Marginal increase in cost and excess length of stay associated with nosocomial bloodstream infections in surviving very low birth weight infants

Abstract

Objective: Nosocomial bloodstream infections (NBIs) are associated with serious morbidity and prolonged length of stay (LOS) in very low birth weight (VLBW) infants. However, the marginal costs and excess LOS associated with these infections have never been measured in different birth weight (BW) categories after adjustment for many of the potentially confounding demographic variables, comorbidities, and treatments. The objective of this study was to measure the marginal cost and excess LOS caused by NBIs in surviving VLBW infants in different BW categories.

Methods: This retrospective study examined data previously collected as part of the Neonatal Intensive Care Quality Improvement Collaborative 2000 and the Vermont Oxford Network clinical outcomes database. Univariate analyses and multiple regression were used to examine the effect of NBIs on hospital costs and LOS. Seventeen neonatal intensive care units that participated in the Neonatal Intensive Care Quality Improvement Collaborative 2000 submitted both clinical and financial data on their VLBW infants who were born from January 1, 1998, to December 31, 1999. This study included data from both university and community hospitals.

Results: NBIs occurred in 19.7% of 2809 patients included in this study. NBI was associated with significantly increased treatment costs for infants with BW 751 to 1500 g. The marginal costs of NBIs, as estimated by multiple regression, varied from 5875 dollars for VLBW infants with a BW of 401 to 750 g to 12,80 dollars for those with BW of 751 to 1000 g. LOS was significantly increased in all BW categories. The excess LOS estimated by multiple regression varied from 4 days in VLBW infants with a BW of 1001 to 1251 g to 7 days in those with a BW of 751 to 1000 g.

Conclusions: NBIs are associated with increased hospital treatment costs and LOS but by varying amounts depending on the BW. Preventing a single NBI could reduce the treatment costs of a VLBW infant by at least several thousand dollars. These savings are a greater percentage of the total treatment costs in VLBW infants with BW 1001 to 1500 g than in smaller infants.