Introduction
This document details the methodology for the Elective Outpatient Percutaneous Coronary Intervention (PCI) measure and should be reviewed along with the Elective Outpatient Percutaneous Coronary Intervention (PCI) Measure Codes List file, which contains the medical codes used in constructing the measure.
Measure Description
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 Elective Outpatient PCI episode-based cost measure evaluates a clinician’s risk-adjusted cost to Medicare for patients who undergo elective outpatient PCI surgery to place a coronary stent for heart disease during the performance period. The measure score is the clinician’s riskadjusted cost for the episode group averaged across all episodes attributed to the clinician. This procedural 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.
Measure Rationale
PCI procedures are performed in 600,000 patients each year and have the highest aggregate costs of all cardiovascular procedures, totaling about $10 billion annually.3 The Elective Outpatient PCI episode-based cost measure was selected for development based on input from 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, high-quality clinical care in this clinical area. Subsequently, members of the Clinical Subcommittee provided extensive, detailed input on this measure.
Measure Numerator
The cost measure numerator is the sum of the ratio of observed to expected4 payment standardized cost to Medicare for all Elective Outpatient PCI episodes attributed to a clinician. This sum is then multiplied by the national average observed episode cost to generate a dollar figure.
Measure Denominator
The cost measure denominator is the total number of episodes from the Elective Outpatient PCI episode group attributed to a clinician.
Data Sources
The Elective Outpatient PCI cost measure uses the following data sources:
- Medicare Part A and B claims data from the Common Working File (CWF)
- Enrollment Data Base (EDB)
- Long Term Care Minimum Data Set (LTC MDS)5
Care Settings
Methodologically, the Elective Outpatient PCI cost measure can be triggered based on claims data from: ambulatory/office-based care centers, outpatient (OP) hospitals, and ambulatory surgical centers (ASC).
Cohort
The cohort for this cost measure consists of patients who are Medicare beneficiaries enrolled in Medicare fee-for-service and who undergo elective outpatient PCI surgery to place a coronary stent for heart disease that triggers an Elective Outpatient PCI episode.
The cohort for this cost measure is also further refined by the definition of the episode group and measure-specific exclusions (refer to Section 4).
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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 Part A and Part B Price (Payment) Standardization - Basics" and “CMS Part A and Part B Price (Payment) Standardization - Detailed Methods” documents posted on the CMS Price (Payment) Standardization Overview page. (https://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.
3 Amin, Amit P., Mark Patterson, John A. House, Helmut Giersiefen, John A. Spertus, Dmitri V. Baklanov, Adnan K. Chhatriwalla et al. "Costs associated with access site and same-day discharge among Medicare beneficiaries undergoing percutaneous coronary intervention: an evaluation of the current percutaneous coronary intervention care pathways in the United States." JACC: Cardiovascular Interventions 10, no. 4 (2017): 342-351.
4 Expected costs refer to costs predicted by the risk adjustment model. For more information on expected costs and risk adjustment, please refer to Section 4.5.
5 For information on how LTC MDS data are used in risk adjustment, please refer to Section 4.5.