Table 2.

Outcomes and Statistical Models

End point

Death within study period*

Prehospital cardiogenic shock

Prehospital cardiac arrest

In-hospital heart failure

Evidence-based therapies: reperfusion treatment, aspirin, β-blockers, angiotensin-converting enzyme inhibitor/angiotensin receptor blocker, statin, P2Y12 antagonist

Statistical models

Unadjusted models

Unadjusted Cox proportional hazards regression or unadjusted logistic regression models

Age-adjusted models

Cox proportional hazards regression or logistic regression adjusted for age

Risk factor–adjusted models

Cox proportional hazards regression model/logistic regression adjusted for risk factors†age, smoking habits, hypertension, diabetes, hyperlipidemia, previous myocardial infarction, previous cardiac surgery, previous PCI, STEMI, and calendar year

Risk factor– and treatment-adjusted models

Propensity score–adjusted Cox proportional hazards regression model adjusted for risk factors and treatment. Propensity scores were calculated from the variables age; smoking habits; hypertension; diabetes; hyperlipidemia; previous myocardial infarction; previous cardiac surgery; previous PCI; STEMI; calendar year; BMI; prehospital cardiac arrest; prehospital cardiogenic shock; in-hospital heart failure; revascularization treatment; and discharged with β-blocker, aspirin, ACEI/ARB, antiplatelet therapy, oral anticoagulant, and/or statin.

All statistical models were multilevel models with patient as the first-level unit and treating hospital as the second-level unit. ACEI indicates angiotensin-converting enzyme inhibitor; ARB, angiotensin receptor blocker; BMI, body mass index; PCI, percutaneous coronary intervention; STEMI, ST-segment elevation myocardial infarction.

^*Primary end point.

^†Primary model.