Comparative effectiveness and safety of methods of insulin delivery and glucose monitoring for diabetes mellitus: A systematic review and meta-analysis

Background: Patients with diabetes mellitus need information about the effectiveness of innovations in insulin delivery and glucose monitoring. Purpose: To review how intensive insulin therapy (multiple daily injections [MDI] vs. rapid-acting analogue-based continuous subcutaneous insulin infusion [CSII]) or method of monitoring (selfmonitoring of blood glucose [SMBG] vs. real-time continuous glucose monitoring [rt-CGM]) affects outcomes in types 1 and 2 diabetes mellitus. Data Sources: MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials through February 2012 without language restrictions. Study Selection: 33 randomized, controlled trials in children or adults that compared CSII with MDI (n = 19), rt-CGM with SMBG (n = 10), or sensor-augmented insulin pump use with MDI and SMBG (n = 4). Data Extraction: 2 reviewers independently evaluated studies for eligibility and quality and serially abstracted data. Data Synthesis: In randomized, controlled trials, MDI and CSII showed similar effects on hemoglobin A_1c (HbA_1c levels and severe hypoglycemia in children or adults with type 1 diabetes mellitus and adults with type 2 diabetes mellitus. In adults with type 1 diabetes mellitus, HbA_1c levels decreased more with CSII than with MDI, but 1 study heavily influenced these results. Compared with SMBG, rt-CGM achieved a lower HbA_1c level (between-group difference of change, -0.26% [95% CI, -0.33% to -0.19%]) without any difference in severe hypoglycemia. Sensor-augmented insulin pump use decreased HbA_1c levels more than MDI and SMBG did in persons with type 1 diabetes mellitus (between-group difference of change, -0.68% [CI, -0.81% to -0.54%]). Little evidence was available on other outcomes. Limitation: Many studies were small, of short duration, and limited to white persons with type 1 diabetes mellitus. Conclusion: Continuous subcutaneous insulin infusion and MDI have similar effects on glycemic control and hypoglycemia, except CSII has a favorable effect on glycemic control in adults with type 1 diabetes mellitus. For glycemic control, rt-CGM is superior to SMBG and sensor-augmented insulin pumps are superior to MDI and SMBG without increasing the risk for hypoglycemia.