Table. Characteristics of the Study Sample by Race.
| Characteristic | Hospitalizations, No. (%)a | P valueb | ||
|---|---|---|---|---|
| White | Black | Total | ||
| Hospitalizationsc | 934 (83.4) | 186 (16.6) | 1120 (100) | NA |
| Unique patients | 878 (82.8) | 183 (17.2) | 1061 (100) | NA |
| Sex | ||||
| Female | 426 (45.6) | 90 (48.4) | 516 (46.1) | .54 |
| Male | 508 (54.4) | 96 (51.6) | 604 (53.9) | |
| Patient age | ||||
| <6 mo | 152 (16.3) | 33 (17.7) | 185 (16.5) | .98 |
| 6 to <12 mo | 83 (8.9) | 16 (8.6) | 99 (8.8) | |
| 12 to <24 mo | 75 (8.0) | 12 (6.5) | 87 (7.8) | |
| 2 to <5 y | 152 (16.3) | 29 (15.6) | 181 (16.2) | |
| 5 to <12 y | 207 (22.2) | 42 (22.6) | 249 (22.2) | |
| 12 to 17 y | 265 (28.4) | 54 (29.0) | 319 (28.5) | |
| Maximum respiratory support | ||||
| None | 35 (3.7) | 8 (4.3) | 43 (3.8) | .002 |
| Supplemental oxygen | 313 (33.5) | 36 (19.4) | 349 (31.2) | |
| Noninvasive positive pressure | 43 (4.6) | 11 (5.9) | 54 (4.8) | |
| Invasive mechanical ventilation | 543 (58.1) | 131 (70.4) | 674 (60.2) | |
| Maximum VIS | ||||
| 0-5 | 551 (59.0) | 115 (61.8) | 666 (59.5) | .51 |
| 6-10 | 120 (12.8) | 18 (9.7) | 138 (12.3) | |
| 11-20 | 111 (11.9) | 26 (14.0) | 137 (12.2) | |
| >20 | 152 (16.3) | 27 (14.5) | 179 (16.0) | |
| SpO2-SaO2 pairs, No./total No. (%)d | 7018/9023 (77.8) | 2005/9023 (22.2) | 9023/9023 (100) | NA |
| SpO2 values, No./total No. (%) | ||||
| <88% | 626/7018 (8.9) | 248/2005 (12.4) | 874/9023 (9.7) | .71 |
| ≥88% | 6392/7018 (91.1) | 1757/2005 (87.6) | 8149/9023 (90.3) | |
| SpO2 – SaO2, mean (SD) | 3.5 (5.0) | 4.3 (5.0) | 3.7 (5.0) | <.001 |
| SaO2 <88% and SpO2 ≥88%, No./total No. (%) | ||||
| SpO2 of 88%-91% | 188/334 (56.3) | 74/106 (69.8) | 262/440 (59.6) | NA |
| SpO2 of 92%-96% | 248/1845 (13.4) | 127/433 (29.3) | 375/2278 (16.5) | |
| SpO2 >96% | 104/4213 (2.5) | 32/1218 (2.6) | 136/5431 (2.5) | |
| Occult hypoxemia, No./total No. (%)e | 352/6058 (5.8) | 159/1651 (9.6) | 511/7709 (6.6) | .03 |
Abbreviations: NA, not applicable; SaO2, arterial oxygen saturation; SpO2, oxygen saturation measured by pulse oximetry; VIS, Vasoactive Infusion Score.
Some percentages may not sum to 100% owing to rounding.
P values for the patient-level analysis were calculated using the χ2 test or analysis of variance; P values for the SpO2 measurement-level analysis were calculated using mixed models to adjust for clustering within patients.
Sex, age, maximum respiratory support, and VIS are reported for each hospitalization.
The sample included SpO2 and SaO2 directly measured by arterial blood gas analysis. Pairs were measured within 10 minutes at the same level of respiratory support.
Occult hypoxemia was defined as SaO2 less than 88% in the presence of SpO2 of 92% or greater.