Patient-to-Nurse Ratios and Outcomes of Moderately Preterm Infants

The quality of health care delivery is determined by the physical composition of the health-delivery system (care structure), the quality of the patient-provider interactions (care processes), and the results of care provision (care outcomes).1 Measures of care structure, such as quantitative measures of physician and nurse-staffing, are relatively easy to ascertain. However, their validity as predictors of patient outcomes may be difficult to determine because many variables may confound this relationship. Nevertheless, previous staffing studies in the adult intensive care setting have demonstrated strong associations with patient outcomes.2-4 However, few authors have examined the effect of quantitative measures of nurse-staffing, such as the patient-to-nurse ratio (PNR), on outcomes of preterm infants. Few studies have examined the effect of patient-to-nurse ratios (PNRs) on clinical outcomes in the NICU setting and results have been inconclusive.5-8 Moderately preterm infants with a gestational age at birth between 30 and 34 6/7 weeks make up nearly half of NICU residents9,10 and experience considerable morbidity and mortality.11,12 Nearly half of these infants receive assisted ventilation, and >10% require readmission within 3 months of discharge. 11 To date, the influence of PNRs on clinical outcomes in this population is unknown. We aimed to add to the current body of literature by determining the association of nurse-staffing with clinical outcomes in moderately preterm infants.