TABLE 3

Observed Major Morbidity Rates by Year for Surviving Infants 501 to 1500 g From 2000 to 2009 (N = 305 770)

2000, %2001, %2002, %2003, %2004, %2005, %2006, %2007, %2008, %2009, %P Valuea
n = 23 248n = 23 493n = 24 903n = 26 872n = 29 742n = 31 912n = 34 186n = 35 822n = 37 575n = 38 017
Any major morbidityb
 All 501–1500 g45.847.246.946.645.946.045.244.042.141.4<.001
 501–750 g84.087.785.787.086.286.585.884.584.082.7<.001
 751–1000 g62.165.464.565.164.863.362.961.259.757.4<.001
 1001–1250 g38.739.239.439.338.338.738.136.334.233.1<.001
 1251–1500 g23.424.323.723.122.822.521.720.819.318.7<.001
Major neonatal morbidities
 Early bacterial infection1.91.81.91.61.81.81.71.61.61.7.074
 Late infection (bacterial or fungal)c21.120.619.720.420.519.919.118.416.915.0<.001
 NEC4.84.74.65.04.75.55.76.15.85.3<.001
 CLDd27.130.030.429.828.328.928.827.726.226.2<.001
 Severe IVH (grades 3 and 4)e6.26.26.66.66.56.46.66.36.36.1.044
 PVLf3.03.22.92.92.82.93.12.92.82.7.019
 Severe ROP (stages 3–5) g10.511.410.910.89.99.58.38.07.56.8<.001
  • Sample sizes vary across outcome measures. Less than 1% of cases have missing data for any measure unless otherwise noted.

  • a P values correspond to the test for linear trend across years, after adjusting for infant characteristics by using logistic regression.

  • b Data were missing for 5.5% of surviving infants.

  • c Among surviving infants in the reporting hospital after day 3 of life, N = 304 615.

  • d Among infants with gestational age of ≤36 wk, N = 304 918.

  • e Among infants who received cranial imaging within 28 d of birth, N = 288 341.

  • f Among infants who received cranial imaging before discharge, N = 292 080.

  • g Among infants who received an eye exam before discharge, N = 236 580.