Assessment of temporal trends in mortality with implementation of a statewide ST-segment elevation myocardial infarction (STEMI) regionalization program

Study objective: Although regionalized care for ST-segment elevation myocardial infarction (STEMI) has improved the use of timely reperfusion therapy, its effect on patient outcomes has been difficult to assess. Our objective is to explore temporal trends in STEMI mortality with the implementation of a statewide STEMI regionalization program (Reperfusion of Acute Myocardial Infarction in North Carolina Emergency Departments [RACE]). Methods: We compared trends in inpatient mortality among STEMI patients treated at North Carolina (NC) hospitals participating in the RACE program, relative to those not participating, using state inpatient claims data. Using Medicare claims data, we compared trends in 30-day mortality among Medicare beneficiaries in NC with those nationally. Logistic models with random effects were used to evaluate the association of the program with mortality. Results: From 2005 to 2007, inpatient mortality for 6,565 STEMI patients treated at NC hospitals participating in RACE decreased from 11.6% to 10.1% (risk difference -1.5%; 95% confidence interval [CI] -3.0% to 0.04%), whereas inpatient mortality among 5,850 STEMI patients treated at NC nonparticipating hospitals decreased from 10.2% to 8.6% (risk difference -1.6%; 95% CI -3.1% to 0.10%); (adjusted odds ratio 1.28; 95% CI 0.88 to 1.85 for temporal differences between groups). During the same period, 30-day STEMI mortality among Medicare beneficiaries decreased from 22.7% to 21.4% in NC (risk difference -1.28%; 95% CI -3.60% to 1.03%) and from 22.3% to 21.6% nationally (risk difference -0.71%, 95% CI -1.13% to -0.29%; adjusted odds ratio 0.99, 95% CI 0.85 to 1.15 for temporal differences between regions). Conclusion: The initiation of a statewide STEMI collaborative care model was associated with a reduction in mortality rates according to claims data, yet these changes were similar to those seen nationally. Further study is needed to evaluate regionalized systems of STEMI care and to determine the role of claims data to evaluate population-based STEMI outcomes.