Carls GS et al. – This retrospective, mixed–methods quasi–experimental study estimated and explained the gap between clinical efficacy in randomized controlled trials (RCTs) and real–world (RW) effectiveness of glucagon–like peptide–1 receptor agonist (GLP–1RA) and dipeptidyl peptidase–4 inhibitor (DPP4) therapies in patients with type 2 diabetes. Poor medication adherence in RW patients significantly reduced the effectiveness when compared with RCT efficacy. This signals an urgent need to effectively address adherence among patients with type 2 diabetes.

Methods

• Twelve months after starting a glucagon–like peptide–1 receptor agonist (GLP–1RA; n = 221) or dipeptidyl peptidase–4 inhibitor (DPP4; n = 652), the change in HbA1c of RW patients with type 2 diabetes was compared with published findings of these drugs from randomized controlled trials (RCTs).
• Regression analysis used in the RW data, adjusted the differences between adherent and poorly adherent patients.

Results

• Smaller reductions in HbA1c (GLP–1RA: -0.52%, DPP4: -0.51%) were noted when compared with RCTs (GLP–1RA: -1.30%; DPP4: -0.68%).
• Significant explanatory factors in the RW HbA1c change include baseline HbA1c, additional medications, and adherence.
• Poor medication adherence accounted for approximately three–fourths of the gap between RW and expected RCT results (gap = 0.51% with GLP1–RA; 0.18% with DPP4).