Abstract P84: Antithrombotic Treatment Patterns, Hospitalizations, and Associated Costs in Acute Coronary Syndrome (ACS) Patients

Abstract

Background: We investigated real-world patterns of use of antithrombotic therapy among ACS patients to evaluate the level of undertreatment, nonadherence to medication use, recurrence of cardiovascular events, and associated costs. Methods: We analyzed the PharMetrics Integrated Claims database from 01/2004 through 12/2009. Patients ≥18 years old with ≥1 claim for ACS during a hospitalization or emergency department visit were included. Adherence to antiplatelet therapy was estimated using proportion of days covered (PDC) by drug available. Persistence was defined as continuous drug claims without a gap of ≥30 days between refills. Major outcomes were cardiovascular disease (CVD)-related hospitalization, readmission, and length of stay. We reported all-cause and CVD-related per-patient-per-month (PPPM) healthcare costs. Incidence rates of major outcomes were calculated as number of patients with an event divided by patient-years of observation, censored at the time of the first event. Results: Among the 173,573 ACS patients, mean age was 55.4 years; 36% (62,914 of 173,573) were female. During follow-up, 36.2% (62,774 of 173,573) and 5.0% (8685 of 173,573) had antiplatelet or anticoagulant prescriptions; 3.4% (5866 of 173,573) had both. Mean duration of antiplatelet therapy was 457 days. At 1.5, 6, and 12 months, mean PDCs were 0.93, 0.78, and 0.70. Kaplan-Meier rates of persistence after 6 and 12 months were 0.66 and 0.47. The incidence rate of CVD-related hospitalization was 0.22 events per patient-year of observation. The rates of CVD-related and all-cause hospital readmissions were 0.32 and 0.41 events per patient-year; mean length of stay was 7.1 and 6.8 days per rehospitalization. All-cause healthcare cost PPPM was $2419; 63% ($1518 of $2419) of total all-cause costs PPPM were associated with claims for CVD-related hospitalization. Conclusions: This observational study suggests undertreatment in secondary prevention of ACS. Persistence with antiplatelet therapy dropped dramatically by 6 months after the initial event. ACS patients have a high risk of repeated CVD-related hospitalizations that incur high costs to the healthcare system. Interventions to improve long-term use of evidence-based therapies may improve ACS management.