TABLE 1.
Comparison of Patients Diagnosed With Aneurysm on Initial Imaging and Those With Delayed Aneurysm Diagnosis, n = 444
| Aneurysm identified on initial imaging | Delayed diagnosis of aneurysm | P value | |
|---|---|---|---|
| Number of patients | 431 | 13 | – |
| Age, mean (SD) | 54.8 ± 13.4 | 53.9 ± 16.2 | .8* |
| Female sex | 307 (71%) | 8 (62%) | .5‡ |
| Modified Fisher | >.9‡ | ||
| 1 | 36 (8%) | 1 (8%) | |
| 2 | 25 (6%) | 1 (8%) | |
| 3 | 114 (26%) | 4 (31%) | |
| 4 | 256 (59%) | 7 (54%) | |
| Hijdra score, median (IQR) | |||
| SAH | 21.5 (13.5-25.5) | 14.0 (12.5-27.5) | .4** |
| IVH | 2.0 (0.5-2.5) | 2.0 (0.0-3.5) | .7** |
| Total | 24.0 (15.0-28.0) | 19.0 (12.5-29.5) | .4** |
| Perimesencephalic SAH pattern on CT | 7 (2%) | 0 (0%) | .6‡ |
| ICH | 89 (21%) | 2 (15%) | .6‡ |
| WFNS ≥ 3 | 173 (40%) | 7 (54%) | .3‡ |
| CSF diversion on admission | 310 (72%) | 8 (62%) | .4‡ |
| Current or former tobacco user | 229 (58%) | 5 (38%) | .3‡ |
Patients in either group were compared and found to have no clinical factors that were statistically significantly different (P > .05) between patients with aneurysms diagnosed on initial imaging work-up and those diagnosed on a second angiogram. As such, these patient groups were combined for subsequent analysis and model derivation. Variables are shown as either number and percentage or average +/– standard deviation. Statistical comparisons are via Student's t-test (**) or chi-squared test (‡) as appropriate.