Mortality Risk Adjustment Methodology for University Health System's Clinical Data Base

for University Health System’s Clinical Data Base The University Health System Consortium (UHC) risk adjusts length of stay (LOS), costs, and mortality in the Clinical Data Base (CDB). Additionally, complications are risk adjusted in the CDB using a complication profiler. The risk adjustment process for LOS, costs and mortality involves four steps: (1) assignment of a Severity of Illness (SOI) and Risk of Mortality (ROM) level to each case; (2) selection of a patient population to serve as the basis of the model to provide norms; (3) use of regression techniques to predict probability of mortality and LOS and costs based on the normative patient population; and (4) assignment of an expected probability of mortality, LOS and costs to every patient in the CDB. (1) Assignment of Severity of Illness and Risk of Mortality Levels Patient characteristics impact resource utilization and clinical outcome greatly. To ensure equitable inter-hospital comparison of outcomes, it is necessary to adjust for differences in patient characteristics. A number of patient classification schemes have been developed to address the issue of patient severity. While each of these schemes defines severity differently, most are similar in one respect: they use specific combinations patient demographics and principal and secondary diagnoses and procedures to define different levels of severity and complexity of treatment. The APR-DRG Grouper, developed by 3M Health Information Systems, is used by UHC to assign a level of illness severity and a risk of mortality level for each patient in the CDB. The APR-DRGs were developed as an expansion of the DRG system to address patient severity of illness and risk of mortality as well as resource intensity. The development process for the APRDRGs involved an iterative process of formulating clinical hypotheses and then testing the hypotheses with historical data. Separate clinical models for severity of illness and risk of