Table 3.

Results of meta-analysis and Grading of Recommendations Assessment, Development and Evaluation assessments for hemoglobin A1c levels, systolic blood pressure, and diastolic blood pressure.

Outcomes	Trials included	Sample size	SMDa (95% CI)	P value	I 2	Egger test		Quality of evidence (GRADE)b
						t value	P value
HbA1cc levels	21	1671	−0.44 (−0.59 to −0.29)	<.001	50	1.15	.26	Lowd,e
SBPf	16	1433	−0.17 (−0.31 to −0.03)	.02	41	0.52	.61	Moderated
DBPg	14	1292	−0.17 (−0.30 to −0.03)	.02	25	0.09	.93	Moderated

^aSMD: standardized mean difference.

^bGRADE: Grading of Recommendations Assessment, Development and Evaluation.

^cHbA_1c: hemoglobin A_1c.

^dDowngraded by one level for indirectness (surrogate outcome).

^eDowngraded by one level for inconsistency (moderate heterogeneity level, I² = 50%).

^fSBP: systolic blood pressure.

^gDBP: diastolic blood pressure.