Table 6.
Ratio of diagnostic interval to the combined biological and analytical variation for World Health Organisation (WHO) and American Diabetes Association (ADA) diagnostic criteria.
| Diagnostic criteria | Diagnostic thresholds | Diagnostic interval (%) | Combined variation | Ratio of diagnostic interval to combined variation | |
|---|---|---|---|---|---|
| WHO | FPG | 6.1–6.9 | 13.1 | 6.2 | 2.1 |
| OGTT | 7.8–11 | 41.0 | 16.9 | 2.4 | |
| HbA1c | 6–6.4 | 6.7 | 3.9 | 1.7 | |
| ADA | FPG | 5.6–6.9 | 23.2 | 6.2 | 3.7 |
| OGTT | 7.8–11 | 29.1 | 16.9 | 1.7 | |
| HbA1c | 5.7–6.4 | 12.3 | 3.9 | 3.1 | |
FPG = fasting plasma glucose, OGTT = oral glucose tolerance test, HbA1c = glycated haemoglobin A1c. Diagnostic interval is calculated by [(upper threshold − lower threshold)/lower threshold], e.g. for FPG = [(6.9–6.1)/6.1 × 100].