Background: We designed a tool to measure the rate and appropriateness of intensive care unit (ICU) nursing coverage as a proxy for the use of resources.
Methods: We tested the tool in 32 Italian ICUs during a cross-sectional study (4 days/week, October 2001 and April 2002). The level of care was classified as high or low. The appropriate patient-to-nurse ratio for both levels (2/1 and 3/1 in this ICU mix) was defined. The provided and theoretical nurse assistance was computed, the difference between the two quantifying the ICU use of personnel: a positive difference means over-utilization, a negative one under-utilization. We calculated the maximum number of high-level and low-level care days available for ICU and the relative utilization rates. These two rates quantify the appropriateness of resource use in relation to the planned use.
Results: Analysing 5783 treatment-days, the tool identified units using almost all available resources (five), overcrowded (14: too small units) or empty (16: too big). Units were overcrowded on account of the high-level of care required (five: utilization rate >100%) or reallocated too much of their residual high-care nursing capacity to low-level care (six). In empty units both utilization rates were lower than expected.
Conclusions: The method quantifies the rate and appropriateness of resource usage and suggests the best management in units with fixed human resources or a fixed number of beds.