Table 2. Repeated Measures Outcomes Analyzed Using Generalized Linear Mixed Model Analysis.
| Variable | P Value | Estimate (95% CI)a | |
|---|---|---|---|
| Residual Group | No Residual Group | ||
| Weekly feedings, mL/kg/d | |||
| Birth weight | .03 | NA | NA |
| GA | <.001 | NA | NA |
| GA × week | <.001 | NA | NA |
| Week | .006 | NA | NA |
| Treatment | .048 | NA | NA |
| Treatment × week | .02 | NA | NA |
| Simple main effects | |||
| Week 1 | .27 | 25.7 (21.8 to 29.5) | 22.6 (18.6 to 26.5) |
| Week 2 | .12 | 83.2 (72.9 to 93.4) | 94.7 (84.3 to 105.2) |
| Week 3 | .28 | 109.2 (98.5 to 120.0) | 117.7 (106.9 to 128.5) |
| Week 4 | .15 | 119.4 (109.5 to 129.4) | 129.6 (119.7 to 139.6) |
| Week 5 | .03 | 123.9 (115.2 to 132.6) | 137.2 (128.6 to 145.8) |
| Week 6 | .03 | 128.4 (119.9 to 136.9) | 141.6 (133.2 to 150.0) |
| Estimated log direct bilirubin | |||
| Week | <.001 | NA | NA |
| GA | <.001 | NA | NA |
| Birth weight | <.001 | NA | NA |
| Treatment | |||
| Transformed values | .98 | −0.777 (−0.892 to −0.661) | −0.778 (−0.895 to −0.661) |
| Untransformed valuesb | NA | 0.690 (0.563 to 0.819)b | 0.671 (0.542 to 0.799)b |
| Occurrence of elevated (>2 mg/dL) direct bilirubin | |||
| GA | .07 | NA | NA |
| Birth weight | .008 | NA | NA |
| Treatment | .53 | 0.040 (0.017 to 0.092) | 0.057 (0.025 to 0.131) |
| Estimated log transformed weight | |||
| Birth weight | <.001 | NA | NA |
| GA | <.001 | NA | NA |
| Week | <.001 | NA | NA |
| GA × treatment | .047 | NA | NA |
| Treatment | |||
| Transformed values | .03 | 6.98 (6.97 to 7.00) | 7.01 (6.99 to 7.02) |
| Untransformed valuesb | NA | 1129.7 (1111 to 1148)b | 1145.3 (1126 to 1164)b |
| Head circumference | |||
| Week | .02 | NA | NA |
| Birth HC | <.001 | NA | NA |
| GA | <.001 | NA | NA |
| Birth HC × week | <.001 | NA | NA |
| GA × week | <.001 | NA | NA |
| Treatment | .56 | 25.94 (25.71 to 26.17) | 25.85 (25.62 to 26.08) |
| Length | |||
| Birth length | <.001 | NA | NA |
| GA | <.001 | NA | NA |
| Week | <.001 | NA | NA |
| Birth length × treatment | .008 | NA | NA |
| GA × treatment | .005 | NA | NA |
| Treatment | .59 | 36.41 (36.08 to 36.74) | 36.78 (36.44 to 37.11) |
Abbreviations: GA, gestational age; HC, head circumference; NA, not applicable.
a
All estimates are least square means except for occurrence of elevated bilirubin, which are odds.
b
Untransformed values provided for clinical reference only.