Figure 2

Heart Failure Relative Risk (Random Effects) in Blood Glucose-Lowering Medications Users and RTI Item Bank Quality Assessment. IV = inverse variance. Note: For rosiglitazone versus metformin, the study by Tzoulaki et al. [42] contributed with the relative risk reported for combination therapy and for Loebstein et al. [40], we included the fixed-effect summary relative risk for monotherapy and combination therapy (see study reported estimates by subgroup in the Additional file 1). For sulfonylureas versus metformin, the study by Tzoulaki et al. [42] contributed with the reported estimate for the second-generation sulfonylureas.