Standards of Medical Care in Diabetes—2013

AClear evidence from well-conducted, generalizable RCTs that are adequately powered, including: c Evidence from a well-conducted multicenter trial c Evidence from a meta-analysis that incorporated quality ratings in the analysis Compelling nonexperimental evidence, i.e., "all or none" rule developed by the Centre for Evidence-Based Medicine at the University of Oxford Supportive evidence from well-conducted RCTs that are adequately powered, including:c Evidence from a well-conducted trial at one or more institutions c Evidence from a meta-analysis that incorporated quality ratings in the analysis B Supportive evidence from well-conducted cohort studies c Evidence from a well-conducted prospective cohort study or registry c 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 c Evidence from randomized clinical trials with one or more major or three or more minor methodological flaws that could invalidate the results c Evidence from observational studies with high potential for bias (such as case series with comparison with historical controls) c Evidence from case series or case reports Conflicting evidence with the weight of evidence supporting the recommendation E Expert consensus or clinical experience S12