Table 2.

Evidence-grading system [2,34,35].

Level of Evidence	Description
A	Clear evidence from well-conducted, generalizable, randomized controlled trials that are adequately powered, including: evidence from a well-conducted multicenter trial; evidence from a meta-analysis that incorporated quality ratings in the analysis. Supportive evidence from well-conducted, randomized, controlled trials that are adequately powered, including: evidence from a well-conducted trial at one or more institutions; evidence from a meta-analysis that incorporated quality ratings in the analysis. Strong recommendations from key national or international guidelines, including RSSDI, ADA, IDF, and AACE guidelines, supported by level A evidence.
B	Supportive evidence from well-conducted cohort studies: evidence from a well-conducted prospective cohort study or registry; evidence from a well-conducted meta-analysis of cohort studies. Supportive evidence from a well-conducted case-control study.
C	Supportive evidence from poorly controlled or uncontrolled studies: evidence from randomized clinical trials with one or more major or three or more minor methodological flaws that could invalidate the results; evidence from observational studies with high potential for bias (such as case series with comparison with historical controls); evidence from case series or case reports. Conflicting evidence with the weight of evidence supporting the recommendation.
E	Expert consensus or clinical experience.

AACE: American Association of Clinical Endocrinologists; ADA: American Diabetes Association; IDF: International Diabetes Federation; RSSDI: Research Society for the Study of Diabetes in India.