Electronic Cigarette Themes on Twitter: Dissemination Patterns and Relations with Online News and Search Engine Queries in South Korea.

This study examines multiple aspects of e-cigarette mentions on different online media channels during the announcement and implementation of a cigarette tax increase policy in South Korea. It consists of three parts. First, a Naive Bayes classifier was used to sort 59,147 tweets about e-cigarettes into five pre-designated themes - promotion, health, policy, product evaluation, and price - and to determine their relative prevalence. Second, social network analysis was used to identify the themes' dissemination patterns. Third, the themes were examined for their associations with e-cigarette mentions in two other media channels - online news articles (n = 580) and search engine queries (64 weeks of Google Trends data). Results show that the most prevalent tweet theme was product evaluation, and the theme with the largest increase during the data collection period was promotion. Promotion-themed tweets were the least connected with tweets about the other five themes, while health-themed tweets were the most connected. Finally, product evaluation-themed tweets exhibited the strongest correlation with search engine query count and had the largest explanatory power.