Table 3.

GRADEpro level of quality evidence assessment

Educational intervention compared with usual care for patients with type 2 diabetes
Patient or population: patients with type 2 diabetes Setting: Intervention: educational interventions Comparison: usual care
Outcomes	Anticipated absolute effects* (95% CI)		Relative effect (95% CI)	Number of participants (studies)	Certainty of the evidence (GRADE)	Comments
	Risk with comparison	Risk with intervention
Glycaemic control (HbA1c) measured with difference in mean HbA1c level after intervention Scale from 1 month to 12 months	–	MD 0.83 lower (1.17 lower to 0.49 lower)	–	2474 (19 RCTs)	⨁⨁⨁◯ Moderatea, b	a. Majority of studies had high or unclear risks of bias for allocation concealment and blinding of participants or investigators. One out of two studies reported low-risk methods for blinding of outcome assessment. b. The certainty in the evidence was downgraded due to imprecision in the intervention, inconsistent with duration of intervention and intervention design.
Diabetes knowledge assessed with diabetes and medication knowledge Scale from 1 month to 12 months	–	SMD 1.16 SD higher (0.71 higher to 1.6 higher)	–	1309 (10 RCTs)	⨁⨁◯◯ Lowc, d	c. Bias was judged to be at ‘high risk’ in this trial. d. Heterogeneity was high in this trial.

GRADE Working Group grades of evidence: high certainty—we are very confident that the true effect lies close to that of the estimate of the effect. Moderate certainty—we are moderately confident in the effect estimate. The true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low certainty—our confidence in the effect estimate is limited. The true effect may be substantially different from the estimate of the effect. Very low certainty—we have very little confidence in the effect estimate. The true effect is likely to be substantially different from the estimate of effect.

*The risk in the intervention group (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).

GRADE, Grading of Recommendations Assessment, Development and Evaluation; HbA1c, glycosylated haemoglobin; MD, mean difference; RCTs, randomised controlled trials; SMD, standardised mean difference.