TABLE 3.

Adjusted Odds Ratios for Mortality and Morbidity

1991–19991991–19951995–1999
OR*(95% CI)OR*(95% CI)OR*(95% CI)
All 362 hospitals
 Mortality0.97(0.95–0.98)0.90(0.87–0.93)1.02(1.00–1.05)
 Pneumothorax0.98(0.96–1.00)0.88(0.84–0.92)1.06(1.03–1.09)
 IVH (any grade)0.98(0.96–0.99)0.97(0.93–1.01)0.98(0.96–1.01)
 IVH (grade 3 or 4)0.96(0.94–0.98)0.95(0.90–0.99)0.99(0.96–1.02)
39 common hospitals
 Mortality0.94(0.92–0.97)0.90(0.86–0.94)1.02(0.99–1.04)
 Pneumothorax0.96(0.94–0.99)0.88(0.82–0.94)1.08(1.02–1.15)
 IVH** (any grade)0.96(0.93–0.99)0.95(0.91–0.99)0.98(0.94–1.03)
 IVH** (grade 3 or 4)0.95(0.91–0.98)0.94(0.88–1.01)0.99(0.93–1.06)
  • OR indicates odds ratio; CI, confidence interval.

  • * Adjusted odds ratios and 95% confidence intervals reflect odds ratios per year.