hierarchical logistic regression analyses controlling for demographics (urbanization, age) examined the independent and multivariate effects of family characteristics for each gender. RESULTS: Girls are less likely than boys to report smoking and are more likely to report positive family relationships, and having parents with negative attitudes toward them smoking. Positive family relationships and age were strongly associated with smoking for both genders. No significant differences exist by gender. CONCLUSION: These findings suggest that the quality of family relationships are important for adolescent female and male smoking in China.

Adolescent↗
PubMed2005

Smoking prevention for ethnically diverse adolescents: 2-year outcomes of a multicultural, school-based smoking prevention curriculum in Southern California.

BACKGROUND: Effective school-based curricula are needed to prevent smoking among ethnically diverse adolescents. This study evaluated a multicultural smoking prevention curriculum in ethnically diverse Southern California middle schools. METHODS: Students in 24 middle schools (N = 3157 sixth graders) received the multicultural curriculum, a similar curriculum without references to cultural issues, or a control condition. Odds ratios for experimentation with smoking over a 2-year period were calculated. RESULTS: The multicultural program was associated with a lower risk of smoking between sixth and eighth grade, relative to the control group. Program effects varied according to the ethnic composition of the schools. In schools with predominantly Hispanic populations, the multicultural curriculum was more effective than the control, but the standard curriculum was not. In schools with predominantly Asian or multicultural populations, the standard curriculum was more effective than the control, but the multicultural curriculum was not. Analyses stratified by ethnicity within the schools revealed that the multicultural curriculum was effective among Hispanic students within predominantly Hispanic schools, but not among Hispanic students within predominantly Asian/multicultural schools. CONCLUSIONS: Smoking prevention for adolescents in culturally diverse school contexts is a challenge. In this study, a multicultural curriculum was most effective among Hispanic students in predominantly Hispanic schools. Further research is needed to determine the best ways to prevent smoking in predominantly Asian and multicultural schools.

Adolescent↗