AHRQ Data Inform Emory University's Efforts to Determine Heart Bypass Surgery Outcomes

January 2009

Research conducted at the Rollins School of Public Health at Emory University used AHRQ's Nationwide Inpatient Sample (NIS), a database from the Healthcare Cost and Utilization Project (HCUP), to analyze how the source and type of hospital admission impact the outcomes of coronary artery bypass graft (CABG) procedures. According to the researchers, conclusions could not have been drawn from their work without HCUP data.

Lead researcher Edmund R. Becker, PhD, Professor of Health Policy and Management at Rollins, has used HCUP since 1998. His graduate students also use the database extensively to study issues surrounding many types of hospital diagnoses, procedures, and admissions.

Becker found that 75 percent of HCUP inpatient records contain race/ethnicity information; he believes this makes HCUP extremely useful for examining racial disparities in outcomes after hospitalization for various procedures and diagnoses. He was particularly pleased to find data for specific minority populations, such as Asian/Pacific Islanders and Hispanics, available in HCUP data.

According to Becker, HCUP data sets are "robust for studying outcomes, admissions, comorbidities, hospital factors, and disparities associated with hospital coronary admissions."

In their investigation, Becker's group used the NIS from 1998 to 2002 to identify the number of CABG procedures, the source of admission (another hospital, long-term care facility, elective, or emergency department), and type of admission (routine, urgent, or emergency). Approximately 1.7 million cases were identified during that time period.

Results show a large difference in outcome based on type and source of admission. Patients admitted for routine/elective CABGs had a mortality rate of just under 1.5 percent, while patients admitted under urgent conditions from long-term care facilities had mortality rates exceeding 3.6 percent. Interestingly, during the five years' studied, CABG procedures decreased by more than 20 percent.

Until this research was published, there was little to no published research on the influence of type and source of admission on in-hospital CABG mortality rates and patient outcomes.

Impact Case Study Identifier: 
AHRQ Product(s): HCUP-Nationwide Inpatient Sample, Healthcare Cost and Utilization Project (HCUP)
Topics(s): Patient Safety, Quality, Outcomes, Heart Health, Prevention, Disparities
Geographic Location: National
Implementer: Rollins School of Public Health, Emory University
Date: 01/01/2009


Becker ER, McPherson MA, Rahimi A. Influence of source and type of admission on in-hospital mortality for coronary artery bypass surgery patients: National results from 1.7 million CABG patients, 1998 to 2002. Journal of Cardiac Surgery 2007; 22:203-210.


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