Defense Date


Document Type


Degree Name

Doctor of Philosophy



First Advisor

Spencer E Harpe


OBJECTIVES: To determine the pattern and predictors of use of antiplatelet agents and beta-blockers given in the emergency department (ED) to older adults with acute myocardial infarction (AMI) and its effects on in-hospital mortality and length of hospital stay (LOS) and to determine the effect of computerized ED guideline reminders on their utilization. METHODS: A cross-sectional study using the National Hospital Ambulatory Medical Care Survey (NHAMCS) ED data for years 1992 to 2010 was conducted. Patients were included if they had an admission diagnosis of AMI (ICD-9-CM code 410.xx) and were ≥55 years. Survey logistic regression was used to examine whether there was a trend in the use of antiplatelet agents and beta-blockers across the years and to explore the association between various predictor variables, including ED computerized guideline reminders, and their utilization rates. The chi-square test was used to see whether users of these drugs were different from non-users in their rates of in-hospital mortality. Survey linear regression was used to explore the effect of utilization of these drugs on LOS. All the visits were weighted to get national estimates. All of the analyses were carried out with SAS 9.3 statistical package. RESULTS: A total of 1,771 visits (weighted frequency = 6.1 million) were eligible for this study. Both antiplatelet agents and beta-blockers were shown to have a positive trend across the years. Age, sex, chest pain, triage, using an ambulance, and metropolitan region were all found to be significant predictors of either antiplatelet agent or beta-blocker utilization. Use of beta-blockers was associated with lower in-hospital mortality. Neither drug class had an effect on LOS. Finally, patients who were treated in EDs with computerized guideline reminders were twice as likely to get an antiplatelet agent, but this was not seen with beta-blockers. CONCLUSION: This study displayed a positive pattern across the years in the use of antiplatelet agents and beta-blockers given to older AMI patients. It also showed that age, sex, and other important variables were significant predictors of their utilization. The use of beta-blockers yielded lower in-hospital mortality. Finally, the use of ED reminders increased antiplatelet agent utilization.


© The Author

Is Part Of

VCU University Archives

Is Part Of

VCU Theses and Dissertations

Date of Submission

May 2013