Optimizing type 1 diabetes after multiple daily injections and capillary blood monitoring: Pump or sensor first? A meta-analysis using pooled differences in outcome measures

Aims/hypothesis Most people living with type 1 diabetes self-manage using multiple dose injection insulin (MDI) regimens and self-monitoring of blood glucose (SMBG). Continuous subcutaneous insulin infusion (CSII) and continuous glucose monitoring (CGM) are adjuncts to education and support self-management optimisation. The aim of this systematic review and meta-analysis was to assess which first line technology is most effective. Methods Electronic databases (Medline, Embase and Web of Science) were systematically searched from 1999 to September 2020. Randomised controlled trials comparing either CSII with MDI or CGM with SMBG in adults with type 1 diabetes were included. Data were extracted in duplicate by two reviewers, and were analysed to assess individual and overall treatment effect measures. (PROSPERO registration: CRD42020149915). Results HbA1c was significantly reduced for CGM when compared with SMBG (Cohen's d -0.62 (95% CI -0.79 to -0.45)) and for CSII when compared with MDI (Cohen's d -0.44 (95% CI -0.67 to -0.22)). Rates of severe hypoglycaemia were significantly reduced with CGM compared with SMBG, but did not change for CSII when compared with MDI. Episodes of diabetic ketoacidosis were more likely to occur with CSII than MDI. Both CSII and CGM reduced glucose standard deviation, compared to MDI and SMBG respectively. Conclusions Both CGM and CSII remain impactful interventions compared to SMBG and MDI but, in adults with type 1 diabetes and in the contexts in which they have been studied, CGM might have a greater positive impact on glycaemic variability and severe hypoglycaemia than CSII, when added to MDI and SMBG. A head-to-head study, including patient reported outcomes, is required to explore these findings further. This article is protected by copyright. All rights reserved.