| Name of study |
None |
| Inclusion criteria |
Individuals undergoing health checkups at a single medical institution (Gangneung Asian Hospital) |
| Exclusion criteria |
Previously diagnosed with diabetes, history of diabetes medication use, only 1 measurement |
| Notes |
Baseline data for the total cohort (N = 3497) |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Study participation: description of source population or population of interest |
Low risk |
Yes |
| Study participation: description of glycaemic status at baseline |
Low risk |
Yes |
| Study participation: adequate description of sampling frame & recruitment |
Low risk |
Yes |
| Study participation: adequate description of period & recruitment place |
Low risk |
Yes |
| Study participation: adequate description of inclusion & exclusion criteria |
Low risk |
Inclusion and exclusion criteria described |
| Study attrition: description of attempts to collect information on participants who dropped out |
Unclear risk |
Not reported |
| Study attrition: reasons for loss to follow‐up provided |
Unclear risk |
Not reported |
| Study attrition: adequate description of participants lost to follow‐up |
Unclear risk |
Not reported |
| Study attrition: no important differences between participants who completed the study and those who did not |
Unclear risk |
Not reported |
| Glycaemic status measurement: provision of clear definition or description of glycaemic status |
Low risk |
Yes |
| Glycaemic status measurement: valid and reliable method of glycaemic status measurement |
Low risk |
Yes |
| Glycaemic status measurement: continuous variables reported or appropriate cut points used |
Low risk |
HbA1c 5.7–6.4 |
| Glycaemic status measurement: same method and setting of measurement of the glycaemic status for all study participants |
Low risk |
Yes |
| Outcome measurement: clear definition of the outcome provided |
Low risk |
HbA1c ≥ 6.5 |
| Outcome measurement: method of outcome measurement used valid & reliable |
Low risk |
Yes |
| Outcome measurement: same method & setting of outcome measurement for all study participants |
Low risk |
Yes |
| Study confounding: important confounders measured |
Unclear risk |
Measurement of cumulative incidence |
| Study confounding: clear definitions of important confounders provided |
Low risk |
Yes for coffee consumption |
| Study confounding: measurement of confounders valid & reliable |
Low risk |
Yes |
| Study confounding: same method & setting for measurements of confounders for all study participants |
Low risk |
Yes |
| Study confounding: appropriate methods used if missing confounder data imputed |
Unclear risk |
Not reported |
| Study confounding: important potential confounders accounted for in study design |
Unclear risk |
1 covariate |
| Study confounding: important potential confounders accounted for in the analysis |
Unclear risk |
No ratios reported |
| Statistical analysis & reporting: sufficient presentation of data to assess adequacy of the analytic strategy |
Unclear risk |
Cumulative incidence |
| Statistical analysis & reporting: the statistical model is adequate for the design of the study |
Low risk |
Kaplan‐Meier survival analysis for progression to diabetes according to coffee consumption |
