GP-OSMOTIC trial protocol : an individually randomised controlled trial to determine the effect of retrospective continuous glucose monitoring (r-CGM) on HbA1c in adults with type 2 diabetes in general practice

• Main Authors: Furler, John, O’Neal, David Norman, Speight, Jane, Blackberry, Irene, Manski-Nankervis, Jo-Anne, Thuraisingam, Sharmala, de La Rue, Katie, Ginnivan, Louise, Browne, Jessica Lea, Holmes-Truscott, Elizabeth, Khunti, Kamlesh, Dalziel, Kim, Chiang, Jason, Audehm, Ralph, Kennedy, Mark, Clark, Malcolm, Jenkins, Alicia Josephine, Liew, Danny, Clarke, Philip, Best, James
• Other Authors: Lee Kong Chian School of Medicine (LKCMedicine)
• Format: Article
• Language: English
• Published: 2018
• Subjects: Clinical Trials; DRNTU::Science::Medicine; Primary Care
• Online Access: https://hdl.handle.net/10356/88150; http://hdl.handle.net/10220/45644
• Institution: Nanyang Technological University

Introduction: Optimal glycaemia can reduce type 2 diabetes (T2D) complications. Observing retrospective continuous glucose monitoring (r-CGM) patterns may prompt therapeutic changes but evidence for r-CGM use in T2D is limited. We describe the protocol for a randomised controlled trial (RCT) examining intermittent r-CGM use (up to 14 days every three months) in T2D in general practice (GP). Methods and analysis: General Practice Optimising Structured MOnitoring To achieve Improved Clinical Outcomes is a two-arm RCT asking ‘does intermittent r-CGM in adults with T2D in primary care improve HbA1c?’ Primary outcome: Absolute difference in mean HbA1c at 12 months follow-up between intervention and control arms. Secondary outcomes: (a) r-CGM per cent time in target (4–10 mmol/L) range, at baseline and 12 months; (b) diabetes-specific distress (Problem Areas in Diabetes). Eligibility: Aged 18–80 years, T2D for ≥1 year, a (past month) HbA1c>5.5 mmol/mol (0.5%) above their individualised target while prescribed at least two non-insulin hypoglycaemic therapies and/or insulin (therapy stable for the last four months). Our general glycaemic target is 53 mmol/mol (7%) (patients with a history of severe hypoglycaemia or a recorded diagnosis of hypoglycaemia unawareness will have a target of 64 mmol/mol (8%)). Our trial compares r-CGM use and usual care. The r-CGM report summarising daily glucose patterns will be reviewed by GP and patient and inform treatment decisions. Participants in both arms are provided with 1 hour education by a specialist diabetes nurse. The sample (n=150/arm) has 80% power to detect a mean HbA1c difference of 5.5 mmol/mol (0.5%) with an SD of 14.2 (1.3%) and alpha of 0.05 (allowing for 10% clinic and 20% patient attrition).