VARIATION IN THE RATES OF NORMAL DIAGNOSTIC CORONARY CATHETERIZATIONS AND NON-INVASIVE PRE-CATHETERIZATION CARDIAC DIAGNOSTIC TESTING BY REFERRING PHYSICIAN IN ONTARIO

Abstract

The Cardiac Care Network of Ontario (CCN) serves as a system support to the Ministry of Health and Long Term Care as well as hospitals, and care providers in the province of Ontario, Canada. CCN works to plan, coordinate, implement and evaluate adult cardiovascular care in Ontario, and is responsible for the CCN Cardiac Registry, a clinical registry. Nineteen hospitals in Ontario perform diagnostic coronary catheterizations (CATH) and all enter data into the CCN Cardiac Registry. CATH data in the CCN Cardiac Registry from patients with stable CAD in Ontario were analyzed. Recognizing that non-elective CATH patients may present with acute symptoms that warrant immediate intervention and non-invasive cardiac diagnostic testing may not be appropriate, we excluded these patients from our analysis. Rates were analyzed at the level of the performing cardiac centre as well as the referring physician. Analysis of data in the CCN Cardiac Registry revealed considerable variation in rate of CATHs performed in Ontario in which significant CAD was found with rates ranging from 34% to 60% at the various cardiac centres across the province for the 2016/17 fiscal year. There was also considerable variation observed in the rate of pre-CATH non-invasive cardiac diagnostic testing being performed, ranging from 44% to 87% across centres. Data were also analyzed at the level of the referring physician. Interestingly, 65% of referring physicians in Ontario refer less than 10 CATHs in a year with a mean of 23 referrals per physician per year. The rate of significant CAD found in patients referred by each referring physician varied widely from 0% to 100%. Similarly the rate of referring physicians that referred their patients for CATH and had done some sort of pre-CATH non-invasive cardiac diagnostic testing also varied widely ranging from 0% to 100%. While a proportion of CATH results are expected to be in the range of normal or non-significant CAD, the target rate is unknown. Our analysis revealed large variation in the rate of CATHs in which significant CAD was found across cardiac centres in Ontario and a larger variation across referring physicians in Ontario. A similar variation was observed in pre-CATH non-invasive cardiac diagnostic testing across centres and referring physicians. These results indicate that CATH referring physicians in Ontario represent an important target for quality improvement. Educational interventions aimed at the referring physician may be an opportunity to reduce variation in these CATH utilization metrics.