|  |  | Cases | Controls | ||
---|---|---|---|---|---|---|
 |  |  | n | % | n | % |
Grading: | 0 | No sub-optimal factors have been identified | 12 | 43 | 18 | 31 |
 | 1 | Sub-optimal factor(s) have been identified, but are unlikely to be related to the occurrence of stroke in this patient | 8 | 29 | 18 | 31 |
 | 2 | Sub-optimal factor(s) have been identified, and possibly have failed to prevent the stroke in this patient | 4 | 14 | 18 | 31 |
 | 3 | Sub-optimal factor(s) have been identified, and are likely to have failed to prevent the stroke in this patient | 4 | 14 | 4 | 7 |
Sub-optimal care | Â | Grading 1, 2, 3 | 16 | 57 | 40 | 69 |
Total | Â | Grading 0, 1, 2, 3 | 28 | 100 | 58 | 100 |