Receiver Operator Curve (receiver + operator_curve)

Distribution by Scientific Domains


Selected Abstracts


Validity of the Alcohol Use Disorders Identification Test in College Students

ALCOHOLISM, Issue 6 2004
Patricia K. Kokotailo
Background: High-risk alcohol use among college students is associated with accidents, partner violence, unwanted sexual encounters, tobacco use, and performance issues. The identification and treatment of high-risk drinking students is a priority for many college campuses and college health centers. The goal of this study was to test the psychometric properties of the Alcohol Use Disorders Identification Test (AUDIT) in college students. Methods: A convenience sample of students coming into a college health clinic was asked to complete the 10-question AUDIT and then participate in a research interview. The interview focused on assessing students for alcohol abuse and dependence by using the Composite International Diagnostic Interview Substance Abuse Module and timeline follow-back procedures to assess a 28-day drinking history. Results: A total of 302 students met the eligibility criteria and agreed to participate in the study. The sample consisted of 185 females (61%) and 117 males (39%), with a mean age of 20.3 years. Forty students were abstinent, 88 were high-risk drinkers, and 103 met criteria for a 12-month history of dependence. Receiver operator curves demonstrated that the AUDIT had the highest area under the cure for detecting high-risk alcohol use (0.872) and the lowest for identifying persons with a lifetime history of alcohol abuse or dependence (0.775). An AUDIT cutoff score of 6 or greater demonstrated a sensitivity of 91.0% and a specificity of 60.0% in the detection of high-risk drinkers. Conclusions: The AUDIT has reasonable psychometric properties in sample of college students using student health services. This study supports the use of the AUDIT in this population. [source]


Elongation Index as a New Index Determining the Severity of Left Ventricular Systolic Dysfunction and Mitral Regurgitation in Patients with Congestive Heart Failure

ECHOCARDIOGRAPHY, Issue 7 2005
Mehmet Yokusoglu M.D.
The shape of the left ventricle is an important echocardiographic feature of left ventricular dysfunction. Progression of the mitral regurgitation and consequent left ventricular remodeling is unpredictable in heart failure. Elongation index is an index of left ventricular sphericity. The surface area of the elongated ventricle is larger than that of a spherical one. The objective of this study was to assess the relation between elongation index and the degree of mitral regurgitation along with noninvasive indices of left ventricular function. Thirty-two patients (21 male, 11 female, mean age: 57 ± 6 yrs) with congestive heart failure and mitral regurgitation were included. Patients were stratified into three groups according to vena contracta width as having mild (n = 11), moderate (n = 11) and severe mitral regurgitation (n = 10). The elongation index (EI) was considered as equal to {[(left ventricular internal area-measured) , (theoretical area of the sphere with measured left ventricular volume)]/(theoretical area of the sphere with measured left ventricular volume)}. Ejection fractions by the modified Simpson rule, dP/dt and sphericity index (SI) were also recorded. The relationship between (EI), ejection fraction, dP/dt and SI reached modest statistical significance (p < 0.05). When the EI and SI were compared, the correlation was also significant (p < 0.01). The areas under the receiver operator curve of EI and SI for discriminating dP/dt < 1000 mm Hg/s were 0.833 and 0.733, respectively. In conclusion, the elongation, which defines the shape of the left ventricle, might be related to the systolic function of the left ventricle and the degree of the mitral regurgitation. Further studies are needed to demonstrate its use in other clinical entities. [source]


Cerebrospinal fluid amyloid ,40 is decreased in cerebral amyloid angiopathy,

ANNALS OF NEUROLOGY, Issue 2 2009
Marcel M. Verbeek MSc
Cerebral amyloid angiopathy is caused by deposition of the amyloid , protein in the cerebral vasculature. In analogy to previous observations in Alzheimer disease, we hypothesized that analysis of amyloid ,40 and ,42 proteins in the cerebrospinal fluid might serve as a molecular biomarker. We observed strongly decreased cerebrospinal fluid amyloid ,40 (p < 0.01 vs controls or Alzheimer disease) and amyloid ,42 concentrations (p < 0.001 vs controls and p < 0.05 vs Alzheimer disease) in cerebral amyloid angiopathy patients. The combination of amyloid ,42 and total tau discriminated cerebral amyloid angiopathy from controls, with an area under the receiver operator curve of 0.98. Our data are consistent with neuropathological evidence that amyloid ,40 as well as amyloid ,42 protein are selectively trapped in the cerebral vasculature from interstitial fluid drainage pathways that otherwise transport amyloid , proteins toward the cerebrospinal fluid. Ann Neurol 2009;66:245,249 [source]


The comparative pressure-flow plot properties of radiological bladder neck and prostatic obstruction

BJU INTERNATIONAL, Issue 11 2009
Sanjin Idriz
OBJECTIVES To test the hypotheses that: (i) significant differences should exist in pressure/flow data between radiologically determined bladder neck and prostatic obstruction; (ii) these differences should inform understanding of the pathophysiology of male outflow obstruction. The biomechanics of the voiding/pressure/flow plot imply that a urodynamic assessment trace should identify outflow obstruction and characterise the urethral viscoelastic properties. Micturating cystourethrograms (MCUG) images might provide a useful diagnostic dichotomy for testing these assumptions. MATERIALS AND METHODS The pressure/flow data from 71 men who also provided video-urodynamic imaging data that a radiologist could classify unequivocally as showing bladder neck obstruction (42) or prostatic obstruction (29) were analysed. The following variables were recorded: the detrusor pressure at initiation of voiding (Pdet.open); the detrusor pressure at the end of voiding (Pdet.close); the detrusor pressure at maximum flow rate (Qmax), (Pdet.Qmax), and Qmax. The urethral resistance relation (URR) was drawn onto the pressure-flow plot and the gradient of the URR, ,Pdet/,Q, was calculated. RESULTS There were significant between group differences in Pdet.open (95% confidence interval of the difference 5.2,28.6, U = 352, P = 0.003); Pdet.close (0.2,15.0, U = 428, P = 0.034); Pdet.Qmax (0.0,18.9, U = 439, P = 0.05); Qmax and ,Pdet/,Q did not distinguish between the MCUG groups (95% confidence interval of the difference 2.3,18, U = 111; P = 0.004). The best-fit model from linear combinations of the data achieved an area under the receiver operator curve of 0.72 for discriminating between the MCUG groups. CONCLUSIONS The urodynamic assessment identified interesting and coherent biomechanical differences, and could distinguish between the obstructions with a moderate degree of accuracy. [source]