The 2003 Index of Hospital Quality

Phase III
C A minimum Severity of Illness Subclass is established based on the patient’s
principal diagnosis. This accounts for patients assigned to codes that contain both
the underlying disease and an associated manifestation of the disease (i.e. diabetes
with hyperosmolar coma), but is only assigned to the APR-DRG that accounts for
the underlying disease.
C A minimum Severity of Illness Subclass is established based on combinations of
principal diagnosis and age for specific APR-DRGs.
C A minimum Severity of Illness Subclass is established for some APR-DRGs with
certain APR-DRG and non-OR procedure combinations as well as principal
diagnosis and non-OR procedure combinations
C A minimum Severity of Illness Subclass is established based on the presence of
certain combinations of secondary diagnoses. Figure 4 shows the combination of
secondary diagnoses necessary to increase the severity of illness subclass to a
minimum severity of illness level. For example, a type 1 combination would be a
major bacterial infection with pleural effusion. If a diagnosis from both of these
categories is present plus at least one other secondary diagnosis that is at least a
major severity of illness level, then the minimum patient severity of illness subclass
will be extreme.