title: A Text-Messaging and Pedometer Program to Promote Physical Activity in People at High Risk of Type 2 Diabetes: The Development of the PROPELS Follow-On Support Program.
abstract: BACKGROUND
  Mobile technologies for health (mHealth) represent a promising strategy for reducing type 2 diabetes (T2DM) risk. The PROPELS trial investigates whether structured group-based education alone or supplemented with a follow-on support program combining self-monitoring with pedometers and tailored text-messaging is effective in promoting and maintaining physical activity among people at high risk of T2DM.
  
  
  OBJECTIVE
  This paper describes the iterative development of the PROPELS follow-on support program and presents evidence on its acceptability and feasibility.
  
  
  METHODS
  We used a modified mHealth development framework with four phases: (1) conceptualization of the follow-on support program using theory and evidence, (2) formative research including focus groups (n=15, ages 39-79 years), (3) pre-testing focus groups using a think aloud protocol (n=20, ages 52-78 years), and (4) piloting (n=11). Analysis was informed by the constant comparative approach, with findings from each phase informing subsequent phases.
  
  
  RESULTS
  The first three phases informed the structure, nature, and content of the follow-on support program, including the frequency of text messages, the need for tailored content and two-way interaction, the importance of motivational messages based on encouragement and reinforcement of affective benefits (eg, enjoyment) with minimal messages about weight and T2DM risk, and the need for appropriate language. The refined program is personalized and tailored to the individual's perceived confidence, previous activity levels, and physical activity goals. The pilot phase indicated that the program appeared to fit well with everyday routines and was easy to use by older adults.
  
  
  CONCLUSIONS
  We developed a feasible and innovative text messaging and pedometer program based on evidence and behavior change theory and grounded in the experiences, views, and needs of people at high diabetes risk. A large scale trial is testing the effectiveness of this 4-year program over and above structured group education alone.
  
  
  BACKGROUND
  International Standard Randomized Controlled Trial Number (ISRCTN): 83465245; http://www.controlled-trials.com/ISRCTN83465245/83465245 (Archived by WebCite at http://www.webcitation.org/6dfSmrVAe).
authors.affiliation: UKCRC Centre for Diet and Activity Research (CEDAR), MRC Epidemiology Unit, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Katie
authors.identifier: http://orcid.org/0000-0002-9961-6491
authors.initials: K
authors.lastname: Morton
authors.forename: Stephen
authors.identifier: http://orcid.org/0000-0003-1610-0404
authors.initials: S
authors.lastname: Sutton
authors.forename: Wendy
authors.identifier: http://orcid.org/0000-0002-6498-9407
authors.initials: W
authors.lastname: Hardeman
authors.forename: Jacqui
authors.identifier: http://orcid.org/0000-0003-3690-9534
authors.initials: J
authors.lastname: Troughton
authors.forename: Tom
authors.identifier: http://orcid.org/0000-0002-6081-1767
authors.initials: T
authors.lastname: Yates
authors.forename: Simon
authors.identifier: http://orcid.org/0000-0002-2157-4797
authors.initials: S
authors.lastname: Griffin
authors.forename: Melanie
authors.identifier: http://orcid.org/0000-0002-9987-9371
authors.initials: M
authors.lastname: Davies
authors.forename: Kamlesh
authors.identifier: http://orcid.org/0000-0003-2343-7099
authors.initials: K
authors.lastname: Khunti
authors.forename: Helen
authors.identifier: http://orcid.org/0000-0002-6023-3661
authors.initials: H
authors.lastname: Eborall
keywords: intervention development; mHealth; pedometer; physical activity; tailoring; text messaging; type 2 diabetes