Understanding MEG Grouping in Healthcare: Structure, Severity, and Cost Adjustments

1. Selected Episode Grouping Issues Frederick Thomas, Ph.D. Centers for Medicare & Medicaid Services

2. Medical Episode Grouper (MEG) • Etiology Based • Disease Staging Framework • Initially developed in 1983 • Ongoing private development by Thomson /Jefferson Medical School • 575 categories plus stages within each category

3. MEG Grouping Structure (v 7.25)

4. Episode Treatment Groups (ETG) • Base Category ETGs (n=330) • Resource consumption basis, with clinical homogeneity • ETG grouping structure allows for presence of surgery, presence of comorbidities, body areas

5. ETG 9 Digit Coding Structure (v 7.0) • Base ETG: 4 digits • EXPANSION ATTRIBUTES: • Body location: 5th, 6th digits • Complications indicator: 7th • Co-morbidity indicator: 8th • Surgery indicator: 9th

6. Example v 7. Coding

7. Severity Adjustment Used to help identify complexity and resource use

8. MEG Severity • MEG: disease stage from 2nd Dx (3 severity levels generally for each MEG) • Examples of Dx that define stages: respiratory failure, shock (along with base condition) • Conditions such as diabetes, ESRD not in stages • User determines severity model • Disease Staging levels along with other information used to adjust costs

9. Disease Staging ClassificationScale: likelihood of mortality Base Category MEGs(n=575) Stage 1 Disease with no complications Stage 2Disease has local complications Stage 3Multiple site involvement; systemic complications Stage 4 Death

10. Disease Staging Example

11. ETG Severity • In ETG v 7.0, up to 4 levels are identified in about 125 ETGs • Severity models use Dx, age, gender to create severity profiles • This model is used to assign a severity level to each ETG episode

12. ETG Severity Score

13. ETG Severity Threshold Example

14. Comparsion: CHF Adjusted Costs

15. Comparing Grouper Logic

16. Some ETG / MEG groups have almost identical Dx Example: CHF

17. Some use same DX codes, but split into different groups Example: Diabetes

18. Most Dx are different

19. Examples of other Logic Differences • Specificity Logic (MEGs): Non-specific Dx MEGs are grouped with specific Dx MEGs • Incidental logic (ETG): some Dx cannot open episodes when another is already open • Ranking logic (ETG): to evaluate some claim combinations

20. Types of Episodes • Chronic: conditions such as COPD, CHF • Usually a calendar year (12 months duration) • Acute: conditions such as fracture, AMI, pneumonia • Episode ends when no more activity for that condition is found, i.e, a “clean period”

21. Resulting Cost Differences

22. Philosophical Issue Example Bundling physician claims with an inpatient stay

23. Inconsistency of Dx on Physician and Inpatient Facility Claims • The hospital stay (facility claim) is usually grouped by the principal Dx, even though multiple conditions may be involved • About 55% of physician claims Dx differ from the Dx on the inpatient claim

24. Episode with IP Stay: MEG 525 Neoplasm, Malignant Other Respiratory System

25. Philosophical Question: • Group all inpatient physician claims with the principal inpatient stay Dx, regardless of physician Dx? Or • Group each physician claim by its Dx into multiple episodes, that may not include the inpatient stay?