To better control for presumed differences in acuity of illness and related costs between the MICU and the NRCU, we compared cost data for the days preceding and following transfer between units. Costs for the first full day in the NRCU were, on average, $744 lower than costs of the last full day in the MICU. These cost savings were confirmed when average daily costs of care for the three days preceding and the three days following transfer were compared for 25 patients. In this analysis, NRCU costs were $991 per day lower than MICU costs. Lower NRCU room costs accounted for $313 of this difference.

Discussion
In this study, we have documented a decrease in the daily costs of care associated with the transfer of mechanically ventilated patients from the MICU to the NRCU. Had the NRCU not been available at our institution and had these patients remained in the MICU for the duration of mechanical ventilation, our analysis suggests that costs of care would have increased by up to $20,000 per patient.
The cost savings in the NRCU as compared to the MICU persisted after subtracting room cost differences between the units and when daily costs were compared around the time of transfer between units. Only 42 percent of the cost savings in the NRCU could be accounted for by reduced room costs. Medical stability was a prerequisite for transfer from the MICU to the NRCU. This suggests to us that the cost savings in the NRCU were not due only to variations in nurse staffing (reflected in room costs) or to variations in patient acuity.