The impact of reducing intensive care unit length of stay on hospital costs: evidence from a tertiary care hospital in Canada.

Purpose: To use theoretical modelling exercises to determine the effect of reduced intensive care unit (ICU) length of stay (LOS) on total hospital costs at a Canadian centre.

Methods: We conducted a retrospective cost analysis from the perspective of one tertiary teaching hospital in Canada. Cost, demographic, clinical, and LOS data were retrieved through case-costing, patient registry, and hospital abstract systems of The Ottawa Hospital Data Warehouse for all new in-patient ward (30,483) and ICU (2,239) encounters between April 2012 and March 2013. Aggregate mean daily variable direct (VD) costs for ICU vs ward encounters were summarized by admission day number, LOS, and cost centre.

Results: The mean daily VD cost per ICU patient was $2,472 (CAD), accounting for 67.0% of total daily ICU costs per patient and $717 for patients admitted to the ward. Variable direct cost is greatest on the first day of ICU admission ($3,708), and then decreases by 39.8% to plateau by the fifth day of admission. Reducing LOS among patients with ICU stays ≥ four days could potentially result in an annual hospital cost saving of $852,146 which represents 0.3% of total in-patient hospital costs and 1.2% of ICU costs.

Conclusion: Reducing ICU LOS has limited cost-saving potential given that ICU costs are greatest early in the course of admission, and this study does not support the notion of reducing ICU LOS as a sole cost-saving strategy.