Electronic Thesis and Dissertation Repository

Thesis Format

Integrated Article


Master of Science


Epidemiology and Biostatistics


Ali, Shehzad

2nd Supervisor

Garg, Pallav

Joint Supervisor


Social determinants of health contribute to variations in clinical outcomes among acute myocardial infarction (AMI) patients. Using the National Inpatient Sample, we conducted retrospective cohort analyses to evaluate the association of income, race, and geography with in-hospital mortality and revascularization procedures among AMI admissions in the United States from 2015 to 2019. Multilevel logistic regression models were used while accounting for hospital clustering and relevant predictors. A sequential model-building approach produced model 1 (unadjusted patient-level exposures), model 2 (lifestyle factors), model 3 (clinical characteristics), and model 4 (fully adjusted hospital-level factors). We identified 2,798,225 AMI hospitalizations (≥18 years) with 1,567,575 undergoing revascularization procedures. Lowest-income, White, Asian or Pacific Islander, Native American, and Southern residents had higher in-hospital mortality, while higher-income, White, Midwestern, Southern, and Western residents had greater use of revascularization procedures. System-level strategies that improve structural factors are recommended to reduce disparities in AMI outcomes.

Summary for Lay Audience

Heart attacks, or acute myocardial infarctions (AMIs), are a leading cause of illness and death in the United States (US). As of 2020, there were approximately one million deaths due to AMI in the US annually. Existing studies have identified non-medical factors, or social determinants of health (SDH), among AMI patients in the US that cause variation in their management and outcomes while in hospital. However, these studies are limited in their scope, causing their results to not be representative of the US population. Our current study addressed these existing gaps by using the National Inpatient Sample, which represents approximately 98% of the US population, to examine the association between income groups, race, and geography with death in hospital and the use of revascularization procedures among AMI patients in the US from 2015 to 2019.

Using biostatistical methods, we assessed the association between AMI and select SDH while adjusting for the impact of external factors at the patient- (i.e., age, sex, existing medical conditions and histories) and hospital-level (i.e., hospital location/teaching status, bed size). We identified variation in in-hospital death where AMI patients in the lowest-income groups, White, Asian or Pacific Islander and Native American patients, and those from the South experienced greater odds of death during their hospital stay. We also identified that AMI patients in the highest-income groups, White patients, and those presenting to hospitals in the Midwest, South and West had greater odds of receiving revascularization procedures while hospitalized. Studying the association between SDH and in-hospital deaths allows us to better understand how poor health outcomes are distributed among income groups, race, and geographic regions in the US. There is also significance in understanding the variation in the revascularization procedure use and what features of certain SDH or social groups make one more or less likely to receive care. These findings aid in recommending health system-level strategies that aim to reduce resource barriers, provider biases, and other structural factors to diminish the disparities observed among AMI patients in the US.

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