Variability in nursing workload within CMGs (case mix groups).

This study examines the differences in workload estimates of three patient classification systems in nursing, within selected Case Mix Groups (CMGs). The amount of variation explained by selected patient-specific variables within CMGs on average nursing workload by each system is also analyzed. Results show that, when patient classification data are used to explain nursing time within the Diagnosis Related Group (DRG) context, absolute hours of care estimates of the various systems may not be equivalent. This inequality may result in biased budget review practices unless relational statements are developed between systems.