title: Clinical Safety and Feasibility of the Advanced Bolus Calculator for Type 1 Diabetes Based on Case-Based Reasoning: A 6-Week Nonrandomized Single-Arm Pilot Study.
abstract: The Advanced Bolus Calculator for Diabetes (ABC4D) is an insulin bolus dose decision support system based on case-based reasoning (CBR). The system is implemented in a smartphone application to provide personalized and adaptive insulin bolus advice for people with type 1 diabetes. We aimed to assess proof of concept, safety, and feasibility of ABC4D in a free-living environment over 6 weeks.
  
  
  
  Prospective nonrandomized single-arm pilot study. Participants used the ABC4D smartphone application for 6 weeks in their home environment, attending the clinical research facility weekly for data upload, revision, and adaptation of the CBR case base. The primary outcome was postprandial hypoglycemia.
  
  
  
  Ten adults with type 1 diabetes, on multiple daily injections of insulin, mean (standard deviation) age 47 (17), diabetes duration 25 (16), and HbA1c 68 (16) mmol/mol (8.4 (1.5) %) participated. A total of 182 and 150 meals, in week 1 and week 6, respectively, were included in the analysis of postprandial outcomes. The median (interquartile range) number of postprandial hypoglycemia episodes within 6-h after the meal was 4.5 (2.0-8.2) in week 1 versus 2.0 (0.5-6.5) in week 6 (P = 0.1). No episodes of severe hypoglycemia occurred during the study.
  
  
  
  The ABC4D is safe for use as a decision support tool for insulin bolus dosing in self-management of type 1 diabetes. A trend suggesting a reduction in postprandial hypoglycemia was observed in the final week compared with week 1.
authors.affiliation: 1 Division of Diabetes, Endocrinology and Metabolism, Imperial College London , London, United Kingdom .
authors.forename: Monika
authors.initials: M
authors.lastname: Reddy
authors.affiliation: 2 Department of Electrical and Electronic Engineering, Centre for Bio-Inspired Technology, Institute of Biomedical Engineering , Imperial College London, London, United Kingdom .
authors.forename: Peter
authors.initials: P
authors.lastname: Pesl
authors.affiliation: 1 Division of Diabetes, Endocrinology and Metabolism, Imperial College London , London, United Kingdom .
authors.forename: Maria
authors.initials: M
authors.lastname: Xenou
authors.affiliation: 2 Department of Electrical and Electronic Engineering, Centre for Bio-Inspired Technology, Institute of Biomedical Engineering , Imperial College London, London, United Kingdom .
authors.forename: Christofer
authors.initials: C
authors.lastname: Toumazou
authors.affiliation: 1 Division of Diabetes, Endocrinology and Metabolism, Imperial College London , London, United Kingdom .
authors.forename: Desmond
authors.initials: D
authors.lastname: Johnston
authors.affiliation: 2 Department of Electrical and Electronic Engineering, Centre for Bio-Inspired Technology, Institute of Biomedical Engineering , Imperial College London, London, United Kingdom .
authors.forename: Pantelis
authors.initials: P
authors.lastname: Georgiou
authors.affiliation: 2 Department of Electrical and Electronic Engineering, Centre for Bio-Inspired Technology, Institute of Biomedical Engineering , Imperial College London, London, United Kingdom .
authors.forename: Pau
authors.initials: P
authors.lastname: Herrero
authors.affiliation: 1 Division of Diabetes, Endocrinology and Metabolism, Imperial College London , London, United Kingdom .
authors.forename: Nick
authors.initials: N
authors.lastname: Oliver
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000032:analysis*; D020000:Decision Support Systems, Clinical; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000188:drug therapy*; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D007328:Insulin / Q000008:administration & dosage* / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D019518:Postprandial Period; D011446:Prospective Studies; D012648:Self Care; D000068997:Smartphone
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D007328:Insulin