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

Objectives: To examine the variation in intraventricular hemorrhage (IVH) i ncidence among neonatal intensive care units and identify potentially modif iable risk factors. Study design: Multiple logistic regression analysis was used to examine var iations in greater than or equal to grade 3 IVH, adjusting for baseline pop ulation risk factors, admission illness severity, and therapeutic risk fact ors. Subjects wore born at <33 weeks' gestational age, admitted within 4 da ys 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 inci dence rates of grade 3-4 IVH (odds ratios [OR] 0.2, 3.2, 2.6, 2.1, 1.9) tha n the hospital with median incidence. With adjustment for baseline populati on risk factors, perinatal risks, and admission illness severity, IVH incid ence 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 characteristic s explain some of the variance. Early treatment of hypotension and acidosis and mode of delivery are potentially modifiable factors and warrant furthe r study in IVH prevention.