Racial and ethnic differences in time to acute reperfusion therapy for patients hospitalized with myocardial infarction

Abstract

Context: Nonwhite patients experience significantly longer times to fibrinolytic therapy (door-to-drug times) and percutaneous coronary intervention (door-to-balloon times) than white patients, raising concerns of health care disparities, but the reasons for these patterns are poorly understood.

Objectives: To estimate race/ethnicity differences in door-to-drug and door-to-balloon times for patients receiving primary reperfusion for ST-segment elevation myocardial infarction; to examine how sociodemographic factors, insurance status, clinical characteristics, and hospital features mediate racial/ethnic differences.

Design, setting, and patients: Retrospective, observational study using admission and treatment data from the National Registry of Myocardial Infarction (NRMI) for a US cohort of patients with ST-segment elevation myocardial infarction or left bundle-branch block and receiving reperfusion therapy. Patients (73,032 receiving fibrinolytic therapy; 37,143 receiving primary percutaneous coronary intervention) were admitted from January 1, 1999, through December 31, 2002, to hospitals participating in NRMI 3 and 4.

Main outcome measure: Minutes between hospital arrival and acute reperfusion therapy.

Results: Door-to-drug times were significantly longer for patients identified as African American/black (41.1 minutes), Hispanic (36.1 minutes), and Asian/Pacific Islander (37.4 minutes), compared with patients identified as white (33.8 minutes) (P<.01 for all). Door-to-balloon times for patients identified as African American/black (122.3 minutes) or Hispanic (114.8 minutes) were significantly longer than for patients identified as white (103.4 minutes) (P<.001 for both). Racial/ethnic differences were still significant but were substantially reduced after accounting for differences in mean times to treatment for the hospitals in which patients were treated; significant racial/ethnic differences persisted after further adjustment for sociodemographic characteristics, insurance status, and clinical and hospital characteristics (P<.01 for all).

Conclusion: A substantial portion of the racial/ethnic disparity in time to treatment was accounted for by the specific hospital to which patients were admitted, in contrast to differential treatment by race/ethnicity inside the hospital.