AVM analysis
2024-10-04
Results
Following the table with patients characteristics at admission and AVM surgery
| Characteristic | Overall N = 64 |
1-2 N = 38 |
3 N = 17 |
4-5 N = 9 |
p-value |
|---|---|---|---|---|---|
| Sex (male) | 36 (56%) | 21 (55%) | 9 (53%) | 6 (67%) | 0.876 |
| Age at AVM diagnosis (years) | 39.64 ± 19.09 | 42.68 ± 20.86 | 37.47 ± 16.93 | 30.89 ± 11.96 | 0.264 |
| Clinical Presentation | 0.124 | ||||
| Hemorrhage | 37 (58%) | 26 (68%) | 7 (41%) | 4 (44%) | |
| Unruptured | 27 (42%) | 12 (32%) | 10 (59%) | 5 (56%) | |
| Glasgow Coma Scale on Admission | 0.450 | ||||
| 3-8 | 12 (19%) | 8 (21%) | 4 (24%) | 0 (0%) | |
| 9-13 | 4 (6.3%) | 2 (5.3%) | 2 (12%) | 0 (0%) | |
| 14-15 | 47 (75%) | 28 (74%) | 11 (65%) | 8 (100%) | |
| Modified Rankin Scale on Admission | 0.426 | ||||
| 0-1 | 40 (63%) | 22 (59%) | 11 (65%) | 7 (78%) | |
| 2-3 | 6 (9.5%) | 5 (14%) | 0 (0%) | 1 (11%) | |
| 4-6 | 17 (27%) | 10 (27%) | 6 (35%) | 1 (11%) | |
| Previous Treatments | 0.027 | ||||
| None | 21 (33%) | 17 (45%) | 4 (24%) | 0 (0%) | |
| Embolization | 40 (63%) | 19 (50%) | 13 (76%) | 8 (89%) | |
| Other | 3 (4.7%) | 2 (5.3%) | 0 (0%) | 1 (11%) | |
| Time from Diagnosis to Surgery | <0.001 | ||||
| 0-1 year | 31 (60%) | 26 (84%) | 3 (25%) | 2 (22%) | |
| > 1 year | 21 (40%) | 5 (16%) | 9 (75%) | 7 (78%) | |
| Age at Surgery (years) | 41.13 ± 18.38 | 43.45 ± 20.37 | 39.88 ± 16.47 | 33.67 ± 10.31 | 0.368 |
| AVM Site | 0.907 | ||||
| Cerebellar | 8 (13%) | 6 (16%) | 1 (5.9%) | 1 (11%) | |
| Frontal | 27 (42%) | 17 (45%) | 7 (41%) | 3 (33%) | |
| Parietal | 9 (14%) | 6 (16%) | 2 (12%) | 1 (11%) | |
| Temporal | 15 (23%) | 7 (18%) | 5 (29%) | 3 (33%) | |
| Other | 5 (7.8%) | 2 (5.3%) | 2 (12%) | 1 (11%) | |
| AVM Side | 0.707 | ||||
| left | 41 (64%) | 23 (61%) | 11 (65%) | 7 (78%) | |
| right | 23 (36%) | 15 (39%) | 6 (35%) | 2 (22%) | |
| AVM Localization | 0.759 | ||||
| infratentorial | 8 (13%) | 6 (16%) | 1 (5.9%) | 1 (11%) | |
| supratentorial | 56 (88%) | 32 (84%) | 16 (94%) | 8 (89%) | |
| Presence of Perforating Arterial Branches | 9 (14%) | 6 (16%) | 2 (13%) | 1 (11%) | >0.999 |
| Presence of Aneurysm | 14 (22%) | 9 (24%) | 2 (12%) | 3 (33%) | 0.421 |
| Aneurysm Location | 0.811 | ||||
| pre-nidus | 3 (21%) | 3 (33%) | 0 (0%) | 0 (0%) | |
| pre-intra-nidus | 1 (7.1%) | 1 (11%) | 0 (0%) | 0 (0%) | |
| intra-nidus | 10 (71%) | 5 (56%) | 2 (100%) | 3 (100%) | |
| AVM Morphology | 0.117 | ||||
| compact | 42 (67%) | 23 (61%) | 14 (88%) | 5 (56%) | |
| diffuse | 21 (33%) | 15 (39%) | 2 (13%) | 4 (44%) | |
| AVM volume (cm³) | 6.08 (0.90-11.60) | 1.30 (0.50-6.08) | 9.84 (7.44-11.86) | 28.00 (11.60-43.70) | <0.001 |
| Spetzler-Martin Size score | <0.001 | ||||
| 1 | 33 (52%) | 30 (79%) | 3 (18%) | 0 (0%) | |
| 2 | 26 (41%) | 8 (21%) | 13 (76%) | 5 (56%) | |
| 3 | 5 (7.8%) | 0 (0%) | 1 (5.9%) | 4 (44%) | |
| Spetzler-Martin Drainage score | <0.001 | ||||
| 0 | 45 (70%) | 32 (84%) | 12 (71%) | 1 (11%) | |
| 1 | 19 (30%) | 6 (16%) | 5 (29%) | 8 (89%) | |
| Spetzler-Martin Eloquence score | <0.001 | ||||
| 0 | 33 (52%) | 27 (71%) | 3 (18%) | 3 (33%) | |
| 1 | 31 (48%) | 11 (29%) | 14 (82%) | 6 (67%) | |
| Lawton-Young Grade | 0.805 | ||||
| 1 | 3 (4.7%) | 1 (2.6%) | 2 (12%) | 0 (0%) | |
| 2 | 10 (16%) | 7 (18%) | 2 (12%) | 1 (11%) | |
| 3 | 33 (52%) | 18 (47%) | 9 (53%) | 6 (67%) | |
| 4 | 18 (28%) | 12 (32%) | 4 (24%) | 2 (22%) | |
| Lawton-Young Age score | 0.189 | ||||
| 1 | 12 (19%) | 7 (18%) | 4 (24%) | 1 (11%) | |
| 2 | 20 (31%) | 9 (24%) | 5 (29%) | 6 (67%) | |
| 3 | 32 (50%) | 22 (58%) | 8 (47%) | 2 (22%) | |
| Lawton-Young Bleeding score | 0.036 | ||||
| 0 | 39 (61%) | 28 (74%) | 8 (47%) | 3 (33%) | |
| 1 | 25 (39%) | 10 (26%) | 9 (53%) | 6 (67%) | |
| Lawton-Young Compactness score | 0.102 | ||||
| 0 | 43 (67%) | 23 (61%) | 15 (88%) | 5 (56%) | |
| 1 | 21 (33%) | 15 (39%) | 2 (12%) | 4 (44%) | |
| Supplemented grade | <0.001 | ||||
| 2-5 | 35 (55%) | 31 (82%) | 4 (24%) | 0 (0%) | |
| 6 | 17 (27%) | 7 (18%) | 9 (53%) | 1 (11%) | |
| 7-8 | 12 (19%) | 0 (0%) | 4 (24%) | 8 (89%) | |
| Emergency Surgery | 0.083 | ||||
| 0 | 45 (70%) | 24 (63%) | 12 (71%) | 9 (100%) | |
| 1 | 19 (30%) | 14 (37%) | 5 (29%) | 0 (0%) | |
| AVM closure | 58 (97%) | 34 (94%) | 15 (100%) | 9 (100%) | >0.999 |
| Post-surgery complications | 26 (41%) | 8 (21%) | 10 (63%) | 8 (89%) | <0.001 |
| Post-surgery deficit | <0.001 | ||||
| none | 35 (56%) | 29 (78%) | 5 (31%) | 1 (11%) | |
| minor | 12 (19%) | 4 (11%) | 5 (31%) | 3 (33%) | |
| major | 15 (24%) | 4 (11%) | 6 (38%) | 5 (56%) | |
| Modified Rankin Scale at Discharge | 0.860 | ||||
| 0-1 | 42 (67%) | 25 (66%) | 10 (63%) | 7 (78%) | |
| 2-3 | 6 (9.5%) | 4 (11%) | 1 (6.3%) | 1 (11%) | |
| 4-6 | 15 (24%) | 9 (24%) | 5 (31%) | 1 (11%) | |
| Modified Rankin Scale at Follw-up | 0.576 | ||||
| 0-1 | 49 (88%) | 30 (86%) | 11 (85%) | 8 (100%) | |
| 2-3 | 3 (5.4%) | 3 (8.6%) | 0 (0%) | 0 (0%) | |
| 4-6 | 4 (7.1%) | 2 (5.7%) | 2 (15%) | 0 (0%) | |
| Follow-up (years) | 5.36 (1.75-7.29) | 5.73 (1.94-7.15) | 5.36 (1.69-7.60) | 5.09 (0.23-6.02) | 0.550 |
| Discharge - Admission MRS difference | -0.05 ± 1.46 | -0.27 ± 1.57 | 0.31 ± 0.95 | 0.22 ± 1.72 | 0.068 |
| Follow-up - DischargeMRS difference | -0.75 ± 1.22 | -0.86 ± 1.38 | -0.77 ± 1.09 | -0.25 ± 0.46 | 0.591 |
| Follow-up - Admission MRS difference | -0.80 ± 1.68 | -1.12 ± 1.82 | -0.38 ± 1.12 | -0.13 ± 1.64 | 0.057 |
Figure shows the change in the percentage of patients by mRS grading from admission to last Follow-up
Figure shows the change in distribution of mRS grading between Admission and Discharge (A) and Admission and Follow-up (B). The red points indicate mean values (the p-value is referred to a Wilcoxon signed-rank test)
Figure shows the proportion of patient by Spetzler-Martin and Lawton-Young Grade
MRS difference models
Table linear regression for Discharge - Admission MRS difference (S-M categories 1-2, 3, 4-5)
Male sex and presence of perforating branches are weakly associated with an improvement in mRS between Discharge and Admission, while the hemorrhage at onset is associated with a worsening
| Characteristic | Beta | 95% CI1 | p-value |
|---|---|---|---|
| Sex (male) | 0.67 | 0.00, 1.3 | 0.050 |
| Age at Surgery (years) | 0.01 | -0.01, 0.03 | 0.4 |
| Onset | |||
| Unruptured | — | — | |
| Hemorrhage | -0.81 | -1.6, -0.01 | 0.047 |
| GCS on Admission | 0.04 | -0.05, 0.14 | 0.4 |
| Perforating branches | 1.0 | 0.04, 2.0 | 0.043 |
| Aneurysm | -0.53 | -1.3, 0.28 | 0.2 |
| Multimodal treatment | 0.28 | -0.47, 1.0 | 0.5 |
| S-M grade | |||
| 1-2 | — | — | |
| 3 | 0.19 | -0.61, 1.0 | 0.6 |
| 4-5 | 0.51 | -0.50, 1.5 | 0.3 |
| 1 CI = Confidence Interval | |||
Table linear regression for Followup - Admission MRS difference (S-M categories 1-2, 3, 4-5)
GCS at admission and presence of perforating branches are associated with an improvement in mRS between Follow-up and Admission, while the hemorrhage at onset is associated with a worsening
| Characteristic | Beta | 95% CI1 | p-value |
|---|---|---|---|
| Sex (male) | 0.43 | -0.27, 1.1 | 0.2 |
| Age at Surgery (years) | 0.01 | -0.01, 0.03 | 0.2 |
| Onset | |||
| Unruptured | — | — | |
| Hemorrhage | -0.90 | -1.7, -0.05 | 0.039 |
| GCS on Admission | 0.16 | 0.05, 0.26 | 0.004 |
| Perforating branches | 1.0 | 0.01, 2.0 | 0.049 |
| Aneurysm | -0.65 | -1.5, 0.17 | 0.12 |
| Multimodal treatment | 0.85 | 0.03, 1.7 | 0.043 |
| S-M grade | |||
| 1-2 | — | — | |
| 3 | -0.10 | -0.99, 0.78 | 0.8 |
| 4-5 | 0.48 | -0.66, 1.6 | 0.4 |
| 1 CI = Confidence Interval | |||
Table linear regression for Discharge - Admission MRS difference (Supplementary grading categories 2-5, 6, 7-8)
Male sex, GCS at admission, presence of perforating branches, and multimodal treatment are associated with an improvement in mRS between Discharge and Admission
| Characteristic | Beta | 95% CI1 | p-value |
|---|---|---|---|
| Sex (male) | 0.78 | 0.12, 1.4 | 0.022 |
| Age at Surgery (years) | 0.00 | -0.02, 0.02 | 0.7 |
| GCS on Admission | 0.07 | -0.02, 0.16 | 0.13 |
| Perforating branches | 1.2 | 0.19, 2.1 | 0.020 |
| Aneurysm | -0.70 | -1.5, 0.10 | 0.086 |
| Multimodal treatment | 0.52 | -0.20, 1.2 | 0.15 |
| Supplemented S-M grade | |||
| 2-5 | — | — | |
| 6 | 0.74 | -0.05, 1.5 | 0.064 |
| 7-8 | 0.62 | -0.28, 1.5 | 0.2 |
| 1 CI = Confidence Interval | |||
Table linear regression for Followup - Admission MRS difference (Supplementary grading categories 2-5, 6, 7-8)
GCS at admission, presence of perforating branches, and multimodal treatment are associated with an improvement in mRS between Discharge and Admission
| Characteristic | Beta | 95% CI1 | p-value |
|---|---|---|---|
| Sex (male) | 0.55 | -0.18, 1.3 | 0.13 |
| Age at Surgery (years) | 0.01 | -0.01, 0.03 | 0.5 |
| GCS on Admission | 0.19 | 0.09, 0.30 | <0.001 |
| Perforating branches | 1.2 | 0.16, 2.2 | 0.025 |
| Aneurysm | -0.77 | -1.6, 0.08 | 0.075 |
| Multimodal treatment | 0.95 | 0.13, 1.8 | 0.025 |
| Supplemented S-M grade | |||
| 2-5 | — | — | |
| 6 | 0.33 | -0.56, 1.2 | 0.5 |
| 7-8 | 0.51 | -0.50, 1.5 | 0.3 |
| 1 CI = Confidence Interval | |||
Deficit models
Table logistic regression for presence of Deficit (S-M categories 1-2, 3, 4-5)
Only S-M grading is associated with a higher risk of post surgery deficit
| Characteristic | OR1 | 95% CI1 | p-value |
|---|---|---|---|
| S-M grade | |||
| 1-2 | — | — | |
| 3 | 14.0 | 3.17, 80.8 | 0.001 |
| 4-5 | 25.7 | 3.37, 563 | 0.007 |
| Sex (male) | 1.30 | 0.34, 5.11 | 0.7 |
| Age at Surgery (years) | 1.00 | 0.96, 1.04 | >0.9 |
| Onset | |||
| Unruptured | — | — | |
| Hemorrhage | 1.75 | 0.37, 9.85 | 0.5 |
| GCS on Admission | 1.12 | 0.92, 1.41 | 0.3 |
| Perforating branches | 1.51 | 0.23, 9.07 | 0.7 |
| Aneurysm | 1.75 | 0.34, 9.04 | 0.5 |
| 1 OR = Odds Ratio, CI = Confidence Interval | |||
Table logistic regression for presence of Deficit (Supplementary grading categories 2-5, 6, 7-8)
Only S-M grading is associated with a higher risk of post surgery deficit
| Characteristic | OR1 | 95% CI1 | p-value |
|---|---|---|---|
| Supplemented S-M grade | |||
| 2-5 | — | — | |
| 6 | 10.7 | 2.30, 71.7 | 0.006 |
| 7-8 | 42.2 | 5.92, 895 | 0.002 |
| Sex (male) | 1.22 | 0.31, 4.82 | 0.8 |
| Age at Surgery (years) | 0.97 | 0.93, 1.01 | 0.2 |
| GCS on Admission | 1.06 | 0.88, 1.31 | 0.6 |
| Perforating branches | 1.57 | 0.25, 8.95 | 0.6 |
| Aneurysm | 1.45 | 0.28, 7.31 | 0.6 |
| 1 OR = Odds Ratio, CI = Confidence Interval | |||
The figure shows the ROC curves for the two logistic models. The model with the Supplemented grading shows a slightly better AUC values not significantly different from the Original S-M model
Deficit models (major vs others)
Vedi considerazioni modelli precedenti
Table logistic regression for presence of Deficit (S-M categories 1-2, 3, 4-5)
| Characteristic | OR1 | 95% CI1 | p-value |
|---|---|---|---|
| S-M grade | |||
| 1-2 | — | — | |
| 3 | 20.8 | 2.97, 248 | 0.006 |
| 4-5 | 76.4 | 7.02, 1,630 | 0.001 |
| Sex (male) | 0.37 | 0.07, 1.74 | 0.2 |
| Age at Surgery (years) | 1.03 | 0.98, 1.08 | 0.3 |
| Onset | |||
| Unruptured | — | — | |
| Hemorrhage | 2.71 | 0.41, 25.0 | 0.3 |
| GCS on Admission | 1.02 | 0.80, 1.32 | 0.9 |
| Perforating branches | 0.00 | >0.9 | |
| Aneurysm | 4.21 | 0.56, 40.6 | 0.2 |
| 1 OR = Odds Ratio, CI = Confidence Interval | |||
Table logistic regression for presence of Deficit (Supplementary grading categories 2-5, 6, 7-8)
| Characteristic | OR1 | 95% CI1 | p-value |
|---|---|---|---|
| Supplemented S-M grade | |||
| 2-5 | — | — | |
| 6 | 15.7 | 2.32, 178 | 0.010 |
| 7-8 | 57.9 | 7.59, 753 | <0.001 |
| Sex (male) | 0.38 | 0.06, 1.95 | 0.3 |
| Age at Surgery (years) | 0.99 | 0.94, 1.04 | 0.8 |
| GCS on Admission | 0.96 | 0.75, 1.25 | 0.8 |
| Perforating branches | 0.00 | >0.9 | |
| Aneurysm | 3.77 | 0.47, 39.2 | 0.2 |
| 1 OR = Odds Ratio, CI = Confidence Interval | |||
Analysis patients with S-M 3
| Characteristic | All 3s N = 17 |
Other 3s N = 6 |
3+ N = 11 |
p-value |
|---|---|---|---|---|
| Sex (male) | 9 (53%) | 3 (50%) | 6 (55%) | >0.999 |
| Age at AVM diagnosis (years) | 37.47 ± 16.93 | 33.33 ± 16.71 | 39.73 ± 17.42 | 0.450 |
| Clinical Presentation | 0.304 | |||
| Hemorrhage | 7 (41%) | 1 (17%) | 6 (55%) | |
| Unruptured | 10 (59%) | 5 (83%) | 5 (45%) | |
| Glasgow Coma Scale on Admission | 0.467 | |||
| 3-8 | 4 (24%) | 1 (17%) | 3 (27%) | |
| 9-13 | 2 (12%) | 0 (0%) | 2 (18%) | |
| 14-15 | 11 (65%) | 5 (83%) | 6 (55%) | |
| Modified Rankin Scale on Admission | 0.333 | |||
| 0-1 | 11 (65%) | 5 (83%) | 6 (55%) | |
| 2-3 | 0 (0%) | 0 (0%) | 0 (0%) | |
| 4-6 | 6 (35%) | 1 (17%) | 5 (45%) | |
| AVM volume (cm³) | 9.84 (7.44-11.86) | 10.71 (5.97-11.80) | 9.60 (7.90-11.86) | >0.999 |
| Previous Treatments | >0.999 | |||
| None | 4 (24%) | 1 (17%) | 3 (27%) | |
| Embolization | 13 (76%) | 5 (83%) | 8 (73%) | |
| Other | 0 (0%) | 0 (0%) | 0 (0%) | |
| Time from Diagnosis to Surgery | >0.999 | |||
| 0-1 year | 3 (25%) | 2 (33%) | 1 (17%) | |
| > 1 year | 9 (75%) | 4 (67%) | 5 (83%) | |
| Age at Surgery (years) | 39.88 ± 16.47 | 36.83 ± 14.82 | 41.55 ± 17.76 | 0.546 |
| AVM Site | 0.762 | |||
| Cerebellar | 1 (5.9%) | 0 (0%) | 1 (9.1%) | |
| Frontal | 7 (41%) | 2 (33%) | 5 (45%) | |
| Parietal | 2 (12%) | 0 (0%) | 2 (18%) | |
| Temporal | 5 (29%) | 3 (50%) | 2 (18%) | |
| Other | 2 (12%) | 1 (17%) | 1 (9.1%) | |
| AVM Side | >0.999 | |||
| left | 11 (65%) | 4 (67%) | 7 (64%) | |
| right | 6 (35%) | 2 (33%) | 4 (36%) | |
| AVM Localization | >0.999 | |||
| infratentorial | 1 (5.9%) | 0 (0%) | 1 (9.1%) | |
| supratentorial | 16 (94%) | 6 (100%) | 10 (91%) | |
| Presence of Perforating Arterial Branches | 2 (13%) | 2 (33%) | 0 (0%) | 0.125 |
| Presence of Aneurysm | 2 (12%) | 1 (17%) | 1 (9.1%) | >0.999 |
| Aneurysm Location | >0.999 | |||
| pre-nidus | 0 (0%) | 0 (0%) | 0 (0%) | |
| pre-intra-nidus | 0 (0%) | 0 (0%) | 0 (0%) | |
| intra-nidus | 2 (100%) | 1 (100%) | 1 (100%) | |
| AVM Morphology | 0.500 | |||
| compact | 14 (88%) | 6 (100%) | 8 (80%) | |
| diffuse | 2 (13%) | 0 (0%) | 2 (20%) | |
| Lawton-Young Grade | >0.999 | |||
| 1 | 2 (12%) | 1 (17%) | 1 (9.1%) | |
| 2 | 2 (12%) | 1 (17%) | 1 (9.1%) | |
| 3 | 9 (53%) | 3 (50%) | 6 (55%) | |
| 4 | 4 (24%) | 1 (17%) | 3 (27%) | |
| Lawton-Young Age score | 0.819 | |||
| 1 | 4 (24%) | 2 (33%) | 2 (18%) | |
| 2 | 5 (29%) | 2 (33%) | 3 (27%) | |
| 3 | 8 (47%) | 2 (33%) | 6 (55%) | |
| Lawton-Young Bleeding score | 0.620 | |||
| 0 | 8 (47%) | 2 (33%) | 6 (55%) | |
| 1 | 9 (53%) | 4 (67%) | 5 (45%) | |
| Lawton-Young Compactness score | 0.515 | |||
| 0 | 15 (88%) | 6 (100%) | 9 (82%) | |
| 1 | 2 (12%) | 0 (0%) | 2 (18%) | |
| Supplemented grade | >0.999 | |||
| 2-5 | 4 (24%) | 2 (33%) | 2 (18%) | |
| 6 | 9 (53%) | 3 (50%) | 6 (55%) | |
| 7-8 | 4 (24%) | 1 (17%) | 3 (27%) | |
| Emergency Surgery | 0.102 | |||
| 0 | 12 (71%) | 6 (100%) | 6 (55%) | |
| 1 | 5 (29%) | 0 (0%) | 5 (45%) | |
| AVM closure | 15 (100%) | 6 (100%) | 9 (100%) | >0.999 |
| Post-surgery complications | 10 (63%) | 4 (67%) | 6 (60%) | >0.999 |
| Post-surgery deficit | >0.999 | |||
| none | 5 (31%) | 2 (33%) | 3 (30%) | |
| minor | 5 (31%) | 2 (33%) | 3 (30%) | |
| major | 6 (38%) | 2 (33%) | 4 (40%) | |
| Modified Rankin Scale at Discharge | 0.281 | |||
| 0-1 | 10 (63%) | 4 (67%) | 6 (60%) | |
| 2-3 | 1 (6.3%) | 1 (17%) | 0 (0%) | |
| 4-6 | 5 (31%) | 1 (17%) | 4 (40%) | |
| Modified Rankin Scale at Follw-up | >0.999 | |||
| 0-1 | 11 (85%) | 5 (83%) | 6 (86%) | |
| 2-3 | 0 (0%) | 0 (0%) | 0 (0%) | |
| 4-6 | 2 (15%) | 1 (17%) | 1 (14%) | |
| Follow-up (years) | 5.36 (1.69-7.60) | 5.27 (3.27-7.60) | 6.72 (0.93-8.07) | 0.886 |
| Discharge - Admission MRS difference | 0.31 ± 0.95 | 0.50 ± 1.38 | 0.20 ± 0.63 | 0.904 |
| Follow-up - DischargeMRS difference | -0.77 ± 1.09 | -0.67 ± 1.21 | -0.86 ± 1.07 | 0.527 |
| Follow-up - Admission MRS difference | -0.38 ± 1.12 | -0.17 ± 0.41 | -0.57 ± 1.51 | >0.999 |
Logistic regression for surgical complications
| Characteristic | OR1 | 95% CI1 | p-value |
|---|---|---|---|
| Supplemented S-M grade | |||
| 2-5 | — | — | |
| 6 | 12.9 | 2.70, 89.9 | 0.003 |
| 7-8 | 51.2 | 7.05, 1,108 | <0.001 |
| Sex (male) | 0.88 | 0.21, 3.58 | 0.9 |
| Age at Surgery (years) | 0.98 | 0.93, 1.02 | 0.4 |
| GCS on Admission | 1.10 | 0.91, 1.38 | 0.4 |
| Perforating branches | 1.90 | 0.30, 11.0 | 0.5 |
| Aneurysm | 0.85 | 0.14, 4.49 | 0.9 |
| 1 OR = Odds Ratio, CI = Confidence Interval | |||
Volume threshold analysis
| Characteristic | OR1 | 95% CI1 | p-value |
|---|---|---|---|
| volume_cat | |||
| <11.1 | — | — | |
| >11.1 | 2.98 | 0.86, 10.5 | 0.084 |
| 1 OR = Odds Ratio, CI = Confidence Interval | |||