The 2003 Index of Hospital Quality

Phase II
C All secondary diagnoses that are closely related to other secondary diagnoses are
eliminated from further analysis, and the secondary diagnosis with the highest
Severity of Illness Level is retained. This prevents double counting clinically similar
diagnoses.
C The Base Severity of Illness Subclass of the patient is set to the highest Standard
Severity of Illness Level of any of the secondary diagnoses.
C Patients with a Base Severity of Illness Subclass of major (3) or extreme (4), will be
reduced to the next lower subclass unless the patient has multiple secondary
diagnoses with a high Standard Severity of Illness Level. Figure 3 displays the
requirements for keeping a severity of illness subclass of major or extreme.
Figure 3. Multiple Secondary Diagnoses Requirements
Base Severity of
Multiple Secondary Diagnoses Requirements
Illness Subclass to Prevent Reduction of Severity of Illness Subclass
Major Two or more secondary diagnoses that are major or one secondary
diagnosis that is major and at least two secondary diagnoses that are
moderate
Extreme Two or more secondary diagnoses that are extreme or one secondary
diagnosis that is extreme and at least two secondary diagnoses that are
major