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With increased media consumption and interpersonal interactions occurring online, social media platforms have become important in both engaging target audiences in public education campaigns and in understanding behaviors and perceptions around emerging public health issues across these target audiences. For example, the US Food and Drug Administration (FDA) Center for Tobacco Products has developed separate public education campaigns on the health consequences of tobacco products for at-risk teens lesbian, gay, bisexual, and transgender young adults multicultural youth rural male teens and adult smokers. Running effective public health education campaigns requires organizations to tailor messages and provide outreach that resonates with their target audience. Public health campaigns are a primary means for government agencies and nongovernmental organizations to raise awareness about important health issues affecting their communities. To evaluate associations between each feature and the outcome, we calculated means and confidence intervals and compared the two age groups, with 2-sample t tests, for each transformed model feature. We ran multiple classification algorithms and tested the performance of the models (precision, recall, F1 score) in predicting the age segments of the users in the labeled data. We split the data into training (n=1660) and test sets (n=415) and performed 5-fold cross validation on the training set to select hyperparameters and perform feature selection. We then collected sample posts, comments, and metadata for the labeled user accounts and created variables to capture linguistic patterns, posting behavior, and account details that would distinguish the adolescent age group (aged 13 to 20 years) from the adult age group (aged 21 to 54 years).
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We manually labeled Reddit users’ age by identifying and reviewing public posts in which Reddit users self-reported their age. This study was conducted between January and September 2020 using publicly available Reddit posts as input data.
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