Table 1a. Frequency of DR grades (eyes).
| Clinical | Combined | Imaging | Screening | |
|---|---|---|---|---|
| Valid data | ||||
| No DR | 274 | 198 | 229 | 71 |
| Mild NPDR | 1074 | 966 | 818 | 1004 |
| Moderate–severe NPDR | 504 | 664 | 791 | 358 |
| Proliferative DR | 147 | 152 | 179 | 147 |
| Total | 1999 | 1980 | 2017 | 1580 |
| Missing | ||||
| Technical | 41 | 58 | 6 | 465 |
| Ungradable | 6 | 8 | 23 | 1 |
| Total | 47 | 66 | 29 | 466 |
| Total | 2046 | 2046 | 2046 | 2046 |
Abbreviations: screening, grade from National Screening Programme; clinical= slit lamp biomicroscopy; imaging, independent wide-field Optomap+OCT; combined, combination of slit lamp with Optomap+OCT; DR, diabetic retinopathy; NPDR, non-proliferative diabetic retinopathy.