title: Long-term outcomes of a Web-based diabetes prevention program: 2-year results of a single-arm longitudinal study.
abstract: BACKGROUND
  Digital therapeutics are evidence-based behavioral treatments delivered online that can increase accessibility and effectiveness of health care. However, few studies have examined long-term clinical outcomes of digital therapeutics.
  
  
  OBJECTIVE
  The objective of this study was to conduct a 2-year follow-up on participants in the Internet-based Prevent diabetes prevention program pilot study, specifically examining the effects on body weight and A1c, which are risk factors for diabetes development.
  
  
  METHODS
  A quasi-experimental research design was used, including a single-arm pre- and post-intervention assessment of outcomes. Participants underwent a 16-week weight loss intervention and an ongoing weight maintenance intervention. As part of the program, participants received a wireless scale, which was used to collect body weight data on an ongoing basis. Participants also received A1c test kits at baseline, 0.5 year, 1 year, and 2-year time points.
  
  
  RESULTS
  Participants previously diagnosed with prediabetes (n=220) were originally enrolled in the pilot study. A subset of participants (n=187) met Centers for Disease Control and Prevention (CDC) criteria for starting the program (starters), and a further subset (n=155) met CDC criteria for completing the program (completers) and were both included in analyses. Program starters lost an average of 4.7% (SD 0.4) of baseline body weight after 1 year and 4.2% (SD 0.8) after 2 years, and reduced A1c by mean 0.38% (SD 0.07) after 1 year and 0.43% (SD 0.08) after 2 years. Program completers lost mean 4.9% (SD 0.5) of baseline body weight after 1 year and 4.3% (SD 0.8) after 2 years, and reduced A1c by 0.40% (SD 0.07) after 1 year and 0.46% (SD 0.08) after 2 years. For both groups, neither 2-year weight loss nor A1c results were significantly different from 1-year results.
  
  
  CONCLUSIONS
  Users of the Prevent program experienced significant reductions in body weight and A1c that are maintained after 2 years. Contrary to the expected progression from prediabetes to diabetes over time, average A1c levels continued to show an average regression from within the prediabetic range (5.7%-6.4%) initially to the normal range (<5.7%) after 2 years. Further investigation is warranted to test digital therapeutics as a scalable solution to address national diabetes and cardiovascular disease prevention efforts.
authors: University of California, San Francisco, Department of Psychiatry, San Francisco, CA, United States. cameron.sepah@ucsf.edu.
authors: S Cameron
authors: http://orcid.org/0000-0002-5792-8489
authors: SC
authors: Sepah
authors: Luohua
authors: http://orcid.org/0000-0002-2281-7260
authors: L
authors: Jiang
authors: Anne L
authors: http://orcid.org/0000-0003-0520-0776
authors: AL
authors: Peters
mesh_terms: D000368:Aged; D001521:Behavior Therapy; D003920:Diabetes Mellitus / Q000517:prevention & control*; D003924:Diabetes Mellitus, Type 2 / Q000517:prevention & control*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D020407:Internet; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D016896:Treatment Outcome; D014481:United States; D015431:Weight Loss
keywords: diabetes prevention program; digital health; internet; intervention; mhealth; mobile apps; obesity; online; prediabetes; type 2 diabetes