Introduction
This document details the methodology for the Routine Cataract Removal with Intraocular Lens (IOL) Implantation measure and should be reviewed along with the Routine Cataract Removal with Intraocular Lens (IOL) Implantation 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 Routine Cataract Removal with IOL Implantation episode-based cost measure evaluates a clinician’s risk-adjusted cost to Medicare for patients who undergo a procedure for routine cataract removal with IOL implantation 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 procedural measure includes costs of services that are clinically related to the attributed clinician’s role in managing care during each episode from 60 days prior to the clinical event that opens, or “triggers,” the episode through 90 days after the trigger.
Measure Rationale
Routine cataract surgery is the most common surgical procedure in the United States, including among Medicare patients, 3 and it was estimated that Medicare spends more than $3.4 billion annually on the treatment of cataracts, with cataract extraction with IOL implantation specifically as the most common procedure.4 The Routine Cataract Removal with IOL Implantation episode based cost measure was recommended for development by an expert clinician committee—the Ophthalmologic 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 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 expected5 payment standardized cost to Medicare for all Routine Cataract Removal with IOL Implantation 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 Routine Cataract Removal with IOL Implantation episode group attributed to a clinician.
Data Sources
The Routine Cataract Removal with IOL Implantation 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)6
Care Settings
Methodologically, the Routine Cataract Removal with IOL Implantation cost measure can be triggered based on claims data from ambulatory surgical centers (ASC), ambulatory/office based care, and hospital outpatient department (HOPD).
Cohort
The cohort for this cost measure consists of patients who are Medicare beneficiaries enrolled in Medicare fee-for-service and who undergo a procedure for routine cataract removal with IOL implantation that triggers a Routine Cataract Removal with IOL Implantation 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).
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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 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 Pershing, S., D. E. Morrison, and T. Hernandez-Boussard. “Cataract Surgery Complications and Revisit Rates among Three States.” [In eng]. Am J Ophthalmol 171 (Nov 2016): 130-38.
4 Brown, G. C., M. M. Brown, A. Menezes, B. G. Busbee, H. B. Lieske, and P. A. Lieke. “Cataract Surgery Cost Utility Revisited in 2012: A New Economic Paradigm.” [In eng]. Ophthalmology 120, no. 12 (Dec 2013): 2367-76.
5 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.
6 For information on how LTC MDS data are used in risk adjustment, please refer to Section A.5.