Development of the Elective Outpatient Percutaneous Coronary Intervention Episode-Based Cost Measure

The Merit-Based Incentive Payment System adjusts clinician payments based on a performance score that includes cost measures. With the Centers for Medicare & Medicaid Services, we developed a novel cost measure that compared interventional cardiologists on a targeted set of costs related to elective percutaneous coronary intervention (PCI). We describe the measure and compare it to a hypothetical version including all expenditures post-PCI.

Measure development was guided by 39 clinician experts. They identified services within 30 days of PCI that could be potentially affected by the interventional cardiologist. Expenditures for these PCI-related services were included as measure costs in a process termed service assignment. We used 1 year of Medicare claims to calculate clinician scores using the final measure that included only PCI-related costs (with service assignment) and a hypothetical version that included all costs post-PCI (without service assignment). We calculated reliability for both measures. This marker of precision breaks measure variance into signal (difference between clinicians) versus noise (difference between PCI episodes for a clinician). We also determined the change in clinician performance quintile between measures.

We identified 100 992 elective outpatient PCI episodes from May 2, 2016, to May 1, 2017. Total Medicare expenditures within 30 days of PCI averaged $13 234. After excluding costs unrelated to PCI, average cost was $10 966. For individual clinicians, mean reliability for the hypothetical measure without service assignment was 0.36. After service assignment, final measure reliability increased to 0.53. When evaluated as clinician groups, reliability increased from 0.43 to 0.73 following service assignment. Approximately 66% (2340 of 3527) of clinicians were reclassified into a different performance quintile after excluding unrelated costs.

The elective outpatient PCI cost measure had increased precision and reclassified clinician performance relative to a hypothetical version that included total expenditures.