Background: There is increasing concern around communities that promote eating disorders (Pro-ED) on social media sites through messages and images that encourage dangerous weight control behaviors. These communities share group identity formed through interactions between members and can involve the exchange of “tips,” restrictive dieting plans, extreme exercise plans, and motivating imagery of thin bodies. Unlike Instagram, Facebook, or Tumblr, the absence of adequate policy to moderate Pro-ED content on Twitter presents a unique space for the Pro-ED community to freely communicate. While recent research has identified terms, themes, and common lexicon used within the Pro-ED online community, very few have been longitudinal. It is important to focus upon the engagement of Pro-ED online communities over time to further understand how members interact and stay connected, which is currently lacking. Objective: The purpose of this study was to explore beyond the common messages of Pro-ED on Twitter to understand how Pro-ED communities get traction over time by using the hashtag considered to symbolize the Pro-ED movement, #proana. Our focus was to collect longitudinal data to gain a further understanding of the engagement of Pro-ED communities on Twitter. Methods: Descriptive statistics were used to identify the preferred tweeting style of Twitter users (either as mentioning another user in a tweet or without) as well as their most frequently used hashtag, in addition to #proana. A series of Mann Whitney U tests were then conducted to compare preferred posting style across number of followed, followers, tweets, and favorites. This was followed by linear models using a forward step-wise approach that were applied for Pro-ED Twitter users to examine the factors associated with their number of followers. Results: This study reviewed 11,620 Pro-ED Twitter accounts that posted using the hashtag #proana between September 2015 and July 2018. These profiles then underwent a 2-step screening of inclusion and exclusion criteria to reach the final sample of 967 profiles. Over 90% (10,484/11,620) of the profiles were found to have less than 6 tweets within the 34-month period. Most of the users were identified as preferring a mentioning style of tweeting (718/967, 74.3%) over not mentioning (248/967, 25.7%). Further, #proana and #thinspo were used interchangeably to propagate shared themes, and there was a reciprocal effect between followers and the followed. Conclusions: Our analysis showed that the number of accounts followed and number of Pro-ED tweets posted were significant predictors for the number of followers a user has, compared to likes. Our results could potentially be useful to social media platforms to understand which features could help or otherwise curtail the spread of ED messages and activity. Our findings also show that Pro-ED communities are transient in nature, engaging in superficial discussion threads but resilient, emulating cybersectarian behavior.

中文翻译：

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通过 Hashtag #proana：统计建模方法在 Twitter 上检查亲饮食障碍社区

背景：人们越来越关注通过鼓励危险的体重控制行为的信息和图像在社交媒体网站上促进饮食失调 (Pro-ED) 的社区。这些社区共享通过成员之间的互动形成的群体身份，并可能涉及“技巧”、限制性节食计划、极限运动计划和激励瘦身形象的交流。与 Instagram、Facebook 或 Tumblr 不同，Twitter 上缺乏适当的政策来管理 Pro-ED 内容，这为 Pro-ED 社区提供了一个独特的自由交流空间。虽然最近的研究已经确定了 Pro-ED 在线社区中使用的术语、主题和常用词典，但很少有纵向研究。目标：本研究的目的是在 Twitter 上探索 Pro-ED 的常见信息之外，以了解 Pro-ED 社区如何通过使用被认为是 Pro-ED 运动象征的主题标签#proana 来随着时间的推移获得牵引力。我们的重点是收集纵向数据，以进一步了解 Pro-ED 社区在 Twitter 上的参与情况。方法：描述性统计数据用于识别 Twitter 用户的首选推文风格（在推文中提及或不提及其他用户）以及他们最常用的主题标签，以及 #proana。然后进行了一系列 Mann Whitney U 测试，以比较喜欢的发帖风格，包括关注人数、关注者、推文和收藏。随后是使用前向逐步方法的线性模型，该模型适用于 Pro-ED Twitter 用户，以检查与其粉丝数量相关的因素。结果：本研究审查了 2015 年 9 月至 2018 年 7 月期间使用 #proana 标签发布的 11,620 个 Pro-ED Twitter 帐户。然后，这些配置文件经过了包含和排除标准的两步筛选，以获得 967 个配置文件的最终样本。在 34 个月内，超过 90% (10,484/11,620) 的个人资料被发现少于 6 条推文。大多数用户被认为更喜欢提及风格的推文 (718/967, 74.3%) 而不是不提及 (248/967, 25.7%)。此外，#proana 和#thinspo 被交替使用以传播共享主题，并且在追随者和被追随者之间存在互惠效应。结论：我们的分析表明，与喜欢相比，关注的帐户数量和发布的 Pro-ED 推文数量是用户拥有的关注者数量的重要预测因素。我们的结果可能对社交媒体平台有用，以了解哪些功能可以帮助或以其他方式减少 ED 消息和活动的传播。我们的研究结果还表明，Pro-ED 社区本质上是短暂的，参与肤浅的讨论线程，但具有弹性，模仿网络宗派行为。