Objective: To estimate the relationship between size of intensive care unit and combined intensive care/high dependency units and average costs per patient day.
Design: Retrospective data analysis. Multiple regression of average costs on critical care unit size, controlling for teaching status, type of unit, occupancy rate and average length of stay.
Setting: Seventy-two United Kingdom adult intensive care and combined intensive care/high dependency units submitting expenditure data for the financial year 2000-2001 as part of the Critical Care National Cost Block Programme.
Interventions: None.
Measurements and results: The main outcome measures were total cost per patient day and the following components: staffing cost, consumables cost and clinical support services costs. Nursing Whole Time Equivalents per patient day were recorded. The unit size variable has a negative and statistically significant ( p<0.05) coefficient in regressions for total, staffing and consumables cost. The predicted average cost for a seven-bed unit is about 96% of that predicted for a six-bed critical care unit.
Conclusion: Policy makers should consider the possibility of economies of scale in planning intensive care and combined intensive care/high dependency units.