Comparative effectiveness of sodium-glucose co-transporter 2 inhibitors for controlling hyperglycaemia in patients with type 2 diabetes: protocol for a systematic review and network meta-analysis

INTRODUCTION: As a new class of glucose-lowering drugs, sodium-glucose co-transporter 2 (SGLT2) inhibitors are effective for controlling hyperglycaemia, however, the relative effectiveness and safety of 6 recently available SGLT2 inhibitors have rarely been studied. Therefore, we aim to perform pairwise comparisons of the 6 SGLT2 inhibitors. METHODS AND ANALYSIS: A systematic review and network meta-analysis will be conducted. Clinical studies that examine effectiveness and safety of either canagliflozin, dapagliflozin, empagliflozin, ipragliflozin, tofogliflozin or luseogliflozin will be included. These studies will be systematically retrieved in MEDLINE, EMBASE and the Cochrane Library, from inception to November 2015. Two reviewers will independently screen for eligible studies and then extract data from the studies as well as assess risk of bias. Discrepancies in screening and data extraction will be arbitrated by a third reviewer. A traditional meta-analysis will be performed to combine the effect sizes calculated from head-to-head comparisons with a random effect model. The effect sizes computed from indirect comparisons will be further combined in a network meta-analysis. Heterogeneity will be tested with the Cochrane's Q statistic, and publication bias will be assessed using a funnel plot and the Egger's test. ETHICS AND DISSEMINATION: Relative effectiveness and harms of the 6 SGLT2 inhibitors will be demonstrated through this systematic review and network meta-analysis. The result of the review will be disseminated through a peer-review journal and conference presentations. Patients, clinicians and policymakers will benefit from this review in selecting a SGLT2 inhibitor for glucose control in patients with type 2 diabetes. TRIAL REGISTRATION NUMBER: PROSPERO CRD42015025981.