Annual and 5-year incidence rates of poor outcome in the different groups
| Group | n/N | Annual IR (95% CI) | Cumulative IR (95% CI) |
| 5 years | |||
| Low risk* | 1/92 | 0.215 (0.030 to 1.527) | 1.875 (0.264 to 13.310) |
| Intermediate risk* | 14/152 | 1.817 (1.076 to 3.067) | 10.744 (4.630 to 27.573) |
| High risk* | 3/7 | 9.883 (3.187 to 30.643) | 75.302 (10.607 to 534.573) |
| Overall | 18/251 | 1.422 (0.896 to 2.257) | 8.431 (3.352 to 24.405) |
*The patients were stratified into three groups according to the presence of two risk factors (NPAN-SAH and GCS 3–12): the low-risk group is without any of the two risk factors, intermediate-risk group only has one risk factor, and high-risk group has >1 risk factor.
GCS, Glasgow Coma Score; IR, incidence rate; N, total number in the corresponding group; n, number of events; NPAN-SAH, non-perimesencephalic angiogram-negative subarachnoid haemorrhage.