Severity
Severity is classified on an ordinal scale from 0 to 3. Severity 1 of one disease may have different implications than Severity 1 of another disease. People with disease at Severity 2 are not “twice” as sick as those at Severity 1. The cost of providing care for an illness at Severity 2 is not “twice” the cost for an illness in Severity 1.
0 |
History of a significant predisposing factor for the disease, but no current pathology, e.g. history of carcinoma or neonate born to mother suspected of infection at time of delivery |
1 |
Conditions with no complications or problems with minimal severity |
2 |
Problems limited to a single organ or system; significantly increased risk of complications than Severity 1 |
3 |
Multiple site involvement; generalized systemic involvement; poor prognosis |
The reported Severity indicates the level of severity observed in episodes of a specific clinical condition (Episode Group). Subdivisions (x.xx) indicate more precise classification. Some Episode Groups have been further classified using age groups.
Comorbidity Group
Comorbidity Group: The DxCG® Relative Risk Score (RRS) of a patient in an episode reflects the number and complexity of diseases of that individual. The impact of comorbidity (as indicated by RRS) on variations in cost varies between episode groups and levels of severity. Little difference in cost is observed across the range of RRS for some conditions and levels of severity. For others, the cost rises consistently and significantly with increasing severity and RRS.
It is important to note that episodes in Comorbidity Group V are not five times more costly or complex as those in Group 1. The mathematical relationship between Severity, Comorbidity, and cost vary greatly from one MEG to another. For more information, click on the following link - MEG-Severity-Comorbidity Group Examples.
While the RRS can range continuously between 0 and 999, very few individuals have an RRS over 50. Over the entire covered population, the aggregate RRS is normalized to 1. The methodology partitions episodes by range of RRS into five Comorbidity Groups. The following steps were followed to define five Comorbidity Groups for each combination of MEG and Severity.
- Possible combinations of RRS were evaluated to find which divisions into five Comorbidity Groups best corresponded to the observed differences in cost attributable to relative risk.
- Where any resulting Comorbidity Group lacked a required minimum frequency it was combined with the adjacent group.
- When no statistically significant difference between the mean costs of adjacent Comorbidity Groups was present, those adjacent Comorbidity Groups were combined.
The RRS on which the Comorbidity Groups are based is created using the DCG/HCC diagnostic classification system developed by DxCG. An individual’s clinical profile is created from diagnosis data using hierarchies to characterize the person’s illness level within each disease process, while accumulating the effects of unrelated disease processes. The hierarchical structures improve the clinical validity and decrease sensitivity to over-coding in the models. For more information, click on the following link - Relative Risk Score Examples
- Ash, A., R. P. Ellis, G. Pope et al. “Using Diagnoses to Describe Populations and Predict Costs.”
Health Care Financing Review 21(3): 7-28. Spring 2000.
- Ellis, R. P. “Creaming, Skimping, and Dumping: Provider Competition on The Intensive and Extensive Margins.” Journal of Health Economics 17: 537-555. 1998.
- Zhao, Y., A. S. Ash, R. P.Ellis, J. P. Slaughter. "Disease Burden Profiles: An Emerging Tool for Managing Managed Care." (forthcoming) Health Care Management Science.
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