Self-awareness of computed tomography ordering in the emergency department.

OBJECTIVES: Physician variation in the use of computed tomography (CT) is concerning due to the risks of ionizing radiation, cost, and downstream effects of unnecessary testing. The objectives of this study were to describe variation in CT-ordering rates among emergency physicians (EPs), to measure correlation between perceived and actual CT-ordering rates, to assess attitudes that influence decisions to order imaging tests, and to identify EP attitudes associated with higher CT utilization. METHODS: This study was a retrospective review of imaging and administrative billing records at two emergency department sites of a tertiary care adult teaching hospital. The study also included a cross-sectional survey of EPs at this hospital. We asked physicians about their perceived ordering behaviour, and what factors influenced their decision to order a CT. We examined correlations between perceived and actual CT-ordering rates. We adjusted ordering rates for shift distribution using a logistic regression model and identified outlier physicians whose ordering rate was significantly lower or higher than expected. We used multivariable regression analysis to determine which survey responses predicted higher CT utilization. RESULTS: During the study period, 59 EPs saw 45,854 patients, and ordered 6,609 CTs - a mean ordering rate of 14.4% (standard deviation (SD)=4.3%). The ordering rate for individual physicians ranged from 5.9% to 25.9%. Of the 59 EPs, 13 EPs were low-ordering outliers; 12 were high-ordering outliers. Forty-five EPs (76.3%) completed the survey. Mean perceived ordering rate was 12.6%, and was weakly correlated with actual ordering (r=0.19, p=0.21). 42 EPs (93.3%) believed they ordered "about the same" or "fewer" CTs than their peers. Of the 17 EPs in the two highest ordering quintiles, only 3 (18%) knew they were high orderers. In the multivariable analysis, higher ordering was associated with increasing strength of response to the following predictors: medico-legal risk (relative risk [RR]=1.18, 95% CI: 1.03-1.21), risk of contrast (RR=1.14, 95% CI: 1.07-1.22), what colleagues would do (RR=1.09, 95% CI: 0.99-1.19), risk of missing a diagnosis (RR=1.08, 95% CI: 0.98-1.21), and patient wishes (RR=1.07, 95% CI: 0.97-1.17). CONCLUSIONS: There is large variation in CT ordering among EPs. Physicians' self-reported ordering rate correlates poorly with actual ordering. High CT orderers were rarely aware that they ordered more than their colleagues. Higher rates of ordering were observed among physicians who reported increased concern with 1) risk of missing a diagnosis, 2) medico-legal risk, 3) risk of contrast, 4) patient wishes, and 5) what colleagues would do.

Radiation doses to emergency department patients undergoing computed tomography.

OBJECTIVES: Computed tomography (CT) use is increasing in the emergency department (ED). Many physicians are concerned about exposing patients to radiation from CT scanning, but estimates of radiation doses vary. This study's objective was to determine the radiation doses from CT scanning for common indications in a Canadian ED using modern multidetector CT scanners. METHODS: We conducted a health records review of consecutive adult patients seen at two busy tertiary care EDs over a 2-month period who underwent CT scanning ordered by emergency physicians. Cases were identified by searching an imaging database. Data collected included patient age and sex, study indication, scanner model, body area, and reported dose-length product. Effective dose per scan was calculated from reported dose-length product. Data were collected on a standardized form, entered into an electronic database, and analyzed with descriptive statistics and 95% CIs. RESULTS: During the study period, emergency physicians assessed 19,880 patients. Overall, 2,720 (13.7%) underwent CT scanning, and of these, 144 (5.3%) patients had more than one scan. Patients had a mean age of 59.0 years, and 45.3% were men. Mean doses for the most common indications were as follows: simple head, 2.9 mSv; cervical spine, 5.7 mSv; complex head, 9.3 mSv; CT pulmonary angiogram, 11.2 mSv; abdomen (nontraumatic abdominal pain), 15.4 mSv; and abdomen (renal colic), 9.8 mSv. CONCLUSIONS: Approximately one in seven ED patients had a CT scan. Emergency physicians should be aware of typical radiation doses for the studies they order and how the dose varies by protocol and indication.

Emergency department visual urinalysis versus laboratory urinalysis.

OBJECTIVE: The primary objective of this study was to compare the results of nurse-performed urinalysis (NPU) interpreted visually in the emergency department (ED) with laboratory performed urinalysis (LPU) interpreted by reflectance photometry. METHODS: This was a prospective observational study based on a convenience sample from my emergency practice. Emergency nurses, who were unaware of the study, performed usual dipstick analysis before sending the same urine sample to the laboratory for testing. RESULTS: Of 140 urinalyses performed during the study period, 124 were suitable for analysis. When compared with the reference standard LPU, the NPU had an overall sensitivity of 100% (95% confidence interval [CI] 95%-100%) and a specificity of 49% (95% CI 33%-65%) for the presence of any 1 of blood, leukocyte esterase, nitrites, protein, glucose or ketones in the urine. Of 20 falsely positive NPUs, 18 were a result of the nurse recording 1 or more components as "trace" positive. CONCLUSION: Although NPU does not yield identical results to LPU, a negative LPU is expected when the initial NPU in the ED is negative.