A hypothetical model using a base case and sensitivity analyses compared averted and incurred costs of in-line monitoring with neonatal intensive care unit satellite laboratory testing. Data were obtained retrospectively for 1 year from 50 consecutive critically ill premature neonates weighing less than 1,000 g at birth whose blood tests were performed in-line and processed at the satellite laboratory. Averted costs included phlebotomies, satellite blood testing, and transfusions; incurred costs included in-line monitor rental, nursing time, and daily monitor validation.

In-line monitoring led to cost savings of $324 per neonate and a benefit/cost ratio (BCR) of 1.23 in our base case. Sensitivity and scenario analyses addressed uncertainty and led to a BCR variation of 0.41 to 2.48.

Compared with satellite laboratory testing, in-line monitoring of critically ill neonates may generate cost savings through reduced laboratory analysis expense, less phlebotomy loss, and fewer blood transfusions for hospitals with high laboratory cost structures. Because most cost savings result from offsetting indirect costs (eg, building space and hospital overhead) that are of a longer term nature, short-run cost savings are less likely to be realized.