Sodium-glucose co-transporter 2 inhibitors improve insulin resistance and β-cell function in type 2 diabetes: A meta-analysis

Table 4 Summarized certainty of evidence using the Grading of Recommendations, Assessment, Development and Evaluation system

Outcome	Quality assessment							Absolute effect MD (95%CI)	Quality
	Number of studies	Design	Risk of bias	Inconsistency	Indirectness	Imprecision	Other considerations
MD for HOMA-IR	17	RCTs	No serious risk of bias	Significant heterogeneity observed	No serious indirectness	No serious imprecision	None	-0.81 (-1.11 to -0.52)	Moderate
MD for HOMA-β	15	RCTs	No serious risk of bias	Significant heterogeneity observed	No serious indirectness	No serious imprecision	None	7.90 (5.44 to 10.37)	Moderate

Specific reasons for each Grading of Recommendations, Assessment, Development and Evaluation domain, including: Risk of bias: Downgraded if a significant proportion of studies had unclear or high risk of bias in key domains (e.g., random sequence generation, allocation concealment, or selective reporting); Inconsistency: Downgraded if substantial heterogeneity was observed (I² > 50%) and could not be explained by subgroup analyses or meta-regression; Indirectness: Evaluated but not downgraded, as all included studies directly assessed the population and outcomes of interest; Imprecision: Downgraded if confidence intervals were wide, overlapping no effect, or if the overall sample size was small; Publication bias: Assessed using funnel plots and Egger’s test, downgraded if significant asymmetry suggested potential bias. RCTs: Randomized controlled trials; MD: Mean difference; CI: Confidence interval; HOMA-IR: Homeostasis model assessment of insulin resistance; HOMA-β: Homeostasis model assessment of beta-cell function.