Rates Of Computed Tomography Use Research Articles

Emergency Department Chest Imaging Utilization in Patients with Cancer

Overutilization of computed tomography (CT) is a growing concern in emergency medicine, particularly in patients with cancer. While previous studies have attempted to characterize the rates of CT use in this population, there are little data available about the comparative yield of this modality compared to conventional radiography (x-ray) and how it affects clinical decision-making. Our aim was to determine whether CT imaging of the chest more frequently identified clinically significant results as compared to chest radiography (CXR) in patients with cancer.

Magnetic Resonance Imaging Availability Reduces Computed Tomography Use for Pediatric Appendicitis Diagnosis.

To determine if introducing magnetic resonance imaging (MRI) as an imaging option for children with suspected appendicitis and an inconclusive ultrasound reduces computed tomography (CT) use. This is a retrospective cohort study of patients aged 5 to 18 years who presented to a pediatric emergency department (ED) with suspected appendicitis. Rates of CT use 1 year before and 1 year after MRI availability are compared. Secondary outcomes include missed and negative appendectomies, imaging charges, time to antibiotics and surgery, time to radiology read, ED length of stay, and test characteristics of MRI and CT. Of the 981 patients screened, 499 patients met inclusion criteria. There was an absolute reduction of CT use of 25% from 38% in year 1 to 13% in year 2 (95% confidence interval, 18% to 33%). Advanced imaging charges were $371 higher in year 2 (MRI) than year 1 (CT), and median time to radiologist reads was longer in MRIs than CTs (129 versus 62 minutes; difference 53 minutes, 95% confidence interval, 23 to 74 minutes). All other secondary outcomes, including ED length of stay and test characteristics, were statistically similar. Introducing MRI for as an imaging option for children with suspected appendicitis and an inconclusive ultrasound markedly reduced CT use, but did result in a small increase in imaging charges and time to preliminary radiology read.

Utility of Emergency Department Chest Imaging in Patients with Cancer: A Descriptive Study.

The use of computed tomography (CT) has been scrutinized in emergency medicine, particularly in patients with cancer. Previous studies have characterized the rate of CT use in this population; however, limited data are available about the yield of this modality compared with radiography and its clinical decision-making effect. To determine whether CT imaging of the chest increases identification of clinically significant results compared with chest radiography (CXR) in patients with cancer. This was a retrospective chart review of patients with a history of solid tumors presenting to an emergency department in 2017. Patients who received both CXR and CT (or CT angiography) of the chest during their assessment were identified and the rate of clinically significant findings on imaging was compared. Clinical findings were further categorized as requiring nonurgent, urgent, or emergent attention. Descriptive statistics and chi-squared testing were performed between the 2 imaging modalities. From 839 patients meeting inclusion criteria, 287 were randomly sampled. The predominant malignancies were lung (32.4%), breast (13.9%), and head and neck cancer (13.6%). A greater number of patients had clinically significant findings identified on CT imaging (n=222) compared with CXR (n=108). Stratification upon urgency of these findings (nonurgent, urgent, or emergent) reveals a significant difference in all strata (p<0.05). Compared with CXR, CT imaging of the chest identified significantly more clinically relevant findings requiring attention and consequently affecting clinical decision making.

Factors Affecting Emergency Department Computed Tomography Use in Children

BackgroundVariability in computed tomography (CT) use during pediatric emergency department (ED) visits has been reported. Our objective was to identify patient and hospital characteristics associated with CT use during pediatric ED visits. MethodsPatients <18 y treated and released from EDs in the 2006-2012 Nationwide Emergency Department Sample were included. Associations were evaluated between pediatric CT scan rate and patient/hospital factors using logistic mixed effects models. Independent predictors of being a high outlier (having a pediatric CT scan rate in the top 10%) were also evaluated using logistic regression models. ResultsThere were 1543 EDs and 20,703,273 visits included. CT scans were prescribed in 4.7% of pediatric ED visits; the highest 10% of EDs prescribed CT scans in >7.63% of all pediatric visits. In multivariable analysis, older age, male gender, private insurance, higher zip code level median income, and higher injury severity were all associated with an increased probability of receiving a CT scan (all P < 0.001). The chance of receiving a CT scan also varied by diagnosis and was independently associated with geographic location and annual pediatric ED volume. Rates of CT use increased with increasing pediatric volume up to approximately 5400 annual pediatric visits, and then decreased with volume >5400 annual visits. ConclusionsSeveral patient-level and ED-level characteristics, including annual pediatric volume, are associated with the probability of a child having a CT scan during an ED visit. Future work should focus on determining drivers behind these associations to develop intervention strategies to decrease pediatric CT use.

Effectiveness of peer pressure on computed tomography use for dizziness/vertigo patients.

Dizziness/vertigo is a common complaint in the emergency department (ED). We aimed to evaluate the effect of peer pressure on decision making in emergency physicians (EPs) to use computed tomography (CT) for patients with dizziness/vertigo.We conducted a before-and-after retrospective case review of patients who visited the ED with dizziness/vertigo. EPs were categorized into 3 groups according to seniority (in years of experience: >12, 7–12, and <7). The rate of CT use for EPs, patient number, and CT use were e-mailed monthly to update the EP team on the benchmark rate and shape of the behavior.Among the 1657 (preintervention) and 1508 (postintervention) patients with dizziness/vertigo, 320 (19.3%) and 230 (15.3%), respectively, underwent brain CT. A decrease in the rate of CT use was observed in the postintervention group (odds ratio [OR] = 0.743, 95% confidence interval [CI] = 0.615–0.897), especially in junior EPs (years of experience, <7; OR = 0.667, 95% CI: 0.474–0.933) and younger patients (age, <60) (OR = 0.625, 95% CI: 0.453–0.857).The intervention strategy created peer pressure through e-mail reminders and decreased the rate of CT use for patients with isolated dizziness/vertigo, especially in junior EPs and younger patients.

The difference of Use of CT in the general versus pediatric emergency departments for adolescent patients in the same tertiary hospital.

ObjectiveThe use of computed tomography (CT) in pediatric patients has decreased since the association between radiation and cancer risk has been reported. However, in adolescent patients being treated as adult patients, there has been a high incidence of CT use in emergency departments (EDs). Thus, this study aimed to evaluate the CT use in adolescent patients with complaints of headache or abdominal pain in the general and pediatric EDs of the same hospital.MethodsA retrospective chart review of patients aged 15 to 18 years, who presented with headache or abdominal pain at the general and pediatric EDs of Seoul National University Hospital from January 2010 to December 2014, was conducted.ResultsA total of 407 adolescent patients with complaints of headache and 980 with abdominal pain were included in this study. The adolescent patients in the general ED were more likely to undergo CT scans than those in the pediatric ED, with both patients having headache (42.4% vs. 20.5%, respectively, P<0.001) and abdominal pain (29.0% vs. 18.4%, respectively, P<0.001). There was no statistical difference in the rates of positive CT findings between the general and pediatric EDs. The frequency of visits to the general ED was associated with high rates of CT use in adolescent patients with complaints of headache (odds ratio, 3.95; 95% confidence interval, 2.01 to 7.77) and those with abdominal pain (odds ratio, 1.76; 95% confidence interval, 1.18 to 2.64).ConclusionThe ED setting influences the use of CT on adolescent patients, and a child-friendly environment could reduce the radiation risks.

Hospital type predicts computed tomography use for pediatric appendicitis

BackgroundEvidence-based guidelines recommend ultrasound (US) over computed tomography (CT) as the primary imaging modality for suspected pediatric appendicitis. Continued high rates of CT use may result in significant unnecessary radiation exposure in children. The purpose of this study was to evaluate variables associated with preoperative CT use in pediatric appendectomy patients. MethodsA retrospective cohort study of pediatric patients who underwent appendectomy for acute appendicitis in 2015–2016 at National Surgical Quality Improvement Program for Pediatrics (NSQIP-P) hospitals was conducted. Pediatric (<18 years old) patients who underwent appendectomy for acute appendicitis in an NSQIP-P hospital from 2015 to 2016 were included. Patients were excluded if they underwent interval or incidental appendectomy or did not have a final diagnosis of appendicitis. Variables associated with imaging evaluation, including age, body mass index (BMI), race/ethnicity, gender and hospital of presentation (NSQIP-P vs. non-NSQIP-P hospital) were evaluated. The primary outcome was receipt of preoperative CT. Secondary outcomes include reimaging practices and trends over time. Results22,333 children underwent appendectomies, of which almost all were imaged preoperatively (96.5%) and 36% of whom presented initially to a non-NSQIP-P hospital. Overall, US only was the most common imaging modality (52%), followed by CT only (27%), US+CT (16%), no imaging (3%), MRI +/− CT/US (1%) and MRI only (<1%). On regression, older age (>11 years), obesity (BMI >95th percentile for age), and female gender were associated with increased odds of receiving a CT scan. However, initial presentation to a non-NSQIP-P hospital was the strongest predictor of CT use (OR 9.4, 95% CI 8.1–10.8). Reimaging after transfer was common, especially after US and MRI at a non-NSQIP-P hospital. CT use decreased between 2015 and 2016 in non-NSQIP-P hospitals but remained the same (25%) in NSQIP-P facilities. ConclusionsThough patient characteristics were associated with different imaging practices, presentation at a referral, nonchildren's hospital is the strongest predictor of CT use in children with appendicitis. NSQIP-P hospitals frequently reimage transferred patients and have not reduced their CT use. Novel strategies are required for all hospital types in order to sustain reduction in CT use and mitigate unnecessary imaging. Level of EvidenceLevel III. Type of StudyRetrospective comparative study.

The Effect of an Observation Unit on Pediatric Minor Head Injury.

The aim of this study was to evaluate the effect of an observation unit (OU) in an emergency department on reducing unnecessary use of computed tomography (CT) for minor blunt head trauma. This study was a retrospective before-and-after study of pediatric patients 18 years or younger with minor blunt head trauma. Patients with a Glasgow Coma Scale score of 14 or 15 who presented to the emergency department were included in the analysis. The rates of head CT use in the period before and after the institution of the OU were compared. In total, 4706 patients were analyzed (2344 from the period before and 2362 from period after OU institution). The median age of the patients was 3 years, and 64% were male in each period. The rates of CT use were 5.7% (95% confidence interval [CI], 4.8%-6.7%) in the period before and 4.0% (95% CI, 3.3%-4.9%) in the period after OU institution (P = 0.01). The relative risk reduction was 0.70 (95% CI, 0.54-0.91). The rate of CT use decreased by 30% as a result of OU institution. The OU was an effective means of avoiding an unnecessary head CT for pediatric minor head injuries.

Variation in Computed Tomography Use for Evaluation of Head Injury in a Pediatric Emergency Department.

Recent research has shown significant variation in rates of computed tomography (CT) use among pediatric hospital emergency departments (ED) for evaluation of head injured children. We examined the rates of CT use by individual ED attending physicians for evaluation of head injured children in a pediatric hospital ED. We used an administrative database to identify children younger than 18 years evaluated for head injury from January 2011 through March 2013 at our children's hospital ED, staffed by pediatric emergency medicine (PEM) fellowship trained physicians and pediatricians. We excluded encounters with trauma team activation or previous head CT performed elsewhere. We excluded physicians whose patient volume was less than 1 standard deviation below the group mean. After exclusions, we evaluated 5340 encounters for head injury by 27 ED attending physicians. For individual physicians, CT rates ranged from 12.4% to 37.3%, with a mean group rate of 28.4%. Individual PEM physician CT rates ranged from 18.9% to 37.3%, versus 12.4% to 31.8% for pediatricians. Of the 1518 encounters in which CT was done, 128 (8.4%) had a traumatic brain injury on CT, and 125 (8.2%) had a simple skull fracture without traumatic brain injury on CT. Patient factors associated with CT use included age younger than 2 years, higher triage acuity, arrival time of 10:00 PM to 6:00 AM, hospital admission, and evaluation by a PEM physician. Physicians at our pediatric hospital ED varied in the use of CT for the evaluation of head-injured children.

Emergency Department Practice Variation in Computed Tomography Use for Children with Minor Blunt Head Trauma

To describe factors associated with computed tomography (CT) use for children with minor blunt head trauma that are evaluated in emergency departments. Planned secondary analysis of a prospective observational study of children <18 years with minor blunt head trauma between 2004 and 2006 at 25 emergency departments. CT scans were obtained at the discretion of treating clinicians. We risk-adjusted patients for clinically important traumatic brain injuries and performed multivariable regression analyses. Outcome measures were rates of CT use by hospital and by clinician training type. CT rates varied between 19.2% and 69.2% across hospitals. Risk adjustment had little effect on the differential rate of CT use. In low- and middle-risk patients, clinicians obtained CTs more frequently at suburban and nonfreestanding children's hospitals. Physicians with emergency medicine (EM) residency training obtained CTs at greater rates than physicians with pediatric residency or pediatric EM training. In multivariable analyses, compared with pediatric EM-trained physicians, the OR for CT use among EM-trained physicians in children <2 years was 1.24 (95% CI 1.04-1.46), and for children >2 years was 1.68 (95% CI 1.50-1.89). Physicians of all training backgrounds, however, overused CT scans in low-risk children. Substantial variation exists in the use of CT for children with minor blunt head trauma not explained by patient severity or rates of positive CT scans or clinically important traumatic brain injuries.

U.S. Trends in Computed Tomography Use and Diagnoses in Emergency Department Visits by Patients With Symptoms Suggestive of Pulmonary Embolism, 2001–2009

Using computed tomography (CT) to evaluate patients with chest symptoms is common in emergency departments (EDs). This article describes recent trends of CT use in U.S. EDs for patients presenting with symptoms common to acute pulmonary embolism (PE). The 2001-2009 National Hospital Ambulatory Medical Care Survey (NHAMCS), a nationally representative survey of U.S. ED encounters, was used for data collection. Patients with at least one of three complaints (chest pain, dyspnea, or hemoptysis) were categorized into the chest symptom study (CSS) group. The yearly increases in CT use for the complaints were tabulated first, then linear regression analysis was used to calculate average rates of increases in CT use between 2001 and 2007, theyears where CT use increased, for the overall population and among specific subgroups. The ratios of the number of visits when CT was ordered and there was a target diagnosis relative to the total number of visits with CT in the CSS group (diagnosis/CT ratio) were calculated for PE and pneumonia. Annual CT rates for the CSS group increased from 2.6% in 2001 to 13.2% in 2007, subsequently leveling off at approximately 12.5% in 2008 and 2009. The average growth rate of CT use for the CSS group was 28.1% (95% confidence interval [CI]=20.9% to 35.7%) per year between 2001 and 2007. Testing rates for all subgroups increased. The lowest growth rate was among Hispanic patients, whose CT rates grew 14.2% (95% CI=5.7% to 23.5%) per year. The highest growth rate was in nonurban hospitals, at 43.1% (95% CI=15.2% to 77.8%) per year. Patients triaged as nonurgent received the fewest CTs, compared to those who should be seen in 2hours or less. With regard to sources of payment, the self-pay subgroup experienced the highest rate of increase at 35.1% (95% CI=18.6% to 53.9%). The PE diagnosis/CT ratio from 2002 to 2009 was 2.7% for the CSS group. The pneumonia diagnosis/CT ratio grew from 5.8% in 2002 to 2005 to 7.8% in 2006 to 2009. Computed tomography use in ED visits by patients with chest symptoms increased dramatically from 2001 to 2007 and seems to have leveled off in subsequentyears. The low PE diagnosis-to-CT ratio suggests that EDs may need to promote evidence-based use of CT.

The Use of Computed Tomography in Pediatrics and the Associated Radiation Exposure and Estimated Cancer Risk

Increased use of computed tomography (CT) in pediatrics raises concerns about cancer risk from exposure to ionizing radiation. To quantify trends in the use of CT in pediatrics and the associated radiation exposure and cancer risk. Retrospective observational study. Seven US health care systems. The use of CT was evaluated for children younger than 15 years of age from 1996 to 2010, including 4 857 736 child-years of observation. Radiation doses were calculated for 744 CT scans performed between 2001 and 2011. Rates of CT use, organ and effective doses, and projected lifetime attributable risks of cancer. RESULTS The use of CT doubled for children younger than 5 years of age and tripled for children 5 to 14 years of age between 1996 and 2005, remained stable between 2006 and 2007, and then began to decline. Effective doses varied from 0.03 to 69.2 mSv per scan. An effective dose of 20 mSv or higher was delivered by 14% to 25% of abdomen/pelvis scans, 6% to 14% of spine scans, and 3% to 8% of chest scans. Projected lifetime attributable risks of solid cancer were higher for younger patients and girls than for older patients and boys, and they were also higher for patients who underwent CT scans of the abdomen/pelvis or spine than for patients who underwent other types of CT scans. For girls, a radiation-induced solid cancer is projected to result from every 300 to 390 abdomen/pelvis scans, 330 to 480 chest scans, and 270 to 800 spine scans, depending on age. The risk of leukemia was highest from head scans for children younger than 5 years of age at a rate of 1.9 cases per 10 000 CT scans. Nationally, 4 million pediatric CT scans of the head, abdomen/pelvis, chest, or spine performed each year are projected to cause 4870 future cancers. Reducing the highest 25% of doses to the median might prevent 43% of these cancers. The increased use of CT in pediatrics, combined with the wide variability in radiation doses, has resulted in many children receiving a high-dose examination. Dose-reduction strategies targeted to the highest quartile of doses could dramatically reduce the number of radiation-induced cancers.

Pediatric Abdominal Pain: Use of Imaging in the Emergency Department in the United States from 1999 to 2007

To evaluate use of imaging in children with acute abdominal pain who present to U.S. emergency departments (EDs). This study received expedited review by the institutional review board. The National Hospital Ambulatory Medical Care Survey is a government-administered yearly survey of EDs that is used to estimate ED care throughout the United States. This retrospective cohort study interrogated the database for the period from 1999 to 2007. Univariate regression analysis was performed, and a multivariate regression model was developed. From 1999 to 2007, 16 900 000 pediatric ED visits were made for acute abdominal pain. Odds of undergoing computed tomography (CT) in this population increased during each year of the study period. No significant changes occurred in use of ultrasonography, number of patients admitted to the hospital, or number of patients with acute appendicitis. A multivariate model for CT use revealed increased odds of CT use in teens, white patients, the Midwest region, urban settings, patients with private insurance, and patients who were admitted or transferred. Odds of undergoing CT were significantly lower among patients who presented to a pediatric-focused emergency department (adjusted odds ratio, 0.72; 95% confidence interval: 0.58, 0.90). The main findings of this study are that the rate of CT use in the evaluation of abdominal pain in children increased every year between 1999 and 2007 and that the use of CT was greater among children seen in adult-focused EDs. Factors affecting CT use include sex, race, age, insurance status, and geographic region.

Computed Tomography for Minor Head Injury: Variation and Trends in Major United States Pediatric Emergency Departments

To investigate the variation and trends in neuroimaging in children examined for minor head injury at major US pediatric emergency departments. We conducted a retrospective study of children <19 years of age with mild head injury who were examined and discharged home from the emergency department at 40 pediatric hospitals from 2005 to 2009 by using the Pediatric Health Information Systems database. Variation in computed tomography (CT) rates between hospitals was assessed for correlation with hospital-specific rates of intracranial hemorrhage, admission, and return visits. Age-adjusted trends in CT use were calculated for the 5 years. In the 5 years, the median rate of imaging for minor head injured patients was 36% (IQR, 29%-42%; range, 19%-58%). There was no correlation between institution-specific rates of CT imaging and intracranial hemorrhage, admission, or return-visit rates. Age-adjusted rates of CT use decreased in the 5-year period (OR, 0.94; 95% CI, 0.92-0.97; P < .001). In this study, we found significant practice variation in CT use at pediatric hospitals examining children with minor head injury. These data may help guide national benchmarks for the appropriate use of CT imaging in pediatric patients with minor head injury.

Radiation Exposure Issues in Orthopaedics*

The topic of radiation exposure for patients, physicians, and staff has become prominent in the lay press. It seems that every week another story about radiation safety makes the evening news. For physicians and surgeons, the largest radiation exposures involve fluoroscopy use with either fixed or mobile units. For patients, fluoroscopy (c-arm), computed tomography (CT), and nuclear medicine studies constitute the vast majority of exposures. The use of each of these modalities has grown dramatically with changes in the practice of medicine. C-arm use in orthopaedic surgery is increasing rapidly as surgery transitions to minimal-access surgery. With less direct visualization, surgery is being conducted with fluoroscopic guidance. When fluoroscopy is combined with a computer for navigation systems, radiation exposure sustained by surgeons can be reduced dramatically. This transition does not decrease the patient's radiation dose, and in some instances it can increase it substantially1. CT scans have become accepted as commonplace. The rate of CT use is thirty times greater than it was twenty years ago, and the radiation exposure sustained by a patient can be dramatic2,3. Less than one-sixth of physicians receive any training in radiation safety4. One questionnaire study of physicians showed that 4% did not know that ultrasound did not involve ionizing radiation and 27% did not know that magnetic resonance imaging (MRI) did not involve radiation at all5. Approximately 90% of physicians underestimated the radiation exposure and risks from pediatric radiographs and CT scans4. A single pediatric abdominal CT scan exposes the patient to more radiation than the seventy-year exposure from living in the vicinity of the Chernobyl accident2. For a five-year-old patient who weighs 19 kg, a chest CT is the equivalent of 600 chest radiographs and a CT of the …

The usefulness of abdominal computed tomography in diagnostic and disposition decisionmaking in the emergency evaluation of elderly patients with abdominal pain

Study objectives: We determine whether the use of abdominal computed tomography (CT) alters diagnosis and disposition in elderly patients presenting to the emergency department (ED) with abdominal pain. Methods: This prospective, observational, multicenter study consisted of a convenience sample of patients aged 60 years and older presenting to 1 of 4 participating EDs with abdominal pain. Patients with abdominal trauma or surgery within the previous 4 weeks were excluded. We analyzed the overall rate of CT use and compared the concordance of ED diagnosis (diagnosis) to final diagnosis (discharge or 2-week follow-up). ED diagnosis was considered concordant to final diagnosis if the ED diagnosis was included among the final diagnoses. In a subgroup of patients (N=100), we used a real-time questionnaire to determine percentage of change (95% confidence interval [CI]) in diagnosis and disposition after CT scan results. Results: Four hundred thirty-eight (87%) of 501 consenting patients were enrolled. Of these, 179 (41%) patients had a CT scan as part of their evaluation. Concordance of ED diagnosis to final diagnosis in admitted patients was 74.1% (95% CI 65.0% to 81.6%) in those receiving CT versus 74.5% (95% CI 66.1% to 81.3%) in those without CT. In the subgroup of patients with real-time questionnaire information, 54 (54%) had CT performed. The percentage of change in diagnosis or disposition after CT in this group was 17 of 54 (32%, 95% CI 19.9% to 45.7%) and 19 of 54 (35%, 95% CI 23.0% to 49.4%), respectively. Conclusion: CT is used for more than 40% of elderly patients treated in the ED for abdominal pain. No difference was observed in concordance of ED to final diagnosis between patients with or without CT. Diagnosis and disposition were each altered about one third of the time in patients for whom CT was obtained. Study objectives: We determine whether the use of abdominal computed tomography (CT) alters diagnosis and disposition in elderly patients presenting to the emergency department (ED) with abdominal pain. Methods: This prospective, observational, multicenter study consisted of a convenience sample of patients aged 60 years and older presenting to 1 of 4 participating EDs with abdominal pain. Patients with abdominal trauma or surgery within the previous 4 weeks were excluded. We analyzed the overall rate of CT use and compared the concordance of ED diagnosis (diagnosis) to final diagnosis (discharge or 2-week follow-up). ED diagnosis was considered concordant to final diagnosis if the ED diagnosis was included among the final diagnoses. In a subgroup of patients (N=100), we used a real-time questionnaire to determine percentage of change (95% confidence interval [CI]) in diagnosis and disposition after CT scan results. Results: Four hundred thirty-eight (87%) of 501 consenting patients were enrolled. Of these, 179 (41%) patients had a CT scan as part of their evaluation. Concordance of ED diagnosis to final diagnosis in admitted patients was 74.1% (95% CI 65.0% to 81.6%) in those receiving CT versus 74.5% (95% CI 66.1% to 81.3%) in those without CT. In the subgroup of patients with real-time questionnaire information, 54 (54%) had CT performed. The percentage of change in diagnosis or disposition after CT in this group was 17 of 54 (32%, 95% CI 19.9% to 45.7%) and 19 of 54 (35%, 95% CI 23.0% to 49.4%), respectively. Conclusion: CT is used for more than 40% of elderly patients treated in the ED for abdominal pain. No difference was observed in concordance of ED to final diagnosis between patients with or without CT. Diagnosis and disposition were each altered about one third of the time in patients for whom CT was obtained.

Computed tomography scan use in the emergency department evaluation of patients with nonspecific abdominal pain is increasing despite decreased patient acuity

Study objectives: Computed tomography (CT) scanner use has become increasingly common in US emergency departments (EDs). We undertake a study to investigate the change in frequency of the use of ED CT scans in patients with abdominal pain. We also investigated the relationship between CT scan use and changes in patient acuity.Methods: Data were obtained from the 1996 to 2000 National Hospital Ambulatory Medical Care Survey (NHAMCS), a national probability sample survey conducted by the National Center for Health Statistics, Centers for Disease Control and Prevention. All visits that were coded as nonspecific abdominal pain (International Classification of Diseases, Ninth Revision code 789) were identified. Data were collected for the use of blood tests. Indicators of patient severity (triage category and hospital admission rates) were also collected, and demographic data were obtained. Continuous variables were summarized by mean and SDs. Proportions were compared with a χ2 test; an a priori significance level of P value less than .05 was selected. Descriptive analyses were performed with statistical software (Microsoft Excel 2000 version 9.0; Microsoft Corporation, Redmond, WA). The data used for this study are openly accessible to the public and excluded all patient identifiers. The study was therefore exempt from institutional board review approval.Results: We analyzed 115,011 visits that represented 496.4 million visits to US EDs during the 5-year study period. Data were weighted in accordance with NHAMCS guidelines for statistical analysis. Three thousand five hundred sixty-four patients with a final ED diagnosis of nonspecific abdominal pain were identified, representing 15,767,037 weighted patient visits nationally. There was a slight increase in the percentage of patients with nonspecific abdominal pain (2.7% in 1996, 3.3% in 2000, χ2=13.7, P=.001). The rate of CT scan use increased from 1.7% to 10.2% (χ2=40.4, P=.001). The hospital admission rate decreased from 15.6% (350,588 admissions) in 1996 to 14.9% (573,784 admissions) in 2000 (χ2=0.13, P=NS). There was a decrease in the triage acuity of patients with abdominal pain presenting to the ED. The presenting acuity of patients as categorized by a triage level one (to be seen within ≤15 minutes) decreased significantly from 22.4% to 10.8% (χ2=36.4, P=.001). There was a 10-fold increase in the rate of CT use in admitted patients (3.3% in 1996, increasing to 37.4% in 2000). The use of a CBC count increased from 56% to 65% (χ2=5.0, P=.05). Overall, the growth in CT scanning was higher than for the growth in the use of a CBC count or hospital admission rate, which suggests that despite a decreasing patient acuity, the rate of CT scan use is increasing. Projections based on 5 years of data suggest that if current growth continues, by 2010 more than 30% of all ED patients with a final diagnosis of nonspecific abdominal pain will undergo a CT scan while in the ED.Conclusion: The use of CT scanning in patients with nonspecific abdominal pain is increasing rapidly. This increase cannot be explained by increasing patient acuity and has not changed the admission rate. These trends need to be factored into ED design. Further studies involving patients most likely to benefit from a CT may result in large cost savings and may ease ED congestion.

The use of abdominal computed tomography scan decreases the frequency of misdiagnosis in cases of suspected appendicitis

Background:Despite considerable experience the reported frequency of misdiagnosis in patients undergoing appendectomy continues in the range of 20% to 40% in some populations. MethodsWe developed a clinical guideline that recommended abdominal computed tomography (CT) for all nonpregnant adults in whom the diagnosis of appendicitis was suspected unless the diagnosis could be ruled out clinically. The records of adult patients that underwent appendectomy from July 1998 through October 2001 were reviewed. The clinical guideline was developed in July 2000. ResultsThere were 194 appendectomies performed, 114 prior to the guideline and 80 after the development of the guideline. The rate of misdiagnosis decreased from 25% to 6% (P <0.05), the rate of CT use increased from 32% to 84% (P <0.05), and the perforation rate remained unchanged. Conclusions:These results support the effectiveness of a clinical guideline that encourage the use of abdominal CT in decreasing the frequency of misdiagnosis in cases of suspected appendicitis.

Variation in ED Use of Computed Tomography for Patients With Minor Head Injury

Study objective: To determine the frequency of utilization, yield for brain injury, incidence of missed injury, and variation in the use of computed tomography (CT) for ED patients with minor head injury. Methods: This retrospective health records survey was conducted over a 12-month period in the EDs at seven Canadian teaching institutions. Included in this review were adult patients who sustained acute minor head injury, defined as witnessed loss of consciousness or amnesia and a Glasgow Coma Scale score of 13 or greater. Data were collected by research assistants who were trained to select cases and abstract data in a standardized fashion according to a resource manual. Subsequently, patient eligibility was reviewed by the study coordinator and principal investigator. Results: Of the 1,699 patients seen, 521 (30.7%) were referred for CT, and 418 (79.8%) of these scans were negative for any type of brain injury. Overall, 105 (6.2%) of these patients sustained acute brain injury, including 9 (.5%) with an epidural hematoma. Cochran's Q test for homogeneity demonstrated significant variation between the seven centers for rate of ordering CT ( P<.0001), from a low of 15.9% to a high of 70.4%. All five cases of “missed” hematoma occurred at the institutions with the highest and third highest rates of CT use. After controlling for possible differences in case severity and patient characteristics at each hospital, logistic regression analysis revealed that five of seven hospitals were significantly associated with use of CT (respective odds ratios [OR], .4, .5, .5, 3.2, and 4.7). Three of the centers (two with the highest ordering rates) showed significant heterogeneity in the ordering of CT among their attending staff physicians, from a low of 6.5% to a high of 80.0%. Conclusion: There was considerable variation among institutions and individual physicians in the ordering of CT for patients with minor head injury. Although emergency physicians were selective when ordering CT, the yield of radiography was very low at all hospitals. None of the cases of “missed” intracranial hematoma came from the lowest ordering institutions, indicating that patients may be managed safely with a selective approach to CT use. These findings suggest great potential for more standardized and efficient use of CT of the head, possibly through the use of a clinical decision rule. [Stiell IG, Wells GA, Vandemheen K, Laupacis A, Brison R, Eisenhauer MA, Greenberg GH, MacPhail I, McKnight RD, Reardon M, Verbeek R, Worthington J, Lesiuk H: Variation in ED use of computed tomography for patients with minor head injury. Ann Emerg Med July 1997;30:14-22.]