Methodology
Name
30-Day In-Hospital Mortality After Coronary Artery Bypass Graft (CABG) and Aortic Valve Replacement (AVR)
Short/Other Names
CABG and AVR Mortality
Description
Risk-adjusted rate of all-cause in-hospital deaths occurring within 30 days for patients undergoing coronary artery bypass graft (CABG) and aortic valve replacement (AVR) surgery.
For further details, please see the Cardiac Care Quality Indicators (CCQI) General Methodology Notes (PDF).
Rationale
Considering that about 2.4 million Canadians are living with heart disease and that Canada's population is increasingly at risk,1 it's important to examine the quality of cardiac care in order to support improvements in care and ultimately in the health of Canadians.
CABG is a well-established procedure to treat coronary artery stenosis and AVR is a common procedure to treat aortic valve stenosis. An increasing number of people in the aging population suffer from the combination of coronary artery stenosis and aortic valve stenosis and are candidates for a combined CABG and AVR surgery. In most cardiac care centres, this is the third most frequent cardiac surgery (after isolated CABG and isolated AVR). Short-term mortality following CABG and AVR surgery has been identified as a key quality indicator for cardiac surgery care by the Canadian Cardiovascular Society.2 Combined CABG and AVR surgery is considered to be high risk compared with isolated CABG and isolated AVR.
The indicator can provide direction for quality improvement and can help hospitals identify peers to facilitate knowledge sharing around best practices of care.
Interpretation
Lower rates are desirable.
HSP Framework Dimension
Health system outputs: Appropriate and effective
Areas of Need
Getting Better
Targets/Benchmarks
Not applicable
Available Data Years
to (fiscal years)
Geographic Coverage
- All provinces/territories
Reporting Level/Disaggregation
- National
- Province/Territory
- Facility
Indicator Results
Update Frequency
There will be no further updates to this indicator.
Latest Results Update Date
Updates
Not applicable. Please refer to the CCQI General Methodology Notes (PDF).
Description
The risk-adjusted rate for a facility is calculated by dividing the observed number of in-hospital deaths for each facility by the expected number of in-hospital deaths for the facility and multiplying by the Canadian average in-hospital death rate.
Unit of analysis: Episode of care
An episode of care refers to all contiguous inpatient hospitalizations and same-day surgery visits. For episodes with transfers within or between facilities, transactions were linked regardless of diagnoses. For further details, please see the CCQI General Methodology Notes (PDF).
Type of Measurement
Rate - Rate - per 100
Denominator
Description:
Number of hospitalization episodes for patients age 18 and older who underwent a CABG and AVR surgery
Inclusions:
- Episodes that had a CABG (CCI code 1.IJ.76.^^) and AVR (CCI code 1.HV.90.LA-^^) during the same operating episode, where the interventions were not coded as out of hospital or abandoned (Out-of-Hospital Indicator not equal to Y and Intervention Status Attribute not equal to A)
- Discharge date at the end of the episode between April 1 and March 31 of the fiscal year
- CABG and AVR surgery date on or before March 1 of the fiscal year (to allow for a 30-day follow-up to capture deaths occurring in the same fiscal year). CABG and AVR surgeries performed prior to the fiscal year may be included if the discharge date at the end of the episode of care was in the following fiscal year.
- First CABG and AVR within 30 days (i.e., repeat CABG and AVR surgeries within 30 days are excluded)
Exclusions:
- Episodes with other valve procedures (CCI codes 1.HS.^^Therapeutic Interventions on the Tricuspid Valve, 1.HT.^^Therapeutic Interventions on the Pulmonary Valve, 1.HU.^^Therapeutic Interventions on the Mitral Valve, 1.HW.^^Therapeutic Interventions on the Annulus not elsewhere classified and other aortic valve procedures not in the inclusion list: 1.HV.80.^^, 1.HV.90.ST-^^, 1.HV.90.GQ-XX-L, 1.HV.90.GR-^^, 1.HV.90.WJ-^^)
- Episodes with core concomitant procedures. Please see the CCQI General Methodology Notes (PDF) for the detailed list of procedures and codes.
Numerator
Description:
Number of hospitalization episodes in the denominator that resulted in an in-hospital death within 30 days of CABG and AVR surgery
Inclusions:
- In-hospital death (Discharge Disposition = 07, 72*, 74*)
Note
*2018–2019 data onward.
Exclusions:
None
Method of Adjustment
Logistic regression
Adjustment Applied
Covariates used in risk adjustment:
Age, sex, urgent admission, shock, NSTEMI, previous acute myocardial infarction, previous cardiac surgery, cardiac dysrhythmias, multiple cardiac interventions, acute renal failure, Charlson Index.
For detailed definitions of covariates and the risk-adjustment methodology, please refer to the CCQI General Methodology Notes (PDF).
Geographic Assignment
Place of service
Data Sources
- DAD
- HMDB
- NACRS
Caveats and Limitations
- Cardiac care is delivered by many different health care professionals, and the resulting outcomes are a reflection of the whole system of care, rather than being attributable to a particular physician in a centre. Quality outcomes depend not only on a physician's technical skills, but also on the structure and care processes that are found in the environment in which health care is delivered.3
- Some cardiac care centres are more specialized, perform interventions on more complex patients or accept higher-risk patients than average. CIHI is able to adjust for some of these differences across patient populations; however, the administrative data submitted is limited in its ability to capture and adjust for all differences associated with patient populations. Centres with more complex patients may have increased mortality and/or readmission rates because not all aspects of complexity can be adjusted for in the administrative data.
- Transferring patients to a different hospital following a cardiac intervention is normal practice for many cardiac care centres. As such, there are potential learning opportunities beyond the centres included in this indicator.
- Rates with wide confidence intervals should be interpreted with caution as they reflect a less-precise estimate.
- Direct comparisons between cardiac care centres or provinces are discouraged. Comparisons with the Canadian average provide more meaningful information.
- Indicator results do not provide a final conclusion about cardiac care performance and can be used as a first step in an improvement process to identify areas for follow-up and potential improvements.
- Out-of-hospital deaths are not captured in CIHI's administrative databases.
Trending Issues
Not applicable
References
- Government of Canada. Heart Disease in Canada. Accessed February 22, 2019.
- Canadian Cardiovascular Society. Quality Indicators for Cardiac Surgery (PDF). 2015.
- Donabedian A. The Criteria and Standards of Quality. 1982.
Comments
This indicator belongs to a suite of Cardiac Care quality indicators (CCQI) that provided pan-Canadian comparable information on outcomes related to selected cardiac interventions. The goal was to support monitoring and quality improvement in cardiac care.
More information on the CCQI Report is available on our Cardiac Care web page.
Publicly available indicator results are based on 3 years of pooled data. Results for 2018–2019 to 2020–2021 are the last that will be published for the CCQI indicators. Note that 3-year pooled results for 2017–2018 to 2019–2020 are not available.
Indicator results based on 1 year of data between 2013–2014 and 2020–2021 are also available: