https://www.selleckchem.com/products/vx-561.html 85, 95% CI=0.83, 0.87). Inter-rater reliability for screen-based sedentary behavior (mean κ=0.72, 95% CI=0.62, 0.82) and nonscreen sedentary behavior (κ=0.69, 95% CI=0.65, 0.72) showed substantial agreement. Inter-rater reliability for location (κ=0.91, 95% CI=0.88, 0.93) showed almost perfect agreement. A reliable annotation protocol to categorize wearable camera data of children into sedentary behavior components was developed. Once applied to larger samples in children, this protocol can ultimately help to better understand the potential harms of screen time and sedentary behavior in children. A reliable annotation protocol to categorize wearable camera data of children into sedentary behavior components was developed. Once applied to larger samples in children, this protocol can ultimately help to better understand the potential harms of screen time and sedentary behavior in children. The goal of the paper is to characterize the geographic and sociodemographic patterns of policies prohibiting tobacco sales to people aged <21 years (i.e., Tobacco 21) at the local, county, and state levels in the U.S. before the national law. This study assessed area-level markers for region, race/ethnicity, education, poverty status, and smoke-free law coverage as predictors of Tobacco 21 passage as of December 20, 2019, using modified Poisson and negative binomial regression models with robust SEs. Data were analyzed in 2020. Before the passage of the national policy, 191 million people were covered by Tobacco 21 laws. Counties with higher percentages of non-Hispanic Blacks and individuals living below the poverty line had a lower probability of coverage, whereas counties with higher percentages of Hispanics/Latinxs and individuals with a college degree had a higher probability of coverage. Tobacco 21 coverage also varied by region, with far greater coverage in the Northeast than in the Midwest and South. The national Tobacco 21 l