Abstract 240: Differences in Test-related Clinical and Economic Outcomes between Patients who underwent Single-photon Emission Computed Tomography using Regadenoson versus Patients who underwent Echocardiograms using Dobutamine

Abstract

Adult patients who underwent single-photon emission computed tomography (SPECT) myocardial perfusion imaging testing with regadenoson and echocardiogram (ECHO) testing with dobutamine on the same day or within 1 day of testing (07/01/2006-05/31/2011) were selected from the MarketScan Commercial and Medicare Supplemental Database (01/01/2006-06/30/2011). The latest test date was designated as the index date. Continuous health plan benefits 6-month pre- and 30-day post-index date, and no stress, planar, SPECT or ECHO test, or regadenoson, dipyridamole, adenosine or dobutamine prescriptions during the 6-month baseline period were required. Test-related complications, symptoms, adverse events, healthcare costs and utilizations were defined as being measured on the index and next day. One-month follow-up healthcare costs and utilizations were estimated and compared. Propensity score matching controlled for baseline age, gender, region, comorbidities, medications and healthcare cost and utilization differences. A total of 161,834 regadenoson and 12,842 dobutamine patients were included. Regadenoson patients were older (66.60 vs. 63.40, p<0.0001), more likely male (49.68% vs. 41.60%, p<0.0001) and with cardiovascular disease (27.16% vs. 19.96%, p<0.0001), and less likely with COPD or asthma (13.51% vs. 15.87%, p<0.0001) and renal failure (7.58% vs. 8.34%, p<0.0001) than dobutamine patients at baseline. At follow-up, regadenoson patients had fewer test-related ER and inpatient visits, lower dyspnea and renal failure rates, and lower inpatient and outpatient costs. After matching, 7,786 patients were included per cohort. Risk-adjusted results showed that regadenoson patients had fewer test-related ER (2.41% vs. 4.16%) and inpatient visits (0.60% vs.1.35%), and other arrhythmias (2.03% vs. 3.63%) (all p<0.0001). Test-related dyspnea (3.19% vs. 6.04%, p<0.0001), chronic airway obstruction (0.62% vs. 1.07%, p=0.0021) and renal failure (0.66% vs. 1.37%, p<0.0001) were also lower for regadenoson patients. Regadenoson patients incurred lower test-related inpatient ($122 vs. $360, p=0.0005), but higher total outpatient ($1,882 vs. $1,412, p<0.0001) and total costs ($2,032 vs. $1799, p=0.0021). In the 1-month follow-up, regadenoson patients had fewer inpatient (10.65% vs.14.5%, p<0.0001) and ER visits ($7.58% vs. 9.17%, p=0.0003) and lower inpatient ($3,057 vs. $4,137, p<0.0001) and higher outpatient costs ($3,887 vs. $3,112, p<0.0001). There was no significant difference in total costs ($7,333 vs. $7,641, p=0.2739). Regadenoson patients had fewer test-related inpatient and ER visits and adverse events, and lower inpatient costs, compared to dobutamine patients. Although total test-related costs were higher for regadenoson, inpatient costs remained significantly lower in the 1 month after testing. The total cost burden was similar for both cohorts.