Patterns in computed tomography utilization among emergency physicians in an urban, academic emergency department.

We sought to determine if CT utilization rates varied by characteristics of the physician. A chart review was performed at an urban academic emergency department (ED) to identify all the CT scans ordered and patients seen for subjects 21 years of age and older by physicians between January 2001 and December 2008. "Years of experience" was defined as years of practice after residency. Various experience cutoffs were determined a priori. Physicians were labeled "academic" if they had reduced clinical hours for academic duties and "clinical" if they were physicians without "protected time." We categorized physicians as "high users" (top quartiles) and "low users" (bottom quartiles), and compared utilization rates from 2001 to 2003 to utilization rates from 2005 to 2007. There were 280 physician-years of practice, with an average experience of 6.1 years. When comparing groups of physicians with more or less than 3, 5, 10, and 15 years of experience, there were no statistically significant differences between the number of CT scans per 1,000 visits (p = 0.85; p = 0.21; p = 0.57; p = 0.08, respectively). Comparison between clinical and academic physicians yielded no differences (clinical = 98.4, academic = 104.2, p = 0.10). Low users ordered 78 CT scans per 1,000 patient visits (95 % CI 76.6-78.5), as compared to the high users that ordered 135 CT scans per 1,000 patient visits (95 % CI 131.8-139.0). We found that all of physicians stayed within their quartiles except one. While there was substantial variation among CT utilization rates by physicians at this urban emergency department, our data shows no differences between physicians with more or less clinical experience and no change in individual utilization patterns during the study period.

Computed tomography utilization rates after the placement of a scanner in an emergency department: a single-center experience.

The convenience of a computed tomography (CT) scanner in the emergency department (ED) may impact utilization rates. Our primary aim was to determine the rate of utilization before and after the placement of an ED CT scanner. Secondary aims were to determine the rate of utilization by anatomic region and during a 5-month period when the ED scanner was unavailable. We performed an electronic chart review of our ED with an annual census of 70,000 patients. We identified all patients over the age of 21 who had a CT scan performed from January 2008 to October 2010. Predetermined data elements were extracted by trained, hypothesis-blinded abstractors. Comparisons overall and within scan subtype were performed using seasonal matching. We found a CT utilization rate of 114 per 1,000 patient visits before and 139 per 1,000 patient visits after the placement of a CT scanner in the ED (p<0.0001). Linear regression analysis found a line with a slope of ß=0.114 (95 % CI=0.107-0.121) and an R2 of 0.508. CT rates increased in the following regions: head CTs by 14 per 1,000 visits (p<0.0001); neck CTs by 3 per 1,000 visits (p<0.0001); abdomen/pelvis CTs by 4 per 1,000 visits (p=0.0015); "other" CTs by 2 per 1,000 visits (p<0.0001). Increased rates of chest and facial CTs approached significance with p values of 0.05. During the 5-month downtime, utilization remained unchanged at 141 per 1,000 visits (p=0.38). Overall CT utilization increased after the placement of a scanner in the ED. Most subtypes of scan increased. Utilization was unchanged during a period of ED scanner unavailability, suggesting that increased utilization may be difficult to reverse.

Radiation exposure among patients with the highest CT scan utilization in the emergency department.

The risk of cancer from computed tomography (CT) scan radiation is a rising concern in the medical field. Our objectives were to determine how many patients received more than ten CT scans in an academic emergency department (ED) over the course of 7 years and to quantify their radiation exposure and lifetime attributable risk of cancer. An electronic chart review was performed at our urban academic institution with an annual census of 110,000 patients. All patients who underwent a CT scan performed during ED management between the dates of January 2001 and December 2007 were identified. Specific predetermined data elements (e.g., subject demographics, type of CT scan) were extracted by two researchers blinded to hypothesis, using a preformatted data form. After identifying patients with more than ten CTs performed during the study period, radiation exposure was calculated based on accepted and reported radiation doses for the respective anatomic CTs, and lifetime attributable cancer risk was calculated based on the seventh report of the Biological Effects of Ionizing Radiation (BEIR VII) projections. Over the 7-year study period, 24,393 patients received 34,671 CT scans. The vast majority of patients (17,909) received a single CT. Twenty-six (0.1 %) patients received more than ten CTs totaling 374 scans with an average radiation exposure of 83.4 mSv. The maximum lifetime attributable risk for any individual in this cohort was 1.7 % above the baseline cancer risk. Among those undergoing CT imaging in our ED, high-exposure patients (greater than ten scans) constituted a significant minority, while more than one in four patients underwent more than one CT scan during the study period. While the presumed overall risk of radiation-induced cancer continues to be low, it is important for the emergency physician to use clinical knowledge as well as concern for the patient when utilizing radiographic imaging. Increasing attributable cancer risk may have important public health implications in the future, regardless of the low individual risk.

Yield of head CT in the alcohol-intoxicated patient in the emergency department.

We aimed to determine the yield of positive head computed tomography (CT) findings among suspected alcohol-intoxicated patients presenting to the emergency department (ED). Our secondary aim was to determine if elderly intoxicated patients were more likely to have an intracranial injury. We identified patients suspected of alcohol intoxication who underwent CT scanning in the ED over a 4-year period. Pre-determined data elements including demographics, diagnosis, and disposition were extracted using a pre-formatted data sheet by blinded abstractors. "Positive" CT was defined as evidence of any type of intracranial hemorrhage. A total of 2,671 subjects with suspected alcohol intoxication and a head CT were identified. Fifty out of the 2,671 (1.9%) had a positive CT. Among CT scans of elderly (≥60 years of age) subjects, 15/555 (2.7%, 95% CI = 1.4-4.1%) were positive compared with 35/2,116 (1.7%, 95% CI = 1.1-2.2%) among those <60 years of age (p = 0.11). The yield of positive head CT among alcohol-intoxicated patients was low, at 1.9%. An age cutoff of 60 years in this population did not predict a significantly higher positive rate.