Grad­ing of Ev­i­dence and Rec­om­men­da­tion De­vel­op­ment

A grad­ing sys­tem (Table 1) de­vel­oped by the ADA and mod­eled af­ter ex­ist­ing meth­ods is used to clar­i­fy and cod­i­fy the ev­i­dence that forms the ba­sis for the rec­om­men­da­tions in the Stan­dards of Care. All of the rec­om­men­da­tions in the Stan­dards of Care are crit­i­cal to com­pre­hen­sive care re­gard­less of rating. ADA rec­om­men­da­tions are as­signed rat­ings of A, B, or C, de­pend­ing on the qual­i­ty of the ev­i­dence in sup­port of the rec­om­men­da­tion. Ex­pert opin­ion E is a sep­a­rate cat­e­go­ry for rec­om­men­da­tions in which there is no ev­i­dence from clin­i­cal tri­als, clin­i­cal tri­als may be im­prac­ti­cal, or there is conflict­ing ev­i­dence. Rec­om­men­da­tions as­signed an E lev­el of ev­i­dence are in­formed by key opin­ion lead­ers in the field of di­a­betes (mem­bers of the PPC) and cov­er im­por­tant el­e­ments of clin­i­cal care. All Stan­dards of Care rec­om­men­da­tions re­ceive a rat­ing for the strength of the ev­i­dence and not for the strength of the rec­om­men­da­tion. Rec­om­men­da­tions with A-​lev­el ev­i­dence are based on large, well-​de­signed ran­dom­ized con­trolled tri­als or well-​done meta­anal­y­ses of ran­dom­ized con­trolled tri­als. Gen­er­al­ly, these rec­om­men­da­tions have the best chance of im­prov­ing out­comes when ap­plied to the pop­u­la­tion for which they are ap­pro­pri­ate. Rec­om­men­da­tions with low­er lev­els of ev­i­dence may be equal­ly im­por­tant but are not as well sup­port­ed.

Of course, pub­lished ev­i­dence is only one com­po­nent of clin­i­cal de­ci­sion-​mak­ing. Clin­i­cians care for peo­ple, not pop­u­la­tions; guide­lines must al­ways be in­ter­pret­ed with the in­di­vid­u­al per­son in mind. In­di­vid­u­al cir­cum­stances, such as co­mor­bid and co­ex­ist­ing dis­eases, age, ed­u­ca­tion, dis­abil­i­ty, and, above all, the val­ues and pref­er­ences of the per­son with di­a­betes, must be con­sid­ered and may lead to dif­fer­ent treat­ment tar­gets and strate­gies. Fur­ther­more, con­ven­tion­al ev­i­dence hi­er­ar­chies, such as the one adapt­ed by the ADA, may miss nu­ances im­por­tant in di­a­betes care. For ex­am­ple, al­though there is ex­cel­lent ev­i­dence from clin­i­cal tri­als sup­port­ing the im­por­tance of achiev­ing mul­ti­ple risk fac­tor con­trol, the op­ti­mal way to achieve this re­sult is less clear. It is difficult to as­sess each com­po­nent of such a com­plex in­ter­ven­tion.

In prepa­ra­tion of the 2023 Stan­dards of Care, the ex­pert pan­el met for a 2-​day in-​per­son/​vir­tu­al meet­ing in Ar­ling­ton, Vir­ginia, in July 2022, to pre­sent the ev­i­dence sum­maries and to de­vel­op the rec­om­men­da­tions. All PPC mem­bers par­tic­i­pate an­nu­al­ly in up­dat­ing the Stan­dards of Care and ap­prove the rec­om­men­da­tions there­in.