title: Characterizing Sleep Issues Using Twitter.
abstract: BACKGROUND
  Sleep issues such as insomnia affect over 50 million Americans and can lead to serious health problems, including depression and obesity, and can increase risk of injury. Social media platforms such as Twitter offer exciting potential for their use in studying and identifying both diseases and social phenomenon.
  
  
  OBJECTIVE
  Our aim was to determine whether social media can be used as a method to conduct research focusing on sleep issues.
  
  
  METHODS
  Twitter posts were collected and curated to determine whether a user exhibited signs of sleep issues based on the presence of several keywords in tweets such as insomnia, "can't sleep", Ambien, and others. Users whose tweets contain any of the keywords were designated as having self-identified sleep issues (sleep group). Users who did not have self-identified sleep issues (non-sleep group) were selected from tweets that did not contain pre-defined words or phrases used as a proxy for sleep issues.
  
  
  RESULTS
  User data such as number of tweets, friends, followers, and location were collected, as well as the time and date of tweets. Additionally, the sentiment of each tweet and average sentiment of each user were determined to investigate differences between non-sleep and sleep groups. It was found that sleep group users were significantly less active on Twitter (P=.04), had fewer friends (P<.001), and fewer followers (P<.001) compared to others, after adjusting for the length of time each user's account has been active. Sleep group users were more active during typical sleeping hours than others, which may suggest they were having difficulty sleeping. Sleep group users also had significantly lower sentiment in their tweets (P<.001), indicating a possible relationship between sleep and pyschosocial issues.
  
  
  CONCLUSIONS
  We have demonstrated a novel method for studying sleep issues that allows for fast, cost-effective, and customizable data to be gathered.
authors.affiliation: Boston Children's Hospital, Harvard Medical School, Boston, MA, United States. david.mciver@childrens.harvard.edu.
authors.forename: David J
authors.identifier: http://orcid.org/0000-0002-9507-1674
authors.initials: DJ
authors.lastname: McIver
authors.forename: Jared B
authors.identifier: http://orcid.org/0000-0002-6352-1618
authors.initials: JB
authors.lastname: Hawkins
authors.forename: Rumi
authors.identifier: http://orcid.org/0000-0002-5346-7259
authors.initials: R
authors.lastname: Chunara
authors.forename: Arnaub K
authors.identifier: http://orcid.org/0000-0001-9695-5829
authors.initials: AK
authors.lastname: Chatterjee
authors.forename: Aman
authors.identifier: http://orcid.org/0000-0003-2121-828X
authors.initials: A
authors.lastname: Bhandari
authors.forename: Timothy P
authors.identifier: http://orcid.org/0000-0001-5223-3883
authors.initials: TP
authors.lastname: Fitzgerald
authors.forename: Sachin H
authors.identifier: http://orcid.org/0000-0003-1761-6322
authors.initials: SH
authors.lastname: Jain
authors.forename: John S
authors.identifier: http://orcid.org/0000-0001-8568-5317
authors.initials: JS
authors.lastname: Brownstein
mesh_terms: D003625:Data Collection; D003863:Depression; D033062:Friends; D006801:Humans; D020407:Internet; D012890:Sleep; D007319:Sleep Initiation and Maintenance Disorders; D061108:Social Media
keywords: depression; insomnia; novel methods; sentiment; sleep issues; social media