A cross-sectional study of neonatal intensive care unit overcrowding and understaffing associated with bacterial outbreaks

Aim To study whether overcrowding and/or nurse understaffing preceded four bacterial outbreaks during a 5-year period in a Norwegian university hospital neonatal intensive care unit (NICU). Methods A repeated cross-sectional study based on prospectively collected data from the Norwegian neonatal network's (NNN) web-based electronic database, digital work schedules and information about the outbreaks from logs, reports and publications. Number of admitted patients, category 4-5 patients (i.e., with the highest nurse to patient ratio), rostered nursing staff and nurse specialists were analysed in relation to periods (1) >28 days before individual outbreaks, (2) <= 28 days before, (3) during and (4) after outbreaks. Overcrowding and understaffing were compared between the four periods with Chi-square test and post hoc analysis with Bonferroni correction. Results When all outbreaks were analysed together, overcrowding was more frequent in the periods within 28 days of outbreaks compared to the other periods (p < 0.001). For understaffing, the periods within 28 days of outbreaks were only different from the periods >28 days before outbreaks (p < 0.001). The trends regarding individual outbreaks were less consistent, but there were more category 4-5 patients before and during the outbreaks. Conclusion Bacterial outbreaks in a 5-year period were weakly associated with overcrowding and understaffing.