Table 1. Baseline Characteristics of the Patients.*.
| Characteristic | Aggressive Phototherapy (N = 990) |
Conservative Phototherapy (N = 984) |
|---|---|---|
| Birth weight — g | 777±134 | 777±134 |
| Gestational age — wk | 26±2 | 26±2 |
| Male sex — no. (%) | 486 (49) | 527 (54) |
| Race or ethnic group — no. (%)† | ||
| Black | 439 (44) | 383 (39) |
| Hispanic | 174 (18) | 190 (19) |
| White | 349 (35) | 369 (38) |
| Other | 28 (3) | 42 (4) |
| Antenatal corticosteroids — no./total no. (%) | 783/986 (79) | 783/978 (80) |
| Born in network center — no. (%) | 906 (92) | 881 (90) |
| Cesarean delivery — no./total no. (%) | 656/990 (66) | 627/981 (64) |
| 5-Min Apgar score <5 — no./total no. (%) | 136/980 (14) | 128/974 (13) |
| Hematocrit at <12 hr of age — % | 43.1±6.7 | 43.9±7.0 |
| Positive result on Coombs test — no./total no. (%) | ||
| Mother | 28/680 (4) | 31/664 (5) |
| Infant | 8/903 (1) | 7/895 (1) |
| Maternal blood group O — no./total no. (%) | 437/946 (46) | 440/940 (47) |
| Maternal Rh positive — no./total no. (%) | 825/946 (87) | 826/940 (88) |
| Supplemental oxygen at 24 hr — no./ total no. (%) | 647/987 (66) | 642/983 (65) |
| Continuous positive airway pressure at 24 hr — no./total no. (%) | 209/988 (21) | 191/983 (19) |
| Ventilation at 24 hr — no. (%)‡ | 693/988 (70) | 698/983 (71) |
| Baseline bilirubin in first 100 infants enrolled — mg/dl | 4.8±1.5 | 5.0±1.7 |
Plus–minus values are means ±SD. The denominator used to calculate the percentage of infants (or mothers) with a specific characteristic was the number for whom the characteristic was known. This number was the total number in each group unless otherwise specified for percentages of patients and except for hematocrit, for which data were available for 967 infants in the aggressive-phototherapy group and 954 in the conservative-phototherapy group, and for baseline bilirubin, for which data were actually obtained for 101 and 102 infants, respectively. Significant differences were found between the two groups for male sex (P = 0.047), race or ethnic group (P = 0.049), and hematocrit at less than 12 hours of age (P = 0.006). To convert the values for bilirubin to micromoles per liter, multiply by 17.1.
Race or ethnic group was reported by parents or guardians of the patients or was determined by the physician on chart review.
Ventilation was defined as high-frequency, intermittent mechanical ventilation or nasal synchronized intermittent mechanical ventilation.