Established in 2002, the SBF program was designed to reduce tobacco use initiation among children from low socio-economic backgrounds attending government schools in Mumbai, India, following an innovative approach focused on building broad-based life skills and confidence to address life's challenges. This study used a quasi-experimental design to test the effectiveness of this program by comparing tobacco use and related knowledge and attitudes among students in SBF schools and in comparable control schools in Mumbai that have not received the SBF intervention. Specifically, we tested the hypotheses that compared to students in control schools, students in schools receiving the SBF program would be more knowledgeable about products containing tobacco and about tobacco control legislation; more likely to take action to prevent others from using tobacco; more likely to demonstrate positive life skills and attitudes; and less likely to report using tobacco in the last 30 days. Notably, these findings indicate that even after only one year of exposure to the program, students in SBF schools were only half as likely as students in control schools to have used tobacco in the last 30 days, and the proportion using tobacco after two years of exposure to the program was even further reduced. Reflecting the central premise of the SBF program, SBF students also reported stronger life skills and self-efficacy than students in control schools. In addition, compared to control school students, SBF students were significantly more knowledgeable about tobacco and related legislation, and reported significantly more efforts to prevent tobacco use among others, including with friends, in their schools and in their neighborhoods.
These findings are consistent with prior studies, including the emerging literature on tobacco use prevention efforts in India. For example, our findings about SBF students' improved knowledge about products containing tobacco and about tobacco control legislation are consistent with a study of students in New Delhi. This study found greater knowledge of tobacco, including types of tobacco and its harmful effects, was associated with lower levels of tobacco use compared to students with less knowledge of tobacco 
. India's Cigarettes and Other Tobacco Products Act (COTPA) of 2003 is relatively new and not well enforced in many parts of the country 
. The 9th
grade SBF intervention included students working with civic authorities to support implementation of the tobacco control law; knowledge of this legislation provided an important foundation for their advocacy work.
We also found support for our hypothesis that SBF students would be more likely to take action to prevent others from using tobacco than control school students. Other studies have noted a crucial role for peer activism and engagement in successful programs designed to prevent youth tobacco use 
. SBF engaged youth in multiple ways and at multiple levels in tobacco use prevention efforts, including at the individual level (friends), the organizational level (schools) and community level (neighborhoods). The use of multiple modalities and domains to deliver program content has been shown to be more effective in reducing tobacco use than in-school activities only 
Students in the SBF schools were more likely to demonstrate positive life skills and attitudes than students in the comparison schools. A wealth of research over the past two decades has demonstrated both short- and long-term prevention effects of life skills training on tobacco use 
. These effects have been found in a variety of school settings and student populations 
. Given that low self-esteem has been found to be an independent predictor of smoking initiation in adolescents 
, SBF's life skills training may confer future tobacco prevention benefits, beyond the duration of the program.
We are aware of only one other school-based intervention study to reduce tobacco use among adolescents in India, based in Delhi and Chennai. Investigators found overall tobacco use increased by 68% in the control group and decreased by 17% in the intervention group over 2 years 
. In this study, we found that 8th
grade students exposed to the SBF intervention for only one academic year were half as likely as students in comparison schools to have used tobacco in the last 30 days. Of particular note, we found that 9th
graders in SBF schools were even less likely to use tobacco (OR
0.34). Outside the context of the SBF program, one would expect to see tobacco use uptake rates increase from 8th
grade to 9th
grade. This apparent decrease in tobacco use prevalence over time, reflected by the difference between 8th
grade students exposed to the SBF intervention, suggests an increased dose effect with greater exposure to the intervention.
The life skills approach used in the SBF program differs in substantial ways from interventions focusing solely on tobacco education and may be particularly relevant for students from low-income communities, who often have restricted access for opportunities to build such life skills. A life skills approach is designed to enhance general personal and social competence, along with providing information and skills specific to tobacco use 
. The goal of enhancing personal and social skills, such as decision-making skills, is to improve self-esteem, decrease motivations to use tobacco, and provide the necessary coping skills to manage social pressures to use. Providing information and skills specific to tobacco use helps promote resistance skills and fosters anti-tobacco attitudes and norms. This broad array of self-management and social skills has application beyond tobacco and can be used by youth in a variety of other settings.
Overall, these findings are consistent with prior reports. In a systematic review of school-based smoking prevention programs, Flay concluded that programs with 15 or more sessions (beginning in upper elementary/middle school and continuing to high school); were based on a social influences model; focused on changing social norms, commitments not to use and intention not to smoke; taught refusal and other life skills and engaged peers in the program delivery could reduce smoking onset by 25–50% 
. Similarly, the Institute of Medicine concluded that school-based prevention programs that are interactive, teach about social influences, provide opportunities to practice social skills, result in a 12 percent reduction in the rate of initiation 
. The SBF contains these elements.
It is important to note several caveats in the interpretation of these results. Tobacco use was measured by self report; even though data were collected by independent evaluators with no connection to the intervention, it is possible that findings could be influenced by a social desirability bias in the intervention schools. We used a quasi-experimental design, wherein schools were not randomly assigned to condition. Although control schools were specifically selected from other government-run schools in the same general locale, we acknowledge that some unmeasured differences between the schools (e.g., location, size) and between the students (e.g., migrant status) may contribute to finding differences between SBF and comparison schools. Nonetheless, we have controlled for age, gender, and mother's education in the analyses to account for potential between-group differences. In addition, it is important to acknowledge that these results can only be generalized to similar school settings. Comparison of 9th grade intervention with 8th standard controls has a limitation of difference in the years of schooling that could not be adjusted. The age distribution was also different but that has been adjusted for. In addition, it was not possible to evaluate the potential differential effects of individual components on the intervention, or to examine the long-term effects of this intervention on tobacco use prevention.
The strengths of this evaluation include its systematic approach to surveying students from both intervention and control schools, carefully controlling for between-group differences, and assuring independence between intervention and evaluation teams. Based on prior research and on-the-ground understanding of local priorities and practices, SBF created this innovative program and had been implementing it in government schools since 2002, before requesting this independent evaluation of the program's impact. Rigorous program evaluations of existing programs, such as this one, can help highlight effective strategies from the field and facilitate their dissemination to different settings.
In India, every day more than 5,500 children under age 15 try tobacco for the first time. Currently, an estimated 5 million Indian children are addicted to tobacco 
. Easy availability of tobacco and lack of social sanctions have made tobacco use a problem of epidemic proportions among children, especially in the lower economic strata. The combined strategies of building students' life skills, providing opportunities for advocacy efforts, changing social norms, and engaging students in their broader communities are central to this tobacco use prevention program. By working closely with the government educational structures to embed these interventions in local infrastructures, SBF has increased the reach of the program and established it as part of institutional practice. This study was among the first life-skills intervention for tobacco use prevention to demonstrate an impact on youth tobacco use in India. This intervention additionally resulted in improved perceptions of one's life prospects and self-efficacy, and increased actions taken to prevent tobacco use among others. Accordingly, the SBF program represents an effective model of school-based tobacco use prevention that low-income schools in India and other low- and middle-income countries can replicate.