A pilot prospective study of the vascular repair response following red cell transfusion in critically ill patients.

BACKGROUND: Red blood cell transfusion has been associated with adverse outcomes including infection, delayed recovery and increased mortality in some patient populations. Circulating cells that yield endothelial-like vascular progenitor cell (VPC) clusters are correlated with vascular repair and recovery after ischaemic injury. The impact of red cell transfusion on VPC clusters and vascular repair remains uncertain. STUDY DESIGN: We prospectively enrolled patients admitted to intensive care requiring red cell transfusion and subjects at low likelihood of requiring red cell transfusion. Levels of VPC clusters and plasma levels of angiogenic cytokines were compared. A total of 17 patients were recruited and had blood samples collected at time of enrolment and at 24-48 h, 48-72 h and 1 week following transfusion. RESULTS: We could not discern differences in the number of VPC clusters between transfused patients (n = 6) and non-transfused subjects (n = 11) at baseline or throughout the study period. VPC cluster levels demonstrated wide variance and were highest at 24-h post-enrolment in the entire cohort. Furthermore, levels of all 16 cytokines analysed were not significantly different between transfused and non-transfused patients and we did not observe a correlation between cytokine concentrations and levels of circulating VPC-cluster forming cells in the overall study population. CONCLUSIONS: Our data suggest that assessment of vascular repair responses after red blood cell transfusion in critically ill patients is challenging. Although our study did not allow us to discern an influence of red cell transfusion on VPC cluster levels or angiogenic cytokines, new methods evaluating vascular repair mechanisms may be required.

Genetic control of yield related stalk traits in sugarcane.

A major focus of sugarcane variety improvement programs is to increase sugar yield, which can be accomplished by either increasing the sugar content of the cane or by increasing cane yield, as the correlation between these traits is low. We used a cross between an Australian sugarcane variety Q165, and a Saccharum officinarum accession, IJ76-514, to dissect the inheritance of yield-related traits in the complex polyploid sugarcane. A population of 227 individuals was grown in a replicated field trial and evaluated over 3 years for stalk weight, stalk diameter, stalk number, stalk length and total biomass. Over 1,000 AFLP and SSR markers were scored across the population and used to identify quantitative trait loci (QTL). In total, 27 regions were found that were significant at the 5% threshold using permutation tests with at least one trait; individually, they explained from 4 to 10% of the phenotypic variation and up to 46% were consistent across years. With the inclusion of digeneic interactions, from 28 to 60% of the variation was explained for these traits. The 27 genomic regions were located on 22 linkage groups (LGs) in six of the eight homology groups (HGs) indicating that a number of alleles or quantitative trait alleles (QTA) at each QTL contribute to the trait; from one to three alleles had an effect on the traits for each QTL identified. Alleles of a candidate gene, TEOSINTE BRANCHED 1 (TB1), the major gene controlling branching in maize, were mapped in this population using either an SSR or SNP markers. Two alleles showed some association with stalk number, but unlike maize, TB1 is not a major gene controlling branching in sugarcane but only has a minor and variable effect.

The effectiveness and cost-effectiveness of computed tomography screening for coronary artery disease: systematic review.

OBJECTIVES: To assess the clinical and cost-effectiveness of computed tomography (CT) screening for asymptomatic coronary artery disease; also to establish whether coronary artery calcification (CAC) predicts coronary events and adds anything to risk factor scores, and whether measuring CAC changes treatment. DATA SOURCES: Main electronic databases were searched up to 2005, with a MEDLINE update in February 2006. METHODS: A systematic review of screening studies and economic evaluations was carried out. Studies were included in the review if screening for coronary heart disease was the principal theme of the study, and if data were provided that allowed comparison of CT screening with current practice, which was taken to be risk factor scoring. Mismatches between CAC scores and risk factor scoring were of particular interest. A review of the case for screening against the criteria used by the National Screening Committee (NSC) for assessing screening programmes was also undertaken. RESULTS: No randomised control trials (RCTs) were found that assessed the value of CT screening in reducing cardiac events. Seven studies were identified that assessed the association between CAC scores on CT and cardiac outcomes in asymptomatic people and included 30,599 people. Six used electron-beam CT. The relative risk of a cardiac event was 4.4 if CAC was present, compared to there being no CAC. As CAC score increased, so did the risk of cardiac events. The correlation between CAC and cardiac risk was consistent across studies. There was evidence that CAC scores varied among people with the same Framingham risk factor scores, and that within the same Framingham bands, people with higher CAC scores had significantly higher cardiac event rates. This applied mainly when the CAC scores exceeded 300. There was little difference in event rates among the groups with no CAC, and scores of 1-100 and 101-300. In one study, CAC score was a better predictor of cardiac events than the Framingham risk scores. No studies were found that showed whether the addition of CAC scores to standard risk factor assessment would improve outcomes. There were reports from two observational studies that lowering of low-density lipoprotein cholesterol to about 3 mmol/l; or below with statin treatment modestly reduced CAC scores, but this was not confirmed in two RCTs. In three studies examining whether knowledge of CAC scores would affect compliance with lifestyle measures, perception of risk was affected, but it did not improve smoking cessation rates, although it did increase anxiety. There were a few economic studies of CT screening for heart disease, which provided useful data on costs of scans, other investigations and treatment, but relied on a number of assumptions, and were unable to provide definitive answers. One modelling study estimated that adding CT screening to risk factor scoring, and only giving statins to those with CAC score over 100, would save money, based on a cost per CT screen of US$400 and statin costs of US$1000 per annum per patient. However, the arrival of generic statins has reduced the price dramatically, and these savings no longer apply. CONCLUSIONS: CT examination of the coronary arteries can detect calcification indicative of arterial disease in asymptomatic people, many of whom would be at low risk when assessed by traditional risk factors. The higher the CAC score, the higher the risk. Treatment with statins can reduce that risk. However, CT screening would miss many of the most dangerous patches of arterial disease, because they are not yet calcified, and so there would be false-negative results: normal CT followed by a heart attack. There would also be false-positive results in that many calcified arteries will have normal blood flow and will not be affected by clinically apparent thrombosis: abnormal CT not followed by a heart attack. For CT screening to be cost-effective, it has to add value over risk factor scoring, by producing sufficient additional information to change treatment and hence cardiac outcomes, at an affordable cost per quality-adjusted life-year. There was insufficient evidence to support this. Most of the NSC criteria were either not met or only partially met. It would be useful to have more data on the distributions of risk scores and CAC scores in asymptomatic people, and the level of concordance between risk factor and CAC scores, the risk of cardiac events per annum according to CAC score and risk factor scores, information on the acceptability of CT screening, after information about the radiation dose, and an RCT of adding CT screening to current risk factor-based practice.

Proton pump inhibitor treatment for acute peptic ulcer bleeding.

BACKGROUND: Peptic ulcer (PU) bleeding is associated with substantial morbidity, mortality and healthcare cost. Randomised controlled trials (RCTs) evaluating the clinical effect of proton pump inhibitors (PPIs) in peptic ulcer bleeding have yielded conflicting results. OBJECTIVES: To evaluate the efficacy of PPIs in the management of acute bleeding from PU using evidence from RCTs. SEARCH STRATEGY: We performed a search of CENTRAL, The Cochrane Library (Issue 3, 2003), MEDLINE (1966 to February 2003) and EMBASE (1980 to February 2003) and proceedings of recent major meetings through to February 2003. We searched the reference lists of articles and contacted pharmaceutical companies and experts in the field for additional published or unpublished data. SELECTION CRITERIA: RCTs of PPI treatment (oral or intravenous) compared with either placebo or H(2)-receptor antagonist (H(2)RA) in patients with acute bleeding from PU were included if they met pre-defined criteria. DATA COLLECTION AND ANALYSIS: Two reviewers extracted data independently on a purpose-designed data extraction form. Validity of included studies was assessed by adequacy of randomisation method and other pre-defined criteria. Studies were summarised and meta-analysis was undertaken. The influence of factors on the outcomes was assessed. MAIN RESULTS: Twenty-one RCTs with a total of 2915 participants were included. Statistical heterogeneity was found among trials for rebleeding (P = 0.05), but not for mortality (P = 0.26) or surgery (P = 0.42). There was no significant difference in mortality rates between PPI and control treatment; pooled rates were 5.2% on PPI versus 4.6% on control (odds ratio (OR) 1.11; 95% CI 0.79 to 1.57). PPI treatment significantly reduced rates of surgical intervention compared with control; pooled rates were 8.4% on PPI versus 13.0% on control (OR 0.59; 95% CI 0.46 to 0.76). PPIs significantly reduced rebleeding compared to control; pooled rates were 10.6% with PPI (range: 0% to 24.4%) versus 18.7% with control treatment (range: 2.3% to 39.1%), the OR was 0.46 (95% CI 0.33 to 0.64). Results on mortality and rebleeding rates were independent of route of PPI administration, type of control treatment or application of initial endoscopic haemostatic treatment. Surgical intervention rates varied with type of control (PPI significantly reduced surgical intervention rates compared with placebo and not when compared with H(2)RA) but not with route of PPI administration or application of initial endoscopic haemostatic treatment. REVIEWERS' CONCLUSIONS: PPI treatment in PU bleeding reduces rebleeding and surgical intervention rates in studies comparing treatment with placebo or H(2)RA, but there is no evidence of an effect on mortality.

Consultant supported intermediate care--a model for remote and island hospitals.

INTRODUCTION: Providing local consultant-delivered hospital services in remote and island communities in the United Kingdom is increasingly problematic due to difficulties with recruitment and retention of staff, statutory restrictions to hours worked by health professionals and the expectation each clinician must manage an externally defined volume of cases to maintain clinical standards. This article describes a before-and-after evaluation of a novel method of providing consultant support for acute internal medicine to an island grouping off the Scottish coast. Under the scheme, local GPs provided acute medical care of inpatients. A consultant general physician was appointed in a district general hospital on the mainland, approximately 100 miles from the island group, to provide a lead clinician role for inpatient services at the island hospital, visiting the island on a twice-monthly basis, undertaking educational sessions and developing local guidelines and care pathways for the management of individual medical conditions. In addition, two junior doctors were appointed to the island hospital to support inpatient care. METHODS: A prospective recording system for case mix was established with agreed evidence-based protocols, developed as integrated care pathways (ICP), for indicator conditions. General case mix was determined during two 6-month periods, June-November 2001 and June-November 2002, before and after implementation of the new arrangements. Performance against an ICP for management of suspected cardiac chest pain was evaluated in detail, examining the process of management, clinical outcome and economics. Data from the clinical literature were used to estimate the potential health gains from observed changes in clinical practice. RESULTS: Total admissions rose by 25% in the second time period, with particular increases noted for cardiovascular, cerebrovascular disease, and cancer. Total air ambulance transfers between the islands and the mainland within these time periods increased by 31%, from 88 to 115 transfers. Recording specific details from the history and frequency of appropriate blood investigations increased and initial steps in management changed considerably after introduction of the ICP. The number of transfers to the mainland teaching hospital increased from 3/37 (8%) in 2001 to 15/56 (27%) in 2002. Based on an estimated 100 patients per year, of whom 15 would receive thrombolysis, total additional patient costs would be 64,000 pounds sterling. The annual cost of the additional resource input into the medical service was 148,000 pounds sterling. Approximately 16 adverse events would be avoided at a combined cost of 212,000 pounds sterling (148,000 pounds sterling direct costs of intervention + 64,000 pounds sterling additional treatment costs) or 13,250 pounds sterling per event avoided. This is a conservative estimate of benefit as all the direct costs of the intervention have been included. CONCLUSIONS: This study shows that appropriate standards of care can be delivered in the setting described. Costs of care increased, but the level of service provided increased concomitantly, and the health benefits were achieved at costs that compare favourably with other interventions recommended by health technology assessment groups. An estimate of notional costs involved in alternative models for the delivery of hospital medical services in a remote area suggests that costs would be similar for a three-consultant service, the present model, and a triage and transfer system. In the future, the models chosen by remote and island communities and healthcare providers are therefore likely to be determined by viability, sustainability and public acceptability rather than cost. Our study indicates that consultant supported intermediate care is a viable model.

Association of IL-1beta and IL-1 receptor antagonist haplotypes with rate of decline in lung function in smokers.

BACKGROUND: There is increasing evidence that the cytokine network is central to the immunopathology of inflammatory airway diseases. The interleukin 1 (IL-1) receptor antagonist (IL-1RN) is a naturally occurring anti-inflammatory agent that binds to the IL-1 receptor but does not possess agonist activity. Each of the genes of the IL-1 locus on chromosome 2q14 is polymorphic. The IL1RN gene contains an 86 bp tandem repeat and allele 2 of this polymorphism has been associated with various inflammatory diseases. The IL-1beta (IL1B) gene contains a promoter polymorphism (C-511T) that has been associated with inflammatory diseases and is in linkage disequilibrium with the IL1RN polymorphism. METHODS: We investigated whether polymorphisms in the IL1B and IL1RN genes were associated with rate of decline of lung function. Genotypes were determined in 284 smokers with a rapid decline in lung function and 306 smokers with no decline in lung function. RESULTS: None of the genotypes was associated with the rate of decline of lung function. However, the distribution of IL1B/IL1RN haplotypes was different between smokers with a rapid decline in lung function and those with no decline in lung function (p=0.0005). CONCLUSION: These results suggest that IL1B/IL1RN haplotypes play a role in the rate of decline in lung function in smokers.

Rater agreement and utility of the mutagen-induced chromosome damage assay.

Chromosomal damage in peripheral blood lymphocytes induced by short-term in vitro exposure to the cytotoxic antibiotic bleomycin was first described in 1983 and proposed as a phenotypic assay for chromosome instability. This assay was subsequently described as potentially useful in assessing an individual's risk to environmental carcinogens in 1989. Since 1995 numerous published studies have used this assay to assess risk for cancer in the aerodigestive tract, particularly lung cancer, in various ethnic populations. Odds ratios up to 8.5 have been reported for individuals deemed "mutagen sensitive" (defined as > or = 1 chromatid break per metaphase averaged in 50 metaphases analyzed). While this phenotypic assay is appealing for lung cancer risk assessment it has not been reproduced by other investigators. Because of our interest in lung cancer biology, epidemiology, and genetics, we sought to independently assess the rater agreement of this assay. We found that 1) the assay is laborious to conduct (8 hours of labor) and relatively expensive (> $100), yet reducing the number of metaphases from 50 to 20 produced a reliable, less expensive, and less laborious test; and 2) the rater agreement of individual metaphase readings is poor, but agreement for a summary measure is high.

A prospective, randomized, double-blind, placebo-controlled trial evaluating the effect of nystatin on the development of oral irritation in patients receiving high-dose intravenous interleukin-2.

Interleukin-2 (IL-2) has been used to treat patients with metastatic melanoma and renal cell cancer for nearly two decades, and much progress has been made in ameliorating its adverse effects. One bothersome adverse effect, oral pain or oral irritation, is usually treated with an oral antifungal antibiotic, nystatin. The authors performed a prospective, randomized, double-blind, placebo-controlled trial involving 64 patients to evaluate the effect of prophylactic administration of nystatin or placebo on the development of oral irritation in patients receiving high-dose intravenous IL-2. No difference was found between patients randomized to receive nystatin or placebo in their rates of development of oral irritation, the severity of IL-2 adverse effects, the duration of their treatment, the rate of development of positive studies for oral yeast, or their pattern of experiencing other adverse effects. Thus, patients who receive high-dose intravenous IL-2 should not be treated prophylactically with nystatin to prevent oral irritation, and clinicians should seek evidence of the presence of oral thrush before using antifungal agents to treat oral pain in these patients.

Dementia with Lewy bodies and Alzheimer's disease.

To investigate similarities and differences between Alzheimer's disease (AD) and dementia with Lewy bodies (DLB), we undertook a demographic analysis of 277 patients from the Kathleen Price Bryan Brain Bank with an antemortem diagnosis of probable AD. Patients with additional, possibly confounding clinical and pathologic diagnoses such as infarcts, hematomas, neoplasms, and other neurodegenerative disorders, were excluded from the analysis. Neuropathologically, AD alone was present in 192 subjects (69%), and DLB was found in 85 subjects (31%). All of the DLB cases had neuropathologic evidence of AD sufficient to meet CERAD criteria for a diagnosis of definite AD plus nigral Lewy bodies. Gender, apolipoprotein E (APOE) genotype, brain weight, age at death, duration of disease and Braak stage were compared between the two groups. Statistical analyses were performed using Fisher's exact test for comparisons of categorical data and Student's t-test for comparison of means for continuous outcomes. The proportion of males and females was balanced in the combined AD and DLB populations. There was a highly statistically significant increased frequency of APOE 3/4 in males with DLB (P = 0.007). We found higher brain weights in males with DLB versus males with AD (P = 0.012). AD was more frequent in females and DLB was more frequent in males (P = 0.019). Our findings with respect to age at death, duration of disease and Braak stage within diagnostic groups confirm previously reported findings. These data suggest that Lewy bodies are more common in males affected with dementia, especially those with the APOE 3/4 genotype.

Early onset baldness and prostate cancer risk.

Prostatic carcinoma is the leading cancer among American men, yet few risk factors have been established. Although increased androgen levels have long been associated with both prostatic carcinoma and baldness, to date no studies have shown an association between hair patterning and prostate cancer risk. A lack of standardized instruments to assess baldness or the assessment of hair patterning during uninformative periods of time may have precluded the ability of previous studies to detect an association. We hypothesized that baldness, specifically vertex baldness, should be assessed using standardized instruments and during early adulthood if an association with prostate cancer risk is to be found. To test this hypothesis, we included identical items related to hair patterning in surveys that were administered in two distinct prostate cancer case-control studies (Duke-based study, n = 149; 78 cases; 71 controls and community-based study, n = 130; 56 cases; 74 controls). In each, participants were provided with an illustration of the Hamilton Scale of Baldness and asked to select the diagrams that best represented their hair patterning at age 30 and again at age 40. From these data, the following five categories were created and compared: not bald (referent group); vertex bald early onset (by age 30); vertex bald later onset (by age 40); frontal bald early onset (by age 30); frontal bald later onset (by age 40); and frontal (at age 30) to vertex bald (at age 40). Separate analyses of the two studies are consistent and suggest an association between vertex baldness and prostate cancer [vertex bald early onset odds ratios, 2.44 [confidence interval (CI), 0.57-10.46)] and 2.11 (CI, 0.66-6.73), respectively; vertex bald later onset odds ratios, 2.10 (CI, 0.63-7.00) and 1.37 (CI, 0.47-4.06), respectively]. Although statistical significance was not achieved in either one of these studies, the concordance between the data suggests a need for future studies to determine whether early onset vertex baldness serves as a novel biomarker for prostate cancer and whether androgen production, metabolism, or receptor status differs among these men when compared to those who exhibit other types of hair patterning.

Evaluation of molecular techniques to biotype Giardia duodenalis collected during an outbreak.

Twenty-seven Giardia duodenalis cyst-positive specimens (human, animal, or drinking water) were obtained from a waterborne outbreak in a community in British Columbia, western Canada. Parasite isolates were characterized using molecular techniques at 4 different steps of organism retrieval. None of the drinking water samples (n = 20) infected gerbils and none was successfully amplified using polymerase chain reaction (PCR). We were able to genotype 4 of 7 (human and animal) isolates by amplification of DNA from original specimens at the triosephosphate isomerase (tpi) gene locus using PCR followed by restriction fragment length polymorphism (RFLP) analysis. Five of the original specimens inoculated into Mongolian gerbils (Meriones unguiculatus) were infective and genotyped at the tpi locus using parasite material collected from the gerbil (cysts and trophozoites). Pulsed field gel electrophoresis (PFGE) was used to biotype trophozoites collected from the gerbils as well as trophozoites from the 4 isolates that adapted to culture. Four of these 5 isolates displayed the same (designated outbreak) biotype at all parasite retrieval steps with all molecular techniques including the originally amplified isolates. PCR-RFLP identified an additional biotype group. The 4 isolates that adapted to in vitro culture were also characterized by isoenzyme electrophoresis (IE). Biotype groups identified in these axenized isolates were all the same with each molecular technique (PCR-RFLP, PFGE, IE) tested. Results of this study demonstrate a need for more sensitive molecular methods to detect and characterize Giardia in original host and environmental samples. Results are also consistent with evidence of biotype changes that occur during the presently used process of isolate retrieval.

Maximizing the motivational impact of feedback of lung cancer susceptibility on smokers' desire to quit.

This two-by-two factorially designed study evaluate approaches for communicating feedback of lung cancer susceptibility to smokers as a method for motivating smoking cessation. The study factors were: method of communicating feedback (by mail with telephone follow-up or in-person) and carbon monoxide feedback (yes or no). One-hundred-forty-four smokers were stratified on race and randomized to one of four conditions. Participants were surveyed at baseline and 2-month follow-up. Polymerase chain reaction (PCR) testing for the absence of the glutathione S transferase mu (GSTM1) gene was the susceptibility marker. Regardless of counseling method or carbon monoxide (CO) feedback, the majority (90%) of smokers accurately recalled the test result and 66% accurately interpreted the meaning of the test result. Smokers who received their result in person were significantly less likely to have read the result booklet than those in the telephone counseling group (OR = .28, 95%; CI .12-.62; p < .05). Neither counseling method nor CO feedback increased smokers' perceived risks for lung cancer. However, at the counseling session those who received in-person counseling were significantly less frightened by the test result than those who received telephone counseling (OR = .42, 95%; CI .20-86; p < .05) and at the 2-month follow-up those who received a CO test were significantly less frightened by their susceptibility result (OR = .40, 95%; CI .17-.92; p < .05) than those who did not have a CO test. Evaluation of further refinements in communicating the meaning of susceptibility results to motivate smoking cessation is warranted.

The sociodemographic predictors of smoking cessation among pregnant women in Canada.

This study examined the sociodemographic predictors of smoking cessation attempts among pregnant women, and compared the characteristics of women who successfully quit smoking during pregnancy with those who relapsed before their child was born. Data, which were derived from the National Longitudinal Survey of Children and Youth, indicate that 23.7% of Canadian mothers smoked at some point during their pregnancies, of whom only 15.8% attempted to quit. Maternal and paternal education were the strongest predictors of successful cessation, whereas women pregnant with their first child, those who drank during pregnancy, and those who immigrated to Canada were the most likely to relapse. This study represents an important first step in identifying Canadian women at highest risk of sustained smoking during pregnancy, and is useful for the design of effective interventions, tailored to meet their needs.

The Sydney Blood Bank Cohort: a case-control study using a transfused HIV-1 seronegative group.

PURPOSE: To compare the immunological function of the Sydney Blood Bank Cohort (SBBC), a unique group of individuals who were all infected with a similar, attenuated strain of HIV-1, with a matched HIV-1 seronegative control group. To establish whether the asymptomatic state of the SBBC, in 1996, was likely to continue, and whether the SBBC were free from immunological signs of disease progression. METHODS: A prospective case-control design using a matched transfused HIV-1 seronegative control group. Immunological testing was performed and compared across the groups. These measurements included CD4+, CD8+, CD3 + subsets, total lymphocytes, beta-2-microgloublin (beta2M), and neopterin. RESULTS: Significant differences were observed between the SBBC and the controls, particularly CD4% (p < 0.05), CD8 counts (p < 0.01), and CD4:CD8 ratios (p < 0.001). CONCLUSIONS: The results suggested that, as a group, the SBBC remained asymptomatic 12 to 16 years after infection with HIV-1. However, elevated CD8+ T lymphocytes, together with decreasing CD4%, suggested that some SBBC members were showing early immunologicalsigns of disease progression during late 1996, confirmed by recent (1998) follow-up studies.

Race, presenting signs and symptoms, use of carotid artery imaging, and appropriateness of carotid endarterectomy.

BACKGROUND AND PURPOSE: We sought to determine whether there are racial differences in use of carotid artery imaging after controlling for clinical factors and to ascertain racial differences in presenting signs and symptoms and overall appropriateness for carotid endarterectomy (CE). METHODS: We performed a retrospective cohort study of 803 patients older than 45 years, hospitalized between 1991 and 1994 at any of 4 Veterans Affairs Medical Centers, with a discharge diagnosis of transient ischemic attack or ischemic stroke. Clinical data were abstracted from the medical record, including presenting symptoms, diagnostic test results, and use of surgical procedures. Appropriateness for CE was determined according to RAND criteria. RESULTS: Black patients were more likely than white patients to present with stroke (78% versus 55%) but less likely to present with transient ischemic attack (22% versus 45%; P=0.001). There was no racial difference in medical comorbidity or preoperative risk. Black patients were less likely to have an imaging study of their carotid arteries (67% versus 79%; P=0.001). Race remained an independent predictor of imaging after adjustment for clinical factors (odds ratio=1.50; 95% CI, 1.06 to 2.13). Because of higher prevalence of significant carotid artery stenosis, whites were significantly more likely than blacks to be assessed as appropriate candidates for surgery with the use of RAND criteria (18% versus 4%; P=0.001). CONCLUSIONS: Use of carotid artery imaging, a critical step in determining eligibility for CE, is influenced by the patient's race after controlling for clinical presentation. Adjustment for appropriateness of CE reduces but does not eliminate the importance of race.