Table 3.
Concordance between criteria in the diagnosis of gestational diabetes mellitus (GDM)
| A – Case-control study: 1999 WHO versus 2015 NICE | |||||
| 1999 WHO∗ | 2015 NICE∗ | Discordant? | n(%) | Median HbA1c, mmol/mol | Proportion with HbA1c≥42 mmol/mol |
| Normal | Normal | No | 233 (44.6) | 30 | 1.7% |
| Normal | GDM | Yes | 42 (8.1) | 36 | 16.7% |
| GDM | Normal | Yes | 0 | - | - |
| GDM | GDM | No | 247 (47.3) | 37 | 22.1% |
| B – Case-control study: 1999 WHO versus 2013 WHO | |||||
| 1999 WHO∗ | 2013 WHO∗ | Discordant? | n(%) | Median HbA1c, mmol/mol | Proportion with HbA1c≥42 mmol/mol |
| Normal | Normal | No | 213 (40.7) | 31 | 1.4% |
| Normal | GDM | Yes | 62 (11.9) | 36 | 12.9% |
| GDM | Normal | Yes | 50 (9.5) | 34 | 8.2% |
| GDM | GDM | No | 198 (37.9) | 38 | 26.2% |
| C – Case-control study: 2015 NICE versus 2013 WHO | |||||
| 2015 NICE∗ | 2013 WHO∗ | Discordant? | n(%) | Median HbA1c, mmol/mol | Proportion with HbA1c≥42 mmol/mol |
| Normal | Normal | No | 213 (40.8) | 30 | 1.4% |
| Normal | GDM | Yes | 20 (3.8) | 33 | 5.0% |
| GDM | Normal | Yes | 50 (9.6) | 36 | 8.2% |
| GDM | GDM | No | 239 (45.8) | 37 | 24.1% |
| D – Cohort study: 1999 WHO versus 2015 NICE | |||||
| 1999 WHO∗ | 2015 NICE∗ | Discordant? | n(%) | Median HbA1c, mmol/mol | Proportion with HbA1c≥42 mmol/mol |
| Normal | Normal | No | 6138 (88.6) | 34 | 2.5% |
| Normal | GDM | Yes | 119 (1.7) | 37 | 17.7% |
| GDM | Normal | Yes | 0 | - | - |
| GDM | GDM | No | 673 (9.7) | 38 | 22.6% |
| E – Cohort study: 1999 WHO versus 2013 WHO | |||||
| 1999 WHO∗ | 2013 WHO∗ | Discordant? | n(%) | Median HbA1c, mmol/mol | Proportion with HbA1c≥42 mmol/mol |
| Normal | Normal | No | 5,780 (83.4) | 33 | 2.0% |
| Normal | GDM | Yes | 477 (6.9) | 37 | 13.2% |
| GDM | Normal | Yes | 203 (2.9) | 35 | 7.4% |
| GDM | GDM | No | 470 (6.8) | 38 | 29.2% |
| F – Cohort study: 2015 NICE versus 2013 WHO | |||||
| 2015 NICE∗ | 2013 WHO∗ | Discordant? | n(%) | Median HbA1c, mmol/mol | Proportion with HbA1c≥42 mmol/mol |
| Normal | Normal | No | 5,780 (83.4) | 34 | 2.0% |
| Normal | GDM | Yes | 358 (5.2) | 37 | 11.7% |
| GDM | Normal | Yes | 203 (2.9) | 35 | 7.4% |
| GDM | GDM | No | 589 (8.5) | 39 | 26.8% |
*Normal is defined as subgroup 1, while GDM is defined as subgroups 2–4 using the categorisation defined in the methods
HbA1c = glycated haemoglobin; NICE = National Institute for Health and Care Excellence; WHO = World Health Organization