Wait Time for Coronary Artery Bypass Graft Surgery Full data definition sign-off completed. Name of Name of (short) Domain Type of Business Context Rationale Notes for Interpretation Organizational Strategy Benchmark Comparisons Cited References: Wait Time for Coronary Artery Bypass Graft (CABG) Surgery by Urgency Level: 90th percentile wait time (in weeks) from date of cardiac catheterization, to date of treatment for Adults. Coronary Artery Bypass Graft (CABG) Surgery 90th Percentile Wait Time: Adults The wait time for coronary artery bypass graft surgery (CABG) is the 90th percentile wait time (in weeks) from the date of cardiac catheterization to the date of surgery. When a cardiac catheterization is not performed, the wait time start date is the date of alternate imaging. If no imaging is performed, the wait time would begin at referral to surgery. Patients whose urgency rating changed during their wait time are included in volumes but not in the wait time calculations. Quality of Health Services. Dimension of Quality: Accessibility. Process This performance measure supports AHS government accountability reporting processes related to health system performance. For example: Health Wellness Ministry 2010-2013 Business Plan: Performance measure 5.c.: Wait time for coronary artery bypass graft surgery: 90 th percentile wait time in weeks, as listed under Goal 5, Appropriate access to services across the continuum of care 3. Alberta Health Services 2010-2015 Health Plan. AHS Senior Leadership Performance Targets For annual reporting, the calculation uses data from patients served in the fiscal period April 1 to March 31. For AWR monthly reporting: Waitlisted cases completed between rolling 3 month period prior to current reporting month end. For quarterly reporting: Waitlisted cases completed during the reporting quarter: June 30, September 30, December 31, March 31. Providing reasonable access to health service is a major objective a defining attribute of the publicly funded health system. Longer waits affect health status quality of life result in more costly health services. Delays due to patient preference or medical reasons are excluded from the wait time calculation. Patients whose urgency/priority rating changed during their wait time are excluded from the wait time calculations. They are included in volume counts. Applies to only adults 18 years of age older. This measure supports the strategy to reduce the wait time for surgical procedures. Alberta Tier 1 Targets are consistent with those of the Canadian Cardiovascular Society Benchmarks 2 : Urgency I (Urgent) - 1 week Urgency II ( Semi-Urgent) - 2 weeks Urgency III (Scheduled) - 6 weeks 1 Draft Tier 1 Performance s for Alberta Health Services linked to 5-Year Funding 2010-2015, Alberta Health Wellness (2010). 2 Canadian Cardiovascular Society, http://www.ccs.ca/download/position_statements/wait%20time%20benchmarks%20for%20cardiovascula r%20services%20%20procedures_e.pdf, page 3. 3 Health Wellness 2010 to 2013 Ministry Business Plan, Alberta Health Wellness (2010), page 9. Page 1 of 5
Technical Specifications Metric Preferred Display Format 9.9 Inclusion Criteria for 90 th Percentile in Weeks Number of days that patients with a coronary artery bypass graft (CABG) performed had waited, converted to weeks All coronary artery bypass graft (CABG) events In Edmonton data the event is identified by the term CABG in the procedure description In Calgary data the event is identified by the term CAB in the procedure description All open heart surgeries with a coronary artery bypass graft (CABG) included Only adults 18 years of age older All Urgency Levels Exclusion Criteria for Data Source(s) for Refresh Rate of Inclusion Criteria for Exclusion Criteria for Data Source(s) for Refresh Rate of Emergency cases Patients whose urgency/priority rating changed during their wait time In Edmonton, the data is contained in a real time Microsoft Access database: "The Open Heart Surgery Waitlist database". In Calgary the data is available from 3 sources: VELOS, APPROACH, OR data from ORIS, the OR database. Monthly Page 2 of 5
Technical Notes Calculation A percentile is defined as a point on a rank-ordered scale, found by sorting a group of observations in order of magnitude from lowest to highest. The first percentile approximates the very lowest/bottom number found, while the 100th percentile is the very highest reported. The nth percentile is the point exceeding n percent of the observations. As follows, the 90th percentile wait time is the observed wait time that is equal to or greater than 90 percent of other observations. Treatment date is the date the surgical intervention took place. For a set of measurements arranged in order of magnitude, the pth, in this case, 90th percentile is the value that has p, or 90 percent of the measurements below it (100-p), or 10 percent above it. AHS The 90 th percentile is calculated using the percentile function in Microsoft Excel. AHW SAS Code Used for BIE Analytics: The 90 th percentile statistic is obtained by use of a SAS module PROC MEANS, to produce simple univariate descriptive statistics for numerical variables. The BY variable in this case is WAITLIST_INTERVENTION_RCAT_ID=16, the numerical variable is weeks_wait, which is the calculated wait time for each observation. The selected SAS output statistic for 90 th percentile is P90. SAS code for calculation of percentile is as follows: rsubmit; data AWRBIE_SELECT_INTV_FY; set ods_prod.detailed_waitlist_event_awr_v_i2; start_date = '01Apr2009:0:0:0'dt; end_date = '31Mar2010:0:0:0'dt; weeks_wait=days_waited/7; data AWRBIE_SELECT_INTV_byurg; set AWRBIE_SELECT_INTV_FY; if date_off ge start_date date_off le end_date INCLUDE_IN_MWT_IND EQ 'Y' SCHEDULED_FOLLOWUP_IND ne 'Y' AND INTERVENTION_POSTPONED_IND NE 'Y' ( MISSING(DECEASED_DT) OR DECEASED_DT gt end_date ) (WAITLIST_INTERVENTION_RCAT_ID eq 16) ; IF substr(urgency_code,1,1) eq '1' THEN REPORT_CATEGORY_ID=71; ELSE IF substr(urgency_code,1,1) eq '2' THEN REPORT_CATEGORY_ID=72; ELSE IF substr(urgency_code,1,1) eq '3' THEN REPORT_CATEGORY_ID=73; Page 3 of 5
Calculation (continued) data AWRBIE_SELECT_INTV_FY; set AWRBIE_SELECT_INTV AWRBIE_SELECT_INTV_byurg; proc sort data=awrbie_select_intv_fy; by REPORT_CATEGORY_ID weeks_wait; PROC MEANS DATA=AWRBIE_SELECT_INTV_FY; Relationship to Other Indicators Level of Reporting Frequency of Reporting Limitations BY REPORT_CATEGORY_ID; VAR weeks_wait; ID REPORT_CATEGORY_ID; OUTPUT OUT=AR_FY_WT_STATS p90=wt90th; title 'AWR 90th Percentile Wait Times for Coronary Artery Bypass Graft Surgery (CABG), by Urgency Level '; proc print; run; endrsubmit; Provincial Zone Facility Urgency Code Annually, Quarterly, Monthly The quality of the data may limit reporting on the measure. Patient related delays are subtracted from wait time calculations in Edmonton but included in wait time calculations in Calgary. This indicator does not measure the entire wait time from a patient perspective. The wait time between referral from a family practitioner to the time seen by a specialist is not measured. In some situations following cardiac catheterization, the decision is made to treat the patient medically. Subsequently either by an event or symptoms, the decision is changed to treat surgically no follow-up catheterization is performed. In these instances, the wait time from cardiac catheterization to surgical treatment is longer than it would have been if surgical treatment was the initial choice. Monthly data is available within 21 days of quarter end. Data collection processes need to be improved which will include data quality auditing. Page 4 of 5
Document Version History Version Version Date Summary of Changes 1.0 May 18, 2010 Final version for initial use. 1.1 May 18, 2010 Initial development, transfer to final template version. 1.2 May 27, 2010 Review completion of final template. 1.3 June 4, 2010 Updated definitions, metrics details of other areas as required 1.4 June 5, 2010 Clean up formatting. 1.5 June 30, 2010 Add approval statement. 1.6 July 20, 2010 Corrected data source definition. 1.7 July 14, 2010 Revisions. 1.8 July 21, 2010 Revisions. 1.9 Update Executive Lead, minor modifications. 2.0 Version ready for signoff. 2.1 August 12, 2010 Review, adjusted formatting, added Document Version History back in. 2.2 September 14, 2010 Full data definition signoff completed. Page 5 of 5