Operating Characteristic Analysis (operating + characteristic_analysis)

Distribution by Scientific Domains
Distribution within Medical Sciences

Kinds of Operating Characteristic Analysis

  • receiver operating characteristic analysis

  • Selected Abstracts

    To link or not to link: a test of the case linkage principles using serial car theft data

    Matthew Tonkin
    Abstract The purpose of the present study is to test the case linkage principles of behavioural consistency and behavioural distinctiveness using serial vehicle theft data. Data from 386 solved vehicle thefts committed by 193 offenders were analysed using Jaccard's, regression and Receiver Operating Characteristic analyses to determine whether objectively observable aspects of crime scene behaviour could be used to distinguish crimes committed by the same offender from those committed by different offenders. The findings indicate that spatial behaviour, specifically the distance between theft locations and between dump locations, is a highly consistent and distinctive aspect of vehicle theft behaviour; thus, intercrime and interdump distance represent the most useful aspects of vehicle theft for the purpose of case linkage analysis. The findings have theoretical and practical implications for understanding of criminal behaviour and for the development of decision-support tools to assist police investigation and apprehension of serial vehicle theft offenders. Copyright © 2008 John Wiley & Sons, Ltd. [source]

    Screening for distress in cancer patients: is the distress thermometer a valid measure in the UK and does it measure change over time?

    PSYCHO-ONCOLOGY, Issue 6 2008
    A prospective validation study
    Abstract A prospective validation study was conducted in 171 consenting patients from oncology and palliative care outpatient clinics to validate the Distress Thermometer (DT) against the Hospital Anxiety and Depression Scale (HADS), General Health Questionnaire-12 (GHQ-12) and Brief Symptom Inventory-18 (BSI-18) at baseline, four weeks and eight weeks. Receiver Operating Characteristic analysis was used to examine the sensitivity and specificity of the DT scores against the clinically significant cut-off scores of the criterion measures reporting 95% confidence intervals. Standardised response means were used to compare DT scores with criterion measures over time. For a cut-off of 4 vs 5, sensitivity against HADS was 79%, specificity 81%; against GHQ-12, sensitivity was 63%, specificity 83%; and against BSI-18, sensitivity was 88%, specificity 74%. At both four and eight weeks, DT scores tended to change significantly in the same direction as the criterion measures. Ninety-five percent of patients found completing the DT acceptable. The DT is valid and acceptable for use as a rapid screening instrument for patients in the UK with cancer. Our results indicate that it can be used to monitor change in psychological distress over time, but further work is needed to confirm this. Copyright © 2007 John Wiley & Sons, Ltd. [source]

    Forecasting migration of cereal aphids (Hemiptera: Aphididae) in autumn and spring

    A. M. Klueken
    Abstract The migration of cereal aphids and the time of their arrival on winter cereal crops in autumn and spring are of particular importance for plant disease (e.g. barley yellow dwarf virus infection) and related yield losses. In order to identify days with migration potentials in autumn and spring, suction trap data from 29 and 45 case studies (locations and years), respectively, were set-off against meteorological parameters, focusing on the early immigration periods in autumn (22 September to 1 November) and spring (1 May to 9 June). The number of cereal aphids caught in a suction trap increased with increasing temperature, global radiation and duration of sunshine and decreased with increasing precipitation, relative humidity and wind speed. According to linear regression analyses, the temperature, global radiation and wind speed were most frequently and significantly associated with migration, suggesting that they have a major impact on flight activity. For subsequent model development, suction trap catches from different case studies were pooled and binarily classified as days with or without migration as defined by a certain number of migrating cereal aphids. Linear discriminant analyses of several predictor variables (assessed during light hours of a given day) were then performed based on the binary response variables. Three models were used to predict days with suction trap catches ,1, ,4 or ,10 migrating cereal aphids in autumn. Due to the predominance of Rhopalosiphum padi individuals (99.3% of total cereal aphid catch), no distinction between species (R. padi and Sitobion avenae) was made in autumn. As the suction trap catches were lower and species dominance changed in spring, three further models were developed for analysis of all cereal aphid species, R. padi only, and Metopolophium dirhodum and S. avenae combined in spring. The empirical, cross-classification and receiver operating characteristic analyses performed for model validation showed different levels of prediction accuracy. Additional datasets selected at random before model construction and parameterization showed that predictions by the six migration models were 33,81% correct. The models are useful for determining when to start field evaluations. Furthermore, they provide information on the size of the migrating aphid population and, thus, on the importance of immigration for early aphid population development in cereal crops in a given season. [source]

    Antibodies against deamidated gliadin peptides identify adult coeliac disease patients negative for antibodies against endomysium and tissue transglutaminase

    C. Dahle
    Aliment Pharmacol Ther 2010; 32: 254,260 Summary Background, This study was done to evaluate the diagnostic utility of antibodies against deamidated gliadin peptides compared to traditional markers for coeliac disease. Aim, To evaluate diagnostic utility of antibodies against deamidated gliadin peptide (DGP). Methods, Sera from 176 adults, referred for endoscopy without previous analysis of antibodies against tissue transglutaminase (tTG) or endomysium (EmA), were retrospectively analysed by ELISAs detecting IgA/IgG antibodies against DGP or a mixture of DGP and tTG, and compared with IgA-tTG and EmA. Seventy-nine individuals were diagnosed with coeliac disease. Results, Receiver operating characteristic analyses verified the manufacturers' cut-off limits except for IgA/IgG-DGP/tTG. In sera without IgA deficiency, the sensitivity was higher for IgA/IgG-DGP (0.85,0.87) compared with IgA-tTg (0.76) and EmA (0.61). All tests showed high specificity (0.95,1.00). Eighteen coeliac disease-sera were negative regarding IgA-tTG, nine of which were positive for IgA/IgG-DGP. Sera from coeliac disease-patients >70 years were more often negative for IgA-tTG (50%) and IgA/IgG-DGP (36%) than younger patients (15% and 8% respectively) (P < 0.01). Three of the four IgA-deficient patients were positive in the IgA/IgG-DGP assay. Conclusions, In this study of patients unselected regarding IgA-tTg/EmA, thus unbiased in this respect, IgA/IgG-DGP identified adult coeliac disease patients negative for antibodies against endomysium and tissue transglutaminase. Serology is often negative in elderly patients with coeliac disease; a small bowel biopsy should therefore be performed generously before coeliac disease is excluded. [source]

    Proliferative alloresponse of T-cytotoxic cells identifies rejection-prone children with steroid-free liver transplantation

    Chethan Ashokkumar
    Donor-induced and third-party,induced proliferation of T-helper and T-cytotoxic (Tc) cells and their naïve and memory subsets was evaluated simultaneously in single blood samples from 77 children who received steroid-free liver transplantation (LTx) after induction with rabbit anti-human thymocyte globulin. Proliferation was measured by dilution of the intravital dye carboxyfluorescein succinimidyl ester (CFSE) in a 3- to 4-day mixed lymphocyte response coculture. The ratio of donor/third-party,induced proliferated (CFSElow) T-cells was reported as the immunoreactivity index (IR) for each subset. Rejectors were defined as those who experienced biopsy-proven acute cellular rejection within 60 days of the assay. IR > 1 signified increased risk of rejection, and IR < 1 implied decreased risk. Demographics for 32 rejectors and 45 nonrejectors were similar. Proliferated CFSElow T-cells and subsets were significantly higher among rejectors compared with nonrejectors. In 33 of 77 randomly selected children, logistic regression, leave-one-out cross-validation, and receiver operating characteristic analyses showed that the IR of Tc cells was best associated with biopsy-proven rejection (sensitivity > 75%, specificity > 88%). Sensitivity and specificity were replicated in the remaining 44 children who composed the validation cohort. IR of CFSElow Tc cells correlated significantly with IR of proinflammatory, allospecific CD154+ Tc cells (r = 0.664, P = 0.0005) and inversely with IR of allospecific, anti-inflammatory, cytotoxic T lymphocyte antigen 4,positive Tc cells (r = ,0.630, P = 0.007). In conclusion, proliferative alloresponses of Tc cells can identify rejection-prone children receiving LTx. Liver Transpl 15:978,985, 2009. © 2009 AASLD. [source]

    Psychopathy scores and violence among juvenile offenders: a multi-measure study,

    Daniel C. Murrie Ph.D.
    This study examined the relations between psychopathy scores and violent behavior in 113 incarcerated adolescents. We compared the results of four different instruments designed to assess psychopathy features among juveniles,the Psychopathy Checklist: Youth Version (PCL:YV), two versions of the Antisocial Processes Screening Device (APSD), and a Psychopathy Content scale on the Millon Adolescent Clinical Inventory (MACI). We found that PCLY:YV scores were significantly correlated with violent offense history, unadjudicated violence, and institutional violence, as well as measures of the severity and instrumentality of prior violence. Receiver operating characteristic analyses generated statistically significant effect sizes (AUC values) ranging from 0.64 to 0.79. The three other measures generated statistically significant correlations with one or more of the violence criteria, although correlations and effect sizes tended to be smaller in magnitude. Our results offer some support for the validity of these measures of psychopathic features, and the value of the PCL:YV in particular, with respect to short-term measures of violence outcome among juvenile offenders. Copyright © 2004 John Wiley & Sons, Ltd. [source]

    Maternal IgG anti-A and anti-B titres predict outcome in ABO-incompatibility in the neonate

    ACTA PAEDIATRICA, Issue 12 2009
    Egil Bakkeheim
    Abstract Aim:, To evaluate predictors for risk of severe hyperbilirubinaemia and kernicterus in ABO-incompatible neonates with emphasize on maternal IgG anti-A/-B titres. Methods:, Blood group O women in labour at Oslo University Hospital, Ullevål, were included in the years 2004,2006. Offspring with blood group A or B had direct antiglobulin test performed and IgG anti-A/-B levels measured in maternal plasma. Blood group A or B infants developing severe hyperbilirubinaemia, received in addition to phototherapy, immunoglobulin treatment and/or exchange transfusion (EXT). Results:, Of 253 neonates, 61.3% had blood group O, 29.6% blood group A and 9.1% blood group B. Twenty neonates with blood group A or B received at least one immunoglobulin treatment. In multivariate analysis, maternal antibody-titres were the only significant predictors for immunoglobulin treatment (p < 0.0001), EXTs (p < 0.05) and duration of phototherapy (p < 0.0001). The need for invasive treatment increased sharply for antibody titres ,512. Receiver operating characteristic analyses demonstrated that titres ,512 had a sensitivity of 90% and a specificity of 72% for predicting immunoglobulin treatment and thus severe hyperbilirubinaemia. Conclusion:, Maternal IgG anti-A/-B titres contribute to the prediction of risk of severe hyperbilirubinaemia in ABO-incompatible neonates, in addition to blood-grouping and direct antiglobulin-testing, especially following early discharge after delivery. [source]

    Identifying Left Ventricular Dysfunction in Pulmonary Hypertension

    Navin Rajagopalan MD
    The significance of left ventricular (LV) dysfunction in patients with pulmonary hypertension (PH) is unknown. Our purpose was to quantify LV function in PH patients by measuring LV myocardial performance index (MPI) and correlating it with invasively determined hemodynamic variables. The authors prospectively measured LV MPI via transthoracic echocardiography in 50 patients with PH (53±11 years; 35 women) who also underwent right heart catheterization within 1 day of echocardiography. For comparative purposes, LV MPI was also measured in 15 healthy volunteers who served as controls. LV MPI was significantly increased in the PH group compared with controls (0.62±0.27 vs 0.36±0.08; P<.001), indicating worse LV dysfunction despite that LV ejection fraction was not significantly different between the groups (58%±4% vs 60%±3%). LV MPI demonstrated significant correlations with invasively determined mean pulmonary artery pressure (r=.50; P<.001), pulmonary vascular resistance (r=.57; P<.001), and cardiac index (r=,.64; P<.001). By receiver operating characteristic analysis, LV MPI >0.75 predicted cardiac index <2 L/min/m2 with 89% sensitivity and 78% specificity (area under the curve, 0.89). In a multivariate model, LV MPI was independently associated with cardiac index (P<.01). Patients with PH demonstrate abnormal LV function as quantified by elevated LV MPI, which correlates significantly with pulmonary vascular resistance and cardiac index. [source]

    HLA-B27 typing: Evaluation of an allele-specific PCR melting assay and two flow cytometric antigen assays

    CYTOMETRY, Issue 1 2005
    Michael T. Seipp
    Abstract Background Human leukocyte antigen B27 (HLA-B27) is a major histocompatibility complex class 1 molecule that is strongly associated with the disease ankylosing spondylitis. Testing for HLA-B27 is of diagnostic value because 90% of patients with ankylosing spondylitis have the B27 antigen. Two commonly used HLA-B27 flow cytometric assays are commercially available. Methods An allele-specific polymerase chain reaction (PCR) melting assay for HLA-B27 was compared with two available antigen assays on 371 clinical samples. The accuracy of the assays was measured by receiver operating characteristic analysis using the PCR method and sequencing as the reference standard. Results When PCR results were compared with those of the antigen assays, complete concordance was observed except for five discrepant results that were resolved by sequence analysis. Using DNA sequencing as the gold standard, the sensitivity and specificity of PCR were 99.6 and 100.0, those of the best single antigen assay were 98.2 and 97.6, and those of a reflex combination of both antigen assays were 98.8 and 97.6. Conclusions The allele-specific PCR melting assay for HLA-B27 genotyping is easy to perform and has better sensitivity and specificity than antigen assays. The performance of the two flow cytometric antigen assays depends on the antibody used and the positive cutoff values assigned. © 2004 Wiley-Liss, Inc. [source]

    Predictive factors for esophageal stenosis after endoscopic submucosal dissection for superficial esophageal cancer

    H. Mizuta
    SUMMARY Endoscopic submucosal dissection (ESD) has been utilized as an alternative treatment to endoscopic mucosal resection for superficial esophageal cancer. We aimed to evaluate the complications associated with esophageal ESD and elucidate predictive factors for post-ESD stenosis. The study enrolled a total of 42 lesions of superficial esophageal cancer in 33 consecutive patients who underwent ESD in our department. We retrospectively reviewed ESD-associated complications and comparatively analyzed regional and technical factors between cases with and without post-ESD stenosis. The regional factors included location, endoscopic appearance, longitudinal and circumferential tumor sizes, depth of invasion, and lymphatic and vessel invasion. The technical factors included longitudinal and circumferential sizes of mucosal defects, muscle disclosure and cleavage, perforation, and en bloc resection. Esophageal stenosis was defined when a standard endoscope (9.8 mm in diameter) failed to pass through the stenosis. The results showed no cases of delayed bleeding, three cases of insidious perforation (7.1%), two cases of endoscopically confirmed perforation followed by mediastinitis (4.8%), and seven cases of esophageal stenosis (16.7%). Monovalent analysis indicated that the longitudinal and circumferential sizes of the tumor and mucosal defect were significant predictive factors for post-ESD stenosis (P < 0.005). Receiver operating characteristic analysis showed the highest sensitivity and specificity for a circumferential mucosal defect size of more than 71% (100 and 97.1%, respectively), followed by a circumferential tumor size of more than 59% (85.7 and 97.1%, respectively). It is of note that the success rate of en bloc resection was 95.2%, and balloon dilatation was effective for clinical symptoms in all seven patients with post-ESD stenosis. In conclusion, the most frequent complication with ESD was esophageal stenosis, for which the sizes of the tumor and mucosal defect were significant predictive factors. Although ESD enables large en bloc resection of esophageal cancer, practically, in cases with a lesion more than half of the circumference, great care must be taken because of the high risk of post-ESD stenosis. [source]

    Real Time Myocardial Contrast Echocardiography During Supine Bicycle Stress and Continuous Infusion of Contrast Agent.

    ECHOCARDIOGRAPHY, Issue 6 2007
    Cutoff Values for Myocardial Contrast Replenishment Discriminating Abnormal Myocardial Perfusion
    Background: Myocardial contrast echocardiography (MCE) is a new imaging modality for diagnosing coronary artery disease (CAD). Objective: The aim of our study was to evaluate feasibility of qualitative myocardial contrast replenishment (RP) assessment during supine bicycle stress MCE and find out cutoff values for such analysis, which could allow accurate detection of CAD. Methods: Forty-four consecutive patients, scheduled for coronary angiography (CA) underwent supine bicycle stress two-dimensional echocardiography (2DE). During the same session, MCE was performed at peak stress and post stress. Ultrasound contrast agent (SonoVue) was administered in continuous mode using an infusion pump (BR-INF 100, Bracco Research). Seventeen-segment model of left ventricle was used in analysis. MCE was assessed off-line in terms of myocardial contrast opacification and RP. RP was evaluated on the basis of the number of cardiac cycles required to refill the segment with contrast after its prior destruction with high-power frames. Determination of cutoff values for RP assessment was performed by means of reference intervals and receiver operating characteristic analysis. Quantitative CA was carried out using CAAS system. Results: MCE could be assessed in 42 patients. CA revealed CAD in 25 patients. Calculated cutoff values for RP-analysis (peak-stress RP >3 cardiac cycles and difference between peak stress and post stress RP >0 cardiac cycles) provided sensitive (88%) and accurate (88%) detection of CAD. Sensitivity and accuracy of 2DE were 76% and 79%, respectively. Conclusions: Qualitative RP-analysis based on the number of cardiac cycles required to refill myocardium with contrast is feasible during supine bicycle stress MCE and enables accurate detection of CAD. [source]

    Risk of harm among gamblers in the general population as a function of level of participation in gambling activities

    ADDICTION, Issue 4 2006
    Shawn R. Currie
    ABSTRACT Aims To examine the relationship between gambling behaviours and risk of gambling-related harm in a nationally representative population sample. Design Risk curves of gambling frequency and expenditure (total amount and percentage of income) were plotted against harm from gambling. Setting Data derived from 19 012 individuals participating in the Canadian Community Health Survey,Mental Health and Well-being cycle, a comprehensive interview-based survey conducted by Statistics Canada in 2002. Measurement Gambling behaviours and related harms were assessed with the Canadian Problem Gambling Index. Findings Risk curves indicated the chances of experiencing gambling-related harm increased steadily the more often one gambles and the more money one invests in gambling. Receiver operating characteristic analysis identified the optimal limits for low-risk participation as gambling no more than two to three times per month, spending no more than $501,1000CAN per year on gambling and investing no more than 1% of gross family income on gambling activities. Logistic regression modelling confirmed a significant increase in the risk of gambling-related harm (odds ratios ranging from 2.0 to 7.7) when these limits were exceeded. Conclusions Risk curves are a promising methodology for examining the relationship between gambling participation and risk of harm. The development of low-risk gambling limits based on risk curve analysis appears to be feasible. [source]

    Predictive factors for platelet increase after partial splenic embolization in liver cirrhosis patients

    Hiromitsu Hayashi
    Abstract Background and Aim:, Partial splenic embolization (PSE) is often performed for improving thrombocytopenia in cirrhotic patients. We investigated the largely unclear predictive factors for platelet increase at both 1 month and 1 year after PSE. Methods:, Aimed at increasing the platelet count, PSE was performed in 42 cirrhotic patients with thrombocytopenia (platelets < 80 × 104/mL) caused by hypersplenism. The clinical data were analyzed to clarify the predictive factors for platelet increase at 1 month (n = 42) and 1 year (n = 38) after PSE. Results:, The mean splenic infarction ratio was 76.7% ± 11.2%. The platelet count increased to 259% ± 112% and 228% ± 75% of the pretreatment values at 1 month and at 1 year after PSE, respectively. Stepwise multiple linear regression analysis showed that the infarcted splenic volume had a positive independent association with the increase in platelet count at both 1 month (P = 0.00004) and 1 year (P = 0.005) after PSE (increase in platelet count (×104/mL): at 1 month = 0.752 + 0.018 × infarcted splenic volume (mL), R2 = 0.344; at 1 year = 2.19 + 0.01 × infarcted splenic volume (mL), R2 = 0.203). Receiver operating characteristic analysis yielded a cut-off value of 388 mL of infarcted splenic volume for achieving an increase of 5.0,8.0 × 104/mL in platelet count at 1 year. Conclusions:, PSE can reduce the platelet pool and induce an increase in platelet count. This increase is greatly dependent on the infarcted splenic volume. [source]

    Comparison of ferucarbotran-enhanced fluid-attenuated inversion-recovery echo-planar, T2-weighted turbo spin-echo, T2*-weighted gradient-echo, and diffusion-weighted echo-planar imaging for detection of malignant liver lesions

    Yoshihiko Fukukura MD
    Abstract Purpose: To compare the diagnostic accuracy of superparamagnetic iron oxide (SPIO)-enhanced fluid-attenuated inversion-recovery echo-planar imaging (FLAIR EPI) for malignant liver tumors with that of T2-weighted turbo spin-echo (TSE), T2*-weighted gradient-echo (GRE), and diffusion-weighted echo-planar imaging (DW EPI). Materials and Methods: SPIO-enhanced magnetic resonance imaging (MRI) that included FLAIR EPI, T2-weighted TSE, T2*-weighted GRE, and DW EPI sequences was performed using a 3 T system in 54 consecutive patients who underwent surgical exploration with intraoperative ultrasonography. A total of 88 malignant liver tumors were evaluated. Images were reviewed independently by two blinded observers who used a 5-point confidence scale to identify lesions. Results were correlated with results of histopathologic findings and surgical exploration with intraoperative ultrasonography. The accuracy of each MRI sequence was measured with jackknife alternative free-response receiver operating characteristic analysis. The sensitivity of each observer with each MRI sequence was compared with McNemar's test. Results: Accuracy values were significantly higher with FLAIR EPI sequence (0.93) than with T2*-weighted GRE (0.80) or DW EPI sequences (0.80) (P < 0.05). Sensitivity was significantly higher with the FLAIR EPI sequence than with any of the other sequences. Conclusion: SPIO-enhanced FLAIR EPI sequence was more accurate in the diagnosis of malignant liver tumors than T2*-weighted GRE and DW EPI sequences. SPIO-enhanced FLAIR EPI sequence is helpful for the detection of malignant liver tumors. J. Magn. Reson. Imaging 2010;31:607,616. ©2010 Wiley-Liss, Inc. [source]

    Phosphatidylethanol and Alcohol Consumption in Reproductive Age Women

    ALCOHOLISM, Issue 3 2010
    Scott H. Stewart
    Background:, Fetal alcohol disorders are preventable, but self-reported alcohol consumption can be misleading and impede effective treatment. Biomarkers represent an alternative method for assessing alcohol use, and this study evaluated the relationship between blood phosphatidylethanol (PEth) and alcohol use in a sample of reproductive age women. Methods:, Alcohol use was estimated by validated self-report methods in 80 nonpregnant women ages 18 to 35. PEth was measured by a contracted laboratory using a liquid chromatography-tandem mass spectrometry assay. Regression methods appropriate for the distribution of PEth were used to define its relationship to alcohol consumption during the prior 2 weeks and explore the effects of drinking patterns on this association. Receiver operating characteristic analysis was used to estimate the sensitivity of PEth for various drinking levels at 95% specific cutoffs. Results:, PEth had a positive linear association with grams of alcohol consumed (p < 0.001), and was detectable in 93% of subjects consuming an average of 2 or more drinks per day. The relationship between total alcohol consumption and PEth may be stronger in women with recent heavy drinking days. The relationship between drinking and PEth varied considerably between individuals, and sensitivity for a certain amount of drinking was low at a highly specific cutoff concentration. Conclusions:, PEth is a highly sensitive indicator of moderate and heavy alcohol consumption in reproductive age women and may complement the use of self-report alcohol screens when additional objective markers of alcohol use are desirable. However, choosing a highly valid cutoff concentration for PEth to differentiate various levels of alcohol consumption may not be feasible. [source]

    Elevated levels of soluble fibrin or D-dimer indicate high risk of thrombosis

    H. WADA
    Summary.,Background:,Fibrin-related markers such as soluble fibrin (SF) and D-dimer are considered useful for the diagnosis of thrombosis. However, the evidence for diagnosis of thrombosis by fibrin-related markers is not well-established. Objective:,To evaluate the cutoff values of D-dimer and SF in the diagnosis of thrombosis. Patients and Methods:,Plasma concentrations of SF and D-dimer were measured in 784 inpatients suspected of having thrombosis between 1 August 2003 and 31 December 2004, and then correlated with thrombosis. Results and Conclusions:,Plasma concentrations of D-dimer and SF were significantly higher in patients with disseminated intravascular coagulation (DIC), deep vein thrombosis (DVT) and cerebral thrombosis, compared with those in patients without thrombosis. When cutoff values of > 3.0 ,g mL,1 for D-dimer and > 6.0 ,g mL,1 for SF were used for the diagnosis, more than 50% of patients (with the exception of liver transplant patients and postoperative patients) had thrombosis. Receiver operating characteristic analysis showed that SF was more useful than D-dimer for the diagnosis of thrombosis (i.e. DVT and DIC). The cutoff value of D-dimer (7.87 ,g mL,1) was the same for DVT and DIC, while that of SF was slightly lower for DVT (7.05 ,g mL,1) than for DIC (8.60 ,g mL,1). Our findings suggest that high levels of plasma fibrin-related markers reflect high risk for thrombosis. [source]

    Comparison of gastric emptying of a nondigestible capsule to a radio-labelled meal in healthy and gastroparetic subjects

    B. KUO
    Summary Background, Gastric emptying scintigraphy (GES) using a radio-labelled meal is used to measure gastric emptying. A nondigestible capsule, SmartPill, records luminal pH, temperature, and pressure during gastrointestinal transit providing a measure of gastric emptying time (GET). Aims, To compare gastric emptying time and GES by assessing their correlation, and to compare GET and GES for discriminating healthy subjects from gastroparetics. Methods, Eighty-seven healthy subjects and 61 gastroparetics enrolled with simultaneous SmartPill and GES. Fasted subjects were ingested capsule and [99mTc]-SC radio-labelled meal. Images were obtained every 30 min for 6 h. Gastric emptying time and percentage of meal remaining at 2/4 h were determined for each subject. The sensitivity/specificity and receiver operating characteristic analysis of each measure were determined for each subject. Results, Correlation between GET and GES-4 h was 0.73 and GES-2 h was 0.63. The diagnostic accuracy from the receiver operating characteristic curve between gastroparetics and healthy subjects was GET = 0.83, GES-4 h = 0.82 and GES-2 h = 0.79. The 300-min cut-off time for GET gives sensitivity of 0.65 and specificity of 0.87 for diagnosis of gastroparesis. The corresponding sensitivity/specificity for 2 and 4 h standard GES measures were 0.34/0.93 and 0.44/0.93, respectively. Conclusion, SmartPill GET correlates with GES and discriminates between healthy and gastroparetic subjects offering a nonradioactive, standardized, ambulatory alternative to scintigraphy. [source]

    Validation of a questionnaire (CARAT10) to assess rhinitis and asthma in patients with asthma

    ALLERGY, Issue 8 2010
    J. A. Fonseca
    To cite this article: Fonseca JA, Nogueira-Silva L, Morais-Almeida M, Azevedo L, Sa-Sousa A, Branco-Ferreira M, Fernandes L, Bousquet J. Validation of a questionnaire (CARAT10) to assess rhinitis and asthma in patients with asthma. Allergy 2010; 65: 1042,1048. Abstract Background and aim:, The Control of Allergic Rhinitis and Asthma Test (CARAT) was developed to be used in the concurrent management of these diseases, as recommended by the Allergic Rhinitis and its Impact on Asthma (ARIA) guidelines. However, it was necessary to statistically identify and remove redundant questions and to evaluate the new version's factor structure, internal consistency and concurrent validity. Methods:, In this cross-sectional study 193 adults with allergic rhinitis and asthma from 15 outpatient clinics in Portugal were included. The CARAT questionnaire was reduced using descriptive analysis, exploratory factor analysis and internal consistency. Spearman's correlations were used to compare the CARAT scores with a medical evaluation and other measures of control, including the Asthma Control Questionnaire and symptoms' visual analogue scales. The performance against physician rating of control was summarized using the area under the curve (AUC) from receiver operating characteristic analysis. In addition, CARAT was compared with the physician's decision to reduce, maintain or increase treatment. Results:, The reduced version has 10 questions and 2 factors (CARAT10). The Cronbach's alpha was 0.85. All correlation coefficients of CARAT10 and factors with the different measures of control met the a priori predictions, ranging from 0.58 to 0.79. The AUC was 0.82. For the physician's decision groups of reduce, maintain or increase treatment, the mean (IC95%) scores of CARAT10 were 24 (21.4;26.6), 21 (19.4;21.9) and 15 (13.6;16.5), respectively. Conclusion:, CARAT10 has high internal consistency and good concurrent validity, making it useful to compare groups in clinical studies. [source]

    Leukocytosis is a risk factor for recurrent arterial thrombosis in young patients with polycythemia vera and essential thrombocythemia,

    Valerio De Stefano
    There is evidence that leukocytosis is associated with an increased risk of first thrombosis in patients with polycythemia vera (PV) and essential thrombocythemia (ET). Whether it is a risk factor for recurrent thrombosis too is currently unknown. In the frame of a multicenter retrospective cohort study, we recruited 253 patients with PV (n = 133) or ET (n = 120), who were selected on the basis of a first arterial (70%) or venous major thrombosis (27.6%) or both (2.4%), and who were not receiving cytoreduction at the time of thrombosis. The probability of recurrent thrombosis associated with the leukocyte count recorded at the time of the first thrombosis was estimated by a receiver operating characteristic analysis and a multivariable Cox proportional hazards regression model. Thrombosis recurred in 78 patients (30.7%); multivariable analysis showed an independent risk of arterial recurrence (hazard ratio [HR] 2.16, 95% CI 1.12,4.18) in patients with a leukocyte count that was >12.4 × 109/L at the time of the first thrombotic episode. The prognostic role for leukocytosis was age-related, as it was only significant in patients that were aged <60 years (HR for arterial recurrence 3.35, 95% CI 1.22,9.19). Am. J. Hematol., 2010. © 2009 Wiley-Liss, Inc. [source]

    Use of thymosin ,15 as a urinary biomarker in human prostate cancer

    THE PROSTATE, Issue 2 2005
    Lloyd M. Hutchinson
    Abstract BACKGROUND Additional prostate cancer (CaP) biomarkers are needed to increase the accuracy of diagnosis and to identify patients at risk of recurrence. In tissue-based assays, thymosin ,15 (T,15) has been linked to an aggressive CaP phenotype and correlated with future tumor recurrence. We hypothesized that T,15 may have clinical utility in biological fluids. METHODS T,15 was measured in urine from CaP patients; untreated (N,=,61), prostatectomy (RP, N,=,46), androgen deprivation therapy (ADT, N,=,14) and control groups; normal (N,=,52), genitourinary carcinoma (N,=,15), non-malignant prostate disease (N,=,81), and other urology (N,=,73). We evaluated the utility of urinary T,15 for CaP diagnosis, alone or in combination with prostate-specific antigen (PSA), and the relationship to CaP progression. RESULTS A normal threshold of 40 (ng/dl)/(,g_protein/mg_creatinine) was defined using receiver operating characteristic analysis and marked the 19th centile for age-matched controls. The proportion of untreated CaP patients with urinary T,15 above the threshold was significantly higher than normal and genitourinary disease controls (P,<,0.001). RP caused urinary T,15 to drop significantly (P,=,0.005). Pre-surgery T,15 concentrations greater than the normal threshold may confer greater risk of CaP recurrence. Relative to normal controls, patients receiving ADT for aggressive CaP were 12 times more likely to have elevated urinary T,15 (P,=,0.001, 95% CI,=,2.8, 51.8). Combining PSA and T,15 (PSA,>,4, or PSA,>,2.5, T,15,>,40, or PSA,=,2.5, T,15,>,90) provided the same sensitivity as a 2.5 ng/ml PSA cutoff, but markedly improved diagnostic specificity. CONCLUSIONS We report that T,15 is a urinary biomarker for CaP and suggest that T,15, in combination with PSA, can be used to improve both the sensitivity and specificity of CaP diagnosis. © 2005 Wiley-Liss, Inc. [source]

    Adequate Early Cyclosporin Exposure is Critical to Prevent Renal Allograft Rejection: Patients Monitored by Absorption Profiling

    C. M. Clase
    This study used receiver operating characteristic analysis to investigate the properties of area under the concentration-time curve during the first 4 h after cyclosporin-microemulsion dosing (AUC0,4) and cyclosporin (CyA) levels immediately before and at 2 and 3 h after dosing (C0, C2 and C3) to predict the risk of biopsy-proven acute rejection (AR) at 6 months. Ninety-eight kidney transplant recipients treated with CyA-microemulsion-based triple therapy immunosuppression were studied on post-transplant days 3, 5, and 7, and at increasing intervals thereafter. The most sensitive and specific predictor of AR was AUC0,4. Of the single time-point measurements, the measurement properties of C2 were closest to those of AUC0,4, and superior to those of C3. The relationship between C0 and subsequent AR was weak and did not reach statistical significance. On day 3, CyA AUC0,4, 4400 ng . h/mL and C2, 1700 ng/mL were each associated with a 92% negative predictive value for rejection in the first 6 months. Pharmacokinetic measurements on or after day 5, and measurements on day 3 in patients with delayed graft function, were not predictive of AR. Adequate exposure within the first 3 days post transplantation may be critically important in preventing subsequent rejection. [source]

    Indentation testing of human cartilage: Sensitivity to articular surface degeneration

    ARTHRITIS & RHEUMATISM, Issue 12 2003
    Won C. Bae
    Objective To determine, for clinical indentation testing of human articular cartilage, the effects of aging and degeneration on indentation stiffness and traditional indices of cartilage degeneration; the relationship between indentation stiffness and indices of degeneration; and the sensitivity and specificity of indentation stiffness to cartilage degeneration. Methods Osteochondral cores from femoral condyles of cadaveric human donors were harvested. Samples were distributed into experimental groups based on donor age (young [20,39 years], middle [40,59 years], and old [,60 years]), and a macroscopic articular surface appearance that was either normal or mildly degenerate, without deep erosion. Samples were analyzed for indentation stiffness, cartilage thickness, India ink staining (quantitated as the reflected light score), and Mankin-Shapiro histopathology score. Results Indentation stiffness, India ink staining, and the histopathology score each varied markedly between normal-sample and degenerate-sample groups but varied relatively little between normal samples obtained from different age groups. A decrease in indentation stiffness (softening) correlated with a decrease in the reflectance score and an increase in the overall histopathology score, especially the surface irregularity component of the histopathology score. Receiver operating characteristic analysis suggested that the indentation testing could accurately detect cartilage degeneration as indicated by macroscopic appearance, India ink staining, and histopathology score. Conclusion The indentation stiffness of the normal to mildly degenerate samples tested in this study was sensitive to mild degeneration at the articular surface and was insensitive to changes associated with normal aging or to slight variations in cartilage thickness. This suggests that indentation testing may be a useful clinical tool for the evaluation of early-stage degenerative changes in articular cartilage. [source]

    Ecological niche conservatism in North American freshwater fishes

    There are many hypotheses of relationships, and also of speciation processes, in North American freshwater fishes, although, to date, there have been no direct tests of whether there is evidence of ecological niche conservatism. In the present study, ecological niche modeling is used to look for evidence of ecological niche conservatism in six clades of freshwater fishes: the starheaded topminnows, sand darters, black basses, Notropis rubellus species group, Notropis longirostris species group, and the Hybopsis amblops species group. This is achieved by evaluating the reciprocal predictivity of distributional predictions based on ecological niche models developed for each individual taxon in a clade under the assumption that high reciprical predictivity between sister species can be taken as evidence of niche conservatism. Omission percentages, total and average commission, and the area under the curve in a receiver operating characteristic analysis, where calculated, are used to evaluate predictive ability. Occurrence data for each species were subset into a training and independent validation data set where possible. Across all clades and species, models predicted the validation data for a given species well. Ecological niche conservatism was found generally across the starheaded topminnows, the sand darters, and the N. longirostris species group. There was some inter-predictivity within the N. rubellus group, but almost no inter-predictivity within the black basses, indicating a lack of conservatism. These results demonstrate that ecological niches generally act as stable constraints on freshwater fish distributions in North America. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 96, 282,295. [source]

    The Long-Term Risk of Stroke in Patients with Acute Myocardial Infarction Complicated with New-Onset Atrial Fibrillation

    Asanin R. Milika MD
    Background The long-term risk of stroke after acute myocardial infarction (AMI) complicated with new-onset atrial fibrillation (AF) remains unclear. The aim of this study was to determine the long-term risk of AF and stroke in patients with AMI complicated with new-onset AF. Methods Patients with AMI complicated with new-onset AF (n = 260) and those without new-onset AF (n = 292) were followed for a mean of 7 years. All patients had sinus rhythm at hospital discharge. Results During the follow-up, AMI patients with new-onset AF had more frequent AF than those without new-onset AF (10.4% vs 2.7%, respectively; P < 0.0001). New-onset AF during AMI was a significant predictor of subsequent AF occurrence (the time elapsing between 2 consecutive R waves [RR] = 3.15, P = 0.004); but AF recurrence in follow-up (RR = 5.08, P = 0.001) and non-anticoagulation at discharge (RR = 0.29, P = 0.008) were independent predictors of stroke (Cox regression analysis). A period of 3.5 hours of AF within the first 48 hours of AMI was the high sensitivity cut-off level for the prediction of low long-term risk of stroke obtained by receiver operating characteristic analysis. Among patients who did not receive anticoagulants at discharge, the patients with short AF did not experience stroke and AF recurrence during follow-up, while those in the other group developed it (10.8%, P = 0.038 and 13.5%, P = 0.019, respectively). Conclusion New-onset AF during AMI identifies the patients at long-term risk for stroke who may potentially benefit from anticoagulant therapy. Atrial fibrillation recurrence in follow-up was independently related to the development of stroke. However, for low-risk patients with AF (those with short AF occurring early in AMI) long-term anticoagulants might not be required. Copyright © 2009 Wiley Periodicals, Inc. [source]

    Indocyanine green elimination but not bilirubin indicates improvement of graft function during MARS therapy

    Stefan Scheingraber
    Abstract:, Measurement of indocyanine green plasma disappearance rate (PDRICG) has been suggested as a meaningful liver function parameter. However, there are only very limited data concerning its value in the monitoring of graft dysfunction (GDF) and primary non-function (PNF) especially during molecular absorbent recirculating system (MARS) therapy. This study was therefore performed to evaluate the diagnostic accuracy to detect and monitor GDF with the measurement of the PDRICG in direct comparison with conventional markers like bilirubin and prothrombin time (PT). Of the 19 liver recipients, four patients with GDF and two patients with PNF were treated with 38 MARS cycles. Only PDRICG did reliably indicate liver function between patients with GDF/PNF and patients with sufficient graft function who served as controls. Moreover, receiver operating characteristic analysis showed the highest areas under the curve (AUC) for PDRICG (AUCPDRICG max: 0.840, AUCPDRICG max: 0.822), followed by bilirubin (AUCbilirubin: 0.528) and PT (AUCPT: 0.546). In contrast to the decrease of the serum bilirubin concentration due to MARS, a noticeable improvement of PDRICG was evident only in patients with GDF. Patients with acute fulminant failure and PNF had significantly lower PDRICG values, which did not improve even during continuous MARS treatments. Conclusively, monitoring of PDRICG is superior to bilirubin and PT measurements to determine the graft function especially in patients with PNF and GDF undergoing MARS therapy. [source]

    Screening for DSM-IV externalizing disorders with the Child Behavior Checklist: a receiver-operating characteristic analysis

    James J. Hudziak
    Background:, This study examines the diagnostic accuracy of the CBCL syndrome AS scales for predicting DSM-IV Attention Deficit-Hyperactivity Disorder (ADHD) and Oppositional Defiant Disorder with or without Conduct Disorder (ODD/CD). Methods:, The sample included 370 children (187 probands and 183 siblings) participating in a family genetic study of attention and aggressive behavior problems. Univariate and stepwise logistic regression analyses were used to derive models for predicting two diagnostic conditions: ADHD and ODD/CD. Results:, The Attention Problems syndrome significantly predicted ADHD, and ODD/CD was significantly predicted by the Aggressive Behavior syndrome. Both scales demonstrated good diagnostic accuracy, as assessed through receiver operating characteristics analyses. Cut-point analyses confirmed the utility of low T -scores, 55 on the respective syndromes, for efficiently discriminating cases from noncases. Conclusions:, CBCL syndromes display good diagnostic efficiency for assessing common externalizing disorders in children. [source]

    Disseminated intravascular coagulation in acute leukemia: clinical and laboratory features at presentation

    Masamitsu Yanada
    Abstract:,Background:,Although there are two major scoring systems for the clinical diagnosis of disseminated intravascular coagulation (DIC), the validity of these systems for leukemia-associated DIC remains to be confirmed. Methods:,By analyzing 125 newly diagnosed acute leukemia patients, we investigated clinical and laboratory features of leukemia-associated DIC, and determined the validity of the two established criteria. Results:,A total of 36 patients (29%) were diagnosed with DIC according to expert opinion, a method regarded as the de facto gold standard. Leukemia-associated DIC is characterized by rare manifestation of organ failure because of thrombosis and no relevance of the platelet count for the diagnosis. The results of receiver operating characteristics analysis favored fibrin degradation product (FDP) rather than D-dimer as the fibrin-related marker test. Although prothrombin time, plasma fibrinogen, and serum FDP levels were significantly different for patients with and without DIC, multivariate analysis identified FDP levels to be the only factor associated with DIC diagnosis. The cut-off level of 15 ,g/mL for FDP was found to be the most effective to differentiate DIC from non-DIC, resulting in diagnostic sensitivity and specificity of 92% and 96%, respectively. The diagnostic results for our patients produced with this FDP-based system were at least comparable with or superior to those obtained with the two currently available scoring systems. Conclusions:,Our findings suggest that an FDP-based criterion may be applicable for the diagnosis of leukemia-associated DIC. Although it appears to be simple and practicable enough for clinical use, prospective validation of this criterion is needed. [source]

    Plasma Antithrombin Activity as a Diagnostic and Prognostic Indicator in Dogs: A Retrospective Study of 149 Dogs

    S. Kuzi
    Background: Antithrombin (AT) is the major inhibitor of coagulation. In people, hypoantithrombinemia is associated with hypercoagulability, thrombosis, and poor prognosis. Veterinary studies, however, have not demonstrated similar prognostic significance. Thus, AT activity (ATA) in dogs currently is interpreted based on human medicine guidelines. Hypothesis: ATA can serve as a prognostic marker in dogs, as has been shown in people. Objectives: (1) To describe the clinical and clinicopathologic findings, diagnoses, and outcome of dogs with decreased versus normal ATA, (2) to identify diseases and mechanisms associated with hypoantithrombinemia, and (3) to assess ATA as a prognostic indicator. Animals and Methods: Retrospective study of 149 dogs with ATA measurement during their disease course. Results: Hypoantithrombinemic dogs had a higher proportion of leukocytosis, hemostatic abnormalities, hypoalbuminemia, and hyperbilirubinemia versus dogs with normal ATA. Hypoantithrombinemia commonly was present in immune-mediated hemolytic anemia (IMHA), pancreatitis, hepatopathy, and neoplasia. It was associated with higher risk of mortality in the entire study population and for specific diseases (eg, IMHA, neoplasia). The odds ratio for mortality significantly and progressively increased when ATA was <60 and <30% (9.9, 14.7, respectively). A receiver operating characteristics analysis of ATA as a predictor of mortality showed an area under the curve of 0.7, and an optimal cutoff point of 60% yielded sensitivity and specificity of 58 and 85%, respectively. Conclusions and Clinical Importance: In dogs, ATA <60% indicates increased mortality risk, similarly to human patients, but ATA has limited value as a single discriminating factor in the outcome. [source]

    Coronary Flow Reserve by Transthoracic Echocardiography Predicts Epicardial Intimal Thickening in Cardiac Allograft Vasculopathy

    F. Tona
    Cardiac allograft vasculopathy (CAV) is the leading cause of morbidity and mortality in heart transplantation (HT). We sought to investigate the role of coronary flow reserve (CFR) by contrast-enhanced transthoracic echocardiography (CE-TTE) in CAV diagnosis. CAV was defined as maximal intimal thickness (MIT) assessed by intravascular ultrasound (IVUS) ,0.5 mm. CFR was assessed in the left anterior descending coronary artery in 22 HT recipients at 6 ± 4 years post-HT. CAV was diagnosed in 10 patients (group A), 12 had normal coronaries (group B). The mean MIT was 0.7 ± 0.1 mm (range 0.03,1.8). MIT was higher in group A (1.16 ± 0.3 mm vs. 0.34 ± 0.07 mm, p < 0.0001). CFR was 3.1 ± 0.8 in all patients and lower in group A (2.5 ± 0.6 vs. 3.7 ± 0.3, p < 0.0001). CFR was inversely related with MIT (r =,0.774, p < 0.0001). A cut point of ,2.9, identified as optimal by receiver operating characteristics analysis was 100% specific and 80% sensitive (PPV = 100%, NPV = 89%, Accuracy = 91%). CFR assessment by CE-TTE is a novel noninvasive diagnostic tool in the detection of CAV defined as MIT ,0.5 mm. CFR by CE-TTE may reduce the need for routine IVUS in HT. [source]

    Progression of Alphafetoprotein Before Liver Transplantation for Hepatocellular Carcinoma in Cirrhotic Patients: A Critical Factor

    E. Vibert
    Liver transplantation (LT) for cirrhotic/Hepatocellular carcinoma (HCC) is associated with reduced survival in patients with poor histological features. Preoperative levels of alphafetoprotein (AFP) could predict negative biological features. AFP progression could be more relevant than static AFP levels in predicting LT outcomes. A total of 252 cirrhotic/HCC patients transplanted between 1985 and 2005 were reviewed. One hundred fifty-three patients were analyzed, 99 excluded (for nonsecreting tumors and/or salvage transplantation). Using receiver operating characteristics analysis for recurrence after LT, ,progression' of AFP was defined by >15 ,g/L per month before LT. A total of 127 (83%) were transplanted under and 26(16%) over this threshold. After 45 months of follow-up (median), 5-year overall survival (OS) and recurrence free-survival (RFS) were 72% and 69%, respectively. Five-year survival in the progression group was lower than the nonprogression group (OS 54% vs. 77%; RFS 47% vs. 74%). Multivariate analysis showed progression of AFP >15 ,g/L per month and preoperative nodules >3 were associated with decreased OS. Progression group and age >60 years were associated with decreased RFS. Male gender, progression of AFP and size of tumor >30 mm were associated with satellite nodules and/or vascular invasion. In conclusion, increasing AFP >15 ,g/L/month while waiting for LT is the most relevant preoperative prognostic factor for low OS/DFS. AFP progression could be a pathological preoperative marker of tumor aggressiveness. [source]