Table 2. Findings in Study Patients before or at Discharge.*.
| Variable or Outcome | Aggressive Phototherapy | Conservative Phototherapy | P Value |
|---|---|---|---|
| Variable | |||
| Total serum bilirubin at start of phototherapy — mg/dl | 4.8±1.6 | 10.0±1.5 | <0.001 |
| Daily total serum bilirubin, day 1–14 — mg/dl | 4.7±1.1 | 6.2±1.5 | <0.001 |
| Peak total serum bilirubin, day 1–14 — mg/dl | 7.0±1.8 | 9.8±2.1 | <0.001 |
| Age at peak bilirubin — hr | 95±69 | 75±45 | <0.001 |
| Unbound bilirubin at day 5 — mg/dl | 0.33±0.25 | 0.48±0.33 | <0.001 |
| Age when phototherapy started — hr | 23±9 | 58±26 | <0.001 |
| Duration of phototherapy — hr | 88±48 | 35±31 | <0.001 |
| Exchange transfusions — no.† | 2 | 3 | 0.69 |
| Days to regain birth weight | 12.6±6.2 | 12.5±6.6 | 0.65 |
| Length of hospital stay among survivors — days | 97±43 | 100±47 | 0.11 |
| Relative Risk (95% CI)‡ | |||
| Predischarge secondary outcome — no./total no. (%) | |||
| Death before day 15 | 96/990 (10) | 95/984 (10) | 1.00 (0.78–1.30) |
| Death before discharge | 209/990 (21) | 201/984 (20) | 1.03 (0.88–1.21) |
| Intraventricular hemorrhage, grade 3 or 4 | 210/969 (22) | 224/955 (23) | 0.93 (0.79–1.10) |
| Death or intraventricular hemorrhage, grade 3 or 4 | 291/984 (30) | 290/976 (30) | 1.0 (0.88–1.14) |
| Patent ductus arteriosus | 459/990 (46) | 487/984 (49) | 0.93 (0.86–1.02) |
| Death or patent ductus arteriosus | 556/990 (56) | 582/984 (59) | 0.95 (0.88–1.02) |
| Necrotizing enterocolitis | 105/990 (11) | 117/984 (12) | 0.90 (0.70–1.14) |
| Death or necrotizing enterocolitis | 269/990 (27) | 268/984 (27) | 1.00 (0.87–1.15) |
| Bronchopulmonary dysplasia at 36 wk postmenstrual age | 327/799 (41) | 383/797 (48) | 0.86 (0.78–0.96) |
| Death or bronchopulmonary dysplasia at 36 wk post-menstrual age | 506/978 (52) | 559/973 (57) | 0.90 (0.84–0.97) |
| Retinopathy of prematurity ≥stage 3§ | 153/802 (19) | 160/798 (20) | 0.98 (0.81–1.18) |
| Death or retinopathy of prematurity ≥stage 3 | 354/967 (37) | 355/955 (37) | 0.99 (0.89–1.10) |
| Late-onset sepsis | 387/946 (41) | 414/942 (44) | 0.93 (0.84–1.04) |
| Death or late-onset sepsis | 502/990 (51) | 519/984 (53) | 0.96 (0.89–1.04) |
Plus–minus values are means ±SD. The denominator used to calculate the percentage of infants with a specific outcome was the number of infants randomly assigned to each treatment group for whom that outcome was known at the time of hospital discharge, unless otherwise noted. These numbers of infants in the aggressive-phototherapy group and the conservative-phototherapy group were as follows: 781 and 755 for total serum bilirubin; 990 and 982 for daily total serum bilirubin, peak total serum bilirubin, and age at peak bilirubin; 498 and 511 for unbound bilirubin; 981 and 757 for age when phototherapy started (215 patients assigned to conservative phototherapy never received phototherapy); 923 and 954 for duration of phototherapy; 990 and 984 for exchange transfusions; 832 and 841 for days to regain birth weight; and 778 and 782 for length of hospital stay among survivors. To convert the values for bilirubin to micromoles per liter, multiply by 17.1.
The P value for the number of exchange transfusions was calculated with the use of Fisher's exact test, without adjustment for birth-weight stratum or center.
The relative risk of each outcome was calculated for aggressive phototherapy as compared with conservative phototherapy. The P values were not significant except for bronchopulmonary dysplasia at 36 weeks of postmenstrual age and death or bronchopulmonary dysplasia at 36 weeks of postmenstrual age, for which the P value was less than 0.05.
Retinopathy of prematurity was defined according to criteria of the International Committee for Classification of Retinopathy of Prematurity.