This document details the methodology for the ST-Elevation Myocardial Infarction (STEMI) with Percutaneous Coronary Intervention (PCI) measure and should be reviewed along with the STElevation Myocardial Infarction (STEMI) with Percutaneous Coronary Intervention (PCI) Measure Codes List file, which contains the medical codes used in constructing the measure.
Episode-based cost measures represent the cost to Medicare for the items and services provided to a patient during an episode of care (“episode”). In all supplemental documentation, “cost” generally means the standardized1 Medicare allowed amount,2 and claims data from Medicare Parts A and B are used to construct the episode-based cost measures.
The STEMI with PCI episode-based cost measure evaluates a clinician’s risk-adjusted cost to Medicare for patients who present with STEMI indicating complete blockage of a coronary artery who emergently receive PCI as treatment during the performance period. The measure score is the clinician’s risk-adjusted cost for the episode group averaged across all episodes attributed to the clinician. This acute inpatient medical condition measure includes costs of services that are clinically related to the attributed clinician’s role in managing care during each episode from the clinical event that opens, or “triggers,” the episode through 30 days after the trigger.
STEMI with PCI represents one of the most common types of hospitalizations among Medicare patients and is associated with high mortality. The STEMI with PCI episode-based cost measure was recommended for development by an expert clinician committee—the Cardiovascular Disease Management Clinical Subcommittee—because of its impact in terms of patient population and clinician coverage, and the opportunity for incentivizing cost-effective, highquality clinical care in this area. Subsequently, members of the Clinical Subcommittee provided extensive, detailed input on this measure.
The cost measure numerator is the sum of the ratio of observed to expected3 paymentstandardized cost to Medicare for all STEMI with PCI episodes attributed to a clinician. This sum is then multiplied by the national average observed episode cost to generate a dollar figure
The cost measure denominator is the total number of episodes from the STEMI with PCI episode group attributed to a clinician.
The STEMI with PCI cost measure uses the following data sources:
- Medicare Parts A and B claims data from the Common Working File (CWF)
- Enrollment Data Base (EDB)
- Long Term Care Minimum Data Set (LTC MDS)4
Methodologically, the STEMI with PCI cost measure can be triggered based on claims data from acute inpatient (IP) hospitals.
The cohort for this cost measure consists of patients who are Medicare beneficiaries enrolled in Medicare fee-for-service and who present with STEMI indicating complete blockage of a coronary artery who emergently receive PCI as treatment that triggers a STEMI with PCI episode.
The cohort for this cost measure is also further refined by the definition of the episode group and measure-specific exclusions (see Appendix A).
1 - Claim payments are standardized to account for differences in Medicare payments for the same service(s) across Medicare providers. Payment standardized costs remove the effect of differences in Medicare payment among health care providers that are the result of differences in regional health care provider expenses measured by hospital wage indexes and geographic price cost indexes (GPCIs) or other payment adjustments such as those for teaching hospitals. For more information, please refer to the “CMS Price (Payment) Standardization - Basics" and “CMS Price (Payment) Standardization - Detailed Methods” documents posted on the CMS Price (Payment) Standardization Overview page. (https://www.resdac.org/articles/cms-price-payment-standardization-overview)
2 - Cost is defined by allowed amounts on Medicare claims data, which include both Medicare trust fund payments and any applicable beneficiary deductible and coinsurance amounts. Claims data from Medicare Parts A and B are used to construct the episode-based cost measures.
3 - Expected costs refer to costs predicted by the risk adjustment model. For more information on expected costs and risk adjustment, please refer to Section A.5.
4 - For information on how LTC MDS data are used in risk adjustment, please refer to Section A.5.