Table 1.
Baseline differences in patient demographic, comorbidity, laboratory, and procedural factors, and primary outcomes by presence or absence of computer-assisted surgery
| With CAS (n=356) | Without CAS (n=16,594) | P | Cases available (n=16,950) | |
|---|---|---|---|---|
| Demographics, n (%) | ||||
| Age (years), mean (SD) | 13.8 (2.8) | 13.8 (2.7) | 0.866 | 16,950 |
| African−American race | 39 (11.8) | 2696 (18.2) | 0.003 | 15,120 |
| Hispanic ethnicity | 31 (8.8) | 1625 (10.6) | 0.292 | 15,712 |
| Female gender | 245 (68.8) | 11,575 (69.8) | 0.704 | 16,950 |
| Comorbidities, n (%) | ||||
| Obese | 56 (16.3) | 2416 (15.3) | 0.619 | 16,132 |
| Pulmonary comorbidity | 69 (19.4) | 2795 (16.8) | 0.206 | 16,950 |
| Cardiac comorbidity | 26 (7.3) | 1453 (8.8) | 0.337 | 16,950 |
| Esophageal/GI disease | 33 (9.3) | 1692 (10.2) | 0.567 | 16,950 |
| Developmental delay | 79 (22.2) | 3505 (21.1) | 0.625 | 16,950 |
| Seizure disorder | 31 (8.7) | 1580 (9.5) | 0.605 | 16,950 |
| Cerebral palsy | 30 (8.4) | 1571 (9.5) | 0.507 | 16,950 |
| Structural CNS abnormality | 49 (13.8) | 2202 (13.3) | 0.786 | 16,950 |
| Neuromuscular disorder | 72 (20.2) | 3668 (22.1) | 0.397 | 16,950 |
| Preoperative steroid use | 3 (0.8) | 179 (1.1) | 1.000# | 16,950 |
| Nutritional support | 26 (7.3) | 1274 (7.7) | 0.793 | 16,950 |
| Hematologic disorder | 10 (2.8) | 309 (1.9) | 0.193 | 16,950 |
| Congenital malformation | 86 (24.2) | 5077 (30.6) | 0.009 | 16,950 |
| Childhood malignancy | 5 (1.4) | 166 (1.0) | 0.450 | 16,950 |
| ASA-class ≥3 | 108 (30.4) | 5055 (30.5) | 0.977 | 16,932 |
| Lab values, mean (SD) | ||||
| White cell count | 7.0 (2.3) | 6.9 (2.3) | 0.758 | 14,089 |
| Hematocrit | 40.5 (3.6) | 39.9 (3.4) | 0.005 | 14,481 |
| INR | 1.1 (0.1) | 1.1 (0.1) | 0.672 | 9657 |
| Procedural factors, median (IQR) | ||||
| Operative time (min) | 331 (248–435) | 269 (205–344) | <0.001 | 16,940 |
| LOS (days) | 4 (3–5) | 4 (3–5) | 0.304 | 16,909 |
| Total RVUs | 57.7 (49.3–77.4) | 53.9 (45.6–74.4) | <0.001 | 16,950 |
| RVUs per minute | 0.18 (0.13–0.26) | 0.21 (0.15–0.28) | <0.001 | 16,940 |
| Total RVUs subtracting NAV | 50.9 (42.5–70.6) | 53.9 (45.6–74.4) | 0.238 | 16,948 |
| Unadjusted primary outcomes, n (%) | ||||
| Readmission | 21 (5.9) | 647 (3.9) | 0.055 | 16,950 |
| Reoperation | 22 (6.2) | 513 (3.1) | 0.001 | 16,950 |
| Mean days to reoperation | 16.3 (7.4) | 14.1 (8.4) | 0.229 | |
| Morbidity | 269 (75.6) | 11,199 (67.5) | 0.001 | 16,950 |
#Fisher’s exact test. Bold values indicate significance (P<0.05). Pulmonary comorbidities include ventilator dependence, asthma, chronic lung disease, chronic oxygen support, tracheostomy, or structural pulmonary or airway abnormalities. Cardiac comorbidities include previous cardiac surgery and cardiac risk factors. IQR - Interquartile ranges; ASA - American Society of Anesthesiologists; RVUs - Relative value units; CAS – Computer-assisted surgery; GI - Gastric/intestinal; CNS - Central nervous system; SD - Standard deviation; LOS - Length of stay; INR - International normalized ratio; NAV - Navigated patients from the NSQIP dataset