Prevalence of normoglycemic, prediabetic and diabetic A1c levels

Table 1 Definitions of current study variables within different groups

Different groups	Responses and A1c levels
Prediabetes group
Self-reported Prediabetes	“Yes” response to “ever told you have prediabetes,” and a “no” response to “doctor told you have diabetes.”
Reversed prediabetes	Self-reported “yes” response to “ever told you have prediabetes,”“no” response to “doctor told you have diabetes” and have normoglycemic A1c levels (< 5.7%).
Diagnosed prediabetes	Self-reported “yes” response to “ever told you have prediabetes,”“no” response to “doctor told you have diabetes” and have prediabetic A1c levels (5.7%-6.4%).
Undiagnosed diabetes	Self-reported “yes” response to “ever told you have prediabetes,”“no” response to “doctor told you have diabetes” and have diabetic A1c levels (≥ 6.5%).
Non-Prediabetes group
Self-reported non-prediabetes	“No” response to “ever told you have prediabetes,” and a “no” response to “doctor told you have diabetes.”
Not having prediabetes	Self-reported “no” response to “ever told you have prediabetes,”“no” response to “doctor told you have diabetes” and have normoglycemic A1c levels (< 5.7%).
Undiagnosed prediabetes	Self-reported “no” response to “ever told you have prediabetes,”“no” response to “doctor told you have diabetes” and have prediabetic A1c levels (5.7%-6.4%).
Undiagnosed diabetes	Self-reported “no” response to “ever told you have prediabetes,”“no” response to “doctor told you have diabetes” and have diabetic A1c levels (≥ 6.5%).