Abstract
Background: Very preterm infants admitted to the Neonatal Intensive Care Unit (NICU) are at a high risk of developing a nosocomial infection (NI). Organizational factors may contribute to the risk of infection. The objective is to evaluate the association of unit occupancy, nursing overtime ratios, and nursing provision ratios with the risk of NI among very preterm infants in the NICU. Â
Methods: This study used a retrospective cohort design, including infants born at <33 weeks and admitted in 3 tertiary-level NICUs in Québec between 2014–2018. The Canadian Neonatal Network database provided data on patient characteristics and outcomes (NI confirmed by positive blood and/or cerebrospinal fluid culture taken >72 hours after birth), and was linked to provincial databases for unit occupancy, nursing overtime ratios (OTR, overtime hours/total hours worked), and nursing provision ratios (NPR, available/recommended nurses). Organizational variables were calculated as a mean in 3-day intervals from admission until the 45th day without NI, prior discharge without NI, or day of first documented NI. Associations of NI and organizational factors were assessed using mixed-effect logistic regression models, adjusted for patient covariates (fixed effects) and site (random effect). Â
Results: 238/2046 (11.6%) infants developed a NI and the median time to infection was 11 days [IQR 7-21]. Median unit occupancy was 89.1% [IQR 81.7%-94.7%], median OTR was 4.7% [IQR 2.4%-7.3%] and median NPR was 101.2% [IQR 86.4%-126.3%]. Median gestational age of infants with an infection was 26 weeks [IQR 25-28]. Unit occupancy and NPR were not associated with NI (adjusted Odds Ratio (aOR) 1.01 (95% CI 0.99–1.04) and 0.98 (0.97–1.00), respectively). OTR was associated with the odds of NI (aOR 1.09 (1.04–1.14)). A sensitivity analysis using 2-day intervals yielded similar results.Â
Conclusion: Nursing overtime is associated with the odds of infection among very preterm infants in the NICU.Â