| Grade | Description |
| 0 | Fully active; able to carry on all predisease activities without restrictions |
| 1 | Restricted in physically strenuous activity, but ambulatory and able to carry out light tasks such as light work in home or office |
| 2 | Requires occasional to considerable care for most needs and frequent medical care |
| 3 | Capable only of limited self-care and confined to bed or chair at least half of waking hours |
| 4 | Almost totally impaired; cannot care for self and totally confined to bed or chair |
