title: The DIAMIND study: postpartum SMS reminders to women who have had gestational diabetes mellitus to test for type 2 diabetes: a randomised controlled trial - study protocol.
abstract: BACKGROUND
  Postpartum follow up of women who have been found to have gestational diabetes during pregnancy is essential because of the strong association of gestational diabetes with subsequent type 2 diabetes. Postal reminders have been shown to increase significantly attendance for oral glucose tolerance testing postpartum. It is possible that a short message service (text) reminder system may also be effective. This trial aims to assess whether a text message reminder system for women who have experienced gestational diabetes in their index pregnancy will increase attendance for oral glucose tolerance testing within six months after birth.
  
  
  METHODS
  
  
  
  METHODS
  Single centre (Women's and Children's Hospital, South Australia), parallel group randomised controlled trial.
  
  
  METHODS
  Women diagnosed with gestational diabetes in their index pregnancy (oral glucose tolerance test with fasting glucose ≥ 5.5 mmol/L and/or two hour glucose ≥ 7.8 mmol/L), with access to a mobile phone, whose capillary blood glucose profile measurements prior to postnatal discharge are all normal (fasting glucose < 6.0 mmol/L, postprandial glucoses < 8.0 mmol/L).
  
  
  METHODS
  Pregestational diabetes mellitus, triplet/higher order multiple birth or stillbirth in the index pregnancy, requirement for interpreter.Trial entry and randomisation: Allocation to intervention will be undertaken using a telephone randomisation service (computer-generated random number sequence generation, with balanced variable blocks, and stratification by insulin requirement).Study groups: Women in the intervention group will receive a text reminder to attend for an oral glucose tolerance test at 6 weeks postpartum, with further reminders at 3 months and 6 months if they do not respond to indicate test completion. Women in the control group will receive a single text message reminder at 6 months postpartum.Blinding: Baseline data collection will be undertaken blinded. Blinding of participants and blinded collection of primary outcome data will not be possible for this study.Primary study outcome: Attendance for the oral glucose tolerance test within 6 months postpartum.
  
  
  METHODS
  276 subjects will be required to show an 18% absolute increase in the rate of attendance (α=0.05 two tailed, β=80%, 5% loss to follow up) from 37% to 55% in the intervention group.
  
  
  CONCLUSIONS
  Given the heightened risk of impaired glucose tolerance and type 2 diabetes in women who have had gestational diabetes, ensuring the highest possible rate of attendance for postpartum glucose tolerance testing, so that early diagnosis and intervention can occur, is important. A text message reminder system may prove to be an effective method for achieving improved attendance for such testing. This randomised controlled trial will assess whether such a system will increase rates of attendance for postpartum oral glucose tolerance testing in women who have experienced gestational diabetes.
  
  
  BACKGROUND
  Australian New Zealand Clinical Trials Registry - ACTRN12612000621819.
authors.affiliation: Australian Research Centre for Health of Women and Babies, Robinson Institute, The University of Adelaide, 72 King William Road North, Adelaide, SA 5006, Australia. emer.heatley@adelaide.edu.au
authors.forename: Emer
authors.initials: E
authors.lastname: Heatley
authors.forename: Philippa
authors.initials: P
authors.lastname: Middleton
authors.forename: William
authors.initials: W
authors.lastname: Hague
authors.forename: Caroline
authors.initials: C
authors.lastname: Crowther
mesh_terms: D001071:Appointments and Schedules; D001786:Blood Glucose / Q000032:analysis; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000209:etiology; D016640:Diabetes, Gestational / Q000097:blood; D005215:Fasting; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D010342:Patient Acceptance of Health Care; D049590:Postpartum Period; D011247:Pregnancy; D017010:Reminder Systems; D012107:Research Design; D060145:Text Messaging
chemical_list: D001786:Blood Glucose