title: A mobile app to aid smoking cessation: preliminary evaluation of SmokeFree28.
abstract: BACKGROUND
  Little is known about the effectiveness of mobile apps in aiding smoking cessation or their validity for automated collection of data on smoking cessation outcomes.
  
  
  OBJECTIVE
  We conducted a preliminary evaluation of SF28 (SF28 is the name of the app, short for SmokeFree28)-an app aimed at helping smokers to be smoke-free for 28 days.
  
  
  METHODS
  Data on sociodemographic characteristics, smoking history, number of logins, and abstinence at each login were uploaded to a server from SF28 between August 2012 and August 2013. Users were included if they were aged 16 years or over, smoked cigarettes at the time of registration, had set a quit date, and used the app at least once on or after their quit date. Their characteristics were compared with data from a representative sample of smokers trying to stop smoking in England. The percentage of users recording 28 days of abstinence was compared with a value of 15% estimated for unaided quitting. Correlations were assessed between recorded abstinence for 28 days and well-established abstinence predictors.
  
  
  RESULTS
  A total of 1170 users met the inclusion criteria. Compared with smokers trying to quit in England, they had higher consumption, and were younger, more likely to be female, and had a non-manual rather than manual occupation. In total, 18.9% (95% CI 16.7-21.1) were recorded as being abstinent from smoking for 28 days or longer. The mean number of logins was 8.5 (SD 9.0). The proportion recording abstinence for 28 days or longer was higher in users who were older, in a non-manual occupation, and in those using a smoking cessation medication.
  
  
  CONCLUSIONS
  The recorded 28-day abstinence rates from the mobile app, SF28, suggest that it may help some smokers to stop smoking. Further evaluation by means of a randomized trial appears to be warranted.
authors.affiliation: Cancer Research UK Health Behaviour Research Centre, Department of Epidemiology and Public Health, University College London, London, United Kingdom. harveenk26@gmail.com.
authors.forename: Harveen Kaur
authors.identifier: http://orcid.org/0000-0002-6592-5763
authors.initials: HK
authors.lastname: Ubhi
authors.forename: Susan
authors.identifier: http://orcid.org/0000-0003-0063-6378
authors.initials: S
authors.lastname: Michie
authors.forename: Daniel
authors.identifier: http://orcid.org/0000-0002-9454-023X
authors.initials: D
authors.lastname: Kotz
authors.forename: Wai Chi
authors.identifier: http://orcid.org/0000-0001-6844-1644
authors.initials: WC
authors.lastname: Wong
authors.forename: Robert
authors.identifier: http://orcid.org/0000-0001-6398-0921
authors.initials: R
authors.lastname: West
mesh_terms: D000293:Adolescent; D000328:Adult; D040421:Cell Phone; D004739:England; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D063731:Mobile Applications; D009042:Motivation; D016540:Smoking Cessation / Q000523:psychology; D000074606:Smoking Prevention; D055815:Young Adult
keywords: PRIME theory; apps; mobile; smartphone; smoking cessation intervention