Association of household smoking status in childhood with young adults' educational attainment and smoking status: Results from a series of population-based cross-sectional surveys in Japan

Secondhand Smoke Exposure and Smoking Prevalence Among Adolescents

Importance

Secondhand smoke is a substantial risk factor for youth health globally, including in Japan, where tobacco control policies should be reassessed.

Objective

To assess trends in the prevalence of secondhand smoke exposure among Japanese adolescents from 2008 to 2017 and to examine the association between its frequency and smoking during the study period.

Design, Setting, and Participants

This study comprised a nationally representative, self-administered, school-based, cross-sectional survey focusing on tobacco and alcohol use and related factors among students in grades 7 to 12 (ages 12-18 years) in Japan. This random sampling survey used single-stage cluster sampling. Using the national school directory, junior and senior high schools throughout Japan were randomly extracted from each regional block. All students enrolled in the sampled schools were included as participants, and school-based surveys were completed in 2008, 2012, and 2017. Data analysis was performed from January 1 to March 15, 2023.

Main Outcomes and Measures

Prevalence of secondhand smoke exposure among adolescents in Japan from 2008 to 2017 and changes in the association between secondhand smoke exposure frequency and prevalence of smoking were examined using multiple logistic regression analysis.

Results

Data were analyzed for 95 680 adolescents in 2008 (50.7% boys), 100 050 in 2012 (51.6% boys), and 64 152 in 2017 (53.9% boys). At baseline, 42.0%, 38.5%, and 34.6% of the participants were junior high school students in 2008, 2012, and 2017, respectively. Based on the 2008 surveys, 51.0% of adolescents in grades 7 to 12 were exposed to secondhand smoke in any place (≥1 day during the past 7 days), 37.2% were exposed at home, and 36.5% were exposed in public places. In 2017, 36.3% of participants were exposed to secondhand smoke in any place, 23.8% were exposed at home, and 27.0% were exposed in public places. An association between secondhand smoke exposure frequency and prevalence of smoking was observed consistently regardless of survey year, location, or pattern of exposure (adjusted odds ratios ranged from 2.29 [95% CI, 1.81-2.91] for 1-2 days at home to 11.15 [95% CI, 8.50-14.62] for 7 days in public places). Stratified analysis by higher education intention indicated that the prevalence of smoking and secondhand smoke exposure decreased but remained higher among adolescents who did not intend to pursue higher education. The association between secondhand smoke and smoking did not differ substantially between groups.

Conclusions and Relevance

In this cross-sectional study, the prevalence of secondhand smoke exposure among adolescents in Japan decreased but remained at high levels overall. There may not be a hazard-free threshold for smoking. Enhancing comprehensive tobacco control strategies is Japan's first step toward achieving smoke-free environments to protect youths. Implementation and verification of the effectiveness of smoke-free legislation should be considered.

Intergenerational transmission of parental risky health behaviors in Chinese children: Are there socioeconomic status differences?

Background

Risky health behaviors in childhood, including smoking, alcohol consumption, and having a poor diet, are the major sources of non-communicable diseases in adulthood. This study aimed to examine how parents affect children's risky health behaviors and whether intergenerational transmission differs based on socioeconomic status (SES).

Methods

Data were extracted from the 1991-2015 China Health and Nutrition Survey (CHNS). Smoking (n = 5,946), alcohol consumption (n = 7,821), and sugar-sweetened beverages (SSBs) consumption (n = 3,537) were used as proxies for risky health behaviors in children. A binary choice model for panel data with a random-effect specification was employed to examine whether risky health behaviors can be transmitted from parents to their children. Subsequently, we conducted a seemingly unrelated estimation test (SUEST) to explore the differences in parental transmission between the different SES groups.

Results

We found strong intergenerational persistence of smoking, alcohol drinking, and SSBs drinking behaviors, except for the mothers' smoking behavior. Mothers had a greater influence on children's alcohol drinking and SSBs drinking behaviors than fathers both in urban and rural areas and in different SES groups. The intergenerational transmission of SSBs drinking behavior exhibited a decreasing trend with increasing SES for both urban and rural families. In urban areas, mothers' alcohol drinking behavior has a decreasing trend with increasing education level, occupation, and income; however, in rural areas, the influence of mothers' alcohol drinking behavior occurred in the same direction with increasing education level and occupation type. In rural areas, the influence of fathers' drinking and smoking behaviors on children appears to mostly increase with increasing SES. Meanwhile, the influence of such behaviors among urban fathers would decrease with increasing SES.

Conclusion

Parents' behaviors and SES can influence the initiation of risky health behaviors in their offspring. Thus, to promote healthy behaviors, policymakers can introduce health education programs for parents, particularly for those living in rural areas and with a low SES.

Influence of Puerperal Health Literacy on Tobacco Use during Pregnancy among Spanish Women: A Transversal Study

Background: Despite the fact that tobacco use during pregnancy produces adverse perinatal effects, some women continue to smoke. Health literacy (HL) is essential for health outcomes in adults. However, little is known about HL in pregnant women or postpartum women. The study aimed to analyse the relationship between the degree of HL of women during the early puerperium and tobacco use during pregnancy. Methods: A multicentre, descriptive, cross-sectional study was carried out with women in the early puerperium in a region of eastern Spain, between November 2017 and May 2018. Their HL level was obtained using the Newest Vital Sign (NVS) tool. Multivariate logistic models were adjusted to estimate the magnitude of association with tobacco use in pregnancy. Odds ratios (OR) were estimated with a 95% confidence interval. Results: 193 were included in the total. 29.5% (57) of pregnant women smoked tobacco during pregnancy, with a smoking cessation rate of 70.1% (40) while pregnant. 42.0% (81) of pregnant women had inadequate or limited HL. A low level of HL was strongly associated with tobacco use, adjusted by catchment area and age of first pregnancy (LRT p < 0.001; ROC curve = 0.71, 95% CI: 0.64–0.79). Conclusion: A low HL is associated with tobacco consumption during pregnancy. Whether low HL reflects the wide constellation of already-known socioeconomic, political and commercial determinants of tobacco use, or whether incorporating HL support interventions strengthens tobacco cessation activities in pregnancy, warrants further research. Still, it should be considered as essential to understanding the health disparities related to its consumption.