Critical care costs per patient-day are inversely related to the annual admission rate

Introduction

The Critical Care National Cost Block Programme collects annual cost data for staff, consumables, and clinical support services. We postulated that larger critical care units reduce the overall running costs (independent of capital expenditure) compared with their smaller counterparts.

Methods

Data were analysed for the financial year 2003–2004 relating to all 80 critical care units in the Cost Block programme. Regression analysis was performed comparing the cost per patient-day with the unit size. Following this, stepwise regression analysis was used to assess the individual components of cost to identify the elements (medical, nursing, consumables and other) most strongly related to admission number.

Results

Figure 1 shows the data relating ICU size (defined as number of admissions per year) with average costs per patient per day. The daily costs per patient were reduced by €53 for every 100 admissions increment. Analysed for the individual components that contribute to the daily cost per patient, we found that nursing costs (€22.3 per 100 admissions increment, P = 0.019) and consumables (€14 per 100 admissions increment, P = 0.003) had the strongest impact. Medical and other costs had lower impacts (€8.9 and €7.5, respectively).

Figure 1

Conclusion

The cost per patient per day is higher for smaller units than that for larger units. There appears to be an economy of scale for larger critical care units relating mainly to a reduction in daily nursing and consumable costs. A previous study examining the data for the financial year 2000–2001 also suggested that there was an association between the cost per patient day and the ICU size [1].