title: One-way versus two-way text messaging on improving medication adherence: meta-analysis of randomized trials.
abstract: BACKGROUND
  Mobile telephone text messaging is a simple potential solution to the failure to take medications as directed. There is uncertainty over the effectiveness of 1-way text messaging (sending text message reminders only) compared with 2-way text messaging (sending reminders and receiving replies confirming whether medication has been taken) as a means of improving medication adherence.
  
  
  METHODS
  A meta-analysis of 8 randomized trials (1994 patients) that tested the effectiveness of text messaging on medication adherence was performed. The trials were divided into 2 groups: trials using 1-way text messaging versus no text messaging and trials using 2-way text messaging versus no text messaging. The summary estimates of the effect of the 2 methods of text messaging (1-way or 2-way) were compared.
  
  
  RESULTS
  The summary relative risk estimate was 1.04 (95% confidence interval, 0.97-1.11) for 1-way text messaging and 1.23 (95% confidence interval, 1.13-1.35) for 2-way text messaging. The difference in effect between the 2 methods was statistically significant (P = .007).
  
  
  CONCLUSIONS
  Two-way text messaging is associated with substantially improved medication adherence compared with 1-way text messaging. This has important implications in the provision of mobile-based messaging in the management of patients taking medication for the prevention of chronic disease.
authors.affiliation: Wolfson Institute of Preventive Medicine, Queen Mary University of London, London, United Kingdom. Electronic address: d.s.wald@qmul.ac.uk.
authors.forename: David S
authors.initials: DS
authors.lastname: Wald
authors.affiliation: Wolfson Institute of Preventive Medicine, Queen Mary University of London, London, United Kingdom.
authors.forename: Shahena
authors.initials: S
authors.lastname: Butt
authors.affiliation: Wolfson Institute of Preventive Medicine, Queen Mary University of London, London, United Kingdom.
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Bestwick
mesh_terms: D006801:Humans; D055118:Medication Adherence; D015233:Models, Statistical; D010043:Outcome and Process Assessment, Health Care; D016032:Randomized Controlled Trials as Topic; D017010:Reminder Systems; D060145:Text Messaging
keywords: Adherence; Medication; Text message