| 0. No symptoms |
| 1. No significant disability. Able to carry out all usual activities, despite some symptoms. |
| 2. Slight disability. Able to look after own affairs without assistance,but unable to carry out all previous activities. |
| 3. Moderate disability. Requires some help, but able to walk unassisted. |
| 4. Moderately severe disability. Unable to attend to own bodily needs without assistance, and unable to walk unassisted. |
| 5. Severe disability. Requires constant nursing care and attention, bedridden, incontinent. |
| 6. Dead. |
