This document details the methodology for the Colon and Rectal Resection measure and should be reviewed along with the Colon and Rectal Resection 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 Colon and Rectal Resection episode-based cost measure evaluates a clinician’s risk-adjusted cost to Medicare for patients who receive colon or rectal resection for either benign or malignant indications 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 15 days prior to the clinical event that opens, or “triggers,” the episode through 90 days after the trigger.
Colorectal resection, or colectomy, is a common treatment for colorectal cancer and complications related to diverticular disease, with the Agency for Healthcare Research and Quality reporting that about 320,000 such procedures were performed annually between 2001 and 2011.3 Colorectal cancer is the second leading cause of cancer-related deaths and the third most common cancer in both men and women in the United States, and is especially common in the 85 and older adult population.4 Similarly, diverticular disease primarily affects older adults, occurring in 50-70% of those aged 80 or older and accounting for more than $2 billion in treatment costs annually.
The Colon and Rectal Resection episode-based cost measure was selected for development based on input from an expert clinician committee—the General and Colorectal Surgery Clinical Subcommittee—because of its impact in terms of patient population and Medicare spending, and the opportunity for incentivizing cost-effective, high-quality clinical care in this clinical area. Based on the initial recommendations from the Clinical Subcommittee, the subsequent measure-specific clinician expert workgroup provided extensive, detailed input on this measure.
The cost measure numerator is the sum of the ratio of observed to expected5 payment-standardized cost to Medicare for all Colon and Rectal Resection 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 Colon and Rectal Resection episode group attributed to a clinician.
The Colon and Rectal Resection 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)6
Methodologically, the Colon and Rectal Resection cost measure can be triggered based on claims data from: ambulatory surgical centers (ASC), hospital outpatient departments (HOPD), and 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 receive colon or rectal resection for either benign or malignant indications that triggers a Colon and Rectal Resection 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).
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 Audrey J Weiss and Anne Elixhauser, Trends in Operating Room Procedures in U.S. Hospitals, 2001–2011: Statistical Brief #171, Healthcare Cost and Utilization Project (HCUP) Statistical Briefs (Rockville, MD: Agency for Healthcare Research and Quality, 2014), http://www.ncbi.nlm.nih.gov/pubmed/24851286; Samuel Eisenstein, Sarah Stringfield, and Stefan D. Holubar, “Using the National Surgical Quality Improvement Project (NSQIP) to Perform Clinical Research in Colon and Rectal Surgery,” Clinics in Colon and Rectal Surgery 32, no. 1 (2019): 41–53, https://doi.org/10.1055/s-0038-1673353.
4 U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, and National Cancer Institute, “U.S. Cancer Statistics Data Visualizations Tool,” n.d., https://gis.cdc.gov/Cancer/USCS/DataViz.html.
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 4.5.
6 For information on how LTC MDS data are used in risk adjustment, please refer to Section 4.5.