Association between publication of appropriate use criteria and the temporal trends in diagnostic angiography in stable coronary artery disease: a population based study

Background — The appropriate use criteria (AUC) were developed to aid clinicians in making clinical decisions regarding coronary angiography. The aim of the present study was to evaluate the association between the publication of the AUC criteria in diagnostic angiography and rates of angiography in Ontario.

Methods — Our cohort consisted of all patients who underwent coronary angiography in Ontario from October 1st, 2008 to October 31st, 2013 for the indication of suspected stable coronary artery disease. We determined monthly age and sex-standardized rates of angiography per 100,000 adults. To determine the association between the publication of the AUC for diagnostic angiograms and the rates of angiography, we conducted a time series analysis using an autoregressive integrated moving average (ARIMA) model. As a sensitivity analyses, we evaluated the impact of the AUC on the rates of percutaneous coronary intervention (PCI) per 100 angiograms.

Results — We included 114,551 angiograms for stable coronary artery disease. In the period prior to the publication of the AUC, the average monthly age-sex standardized rate of angiography was 18.7 per 100,000; post-AUC, the average monthly rate decreased to 17.6 per 100,000 adults (p=0.037). In contrast, in the 29,358 PCI’s included in the analysis, the monthly PCI rates per 100 angiograms was unchanged (25.2 pre AUC; 26.8 post AUC; p=0.29). In the sensitivity analysis, the rate of appropriate/inappropriate and uncertain indication did not significantly change over the study period.

Conclusions — The publication of the diagnostic angiography AUC criteria was associated with a decrease in the population rates of diagnostic angiography. This suggests that the AUC potentially was associated with an increased threshold to pursue invasive diagnostic testing.