Variations in intraventricular hemorrhage incidence rates among Canadian neonatal intensive care units.

Objectives: To examine the variation in intraventricular hemorrhage (IVH) incidence among neonatal intensive care units and identify potentially modifiable risk factors.

Study Design: Multiple logistic regression analysis was used to examine variations in > or =grade 3 IVH, adjusting for baseline population risk factors, admission illness severity, and therapeutic risk factors. Subjects were born at <33 weeks' gestational age, admitted within 4 days of life to 1 of 17 participating Canadian NICU network sites in 1996-97, and had neuroimaging in the first 2 weeks of life.

Results: Of 5126 subjects <33 weeks' gestational age, 3806 had neuroimaging reports. Five of 17 sites had significantly (P <.05) different crude incidence rates of grade 3-4 IVH (odds ratios [OR] 0.2, 3.2, 2.6, 2.1, 1.9) than the hospital with median incidence. With adjustment for baseline population risk factors, perinatal risks, and admission illness severity, IVH incidence rates remained significantly (P <.05) higher at 3 sites (OR 2.9, 2.3 and 2.1). Inclusion of therapy-related variables (treatment of acidosis and vasopressor use on the day of admission) in the model eliminated all site differences.

Conclusions: IVH incidence rates vary significantly. Patient characteristics explain some of the variance. Early treatment of hypotension and acidosis and mode of delivery are potentially modifiable factors and warrant further study in IVH prevention.