| Name of study |
Baltimore Longitudinal Study of Aging (BLSA) |
| Inclusion criteria |
Community dwelling volunteers, largely from the Baltimore (MD) and Washington, D.C. areas; primarily white middle‐ and upper‐middle socioeconomic class aged 21–96 years, being examined approximately every 2 years; open cohort design with dropouts replaced (around 1000 persons at each study cycle); attending at least 3 examinations and an OGTT within an 8‐year period |
| Exclusion criteria |
2 or fewer OGTTs or > 4 years elapsed between any 2 OGTTs |
| Notes |
Baseline data for the IFG‐IGT cohort (N = 265); follow‐up time: at least 6 years 77%, at least 10 years 44%, at least 16 years 16%, at least 20 years 4.5% |
| 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 |
High risk |
Scarce data |
| Study attrition: reasons for loss to follow‐up provided |
Unclear risk |
Scarce data |
| Study attrition: adequate description of participants lost to follow‐up |
Unclear risk |
Scarce data |
| 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 |
IFG: FPG 6.1–6.9 and 2‐h PG ≤ 7.8; IGT: FPG < 6.1 and 2‐h PG 7.8–11.0; IFG/IGT |
| 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 |
FPG ≥ 7.0; 2‐h PG ≥ 11.1 (IFG‐IGT: diabetes defined by OGTT) |
| 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 |
Cumulative incidence, incidence rates |
| Study confounding: clear definitions of important confounders provided |
Unclear risk |
Cumulative incidence, incidence rates |
| Study confounding: measurement of confounders valid & reliable |
Unclear risk |
Cumulative incidence, incidence rates |
| Study confounding: same method & setting for measurements of confounders for all study participants |
Unclear risk |
Cumulative incidence, incidence rates |
| Study confounding: appropriate methods used if missing confounder data imputed |
Unclear risk |
Cumulative incidence, incidence rates |
| Study confounding: important potential confounders accounted for in study design |
Unclear risk |
Cumulative incidence, incidence rates |
| Study confounding: important potential confounders accounted for in the analysis |
Unclear risk |
Cumulative incidence, incidence rates |
| Statistical analysis & reporting: sufficient presentation of data to assess adequacy of the analytic strategy |
Low risk |
Cumulative incidence, incidence rate |
| Statistical analysis & reporting: the statistical model is adequate for the design of the study |
Low risk |
Kaplan‐Meier product limit estimates |
