Introduction
This document details the methodology for the Inpatient Chronic Obstructive Pulmonary Disease (COPD) Exacerbation measure and should be reviewed along with the Inpatient Chronic Obstructive Pulmonary Disease (COPD) Exacerbation 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 Inpatient COPD Exacerbation episode-based cost measure evaluates a clinician’s risk-adjusted cost to Medicare for patients who receive inpatient treatment for an acute exacerbation of COPD 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 60 days after the trigger.
Measure Rationale
Studies in 2008 found Medicare patients with COPD incur annual health care costs $15,000 to $20,000 greater than costs for patients without COPD, with the majority of this cost resulting from inpatient hospitalizations for COPD.3 In one study, hospitalizations due to COPD cost over $19,000 on average whereas hospitalizations unrelated to COPD had an average cost below $4,000.4 In addition, patients who are admitted for COPD exacerbations have been shown to have a higher rate of subsequent readmission and mortality.5 The Inpatient COPD Exacerbation episode-based cost measure was selected for development based on input from an expert clinician committee—the Pulmonary 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. Based on the initial recommendations from the Clinical Subcommittee, the subsequent measure-specific clinician expert workgroup provided extensive, detailed input on this measure.
Measure Numerator
The cost measure numerator is the sum of the ratio of observed to expected6 payment-standardized cost to Medicare for all Inpatient COPD Exacerbation 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 Inpatient COPD Exacerbation episode group attributed to a clinician.
Data Sources
The Inpatient COPD Exacerbation 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)7
Care Settings
Methodologically, the Inpatient COPD Exacerbation cost measure can be triggered based on claims data from: acute inpatient (IP) hospitals.
Cohort
The cohort for this cost measure consists of patients who are Medicare beneficiaries enrolled in Medicare fee-for-service and who receive inpatient treatment for an acute exacerbation of COPD that triggers an Inpatient COPD Exacerbation 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 Menzin, J., L. Boulanger, J. Marton, L. Guadagno, H. Dastani, R. Dirani, A. Phillips, and H. Shah. "The Economic Burden of Chronic Obstructive Pulmonary Disease (COPD) in a U.S. Medicare Population." [In Eng]. Respir Med 102, no. 9 (Sep 2008): 1248-56.
4 Ibid.
5 Almagro, Pedro, Joan B. Soriano, Francisco J. Cabrera, Ramon Boixeda, M. Belen Alonso-Ortiz, Bienvenido Barreiro, Jesus Diez-Manglano, Cristina Murio, and Josep L. Heredia. "Short- and Medium-Term Prognosis in Patients Hospitalized for COPD Exacerbation: The CODEX Index." Chest 145, no. 5 (2014): 972-980.
6 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.
7 For information on how LTC MDS data are used in risk adjustment, please refer to Section 4.5.