Table 3.
Patient Characteristics Before and After Propensity Score Matching by Identified IBI Threshold (138.03)
| Patient Characteristics | IBI on Admission Pre-PSM (n=408) | ASMD | IBI on Admission Post-PSM (n=114) | ASMD | ||
|---|---|---|---|---|---|---|
| <138.03 | ≥138.03 | <138.03 | ≥138.03 | |||
| 349 | 59 | 57 | 57 | |||
| Age, yrs, mean±SD | 55.32±12.16 | 54.88±13.01 | 0.022 | 53.86±11.88 | 54.61±13.11 | 0.077 |
| Female sex, n (%) | 227 (65.0) | 32 (54.2) | 0.217 | 32 (56.1) | 32 (56.1) | 0.000 |
| Prior medical history | ||||||
| Hypertension, n (%) | 186 (53.3) | 36 (61.0) | 0.158 | 32 (56.1) | 36 (63.2) | 0.141 |
| Hyperlipidemia, n(%) | 25 (7.2) | 3 (5.1) | 0.095 | 5 (8.8) | 3 (5.3) | 0.124 |
| Diabetes mellitus, n (%) | 23 (6.6) | 2 (3.4) | 0.177 | 4 (7.0) | 2 (3.5) | 0.137 |
| Heart Disease, n (%) | 27 (7.7) | 4 (6.8) | 0.038 | 7 (12.3) | 4 (7.0) | 0.160 |
| Aneurysm characteristics | ||||||
| Posterior circulation, n(%) | 35 (10.0) | 7 (11.9) | 0.057 | 5 (8.8) | 7 (12.3) | 0.124 |
| Neurological data/score | ||||||
| Early seizures, n (%) | 16 (4.6) | 6 (10.2) | 0.185 | 5 (8.8) | 6 (10.5) | 0.062 |
| Early loss of consciousness, n (%) | 81 (23.2) | 29 (49.2) | 0.519 | 27 (47.4) | 27 (47.4) | 0.000 |
| WFNS grade 4–5, n (%) | 60 (17.2) | 23 (39.0) | 0.447 | 20 (35.1) | 21 (36.8) | 0.037 |
| mFS grade 3–4, n (%) | 230 (65.9) | 51 (86.4) | 0.600 | 49 (86.0) | 49 (86.0) | 0.000 |
| Graeb score 5–12, n (%) | 23 (6.6) | 9 (15.3) | 0.241 | 8 (14.0) | 9 (15.8) | 0.051 |
| SEBES score 3–4, n (%) | 138 (39.5) | 30 (50.8) | 0.226 | 31 (54.4) | 28 (49.1) | 0.106 |
| Acute hydrocephalus, n (%) | 135 (38.7) | 33 (55.9) | 0.347 | 31 (54.4) | 31 (54.4) | 0.000 |
| Laboratory values on admission | ||||||
| IBI a, median (IQR) | 19.03 (8.49–44.40) | 295.74 (204.37–636.86) | 1.044 | 3.66 (1.50–8.76) | 288.28 (202.54–557.71) | 1.072 |
| N/L, median (IQR) | 10.63 (6.94–15.53) | 16.79 (12.19–26.27) | 0.811 | 8.90 (5.43–15.93) | 16.74 (12.05–25.96) | 0.971 |
| C-reactive protein b, median (IQR) | 1.76 (0.88–4.16) | 18.68 (10.95–35.38) | 0.919 | 0.45 (0.28–0.99) | 18.68 (10.63–35.26) | 0.983 |
| Neutrophils c, median (IQR) | 0.72 (8.07–13.12) | 13.93 (10.53–19.11) | 0.773 | 11.41 (7.37–35.26) | 13.72 (10.39–19.09) | 0.688 |
| Lymphocytes d, median (IQR) | 1.00 (0.73–1.41) | 0.81 (0.60–1.10) | 0.753 | 1.23 (0.84–1.92) | 0.81 (0.60–1.09) | 1.548 |
| Glucose e, median (IQR) | 7.50 (6.52–9.28) | 8.12 (7.06–9.11) | 0.111 | 7.83 (6.64–10.15) | 8.12 (7.07–9.19) | 0.067 |
| Hemoglobin f, median (IQR) | 140 (129–151) | 147 (136–155) | 0.273 | 139 (130–149) | 147 (135–155) | 0.204 |
| Leukocytes g, median (IQR) | 12.25 (9.65–14.71) | 15.09 (11.79–20.32) | 0.716 | 13.08 (9.50–15.98) | 15.06 (11.71–20.32) | 0.553 |
| Platelet h, median (IQR) | 224 (189–269) | 230 (189–293) | 0.170 | 223 (189–265) | 230 (194–294) | 0.300 |
| Monocytes i, median (IQR) | 0.39 (0.27–0.54) | 0.55 (0.37–0.76) | 0.452 | 0.46 (0.30–0.77) | 0.55 (0.36–0.73) | 0.010 |
| Treatment modality | 0.445 | 0.000 | ||||
| Surgical clipping, n (%) | 164 (47.0) | 40 (67.8) | 38 (66.7) | 38 (66.7) | ||
| Endovascular coiling, n (%) | 185 (53.0) | 19 (32.2) | 19 (33.3) | 19 (33.3) | ||
Notes: Propensity score matching (caliper 0.02, ratio 1:1, nearest neighbor approach) was performed according to the following parameters: Female, Early loss of consciousness, WFNS grade, mFS grade, GRAEB score, SEBES score, Acute hydrocephalus and surgical clipping. After PS matching, 2 evenly balanced cohorts consisting of 57 patients each and without significant differences in outcome-relevant parameters were available for further analyses. aUnit of measurement: mg/L. bUnit of measurement: mg/L. cUnit of measurement: 109/L. dUnit of measurement: 109/L. eUnit of measurement: mg/L. fUnit of measurement: g/L. gUnit of measurement: 109/L. hUnit of measurement: 109/L. iUnit of measurement: 109/L.
Abbreviations: IBI, inflammatory burden index; PSM, propensity score matching; ASMD, absolute standardized mean difference; WFNS, world federation of neurological societies; mFS, modified Fisher; SEBES, subarachnoid hemorrhage early brain edema score; N/L, neutrophils to lymphocytes ratio.