OBJECTIVES: Computed Tomography (CT) is widely used as a diagnostic tool for medical conditions of the head, chest, cardiac, pulmonary and abdominal system. The objective of this retrospective study was to identify predictors of CT scan use in emergency department (ED) of hospitals in the United States amongst patients suffer- ing from Coronary Artery Disease (CAD).
METHODS: ED component of National Hospital Ambulatory Medical Care Survey (NHAMCS) for years 2005 and 2006 was used for the analysis. Patients were identified based on chief complaint, physician diagnosis and discharge diagnosis for CAD by ICD 9 codes or reason for visit codes. The binary outcome variable was use of CT scan. Independent variables were selected based on available literature on utilization of health services and general demographics. SAS version 9.2 was used for analyses of data. Descriptive statistics were obtained by using survey frequency procedures that accounted for survey design and weighting. Weighted analyses were performed using survey logistic procedure controlling for interactions amongst the independent variables.
RESULTS: During the 2 year period from 2005 and 2006, 3500 patients representing 12,769,828 CAD patients were identified. A total of 340 CAD patients representing 1,229,496 patients underwent CT scan procedure. Observations with missing data were deleted as it constituted less than 1% of the total identified population. Following variables were found signifi- cantly associated with probability of getting a CT scan: Painlevel, EKG use, Physician seen, Physician assistant seen, Race/ethnicity and Mode of arrival. These variables do not act in isolation and interactions between them were considered in the analyses.
CONCLUSIONS: The use of CT scan as a diagnostic tool in CAD patients admitted in ED depends on a multitude of interdependent factors such as patient characteristics defined by painlevel, race/ethnicity, provider characteristics or the type of provider seen and type of health service utilized such as ambulance and concurrent EKG use.
