We cannot comment on the cost-effectiveness to the hospital of the decision to close the ICA because we do not have accurate cost per patient data and because the case-mix distribution clearly changed. The patient population served by the ICA was admitted to either the wards or to the CCU in the post-ICA closure period. After ICA closure, we found an increased proportion of CCU admissions and patient days that were accounted for by patients requiring less nursing care with lower APACHE II scores. The potential for inefficient use of critical care personnel and resources increased when the ICA with its “graded” level of care was withdrawn without a change in CCU management. Since personnel costs account for approximately 80 percent of critical care expenditures, the need for a nursing workload management system during periods of changing utilization is particularly important.
In the absence of an ICA, increased cost-effectiveness might be gained by providing graded levels of care within a CCU to patients with possible acute myocardial infarction, respiratory failure, and medical surgical patients. Henning et al proposed using severity of illness measures (APACHE II system) to identify patients eligible for intermediate levels of care. However, this index alone may not be appropriate for all groups and must be investigated further, because nursing workload and level of care do not always correlate directly with APACHE II scores. Thus, a utilization analysis process that includes nursing workload assessment is most important when the heterogeneity of severity of illness increases within a CCU.
A successful ICA strategy should emphasize that unit managers focus on discharge policies and priorities, and design ICA units to meet specific hospital needs. Our data suggest that discharge criteria (eg, modified TISS) are as important as admission criteria for efficient utilization. Physicians can alter priorities for admission and discharge when confronted with a resource (bed or nursing) shortage. Strauss et al have shown that the relationship between bed availability on a given day and the severity of illness of patients admitted and discharged was inversely proportional. Factors other than bed availability that can influence admission and discharge criteria are prognostic uncertainty, patient age, expected social capacity, quality of life, family preferences, and the organization of critical care delivery. Kalb and Miller suggested that severity of illness and medical suitability rather than “marginal benefit” should be the overriding determinant in allocating access to critical care.