Overview
Measure Overview
The goal of this measure is to improve patient outcomes by providing patients, physicians, hospitals, and policymakers with information about hospital-level, risk-standardized mortality rates following hospitalization for a qualifying isolated CABG procedure. Measurement of patient outcomes allows for a broad view of quality of care that encompasses more than what can be captured by individual process-of-care measures. Complex and critical aspects of care, such as communication between providers, prevention of and response to complications, patient safety, and coordinated transitions to the outpatient environment, all contribute to patient outcomes but are difficult to measure by individual process measures. The goal of outcomes measurement is to risk adjust for patient conditions at the time of hospital admission and then evaluate patient outcomes. This measure was developed to identify institutions whose performance is better or worse than would be expected based on their case mix and therefore promote hospital quality improvement and better inform consumers about care quality.
Measurement of patient outcomes related to risk-standardized mortality rates after inpatient hospitalization related to coronary artery bypass graph (CABG) procedures permits an overall view of care provided by individual hospitals as compared to like facilities with similar patient populations. This process can assist patients and caregivers in evaluating outcomes for specific hospitals in relation to care and services for treatment of patients undergoing CABG procedures. This process provides patients with the opportunity to choose an in-patient facility based on their needs and hospital performance and provides hospitals with the chance to identify quality improvement opportunities.
Measure currently used in a Medicare program, but the measure is undergoing substantive change.
Initial endorsement 2014. Endorsed during maintenance review in 2022.
Integration of MA beneficiaries into the cohort and modifying performance period from 3 years to 2 years.
Measure Specification
The outcome for this measure is 30-day, all-cause mortality. We define mortality as death from any cause within 30 days of the procedure date from the CABG index admission for patients discharged from the hospital after undergoing a qualifying isolated CABG procedure.
Not applicable
Not applicable
The cohort includes admissions for patients that meet all of the following inclusion criteria:
Enrolled in Medicare FFS Part A and Part B or MA for the first 12 months prior to the date of admission and enrolled in Part A or MA during the index admission. [For US Department of Veterans Affairs (VA) beneficiaries hospitalized in VA hospitals, there are no Medicare FFS or MA enrollment requirements. For VA beneficiaries hospitalized in non-VA hospitals, they must be concurrently enrolled in Medicare FFS Part A or MA at the time of the index admission, to be eligible for cohort inclusion, but the 12-month Part A and B or MA enrollment prior to admission is not required.]; Aged 65 or over; Having a qualifying isolated CABG procedure during the index admission. Isolated CABG surgeries are defined as those procedures performed without the following concomitant valve or other major cardiac, vascular, or thoracic procedures: valve procedures; atrial and/or ventricular septal defects; congenital anomalies; other open cardiac procedures; heart transplants; aorta or other non-cardiac arterial bypass procedures; head, neck, intracranial vascular procedures; or other chest and thoracic procedures.
Not applicable
This measure excludes index admissions for patients that meet any of the following exclusion criteria:
- With inconsistent or unknown vital status or other unreliable demographic data (e.g., age and sex);
- Discharged against medical advice;
- Admissions for subsequent qualifying CABG procedures during the measurement period;
- For patients with more than one eligible CABG admission in the reporting period, only one index admission per year is randomly selected for inclusion in the cohort. Additional admissions within that time period are excluded.
Meaningfulness
Importance
This measure seeks to improve patient outcomes by reporting hospital-level, risk-standardized mortality rates after isolated CABG procedures. By focusing on patient outcomes rather than individual care processes, it provides a comprehensive view of care quality, including factors such as provider communication, complication management, patient safety, and care transitions. Evidence from recent studies provided by the developer shows that factors such as hospital volume and timing of mortality are relevant, reinforcing the appropriateness and utility of the 30-day mortality definition for evaluating CABG outcomes.
During CBE endorsement review in 2022, the committee found the evidence supporting the importance of this measure to be sufficient.
Conformance
The intent of this measure is to improve patient outcomes by providing patients, physicians, hospitals, and policymakers with information about hospital-level, risk-standardized mortality rates following hospitalization for a qualifying isolated CABG procedure. The numerator is the number of patients aged 65 or older who died from any cause within 30 days after discharge from a qualifying isolated CABG procedure, while the denominator includes eligible Medicare or VA patients who underwent such procedures, excluding those with unreliable data, multiple admissions, or who were discharged against medical advice. This measure aligns with the Hospital IQR objective to improve the quality of care that hospitals provide and to distribute clearly defined and objective data about hospital performance as well as the Hospital VBP Program goal to encourages hospitals to improve the quality, efficiency, patient experience, and safety of care.
Feasibility
No, not an eCQM.
All data elements are in defined fields in electronic sources; alignment with United States Core Data for Interoperability (USCDI)/USCDI+ Quality was not assessed.
Claims data are widely available, standardized, and cost effective, as they are routinely collected for billing purposes. They also allow for large-scale and longitudinal analysis across diverse patient populations and care settings.
During CBE endorsement review in 2022, the committee found the feasibility of this measure to be sufficiently demonstrated.
Validity
Empiric Validity [MERIT Submission Form, Attachments]
Facility
Yes
Empiric validity testing was done at the facility level in a sample of 971 patients with a reliability result of 0.726. Because the CABG Mortality measure follows a lower-is-better scale while Star Rating measures follow a higher-is-better scale, the developer hypothesized a weak-to-moderate negative correlation between the CABG Mortality measure and Star Rating-related measures. The CABG Mortality measure showed negative correlations with the Star Rating Overall Summary Scores (-0.298, p < .0001), the Star Ratings Adjusted summary score excluding the Mortality Group (-0.131, p < .0001), the Star Rating Mortality Group Scores (-0.408, p < .0001), and the Star Rating Adjusted Mortality Group Scores excluding the CABG Mortality Measure (-0.325, p < .0001). Data were not used in testing but will be included once the measure is implemented, as it was with the original CABG Mortality measure.
During CBE endorsement review in 2022, the committee found the validity of this measure to be sufficiently demonstrated.
The developer addressed threats to validity through use of a risk-adjustment model. The risk model uses patient functional status, patient-level demographics, patient-level health status, and clinical conditions including a case-mix adjustment for comorbidities and severity of Illness.
Reliability
Random Split-half Correlation [MERIT Submission Form, Attachments]
Facility
The developer conducted split-half reliability to calculate the intraclass correlation coefficient (ICC) at the accountable entity level across 100 permutation split samples. The overall ICC for hospitals with at least 25 admissions was 0.726. When at least 70% of the entities have a reliability >0.6, a measure is considered capable of differentiating entities by quality of performance. Reliability results used 2 years of data (2022-2023) from 971 facilities with at least 25 admissions. During collaboration on this PA, the developer provided the minimum, maximum, median, and 25th and 75th percentiles. Among hospitals with at least 25 admissions, the minimum reliability was 0.633, the median reliability was 0.729 (IQR: 0.715-0.744), and the maximum reliability was 0.768. All facilities exceeded the recommended minimum reliability threshold of 0.6.
During CBE endorsement review in 2022, the committee found the reliability of this measure to be demonstrated sufficiently.
No additional analyses were conducted.
Usability
Yes, the submission materials briefly discuss the measure’s usability within relevant programs.
The measure is currently used in both Hospital IQR and Hospital VBP and has demonstrated actionable insights for providers in the intended setting. The expansion of MA data doubles the cohort size, improves measure reliability and more accurately reflects the quality of care for both FFS and MA beneficiaries. Since implementation of the current version of the measure, the developer has not identified unintended consequences, but they are committed to monitoring this measure’s use and assessing potential unintended consequences over time, such as the inappropriate shifting of care, increased patient morbidity and mortality, and other negative unintended consequences for patients.
During CBE endorsement review in 2022, the committee found the use/usability of this measure to be sufficiently demonstrated.
Appropriateness of Scale
Overview
Hybrid Hospital-Wide (All-Cause, All-Procedure) Risk-Standardized Mortality (HWM) in Hospital IQR
Hospital 30-day, All-Cause, Risk-Standardized Mortality Rate Following Coronary Artery Bypass Graft (CABG) Surgery in Hospital VBP
Hospital 30-Day, All-Cause, Unplanned, Risk-Standardized Readmission Rate (RSRR) Following Coronary Artery Bypass Graft (CABG) Surgery in Hospital Readmissions Reduction Program
While the measure developer identified several related measures within other CMS programs, only one similar measure was identified within either Hospital IQR or Hospital VBP programs. The current measure under consideration is distinct from the related measure because it is a procedure specific to CABG mortality. The identified related measure assess a different outcome and/or cohort.
Regarding balance of this measure’s performance, burden, and benefit across populations, the developer’s literature review and analysis do not indicate a potential for differential benefit or harm to specific subgroups of participating entities or their patient populations.
Considerations for the committee: Based on clinical and professional experience, the committee should consider the distribution of benefits and risks/burdens of the measure within the proposed program population.
Time to Value Realization
Overview
None specified
Incorporating MA data will extend the measure to a broader group of Medicare beneficiaries, thereby improving representativeness and reducing potential selection bias. In the near term, some hospitals may experience modest changes in scores as MA beneficiaries are incorporated. Over the longer term, a single, comprehensive Medicare cohort will provide more consistent tracking of performance trends, enhance comparability across hospitals and regions, and better reflect true differences in hospital quality.
Considerations for the committee:
- What are the potential near- and long-term impacts of this measure’s revisions on measured entities, Hospital IQR and Hospital VBP programs, and patient populations?
- Will benefits and burdens associated with this measure be realized within an appropriate implementation time frame?
- How will this measure mature through revisions in the future if added to the Hospital IQR and Hospital VBP measure sets?
Public Comments
MUC2025-046
The Kansas Hospital Associaton has concerns regarding the substantive changes identified in this measure.
The inclusion of Medicare Advantage (MA) beneficiaries raises concern, as hospitals have limited ability to account for or influence MA plan utilization management policies, including prior authorization requirements, network limitations, plan directed discharges and post-acute care restrictions. These plan-level factors may affect utilization outcomes in ways that are unrelated to hospital performance and could introduce variability that is outside the hospital’s control.
We recommend reconsideration of the inclusion of MA beneficiaries in the cohort utilization calculations to ensure the measure more accurately reflects hospital performance.
RSMR Following CABG Hospitalization
The American Medical Association (AMA) believes that additional analyses are needed before revised measures are implemented. Like our concerns raised on the readmission and excess days in acute care measures, it is not clear to what degree is the reported association of lower readmissions with higher mortality found over longer or shorter time periods such as, one year or one week, as compared to the first 30-days post discharge. Gupta and co-authors report that the inverse association was still evident at one year.2 To what degree are any positive or negative correlations related to all-cause mortality and/or readmissions versus the condition-specific outcome? It is also worth examining whether trends exist based on unadjusted data and adjusted data. Most of the studies identified through our search of the literature, including Dharmarajan, et al.[1], used risk-adjusted data. Most individual patient care decisions are not made with risk-adjustment in mind. To better understand the outliers (those who died), there is a need to investigate and determine whether there is small, but important associations between patient mortality and readmissions rates. Therefore, are we masking the issue by only examining the adjusted rates? Examination of unadjusted and risk-adjusted rates could help address this concern. We also believe that the timeframe of the mortality measures and whether the post discharge period is appropriate must be reexamined.
In addition, this measure includes some of the same changes that CMS has made to the readmission measures in Hospital Readmissions Reduction Program (HRRP); specifically, the risk adjustment model was updated to use individual ICD-10 codes rather than the CMS Hierarchical Condition Category (HCC) model; the measure now includes Medicare Advantage (MA) beneficiaries; and the data collection timeframe is two years. How each of these changes impact the reliability and validity of the measure has not been provided in this submission and we are concerned that without a phased approach, it will be extremely difficult for hospitals to determine their impact (e.g., what is the effect of the expansion to MA beneficiaries as compared to the reduction in the number of years of data used to calculate the measure). We also recommend CMS provide data on how hospitals’ performance shift since the potential impact on each hospital is critical to ensure that the results can be used to drive further improvement in patient care.
Lastly, we also question the lack of socio-economic factors in the risk adjustment due to evidence that hospitals with larger populations of poor patients perform poorly on the measures. We recognize that some of the measures have been tested to consider economic related variables; however, we do not believe the appropriate risk models were tested. The traditional approach of risk adjusting at the patient level may not be appropriate for measures where the measurement period includes care that is outside of the control of the hospital and a 30-day post-acute phase where the availability of community supports, and other resources directly impact a patient’s care. We believe that there may be community-level variables that affect the risk of mortality during the days following hospital admission but are not currently addressed. Measures that extend beyond the hospital stay or outside the locus of control of the measured entity should continue to have socio-economic adjustments addressed and analyzed at different levels (e.g., patient, hospital, and community).
Due to these concerns and unanswered questions, the AMA does not support inclusion of this measure in the Hospital Inpatient Quality Reporting Program or the Hospital Value-Based Purchasing Program.
[1] Dharmarajan, Wang, Lin, et al. Association of Changing Hospital Readmission Rates With Mortality Rates After Hospital Discharge. JAMA. 2017;318:270-278.
RSMR- CABG
As the agency did in last year’s PRMR process, CMS included this updated measure on the MUC list because it intends to include Medicare Advantage beneficiaries in the denominator. We appreciate the general effects this change would have to improve the accuracy and timeliness of this measure, namely doubling the patient cohort and allowing CMS to shorten the performance period. However, it is unclear from the supporting documentation whether any analysis has been done to determine the implications of including these beneficiaries for the outcomes of the HVBP program, and testing has only been conducted on the existing (rather than updated) measure using one year of data from 2024. While MA beneficiaries are increasing as a proportion of total Medicare enrollees nationally, MA market penetration and specifics of enrollee makeup still varies widely. Because HVBP payment adjustments are calculated based on the distribution of all participating hospitals’ performance on measures within the program, the inclusion of MA beneficiaries in this calculation could mean significant changes in the distribution of scores, and as a result, in the payments hospitals experience under the HVBP program. We hope that the measure developer can provide additional insight into how this significant change to the measure’s specifications would impact the HVBP program and the hospitals that participate in it.
Comments on MUC2025-046
Vizient appreciates efforts to update the MUC2025-046: Hospital 30-Day, All-Cause, Risk-Standardized Mortality Rate (RSMR) Following Coronary Artery Bypass Graft (CABG) Surgery measure by adding Medicare Advantage (MA) population data as more than half of Medicare patients are covered through MA plans. While Vizient recognizes the importance of updating quality measures to reflect a broader range of Medicare beneficiaries, we continue to believe that additional steps are needed to ensure that MA data can be used reliably alongside fee-for-service (FFS) data. For example, as noted in Vizient’s FY 2026 IPPS Proposed Rule comments, there may be differences in how FFS claims and MA encounter data are recorded, yet it does not appear that an analysis to identify the impact of these types of differences has been completed. Vizient encourages P4QM to consider our recommendation that CMS analyze the data to ensure encounter data is accurate and comparable between FFS and MA before including MA beneficiaries in these measures.
In addition, another important consideration is that MA populations can vary significantly across plans, and in some cases may be selectively healthier. Without careful attention to appropriate risk adjustment, these differences could unintentionally bias performance results. Ensuring that MA data are risk‑adjusted correctly is essential for fair and meaningful comparisons across hospitals.
Comment re: MUC2025-046
We request transparent model specifications, transition periods, and social risk adjustment to avoid penalizing hospitals serving vulnerable populations.
Premier supports Hospital…
Premier supports Hospital-Level, 30-Day, Risk-Standardized Mortality Rate quality measures. Given the growth in Medicare Advantage (MA) enrollment, Premier supports the expansion of these measures to include MA beneficiaries.
However, Premier questions the application of these quality measures for improvement purposes when the data lags by two years. This can impact both the observed performance by not reflecting today’s outcomes and the risk adjustment by using older data to create expected values for more recent patients. Premier has also observed that the risk standardized results do not change much over time and may not reflect performance improvement because it is heavily driven by the random effect in the model. The use of the Predicted to Expected ratio rather than the Observed to Expected ratio, while helpful to reduce undue influence from outliers, does not provide a good reflection of actual performance. Consequently, CMS should emphasize that this methodology is best suited for payment purposes and not quality improvement purposes. The utility of the measure is further hindered by the facility level hierarchical methodology, which does not allow for drill downs into further subgroups, e.g. by physician grouping.
Additionally, Premier is concerned that the quality measurement risk adjustment methodology developed by CMS does not perform well. Premier disagrees with the prior research methodology committee’s decision that a C-statistic of 0.6 for model performance is sufficient to use the risk model to adjust quality measure performance. Similarly, the thresholds for validation and reliability are also too low for both public reporting and payment purposes. CMS should revisit its methodology immediately to ensure it is rewarding and/or penalizing hospitals accurately.
MUC2025-046 measure
Support with modification: Requires careful attribution to avoid penalizing MA Plans for facility-driven variation.
30-Day Mortality Rate Following CABG Surgery Hospitalization
The American Occupational Therapy Association (AOTA) supports capturing data for Medicare Advantage (MA) beneficiaries in the Hospital 30-Day, All-Cause, Risk-Standardized Mortality Rate (RSMR) Following CABG Surgery measure. Including MA data is critical to providing a complete and accurate picture of outcomes, given the growing enrollment in MA plans. This addition will enhance transparency, allow for meaningful comparisons across coverage types, and ensure accountability for all payers to cover necessary, high-quality care provided to Medicare beneficiaries.