Abstract 130: Revascularization Rates Have Decreased for Commercially-Insured Adults in Michigan, 2006-2010

Abstract

Introduction: Recently published trend studies of Percutaneous Coronary Intervention (PCI) and Coronary Artery Bypass Graft (CABG) in the U.S. have used primarily Medicare data, and most focus on inpatient claims. These studies have observed a decrease in CABG, with steady or declining PCI from 2001-2009. Little is known about trends in revascularization among a non-Medicare population. This study aims to understand recent trends in rates of coronary revascularization among a commercially-insured non-Medicare population, using both inpatient and outpatient claims data. The study will describe potential areas of focus for an incentive program to engage primary care physicians (PCPs) and cardiologists. Methods: The study population (median 1,920,169 persons/month) included members of Blue Cross Blue Shield of Michigan aged 18-64 and residing in Michigan. Using inpatient and outpatient administrative claims data, monthly crude and sex- and age-adjusted PCI and CABG utilization rates (per 1,000 member-months) were calculated from January 1, 2006 to December 31, 2010. Trend was assessed using Spearman's Rank Correlation test. The Wilcoxon Rank Sum test was used to compare the median age for those receiving PCI and CABG services. The Pearson Chi-Square test was used to assess differences in the distribution of demographic factors by procedure type and by year (2006 vs. 2010). Results: The overall annual crude rate of PCI decreased by 23.5% over the study period, from 0.319 in 2006 to 0.244 in 2010; there was a greater decrease for women than men (25.2% vs 21.4%). Annual CABG rates decreased by 30.7%, from 0.077 in 2006 to 0.053 in 2010 (women: 31.1%; men: 29.1%). Compared to men, PCI accounted for a higher proportion of revascularization procedures among women (82.1% vs 79.0%, p <0.01). The median age for those having a PCI was lower than for those having a CABG (57 vs. 59 years; p <0.01). There was a significant association between type of revascularization and age group ( p <0.01). The majority of procedures were performed in older adults aged 55-64 (CABG: 72.3%, PCI: 62.9%). Conclusions: Both PCI and CABG rates have decreased from 2006 to 2010 for a commercially-insured population in Michigan. Persons receiving CABG were generally older than those receiving PCI. Future studies will examine time trends by type of PCI and explore potential factors contributing to the observed decrease in revascularization rates. The current findings may be used to encourage increased discussions between PCPs and cardiologists about the care of shared patients.