Baseline characteristics of patients undergoing surgery for intracranial aneurysm in the unmatched cohorts
| Characteristics | Age groups | >60 vs <50 | >60 vs 50–60 | ||||
|---|---|---|---|---|---|---|---|
| >60 Years (n=266) (%) | <50 Years (n=221) (%) | 50–60 Years (n=234) (%) | p Value* | Absolute standardized difference‡ | p Value* | Absolute standardized difference‡ | |
| Female | 74.1 | 66.5 | 73.5 | 0.07 | 0.17 | 0.89 | 0.01 |
| Caucasian | 69.0 | 60.6 | 64.8 | 0.06 | 0.18 | 0.34 | 0.09 |
| Admitted from home | 73.3 | 73.3 | 69.2 | 1.0 | 0.00 | 0.31 | 0.09 |
| Smoking status | |||||||
| Current | 28.8 | 50.0 | 51.1 | <0.01 | 0.49 | <0.01 | 0.47 |
| Previous | 15.2 | 6.1 | 9.9 | ||||
| >2 Drinks a day | 2.2 | 7.0 | 7.1 | 0.02 | 0.23 | 0.02 | 0.23 |
| Dependent functional status | 15.0 | 13.1 | 13.8 | 0.55 | 0.06 | 0.69 | 0.04 |
| ASA classification | |||||||
| 1+2 | 16.5 | 21.3 | 14.1 | 0.40 | 0.12 | 0.48 | 0.11 |
| 3+4 | 82.7 | 77.8 | 84.2 | ||||
| BMI, kg/m2, mean±SD | 28±6 | 29±7 | 28±7 | 0.29 | 0.15 | 0.74 | 0.07 |
| Cardiopulmonary comorbidities | 29.3 | 19.9 | 26.9 | 0.02 | 0.13 | 0.55 | 0.05 |
| Diabetes mellitus | 14.7 | 3.2 | 13.7 | <0.01 | 0.41 | 0.75 | 0.03 |
| Hypertension requiring medication | 68.4 | 37.1 | 52.1 | <0.01 | 0.67 | <0.01 | 0.34 |
| Cerebrovascular comorbidities | 17.0 | 18.2 | 15.7 | 0.75 | 0.03 | 0.73 | 0.03 |
| Renal comorbidities | 25.6 | 23.1 | 19.7 | 0.11 | 0.15 | 0.52 | 0.14 |
| Cancer-related comorbidities | 1.5 | 0.5 | 0.9 | 0.25 | 0.10 | 0.51 | 0.06 |
| Steroid use for chronic condition | 2.6 | 1.4 | 0.9 | 0.32 | 0.09 | 0.14 | 0.14 |
| Preoperative SIRS or sepsis | 3.8 | 10.0 | 10.3 | 0.01 | 0.25 | <0.01 | 0.26 |
| Bleeding risk factors | 12.4 | 9.5 | 8.6 | 0.31 | 0.05 | 0.31 | 0.13 |
| Prior operation within 30 days | 1.4 | 4.3 | 0.5 | 0.07 | 0.18 | 0.37 | 0.09 |
| Preoperative anemia | 38.4 | 29.4 | 28.2 | 0.04 | 0.05 | 0.02 | 0.07 |
| Abnormal LFT | 12.8 | 14.9 | 12.0 | 0.49 | 0.18 | 0.78 | 0.02 |
| Abnormal WBC | 26.1 | 37.1 | 28.6 | 0.01 | 0.24 | 0.54 | 0.06 |
| Emergency | 26.7 | 27.2 | 26.9 | 0.91 | 0.01 | 0.95 | 0.01 |
| Resident in operating room | 81.3 | 83.7 | 83.3 | 0.53 | 0.06 | 0.59 | 0.05 |
| Intra- and postoperative transfusion | 20.7 | 7.2 | 12.0 | <0.01 | 0.40 | 0.01 | 0.24 |
| Ruptured aneurysm | 35.0 | 44.3 | 39.7 | 0.04 | 0.19 | 0.27 | 0.10 |
| Hunt and Hess grade† | |||||||
| 1 and 2 | 63.4 | 71.4 | 65.6 | 0.61 | 0.20 | 0.66 | 0.19 |
| 3 | 21.5 | 18.4 | 15.1 | ||||
| 4 | 7.5 | 4.1 | 9.7 | ||||
| 5 | 7.5 | 6.1 | 9.7 | ||||
*p Values shown in bold are significant.
†Only for patients with subarachnoid hemorrhage.
‡Absolute standardized difference shown in bold indicate covariate imbalance.
ASA, American Association of Anesthesiologists; BMI, body mass index; LFT, liver function test; SIRS, systemic inflammatory response syndrome; WBC, white blood cell.