Comparing diagnostic tests on benefit-risk.

PubMed

Pennello, Gene; Pantoja-Galicia, Norberto; Evans, Scott

2016-01-01

Comparing diagnostic tests on accuracy alone can be inconclusive. For example, a test may have better sensitivity than another test yet worse specificity. Comparing tests on benefit risk may be more conclusive because clinical consequences of diagnostic error are considered. For benefit-risk evaluation, we propose diagnostic yield, the expected distribution of subjects with true positive, false positive, true negative, and false negative test results in a hypothetical population. We construct a table of diagnostic yield that includes the number of false positive subjects experiencing adverse consequences from unnecessary work-up. We then develop a decision theory for evaluating tests. The theory provides additional interpretation to quantities in the diagnostic yield table. It also indicates that the expected utility of a test relative to a perfect test is a weighted accuracy measure, the average of sensitivity and specificity weighted for prevalence and relative importance of false positive and false negative testing errors, also interpretable as the cost-benefit ratio of treating non-diseased and diseased subjects. We propose plots of diagnostic yield, weighted accuracy, and relative net benefit of tests as functions of prevalence or cost-benefit ratio. Concepts are illustrated with hypothetical screening tests for colorectal cancer with test positive subjects being referred to colonoscopy.

Diagnostic Accuracy of Tests for Polyuria in Lithium-Treated Patients.

PubMed

Kinahan, James Conor; NiChorcorain, Aoife; Cunningham, Sean; Freyne, Aideen; Cooney, Colm; Barry, Siobhan; Kelly, Brendan D

2015-08-01

In lithium-treated patients, polyuria increases the risk of dehydration and lithium toxicity. If detected early, it is reversible. Despite its prevalence and associated morbidity in clinical practice, it remains underrecognized and therefore undertreated. The 24-hour urine collection is limited by its convenience and practicality. This study explores the diagnostic accuracy of alternative tests such as questionnaires on subjective polyuria, polydipsia, nocturia (dichotomous and ordinal responses), early morning urine sample osmolality (EMUO), and fluid intake record (FIR). This is a cross-sectional study of 179 lithium-treated patients attending a general adult and an old age psychiatry service. Participants completed the tests after completing an accurate 24-hour urine collection. The diagnostic accuracy of the individual tests was explored using the appropriate statistical techniques. Seventy-nine participants completed all of the tests. Polydipsia severity, EMUO, and FIR significantly differentiated the participants with polyuria (area under the receiver operating characteristic curve of 0.646, 0.760, and 0.846, respectively). Of the tests investigated, the FIR made the largest significant change in the probability that a patient experiences polyuria (<2000 mL/24 hours; interval likelihood ratio, 0.18 and >3500 mL/24 hours; interval likelihood ratio, 14). Symptomatic questioning, EMUO, and an FIR could be used in clinical practice to inform the prescriber of the probability that a lithium-treated patient is experiencing polyuria.

How to: evaluate a diagnostic test.

PubMed

Leeflang, Mariska M G; Allerberger, Franz

2018-06-12

The development of an in vitro diagnostic test from a good idea to a clinically relevant tool takes several steps, with more stringent requirements at every step. This article aims to summarize the necessary questions to be asked about a test and to illustrate study designs answering these questions. We also aim to relate the Regulation (EU) 2017/746 to the needs of evidence-based diagnostic testing, where applicable. We used literature on evidence-based diagnostics, a text book on clinical trials in the development and marketing of medical devices and the English version of Regulation 2017/746 of the European Parliament and of the Council on in vitro diagnostic medical devices. The combination of different test uses and different stages of development determine the required test characteristics and suitability of study designs. In an earlier stage of test development it may be crucial to know whether a test can differentiate diseased persons from healthy controls, while this tells us little about how a test will perform in practice. Later stages focus on the diagnostic accuracy of a test in a clinically relevant situation. However, a test that perfectly distinguishes between patients with and without a certain condition may still have little effect on patient outcomes. Therefore, randomized controlled trials of testing may be needed, as well as post-marketing monitoring. Both researchers and users of tests need to be aware of the limitations of diagnostic test accuracy and realize that accuracy is only indirectly linked to people's health status. Copyright © 2018. Published by Elsevier Ltd.

Diagnostic value of two commercial chromatographic "patient-side" tests in the diagnosis of acute canine leptospirosis.

PubMed

Gloor, C I; Schweighauser, A; Francey, T; Rodriguez-Campos, S; Vidondo, B; Bigler, B; Schuller, S

2017-03-01

To determine the diagnostic performance of two patient-side tests (RDT-1: Test-it™ and RDT-2 Witness®Lepto) in the early diagnosis of canine leptospirosis. Retrospective study of 108 dogs with leptospirosis and 53 controls. Leptospirosis was diagnosed based on compatible clinical and clinicopathologic signs and either a single microscopic agglutination test titre_ >800 (n=49), seroconversion (n=53), positive urine real time PCR (RT-PCR) (n=1), evidence of spirochaetes in silver-stained tissues (n=1) or a combination of these (n=4). Leptospirosis was excluded in dogs with a convincing alternative diagnosis and single microscopic agglutination testing titres _<200 (n=46) or lack of seroconversion (n=7). Indices of diagnostic accuracy of the rapid diagnostic tests were calculated by comparing admission rapid diagnostic test results to the final disease status. Rapid diagnostic test-1 was performed in 118 dogs, rapid diagnostic test-2 in 69 dogs and both tests in 26 dogs. Weak positive results occurred frequently representing 22·6% (rapid diagnostic test-1) and 32·3% (rapid diagnostic test-2) of all positive tests in dogs with leptospirosis. If weak positive rapid diagnostic tests were considered positive, rapid diagnostic test-1 and rapid diagnostic test-2 had sensitivities of 82 and 76%, specificities of 91 and 100%, positive predictive values of 94% and 100% and negative predictive values of 73% and 74%, respectively. There were some technical problems with rapid diagnostic test-1. The diagnostic performance of the rapid diagnostic tests is similar to that reported for the microscopic agglutination test. Both can support a diagnosis of leptospirosis with high specificity but leptospirosis cannot be excluded based on a negative admission test result. Both RDTs are useful in conjunction with other confirmatory tests. © 2017 British Small Animal Veterinary Association.

Occult Blood Testing for Early Detection of Colorectal Cancer: Diagnostic Outcomes

PubMed Central

Hislop, T. Gregory; Morrison, Brenda J.; Hoogewerf, Peter E.; Burns, Sheilagh D.; Sizto, Ronald

1987-01-01

Three thousand five hundred and fifty-four asymptomatic persons from 32 family practices returned hemoccult II tests for colorectal cancer; 2.2% of these returned tests were positive. The diagnoses for the 47 persons with positive tests which were done while on meat restriction included six cancers (1.7/1000) and five polyps (1.4/1000); 18 were diagnosed with other known sources, and 18 were undiagnosed. All polyps and four of six cancers were diagnosed by combined barium enema with sigmoidoscopy or by colonoscopy. Five of six cancers were diagnosed at early stages. Meat restriction, the method of returning the test for analysis, the number of holes completed in the test, and the delay time from completing the test to analysis did not influence the likelihood of a positive test. PMID:20469468

14-3-3η Autoantibodies: Diagnostic Use in Early Rheumatoid Arthritis.

PubMed

Maksymowych, Walter P; Boire, Gilles; van Schaardenburg, Dirkjan; Wichuk, Stephanie; Turk, Samina; Boers, Maarten; Siminovitch, Katherine A; Bykerk, Vivian; Keystone, Ed; Tak, Paul Peter; van Kuijk, Arno W; Landewé, Robert; van der Heijde, Desiree; Murphy, Mairead; Marotta, Anthony

2015-09-01

To describe the expression and diagnostic use of 14-3-3η autoantibodies in early rheumatoid arthritis (RA). 14-3-3η autoantibody levels were measured using an electrochemiluminescent multiplexed assay in 500 subjects (114 disease-modifying antirheumatic drug-naive patients with early RA, 135 with established RA, 55 healthy, 70 autoimmune, and 126 other non-RA arthropathy controls). 14-3-3η protein levels were determined in an earlier analysis. Two-tailed Student t tests and Mann-Whitney U tests compared differences among groups. Receiver-operator characteristic (ROC) curves were generated and diagnostic performance was estimated by area under the curve (AUC), as well as specificity, sensitivity, and likelihood ratios (LR) for optimal cutoffs. Median serum 14-3-3η autoantibody concentrations were significantly higher (p < 0.0001) in patients with early RA (525 U/ml) when compared with healthy controls (235 U/ml), disease controls (274 U/ml), autoimmune disease controls (274 U/ml), patients with osteoarthritis (259 U/ml), and all controls (265 U/ml). ROC curve analysis comparing early RA with healthy controls demonstrated a significant (p < 0.0001) AUC of 0.90 (95% CI 0.85-0.95). At an optimal cutoff of ≥ 380 U/ml, the ROC curve yielded a sensitivity of 73%, a specificity of 91%, and a positive LR of 8.0. Adding 14-3-3η autoantibodies to 14-3-3η protein positivity enhanced the identification of patients with early RA from 59% to 90%; addition of 14-3-3η autoantibodies to anticitrullinated protein antibodies (ACPA) and/or rheumatoid factor (RF) increased identification from 72% to 92%. Seventy-two percent of RF- and ACPA-seronegative patients were positive for 14-3-3η autoantibodies. 14-3-3η autoantibodies, alone and in combination with the 14-3-3η protein, RF, and/or ACPA identified most patients with early RA.

Introducing First-Year Medical Students to Early Diagnostic Hypotheses

ERIC Educational Resources Information Center

Taylor, P. J.; And Others

1978-01-01

A method of instruction in gynecology is described that encouraged the formulation of early diagnostic hypotheses, an important part of clinical problem-solving. Students were given a set of clinical clues to help them make broad diagnostic hypotheses. Student ability, results, and student perceptions of the course are provided. (Author/LBH)

What Do Diagnostic Reading Tests Really Diagnose?

ERIC Educational Resources Information Center

Winkley, Carol K.

A study was made of nine reading tests, including both group and individually-administered measures, which are claimed to be chiefly diagnostic. Instruments analyzed were the following: Silent Reading Diagnostic Tests (Bond, Balow, and Hoyt), Botel Reading Inventory, Durrell Analysis of Reading Difficulty, Gates-McKillop Reading Diagnostic Tests,…

Myasthenia Gravis: Tests and Diagnostic Methods

MedlinePlus

... Focus on MG Newsletter MG Quarterly Test & Diagnostic methods In addition to a complete medical and neurological ... How can I help? About MGFA Test & Diagnostic methods Treatment for MG FAQ's Upcoming Events 2018 MG ...

Diagnosis of asthma: diagnostic testing.

PubMed

Brigham, Emily P; West, Natalie E

2015-09-01

Asthma is a heterogeneous disease, encompassing both atopic and non-atopic phenotypes. Diagnosis of asthma is based on the combined presence of typical symptoms and objective tests of lung function. Objective diagnostic testing consists of 2 components: (1) demonstration of airway obstruction, and (2) documentation of variability in degree of obstruction. A review of current guidelines and literature was performed regarding diagnostic testing for asthma. Spirometry with bronchodilator reversibility testing remains the mainstay of asthma diagnostic testing for children and adults. Repetition of the test over several time points may be necessary to confirm airway obstruction and variability thereof. Repeated peak flow measurement is relatively simple to implement in a clinical and home setting. Bronchial challenge testing is reserved for patients in whom the aforementioned testing has been unrevealing but clinical suspicion remains, though is associated with low specificity. Demonstration of eosinophilic inflammation, via fractional exhaled nitric oxide measurement, or atopy, may be supportive of atopic asthma, though diagnostic utility is limited particularly in nonatopic asthma. All efforts should be made to confirm the diagnosis of asthma in those who are being presumptively treated but have not had objective measurements of variability in the degree of obstruction. Multiple testing modalities are available for objective confirmation of airway obstruction and variability thereof, consistent with a diagnosis of asthma in the appropriate clinical context. Providers should be aware that both these characteristics may be present in other disease states, and may not be specific to a diagnosis of asthma. © 2015 ARS-AAOA, LLC.

Comparison of Laser Scanning Diagnostic Devices for Early Glaucoma Detection.

PubMed

Schulze, Andreas; Lamparter, Julia; Pfeiffer, Norbert; Berisha, Fatmire; Schmidtmann, Irene; Hoffmann, Esther M

2015-08-01

To compare the diagnostic accuracy and to evaluate the correlation of optic nerve head and retinal nerve fiber layer thickness values between Fourier-Domain optical coherence tomography (FD-OCT), confocal scanning laser ophthalmoscopy (CSLO), and scanning laser polarimetry (SLP) for early glaucoma detection. Ninety-three patients with early open-angle glaucoma, 58 patients with ocular hypertension, and 60 healthy control subjects were included in this observational, cross-sectional study. All study participants underwent FD-OCT (RTVue-100), CSLO (HRT3), and SLP (GDx VCC) imaging of the optic nerve head and the retinal nerve fiber layer. Area under the receiver operating characteristic curves (AUROC) and Bland-Altman analysis were performed. The parameters with the highest diagnostic accuracy were found for FD-OCT cup-to-disc ratio (AUROC=0.841), for SLP NFI (AUROC=0.835), and for CSLO cup-to-disc ratio (AUROC=0.789). Diagnostic accuracy of the best CSLO and SLP parameter was similar (P=0.259). There was a small statistically significant difference between the best CSLO and FD-OCT parameters for differentiating between glaucoma and healthy eyes (P=0.047). FD-OCT and SLP have a similarly good diagnostic ability to distinguish between early glaucoma and healthy subjects. The diagnostic accuracy of CSLO was comparable with SLP and marginally lower compared with FD-OCT.

Improvements in diagnostic tools for early detection of psoriatic arthritis.

PubMed

D'Angelo, Salvatore; Palazzi, Carlo; Gilio, Michele; Leccese, Pietro; Padula, Angela; Olivieri, Ignazio

2016-11-01

Psoriatic arthritis (PsA) is a heterogeneous chronic inflammatory disease characterized by a wide clinical spectrum. The early diagnosis of PsA is currently a challenging topic. Areas covered: The literature was extensively reviewed for studies addressing the topic area "diagnosis of psoriatic arthritis". This review will summarize improvements in diagnostic tools, especially referral to the rheumatologist, the role of patient history and clinical examination, laboratory tests, and imaging techniques in getting an early and correct diagnosis of PsA. Expert commentary: Due to the heterogeneity of its expression, PsA may be easily either overdiagnosed or underdiagnosed. A diagnosis of PsA should be taken into account every time a patient with psoriasis or a family history of psoriasis shows peripheral arthritis, especially if oligoarticular or involving the distal interphalangeal joints, enthesitis or dactylitis. Magnetic resonance imaging and ultrasonography are useful for diagnosing PsA early, particularly when isolated enthesitis or inflammatory spinal pain occur.

9 CFR 93.406 - Diagnostic tests.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Diagnostic tests. 93.406 Section 93... CONVEYANCE AND SHIPPING CONTAINERS Ruminants § 93.406 Diagnostic tests. (a) Tuberculosis and brucellosis tests of cattle. Except as provided in paragraph (d) of this section and in §§ 93.418, 93.427(d), and 93...

9 CFR 93.406 - Diagnostic tests.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Diagnostic tests. 93.406 Section 93... CONVEYANCE AND SHIPPING CONTAINERS Ruminants § 93.406 Diagnostic tests. (a) Tuberculosis and brucellosis tests of cattle. Except as provided in paragraph (d) of this section and in §§ 93.418, 93.427(d), and 93...

A readers' guide to the interpretation of diagnostic test properties: clinical example of sepsis.

PubMed

Fischer, Joachim E; Bachmann, Lucas M; Jaeschke, Roman

2003-07-01

One of the most challenging practical and daily problems in intensive care medicine is the interpretation of the results from diagnostic tests. In neonatology and pediatric intensive care the early diagnosis of potentially life-threatening infections is a particularly important issue. A plethora of tests have been suggested to improve diagnostic decision making in the clinical setting of infection which is a clinical example used in this article. Several criteria that are critical to evidence-based appraisal of published data are often not adhered to during the study or in reporting. To enhance the critical appraisal on articles on diagnostic tests we discuss various measures of test accuracy: sensitivity, specificity, receiver operating characteristic curves, positive and negative predictive values, likelihood ratios, pretest probability, posttest probability, and diagnostic odds ratio. We suggest the following minimal requirements for reporting on the diagnostic accuracy of tests: a plot of the raw data, multilevel likelihood ratios, the area under the receiver operating characteristic curve, and the cutoff yielding the highest discriminative ability. For critical appraisal it is mandatory to report confidence intervals for each of these measures. Moreover, to allow comparison to the readers' patient population authors should provide data on study population characteristics, in particular on the spectrum of diseases and illness severity.

Diagnostic value of isoproterenol testing in arrhythmogenic right ventricular cardiomyopathy.

PubMed

Denis, Arnaud; Sacher, Frédéric; Derval, Nicolas; Lim, Han S; Cochet, Hubert; Shah, Ashok J; Daly, Matthew; Pillois, Xavier; Ramoul, Khaled; Komatsu, Yuki; Zemmoura, Adlane; Amraoui, Sana; Ritter, Philippe; Ploux, Sylvain; Bordachar, Pierre; Hocini, Mélèze; Jaïs, Pierre; Haïssaguerre, Michel

2014-08-01

Although the Task Force Criteria for arrhythmogenic right ventricular cardiomyopathy (ARVC) have recently been updated, the diagnosis remains challenging in the early stages. The aim of this study was to evaluate the diagnostic value of β-adrenergic stimulation in ARVC. We evaluated 412 consecutive patients (213 men, age 41.5±16 years) referred for premature ventricular contractions evaluation or suspected ARVC. Isoproterenol testing was performed with continuous infusion of isoproterenol (45 μg/min) for 3 minutes. It was considered positive if there were either (1) polymorphic premature ventricular contractions with ≥1 couplet or (2) sustained or nonsustained ventricular tachycardia with left bundle branch block excluding right ventricular outflow tract ventricular tachycardia. ARVC was diagnosed in 35 patients at initial evaluation (23 men, aged 42±15 years). Isoproterenol testing was positive in 32 of 35 (91.4%) patients with ARVC and in 42 of 377 (11.1%) patients without ARVC (P<0.0001). Sensitivity, specificity, positive, and negative predictive values of isoproterenol testing to diagnose ARVC were 91.4%, 88.9%, 43.2%, and 99.1%, respectively. During a mean follow-up period of 5.6±4.4 years, 6 additional patients met diagnostic criteria for ARVC. Importantly, initial isoproterenol testing was positive in 6 of 6 (100%) of these patients. Survival free from ARVC diagnosis was significantly lower in the positive isoproterenol group than in the negative isoproterenol group (P<0.0001, exact log-rank test). Ventricular arrhythmogenicity during isoproterenol testing is highly sensitive (sensitivity, 91.4%) for the diagnosis of ARVC, particularly in its early stages. © 2014 American Heart Association, Inc.

Measures of accuracy and performance of diagnostic tests.

PubMed

Drobatz, Kenneth J

2009-05-01

Diagnostic tests are integral to the practice of veterinary cardiology, any other specialty, and general veterinary medicine. Developing and understanding diagnostic tests is one of the cornerstones of clinical research. This manuscript describes the diagnostic test properties including sensitivity, specificity, predictive value, likelihood ratio, receiver operating characteristic curve. Review of practical book chapters and standard statistics manuscripts. Diagnostics such as sensitivity, specificity, predictive value, likelihood ratio, and receiver operating characteristic curve are described and illustrated. Basic understanding of how diagnostic tests are developed and interpreted is essential in reviewing clinical scientific papers and understanding evidence based medicine.

40 CFR 85.2223 - On-board diagnostic test report.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 18 2010-07-01 2010-07-01 false On-board diagnostic test report. 85... Tests § 85.2223 On-board diagnostic test report. (a) Motorists whose vehicles fail the on-board diagnostic test described in § 85.2222 shall be provided with the on-board diagnostic test results, including...

40 CFR 85.2223 - On-board diagnostic test report.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 18 2011-07-01 2011-07-01 false On-board diagnostic test report. 85... Tests § 85.2223 On-board diagnostic test report. (a) Motorists whose vehicles fail the on-board diagnostic test described in § 85.2222 shall be provided with the on-board diagnostic test results, including...

An optimal ultrasonographic diagnostic test for early gout: A prospective controlled study

PubMed Central

Petraitis, Mykolas; Apanaviciene, Indre; Virviciute, Dalia; Baranauskaite, Asta

2017-01-01

Objective To identify the optimal sites for classification of early gout by ultrasonography. Methods Sixty patients with monosodium urate crystal-proven gout (25 with early gout [≤2-year symptom duration], 35 with late gout [>2-year symptom duration], and 36 normouricemic healthy controls) from one centre were prospectively evaluated. Standardized blinded ultrasound examination of 36 joints and the triceps and patellar tendons was performed to identify tophi and the double contour (DC) sign. Results Ultrasonographic sensitivity was lower in early than late gout. Binary logistic regression analysis showed that two ultrasonographic signs (tophi in the first metatarsophalangeal joint [odds ratio, 16.46] and the DC sign in the ankle [odds ratio, 25.18]) significantly contributed to the final model for early gout diagnosis (sensitivity and specificity of 84% and 81%, respectively). The inter-reader reliability kappa value for the DC sign and tophi was 0.712. Conclusions Four-joint investigation (both first metatarsophalangeal joints for tophi and both ankles for the DC sign) is feasible and reliable and could be proposed as a screening test for early ultrasonographic gout classification in daily practice. PMID:28617199

An optimal ultrasonographic diagnostic test for early gout: A prospective controlled study.

PubMed

Norkuviene, Eleonora; Petraitis, Mykolas; Apanaviciene, Indre; Virviciute, Dalia; Baranauskaite, Asta

2017-08-01

Objective To identify the optimal sites for classification of early gout by ultrasonography. Methods Sixty patients with monosodium urate crystal-proven gout (25 with early gout [≤2-year symptom duration], 35 with late gout [>2-year symptom duration], and 36 normouricemic healthy controls) from one centre were prospectively evaluated. Standardized blinded ultrasound examination of 36 joints and the triceps and patellar tendons was performed to identify tophi and the double contour (DC) sign. Results Ultrasonographic sensitivity was lower in early than late gout. Binary logistic regression analysis showed that two ultrasonographic signs (tophi in the first metatarsophalangeal joint [odds ratio, 16.46] and the DC sign in the ankle [odds ratio, 25.18]) significantly contributed to the final model for early gout diagnosis (sensitivity and specificity of 84% and 81%, respectively). The inter-reader reliability kappa value for the DC sign and tophi was 0.712. Conclusions Four-joint investigation (both first metatarsophalangeal joints for tophi and both ankles for the DC sign) is feasible and reliable and could be proposed as a screening test for early ultrasonographic gout classification in daily practice.

Missed diagnostic opportunities within South Africa's early infant diagnosis program, 2010-2015.

PubMed

Haeri Mazanderani, Ahmad; Moyo, Faith; Sherman, Gayle G

2017-01-01

Samples submitted for HIV PCR testing that fail to yield a positive or negative result represent missed diagnostic opportunities. We describe HIV PCR test rejections and indeterminate results, and the associated delay in diagnosis, within South Africa's early infant diagnosis (EID) program from 2010 to 2015. HIV PCR test data from January 2010 to December 2015 were extracted from the National Health Laboratory Service Corporate Data Warehouse, a central data repository of all registered test-sets within the public health sector in South Africa, by laboratory number, result, date, facility, and testing laboratory. Samples that failed to yield either a positive or negative result were categorized according to the rejection code on the laboratory information system, and descriptive analysis performed using Microsoft Excel. Delay in diagnosis was calculated for patients who had a missed diagnostic opportunity registered between January 2013 and December 2015 by means of a patient linking-algorithm employing demographic details. Between 2010 and 2015, 2 178 582 samples were registered for HIV PCR testing of which 6.2% (n = 134 339) failed to yield either a positive or negative result, decreasing proportionally from 7.0% (n = 20 556) in 2010 to 4.4% (n = 21 388) in 2015 (p<0.001). Amongst 76 972 coded missed diagnostic opportunities, 49 585 (64.4%) were a result of pre-analytical error and 27 387 (35.6%) analytical error. Amongst 49 694 patients searched for follow-up results, 16 895 (34.0%) had at least one subsequent HIV PCR test registered after a median of 29 days (IQR: 13-57), of which 8.4% tested positive compared with 3.6% of all samples submitted for the same period. Routine laboratory data provides the opportunity for near real-time surveillance and quality improvement within the EID program. Delay in diagnosis and wastage of resources associated with missed diagnostic opportunities must be addressed and infants actively followed-up as South Africa works towards

Early detection of probable idiopathic Parkinson's disease: I. development of a diagnostic test battery.

PubMed

Montgomery, Erwin B; Koller, William C; LaMantia, Theodora J K; Newman, Mary C; Swanson-Hyland, Elizabeth; Kaszniak, Alfred W; Lyons, Kelly

2000-05-01

We developed a test battery as an inexpensive and objective aid for the early diagnosis of idiopathic Parkinson's disease (iPD) and its differential diagnoses. The test battery incorporates tests of motor function, olfaction, and mood. In the motor task, a wrist flexion-and-extension task to different targets, movement velocities were recorded. Olfaction was tested with the University of Pennsylvania Smell Identification Test. Mood was assessed with the Beck Depression Inventory. An initial regression model was developed from the results of 19 normal control subjects and 18 patients with early, mild, probable iPD. Prospective application to an independent validation set of 122 normal control subjects and 103 patients resulted in an 88% specificity rate and 69% sensitivity rate, with an area under the Receiver Operator Characteristic curve of 0.87. Copyright © 2000 Movement Disorder Society.

Two-Year Diagnostic Stability in Early-Onset First-Episode Psychosis

ERIC Educational Resources Information Center

Castro-Fornieles, Josefina; Baeza, Immaculada; de la Serna, Elena; Gonzalez-Pinto, Ana; Parellada, Mara; Graell, Montserrat; Moreno, Dolores; Otero, Soraya; Arango, Celso

2011-01-01

Background: Only one study has used a prospective method to analyze the diagnostic stability of first psychotic episodes in children and adolescents. The Child and Adolescent First-Episode Psychosis Study (CAFEPS) is a 2-year, prospective longitudinal study of early-onset first episodes of psychosis (EO-FEP). Aim: To describe diagnostic stability…

[Development of a diagnostic test system for early non-invasive detection of prostate cancer based on PCA3 mRNA levels in urine sediment using quantitative reverse tanscription polymerase chain reaction (qRT-PCR)].

PubMed

Pavlov, K A; Shkoporov, A N; Khokhlova, E V; Korchagina, A A; Sidorenkov, A V; Grigor'ev, M É; Pushkar', D Iu; Chekhonin, V P

2013-01-01

The wide introduction of prostatic specific antigen (PSA) determination into clinical practice has resulted in a larger number of prostate biopsies, while the lower age threshold for PSA has led to a larger number of unnecessary prostate biopsies. Hence, there is a need for new biomarkers that can detect prostate cancer. PCA3 is a noncoding messenger ribonucleic acid (mRNA) that is expressed exclusively in prostate cells. The aim of the study has been to develop a diagnostic test system for early non-invasive detection of prostate cancer based on PCA3 mRNA levels in urine sediment using quantitative reverse transcription polymerase chain reaction (qRT-PCR). As part of the study, a laboratory diagnostic test system prototype has been designed, an application methodology has been developed and specificity and sensitivity data of the method has been assessed. The diagnostic system has demonstrated its ability to detect significantly elevated levels of PCA 3/KLK 3 in samples from prostate cancer (PCa) patients compared with those from healthy men. The findings have shown relatively high diagnostic sensitivity, specificity and negative-predictive values for an early non-invasive screening of prostate cancer

Malaria rapid diagnostic tests in tropical climates: the need for a cool chain.

PubMed

Jorgensen, Pernille; Chanthap, Lon; Rebueno, Antero; Tsuyuoka, Reiko; Bell, David

2006-05-01

Malaria control programs in endemic countries increasingly rely on early case detection and treatment at village level. The rapid diagnostic tests (RDTs) and accompanying drugs on which the success of these programs depends deteriorate to varying degrees at high temperatures. To assess the ability of health systems to maintain RDTs within manufacturers' specifications, we monitored temperatures in the delivery chain from manufacturer through to the village health worker in Cambodia and the Philippines. In both countries, storage temperatures regularly exceeded those recommended for most RDTs intended for field use, whereas temperatures during transport greatly exceeded the lower and upper limits. These results emphasize the need for good logistical planning during the introduction of point-of-care tests in tropical countries and the importance of considering the stability of diagnostic tests during procurement.

20 CFR 404.1519m - Diagnostic tests or procedures.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false Diagnostic tests or procedures. 404.1519m... Report Content § 404.1519m Diagnostic tests or procedures. We will request the results of any diagnostic... will not order diagnostic tests or procedures that involve significant risk to you, such as myelograms...

Prenatal Genetic Diagnostic Tests

MedlinePlus

... inherited disorders. The main disadvantage is that diagnostic testing carries a very small risk of losing the pregnancy. A genetic counselor or other health care professional with expertise in genetics can study ...

Molecular tissue changes in early myocardial ischemia: from pathophysiology to the identification of new diagnostic markers.

PubMed

Aljakna, Aleksandra; Fracasso, Tony; Sabatasso, Sara

2018-03-01

Diagnosing early myocardial ischemia (the initial 4 to 6 h after interruption of blood flow to part of the myocardium) remains a challenge for clinical and forensic pathologists. Several immunohistochemical markers have been proposed for improving postmortem detection of early myocardial ischemia; however, no single marker appears to be both sufficiently specific as well as sensitive. This review summarizes the diverse categories of molecular tissue markers that have been investigated in human autopsy samples with acute myocardial infarction as well as in the well-established and widely used in vivo animal model of early myocardial ischemia (permanent ligation of the coronary artery). Recently identified markers appearing during the initial 2 h of myocardial ischemia are highlighted. Among them, only six were tested for specificity (C5b-9, hypoxia-inducible factor 1-alpha, vascular endothelial growth factor, heart fatty acid binding protein, connexin 43, and JunB). Despite the discovery of several potentially promising markers (in terms of early expression and specificity), many of them remain to be tested and validated for application in routine diagnostics in clinical and forensic pathology. In particular, research investigating the postmortem stability of these markers is required before any might be implemented into routine diagnostics. Establishing a standardized panel of immunohistochemical markers may be more useful for improving sensitivity and specificity than searching for a single marker.

ACER Physics Unit Tests: Unit Tests, Diagnostic Aids, [and] Teachers Handbook.

ERIC Educational Resources Information Center

Australian Council for Educational Research, Hawthorn.

The Physics Unit Tests are designed to assist in the diagnostic evaluation of students' progress in the study of physics during the last two years of secondary schooling. They consist of a collection of 21 separate tests, each related to a different topic, and 21 diagnostic aids corresponding to the tests. The topics covered are: physical…

40 CFR 85.2222 - On-board diagnostic test procedures.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 19 2013-07-01 2013-07-01 false On-board diagnostic test procedures... Warranty Short Tests § 85.2222 On-board diagnostic test procedures. The test sequence for the inspection of on-board diagnostic systems on 1996 and newer light-duty vehicles and light-duty trucks shall consist...

40 CFR 85.2222 - On-board diagnostic test procedures.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 19 2012-07-01 2012-07-01 false On-board diagnostic test procedures... Warranty Short Tests § 85.2222 On-board diagnostic test procedures. The test sequence for the inspection of on-board diagnostic systems on 1996 and newer light-duty vehicles and light-duty trucks shall consist...

40 CFR 85.2222 - On-board diagnostic test procedures.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 18 2011-07-01 2011-07-01 false On-board diagnostic test procedures... Warranty Short Tests § 85.2222 On-board diagnostic test procedures. The test sequence for the inspection of on-board diagnostic systems on 1996 and newer light-duty vehicles and light-duty trucks shall consist...

Diagnostic Delay Is Associated with a Greater Risk of Early Surgery in a French Cohort of Crohn's Disease Patients.

PubMed

Nahon, Stéphane; Lahmek, Pierre; Paupard, Thierry; Lesgourgues, Bruno; Chaussade, Stanislas; Peyrin-Biroulet, Laurent; Abitbol, Vered

2016-11-01

To investigate whether a diagnostic delay is associated with a poor outcome in Crohn's disease (CD). Medical and socioeconomic characteristics as well as medications and need for surgery of consecutive CD adults patients followed in three referral centers were prospectively recorded using an electronic database (Focus_MICI ® ). A long diagnostic delay was defined by the upper quartile. We compared patients with long diagnostic delay to those with earlier diagnosis regarding the time to: (1) first intestinal surgery, (2) first use of immunosuppressants (IMSs), and (3) first use of anti-tumor necrosis factor (anti-TNF) therapy using the Kaplan-Meier test and the log-rank test. A total of 497 patients with CD (53.6 % women) were analyzed. Median diagnostic delay was 5 months (IQR 25-75 %: 2-13 months). Median follow-up was 9 years (IQR 4-16.2), and 148 (29.8 %) patients had major surgery. There were no significant differences between patients with late and early diagnosis regarding age at diagnosis, disease phenotype, need for IMS therapy, and need for anti-TNF therapy. Time to first major surgery was shorter in patients with late diagnosis (p = 0.05). In this large multicenter prospective cohort of French CD patients, a long diagnostic delay (>13 months) increased the risk of early surgery. No associated factors could be identified in this study.

DATAS Hardware Diagnostic Tests

DOT National Transportation Integrated Search

1990-10-01

This document is reference material for personnel using the Data Link and : Analysis System (DATAS) for hardware diagnostic testing. Included in this : document is a brief overall description of the DATAS, and a thorough : description of how to opera...

20 CFR 416.919m - Diagnostic tests or procedures.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false Diagnostic tests or procedures. 416.919m... for Report Content § 416.919m Diagnostic tests or procedures. We will request the results of any diagnostic tests or procedures that have been performed as part of a workup by your treating source or other...

Evaluating Diagnostic Point-of-Care Tests in Resource-Limited Settings

PubMed Central

Drain, Paul K; Hyle, Emily P; Noubary, Farzad; Freedberg, Kenneth A; Wilson, Douglas; Bishai, William; Rodriguez, William; Bassett, Ingrid V

2014-01-01

Diagnostic point-of-care (POC) testing is intended to minimize the time to obtain a test result, thereby allowing clinicians and patients to make an expeditious clinical decision. As POC tests expand into resource-limited settings (RLS), the benefits must outweigh the costs. To optimize POC testing in RLS, diagnostic POC tests need rigorous evaluations focused on relevant clinical outcomes and operational costs, which differ from evaluations of conventional diagnostic tests. Here, we reviewed published studies on POC testing in RLS, and found no clearly defined metric for the clinical utility of POC testing. Therefore, we propose a framework for evaluating POC tests, and suggest and define the term “test efficacy” to describe a diagnostic test’s capacity to support a clinical decision within its operational context. We also proposed revised criteria for an ideal diagnostic POC test in resource-limited settings. Through systematic evaluations, comparisons between centralized diagnostic testing and novel POC technologies can be more formalized, and health officials can better determine which POC technologies represent valuable additions to their clinical programs. PMID:24332389

Combining simple patient-oriented tests with state-of-the-art molecular diagnostics for early diagnosis of cancer.

PubMed

Fitzgerald, Rebecca C

2015-06-01

Early diagnosis is an important strategy to improve outcomes from cancer. Oesophageal adenocarcinoma is an example of a cancer that presents late, with very poor outcomes, and for which the presence of the precursor lesion Barrett's oesophagus provides the opportunity to intervene at an early stage. In this review, I describe the challenges in the field and the work that we have done to devise a conceptually novel approach to early diagnosis, using a cell collection device (Cytosponge), coupled with molecular assays. This is a personal perspective in which I also describe the career pathway that led me into academic gastroenterology, and the rewards and challenges of translational research in molecular diagnostics. There are fantastic opportunities for clinicians wishing to pursue academic medicine, because it is a time when massive strides are being made in a whole number of areas; for example: imaging, sequencing technology and targeted therapies. Clinicians who can straddle the laboratory and the clinic are essential, to maximise the progress that can be made for the benefit of patients.

[Diagnostic test scale SI5: Assessment of sacroiliac joint dysfunction].

PubMed

Acevedo González, Juan C; Quintero Oliveros, Silvia

2015-01-01

Sacroiliac joint dysfunction is a known cause of low back pain. We think that a diagnostic score scale (SI5) may be performed to assess diagnostic utility of clinical signs of sacroiliac joint dysfunction. The primary aim of the present study was to conduct the pilot study of our new diagnostic score scale, the SI5, for sacroiliac joint syndrome. We reviewed the literature on clinical characteristics, diagnostic tests and imaging most commonly used in diagnosing sacroiliac joint dysfunction. Our group evaluated the diagnostic utility of these aspects and we used those considered most representative to develop the SI5 diagnostic scale. The SI5 scale was applied to 22 patients with low back pain; afterwards, the standard test for diagnosing this pathology (selective blockage of the SI joint) was also performed on these patients. The sensitivity and specificity for each sign were also assessed and the diagnostic scale called SI5 was then proposed, based on these data. The most sensitive clinical tests for diagnosing SI joint dysfunction were 2 patient-reported clinical characteristics, the Laguerre Test, sacroiliac rocking test and Yeomans test (greater than 80% sensitivity). The tests with greatest diagnostic specificity (>80%) were the Lewitt test, Piedallu test and Gillet test. The proposed SI5 test score scale showed sensitivity of 73% and specificity of 71%. Sacroiliac joint syndrome has been shown to produce low back pain frequently; however, the diagnostic value of examination tests for sacroiliac joint pain has been questioned by other authors. The pilot study on the SI5 diagnostic score scale showed good sensitivity and specificity. However, the process of statistical validation of the SI5 needs to be continued. Copyright © 2014 Sociedad Española de Neurocirugía. Published by Elsevier España. All rights reserved.

External quality assurance for HIV point-of-care testing in Africa: A collaborative country-partner approach to strengthen diagnostic services

PubMed Central

2016-01-01

It is important to consider the role of diagnostics and the critical need for quality diagnostics services in resource-limited settings. Accurate diagnostic tests play a key role in patient management and the prevention and control of most infectious diseases. As countries plan for implementation of HIV early infant diagnosis and viral load point-of-care testing, the London School of Hygiene & Tropical Medicine has worked with countries and partners with an interest in external quality assurance to support quality point-of-care testing on the continent. Through a series of collaborative consultations and workshops, the London School of Hygiene & Tropical Medicine has gathered lessons learned, tools, and resources and developed quality assurance models that will support point-of-care testing. The London School of Hygiene & Tropical Medicine is committed to the continued advancement of laboratory diagnostics in Africa and quality laboratory services and point-of-care testing. PMID:28879132

Toxoplasma gondii: history and diagnostic test development.

PubMed

Wyrosdick, Heidi M; Schaefer, John J

2015-12-01

Toxoplasma gondii is a protozoa that causes toxoplasmosis in people and other animals. It is considered one of the most common parasitic infections in the world due to its impressive range of hosts, widespread environmental contamination and the diverse means by which animals can be infected. Despite its ubiquity and numerous ongoing research efforts into both its basic biology and clinical management, many aspects of diagnosis and management of this disease are poorly understood. The range of diagnostic options that is available for veterinary diagnostic investigators are notably more limited than those available to medical diagnosticians, making accurate interpretation of each test result critical. The current review joins other reviews on the parasite with a particular emphasis on the history and continued development of diagnostic tests that are useful for veterinary diagnostic investigations. An understanding of the strengths and shortcomings of current diagnostic techniques will assist veterinary and public health officials in formulating effective treatment and control strategies in diverse animal populations.

40 CFR 85.2231 - On-board diagnostic test equipment requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 19 2012-07-01 2012-07-01 false On-board diagnostic test equipment... Warranty Short Tests § 85.2231 On-board diagnostic test equipment requirements. (a) The test system interface to the vehicle shall include a plug that conforms to SAE J1962 “Diagnostic Connector.” The...

40 CFR 85.2231 - On-board diagnostic test equipment requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 18 2011-07-01 2011-07-01 false On-board diagnostic test equipment... Warranty Short Tests § 85.2231 On-board diagnostic test equipment requirements. (a) The test system interface to the vehicle shall include a plug that conforms to SAE J1962 “Diagnostic Connector.” The...

40 CFR 85.2231 - On-board diagnostic test equipment requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 19 2013-07-01 2013-07-01 false On-board diagnostic test equipment... Warranty Short Tests § 85.2231 On-board diagnostic test equipment requirements. (a) The test system interface to the vehicle shall include a plug that conforms to SAE J1962 “Diagnostic Connector.” The...

Evaluation of a 5-Marker Blood Test for Colorectal Cancer Early Detection in a Colorectal Cancer Screening Setting.

PubMed

Werner, Simone; Krause, Friedemann; Rolny, Vinzent; Strobl, Matthias; Morgenstern, David; Datz, Christian; Chen, Hongda; Brenner, Hermann

2016-04-01

In initial studies that included colorectal cancer patients undergoing diagnostic colonoscopy, we had identified a serum marker combination able to detect colorectal cancer with similar diagnostic performance as fecal immunochemical test (FIT). In this study, we aimed to validate the results in participants of a large colorectal cancer screening study conducted in the average-risk, asymptomatic screening population. We tested serum samples from 1,200 controls, 420 advanced adenoma patients, 4 carcinoma in situ patients, and 36 colorectal cancer patients with a 5-marker blood test [carcinoembryonic antigen (CEA)+anti-p53+osteopontin+seprase+ferritin]. The diagnostic performance of individual markers and marker combinations was assessed and compared with stool test results. AUCs for the detection of colorectal cancer and advanced adenomas with the 5-marker blood test were 0.78 [95% confidence interval (CI), 0.68-0.87] and 0.56 (95% CI, 0.53-0.59), respectively, which now is comparable with guaiac-based fecal occult blood test (gFOBT) but inferior to FIT. With cutoffs yielding specificities of 80%, 90%, and 95%, the sensitivities for the detection of colorectal cancer were 64%, 50%, and 42%, and early-stage cancers were detected as well as late-stage cancers. For osteopontin, seprase, and ferritin, the diagnostic performance in the screening setting was reduced compared with previous studies in diagnostic settings while CEA and anti-p53 showed similar diagnostic performance in both settings. Performance of the 5-marker blood test under screening conditions is inferior to FIT even though it is still comparable with the performance of gFOBT. CEA and anti-p53 could contribute to the development of a multiple marker blood-based test for early detection of colorectal cancer. ©2015 American Association for Cancer Research.

9 CFR 93.406 - Diagnostic tests.

Code of Federal Regulations, 2014 CFR

2014-01-01

... CONVEYANCE AND SHIPPING CONTAINERS Ruminants § 93.406 Diagnostic tests. (a) Tuberculosis and brucellosis...; and (2) Tuberculosis. (i) For steers and spayed heifers, the cattle originated from a herd of origin that tested negative to a whole herd test for tuberculosis within 1 year prior to the date of...

9 CFR 93.406 - Diagnostic tests.

Code of Federal Regulations, 2013 CFR

2013-01-01

... CONVEYANCE AND SHIPPING CONTAINERS Ruminants § 93.406 Diagnostic tests. (a) Tuberculosis and brucellosis...; and (2) Tuberculosis. (i) For steers and spayed heifers, the cattle originated from a herd of origin that tested negative to a whole herd test for tuberculosis within 1 year prior to the date of...

Understanding the properties of diagnostic tests - Part 2: Likelihood ratios.

PubMed

Ranganathan, Priya; Aggarwal, Rakesh

2018-01-01

Diagnostic tests are used to identify subjects with and without disease. In a previous article in this series, we examined some attributes of diagnostic tests - sensitivity, specificity, and predictive values. In this second article, we look at likelihood ratios, which are useful for the interpretation of diagnostic test results in everyday clinical practice.

The diagnostic value of narrow-band imaging for early and invasive lung cancer: a meta-analysis.

PubMed

Zhu, Juanjuan; Li, Wei; Zhou, Jihong; Chen, Yuqing; Zhao, Chenling; Zhang, Ting; Peng, Wenjia; Wang, Xiaojing

2017-07-01

This study aimed to compare the ability of narrow-band imaging to detect early and invasive lung cancer with that of conventional pathological analysis and white-light bronchoscopy. We searched the PubMed, EMBASE, Sinomed, and China National Knowledge Infrastructure databases for relevant studies. Meta-disc software was used to perform data analysis, meta-regression analysis, sensitivity analysis, and heterogeneity testing, and STATA software was used to determine if publication bias was present, as well as to calculate the relative risks for the sensitivity and specificity of narrow-band imaging vs those of white-light bronchoscopy for the detection of early and invasive lung cancer. A random-effects model was used to assess the diagnostic efficacy of the above modalities in cases in which a high degree of between-study heterogeneity was noted with respect to their diagnostic efficacies. The database search identified six studies including 578 patients. The pooled sensitivity and specificity of narrow-band imaging were 86% (95% confidence interval: 83-88%) and 81% (95% confidence interval: 77-84%), respectively, and the pooled sensitivity and specificity of white-light bronchoscopy were 70% (95% confidence interval: 66-74%) and 66% (95% confidence interval: 62-70%), respectively. The pooled relative risks for the sensitivity and specificity of narrow-band imaging vs the sensitivity and specificity of white-light bronchoscopy for the detection of early and invasive lung cancer were 1.33 (95% confidence interval: 1.07-1.67) and 1.09 (95% confidence interval: 0.84-1.42), respectively, and sensitivity analysis showed that narrow-band imaging exhibited good diagnostic efficacy with respect to detecting early and invasive lung cancer and that the results of the study were stable. Narrow-band imaging was superior to white light bronchoscopy with respect to detecting early and invasive lung cancer; however, the specificities of the two modalities did not differ

Clinically expedient reporting of rapid diagnostic test information.

PubMed

Doern, G V

1986-03-01

With the development of rapid diagnostic tests in the clinical microbiology laboratory has come an awareness of the importance of rapid results reporting. Clearly, the potential clinical impact of rapid diagnostic tests is dependent on expeditious reporting. Traditional manual reporting systems are encumbered by the necessity of transcription of test information onto hard copy reports and then the subsequent distribution of such reports into the hands of the user. Laboratory computers when linked directly to CRTs located in nursing stations, ambulatory clinics, or physician's offices, both inside and outside of the hospital, permit essentially instantaneous transfer of test results from the laboratory to the clinician. Computer-assisted results reporting, while representing a significant advance over manual reporting systems is not, however, without problems. Concerns include validation of test information, authorization of users with access to test information, mechanical integrity, and cost. These issues notwithstanding, computerized results reporting will undoubtedly play a central role in optimizing the clinical impact of rapid diagnostic tests.

Parkinson's Disease Diagnostic Observations (PADDO): study rationale and design of a prospective cohort study for early differentiation of parkinsonism.

PubMed

van Rumund, Anouke; Aerts, Marjolein B; Esselink, Rianne A J; Meijer, Frederick J A; Verbeek, Marcel M; Bloem, Bastiaan R

2018-05-16

Differentiation of Parkinson's disease (PD) from the various types of atypical parkinsonism (AP) such as multiple system atrophy (MSA), progressive supranuclear palsy (PSP), dementia with Lewy bodies (DLB), corticobasal syndrome (CBS) and vascular parkinsonism (VP), can be challenging, especially early in the disease course when symptoms overlap. A major unmet need in the diagnostic workup of these disorders is a diagnostic tool that differentiates the various disorders, preferably in the earliest disease stages when the clinical presentation is similar. Many diagnostic tests have been evaluated, but their added value was studied mostly in retrospective case-control studies that included patients with a straightforward clinical diagnosis. Here, we describe the design of a prospective cohort study in patients with parkinsonism in an early disease stage who have an uncertain clinical diagnosis. Our aim is to evaluate the diagnostic accuracy of (1) detailed clinical examination by a movement disorder specialist, (2) magnetic resonance imaging (MRI) techniques and (3) cerebrospinal fluid (CSF) biomarkers. Patients with parkinsonism with an uncertain clinical diagnosis and a disease course less than three years will be recruited. Patients will undergo extensive neurological examination, brain MRI including conventional and advanced sequences, and a lumbar puncture. The diagnosis (including level of certainty) will be defined by a movement disorders expert, neuroradiologist and neurochemist based on clinical data, MRI results and CSF results, respectively. The clinical diagnosis after three years' follow-up will serve as the "gold standard" reference diagnosis, based on consensus criteria and as established by two movement disorder specialists (blinded to the test results). Diagnostic accuracy of individual instruments and added value of brain MRI and CSF analysis after evaluation by a movement disorder expert will be calculated, expressed as the change in percentage of

Understanding the medical and nonmedical value of diagnostic testing.

PubMed

Lee, David W; Neumann, Peter J; Rizzo, John A

2010-01-01

To develop a framework for defining the potential value of diagnostic testing, and discuss its implications for the health-care delivery system. We reviewed the conceptual and empirical literature related to the valuing of diagnostic tests, and used this information to create a framework for characterizing their value. We then made inferences about the impact of this framework on health insurance coverage, health technology assessment, physician-patient relationships, and public health policy. Three dimensions can effectively classify the potential value created by diagnostic tests: 1) medical value (impact on treatment decisions); 2) planning value (affect on patients' ability to make better life decisions); and 3) psychic value (how test information affects patients' sense of self). This comprehensive framework for valuing diagnostics suggests that existing health technology assessments may systematically under- or overvalue diagnostics, leading to potentially incorrect conclusions about cost-effectiveness. Further, failure to account for all value dimensions may lead to distorted payments under a value-based health-care system. The potential value created by medical diagnostics incorporates medical value as well as value associated with well-being and planning. Consideration of all three dimensions has important implications for technology assessment and value-based payment.

Diagnostic hearing testing of infants aged 0-36 months in 3 South African provinces - Comparison of audiology records to HPCSA guidelines.

PubMed

Moodley, Selvarani; Störbeck, Claudine

2016-12-01

Within the Early Hearing Detection and Intervention (EHDI) pathway, which includes the processes of screening, diagnosis and intervention for paediatric hearing loss, paediatric diagnostic audiology involves a battery of specific tests and procedures. International studies have highlighted a golden standard for diagnosis of paediatric hearing loss as based on the Joint Committee of Infant Hearing (2007) diagnostic guidelines, closely resembling the HPCSA diagnostic guidelines. There are limited South African studies on the processes and protocols followed in diagnostic paediatric audiology. This study aims to provide a comparison for how the tests used for diagnosis of paediatric hearing loss in South Africa (within both the public and private healthcare sectors) compare to the HPCSA recommended diagnostic guidelines. A retrospective record review of paediatric clients with hearing loss (recruited through nonprobability convenience sampling) was conducted. This study is part of a longitudinal study of 711 deaf or hard of hearing children referred to the HI HOPES early intervention programme from September 2006 to December 2011. Diagnostic data from audiology reports of 117 children between 0 and 36 months were coded and analysed. Large variation was found in the tests included in the diagnostic audiology reports. For 22 children (19%) a comprehensive test battery was used. Health Professions Council of South Africa (HPCSA) recommended guidelines for diagnostic testing were not followed in any of the records analysed. Components of the HPCSA recommended test battery most frequently omitted was bone conduction testing. For both electrophysiology and behavioural testing, there was limited frequency specificity information. This exclusion of information is evidence of deficiencies in data recording and management, as well as having an effect on accuracy of classification of degree and type of hearing loss. There are gaps in age-appropriate assessment protocols, which

Predictive ability of an early diagnostic guess in patients presenting with chest pain; a longitudinal descriptive study

PubMed Central

2010-01-01

Background The intuitive early diagnostic guess could play an important role in reaching a final diagnosis. However, no study to date has attempted to quantify the importance of general practitioners' (GPs) ability to correctly appraise the origin of chest pain within the first minutes of an encounter. Methods The validation study was nested in a multicentre cohort study with a one year follow-up and included 626 successive patients who presented with chest pain and were attended by 58 GPs in Western Switzerland. The early diagnostic guess was assessed prior to a patient's history being taken by a GP and was then compared to a diagnosis of chest pain observed over the next year. Results Using summary measures clustered at the GP's level, the early diagnostic guess was confirmed by further investigation in 51.0% (CI 95%; 49.4% to 52.5%) of patients presenting with chest pain. The early diagnostic guess was more accurate in patients with a life threatening illness (65.4%; CI 95% 64.5% to 66.3%) and in patients who did not feel anxious (62.9%; CI 95% 62.5% to 63.3%). The predictive abilities of an early diagnostic guess were consistent among GPs. Conclusions The GPs early diagnostic guess was correct in one out of two patients presenting with chest pain. The probability of a correct guess was higher in patients with a life-threatening illness and in patients not feeling anxious about their pain. PMID:20170544

Predictive ability of an early diagnostic guess in patients presenting with chest pain; a longitudinal descriptive study.

PubMed

Verdon, François; Junod, Michel; Herzig, Lilli; Vaucher, Paul; Burnand, Bernard; Bischoff, Thomas; Pécoud, Alain; Favrat, Bernard

2010-02-21

The intuitive early diagnostic guess could play an important role in reaching a final diagnosis. However, no study to date has attempted to quantify the importance of general practitioners' (GPs) ability to correctly appraise the origin of chest pain within the first minutes of an encounter. The validation study was nested in a multicentre cohort study with a one year follow-up and included 626 successive patients who presented with chest pain and were attended by 58 GPs in Western Switzerland. The early diagnostic guess was assessed prior to a patient's history being taken by a GP and was then compared to a diagnosis of chest pain observed over the next year. Using summary measures clustered at the GP's level, the early diagnostic guess was confirmed by further investigation in 51.0% (CI 95%; 49.4% to 52.5%) of patients presenting with chest pain. The early diagnostic guess was more accurate in patients with a life threatening illness (65.4%; CI 95% 64.5% to 66.3%) and in patients who did not feel anxious (62.9%; CI 95% 62.5% to 63.3%). The predictive abilities of an early diagnostic guess were consistent among GPs. The GPs early diagnostic guess was correct in one out of two patients presenting with chest pain. The probability of a correct guess was higher in patients with a life-threatening illness and in patients not feeling anxious about their pain.

The psychological impact of test results following diagnostic coronary CT angiography.

PubMed

Devcich, Daniel A; Ellis, Christopher J; Broadbent, Elizabeth; Gamble, Greg; Petrie, Keith J

2012-11-01

Coronary computed tomography (CT) angiography is an advanced cardiac imaging test commonly used for diagnosing early signs of ischemic heart disease. Despite its importance in cardiology, little is known about its psychological effect on patients. The present study sought to examine these effects in relation to illness perceptions, cardiac health behavior intentions, and subsequent health behaviors. Forty-five nonacute cardiac patients who were referred for diagnostic coronary CT angiography completed questionnaires prior to testing and following the receipt of test results, at which point illness perceptions and intentions to take cardiac medication, as well as diet and exercise intentions were measured. Exercise and dietary behaviors were measured at follow-up 6 weeks later. Changes on these variables were then compared between patients diagnosed with normal arteries and patients diagnosed with diseased arteries. Compared to positive-testing patients, patients with normal test results reported significant changes toward more positive illness perceptions following testing, with improvements in emotional effect of illness, illness concern, consequences, and personal control of illness. The illness perception of treatment control was seen as more important among positive-testing patients, whereas both groups reported increases in illness coherence. Health behavior intentions (cardiac medication intentions and exercise intentions) increased for positive-testing patients only, as did physical activity at follow-up. Diagnosis-dependent psychological effects can be detected following coronary CT angiography. These effects have important implications for patient health and health care in diagnostic contexts, and the results from this study can be used to guide further research in this area.

Juvenile retinoschisis: a model for molecular diagnostic testing of X-linked ophthalmic disease.

PubMed

Sieving, P A; Yashar, B M; Ayyagari, R

1999-01-01

X-linked juvenile retinoschisis (RS) provides a starting point to define clinical paradigms and understand the limitations of diagnostic molecular testing. The RS phenotype is specific, but the broad severity range is clinically confusing. Molecular diagnostic testing obviates unnecessary examinations for boys at-risk and identifies carrier females who otherwise show no clinical signs. The XLRS1 gene has 6 exons of 26-196 base-pair size. Each exon is amplified by a single polymerase chain reaction and then sequenced, starting with exons 4 through 6, which contain mutation "hot spots." The 6 XLRS1 exons are sequenced serially. If alterations are found, they are compared with mutations in our > 120 XLRS families and with the > 300 mutations reported worldwide. Point mutations, small deletions, or rearrangements are identified in nearly 90% of males with a clinical diagnosis of RS. XLRS1 has very few sequence polymorphisms. Carrier-state testing produces 1 of 3 results: (1) positive, in which the woman has the same mutation as an affected male relative or known in other RS families; (2) negative, in which she lacks the mutation of her affected male relative; and (3) uninformative, in which no known mutation is identified or no information exists about the familial mutation. Molecular RS screening is an effective diagnostic tool that complements the clinician's skills for early detection of at-risk males. Useful outcomes of carrier testing depend on several factors: (1) a male relative with a clear clinical diagnosis; (2) a well-defined inheritance pattern; (3) high disease penetrance; (4) size and organization of the gene; and (5) the types of disease-associated mutations. Ethical questions include molecular diagnostic testing of young at-risk females before the age of consent, the impact of this information on the emotional health of the patient and family, and issues of employability and insurance coverage.

Antimicrobial susceptibility testing by Australian veterinary diagnostic laboratories.

PubMed

Hardefeldt, L Y; Marenda, M; Crabb, H; Stevenson, M A; Gilkerson, J R; Billman-Jacobe, H; Browning, G F

2018-04-01

The national strategy for tackling antimicrobial resistance highlights the need for antimicrobial stewardship in veterinary practice and for surveillance of antimicrobial susceptibility in veterinary pathogens. Diagnostic laboratories have an important role in facilitating both of these processes, but it is unclear whether data from veterinary diagnostic laboratories are similar enough to allow for compilation and if there is consistent promotion of appropriate antimicrobial use embedded in the approaches of different laboratories to susceptibility testing. A cross-sectional study of antimicrobial susceptibility testing and reporting procedures by Australian veterinary diagnostic laboratories was conducted in 2017 using an online questionnaire. All 18 veterinary diagnostic laboratories in Australia completed the questionnaire. Kirby-Bauer disc diffusion was the method predominantly used for antimicrobial susceptibility testing and was used to evaluate 86% of all isolates, although two different protocols were used across the 18 laboratories (CLSI 15/18, CDS 3/18). Minimum inhibitory concentrations were never reported by 61% of laboratories. Common isolates were consistently reported on across all species, except for gram-negative isolates in pigs, for which there was some variation in the approach to reporting. There was considerable diversity in the panels of antimicrobials used for susceptibility testing on common isolates and no consistency was apparent between laboratories for any bacterial species. We recommend that nationally agreed and consistent antimicrobial panels for routine susceptibility testing should be developed and a uniform set of guidelines should be adopted by veterinary diagnostic laboratories in Australia. © 2018 Australian Veterinary Association.

Improved diagnostic testing and malaria treatment practices in Zambia.

PubMed

Hamer, Davidson H; Ndhlovu, Micky; Zurovac, Dejan; Fox, Matthew; Yeboah-Antwi, Kojo; Chanda, Pascalina; Sipilinyambe, Naawa; Simon, Jonathon L; Snow, Robert W

2007-05-23

Improving the accuracy of malaria diagnosis with rapid antigen-detection diagnostic tests (RDTs) has been proposed as an approach for reducing overtreatment of malaria in the current era of widespread implementation of artemisinin-based combination therapy in sub-Saharan Africa. To assess the association between use of microscopy and RDT and the prescription of antimalarials. Cross-sectional, cluster sample survey, carried out between March and May 2006, of all outpatients treated during 1 working day at government and mission health facilities in 4 sentinel districts in Zambia. Proportions of patients undergoing malaria diagnostic procedures and receiving antimalarial treatment. Seventeen percent of the 104 health facilities surveyed had functional microscopy, 63% had RDTs available, and 73% had 1 or more diagnostics available. Of patients with fever (suspected malaria), 27.8% (95% confidence interval [CI], 13.1%-42.5%) treated in health facilities with malaria diagnostics were tested and 44.6% had positive test results. Of patients with negative blood smear results, 58.4% (95% CI, 36.7%-80.2%) were prescribed an antimalaria drug, as were 35.5% (95% CI, 16.0%-55.0%) of those with a negative RDT result. Of patients with fever who did not have diagnostic tests done, 65.9% were also prescribed antimalarials. In facilities with artemether-lumefantrine in stock, this antimalarial was prescribed to a large proportion of febrile patients with a positive diagnostic test result (blood smear, 75.0% [95% CI, 51.7%-98.3%]; RDT, 70.4% [95% CI, 39.3%-100.0%]), but also to some of those with a negative diagnostic test result (blood smear, 30.4% [95% CI, 8.0%-52. 9%]; RDT, 26.7% [95% CI, 5.7%-47.7%]). Despite efforts to expand the provision of malaria diagnostics in Zambia, they continue to be underused and patients with negative test results frequently receive antimalarials. Provision of new tools to reduce inappropriate use of new expensive antimalarial treatments must be

Carrier diagnostics and prevention of hemoglobinopathies in early pregnancy in The Netherlands: a pilot study.

PubMed

Giordano, P C; Plancke, A; Van Meir, C A; Janssen, C A H; Kok, P J M J; Van Rooijen-Nijdam, I H; Tanis, B C; van Huisseling, J C M; Versteegh, F G A

2006-08-01

We have offered, for the first time in The Netherlands, carrier diagnostics for hemoglobinopathies (HbP) to early pregnant women. The aim of this study was to establish whether carrier analysis would be welcome by the public and feasible at the outpatient level. One hundred and thirty-nine randomly selected women were informed and offered basic carrier diagnostics at the first pregnancy control. Carrier diagnostics was accepted by 136 women (97.8%). The population consisted of 31% of recent immigrants and 69% of native Dutch. One carrier of HbS and one of beta-thalassemia were found, both among the group of the recent immigrants. In both cases, partners were tested excluding a couple at risk. In addition, five carriers of alpha(+)-thalassemia were diagnosed at the molecular level, one of them in the native Dutch population. Basic carrier analysis was done both at the Hospital Laboratory and at the Reference Laboratory. No discrepancies were found. This pilot study shows that (1) as predicted the prevalence of risk-related HbP and of alpha(+)-thalassemia is high in the immigrant population. (2) The compliance with carrier analysis in both native Dutch and immigrants is virtually total and (3) carrier diagnosis in early pregnancy and partner analysis in Hospital Laboratories is possible and is an effective tool for primary prevention of HbP in The Netherlands.

Early-Onset Neonatal Sepsis: Still Room for Improvement in Procalcitonin Diagnostic Accuracy Studies

PubMed Central

Chiesa, Claudio; Pacifico, Lucia; Osborn, John F.; Bonci, Enea; Hofer, Nora; Resch, Bernhard

2015-01-01

Abstract To perform a systematic review assessing accuracy and completeness of diagnostic studies of procalcitonin (PCT) for early-onset neonatal sepsis (EONS) using the Standards for Reporting of Diagnostic Accuracy (STARD) initiative. EONS, diagnosed during the first 3 days of life, remains a common and serious problem. Increased PCT is a potentially useful diagnostic marker of EONS, but reports in the literature are contradictory. There are several possible explanations for the divergent results including the quality of studies reporting the clinical usefulness of PCT in ruling in or ruling out EONS. We systematically reviewed PubMed, Scopus, and the Cochrane Library databases up to October 1, 2014. Studies were eligible for inclusion in our review if they provided measures of PCT accuracy for diagnosing EONS. A data extraction form based on the STARD checklist and adapted for neonates with EONS was used to appraise the quality of the reporting of included studies. We found 18 articles (1998–2014) fulfilling our eligibility criteria which were included in the final analysis. Overall, the results of our analysis showed that the quality of studies reporting diagnostic accuracy of PCT for EONS was suboptimal leaving ample room for improvement. Information on key elements of design, analysis, and interpretation of test accuracy were frequently missing. Authors should be aware of the STARD criteria before starting a study in this field. We welcome stricter adherence to this guideline. Well-reported studies with appropriate designs will provide more reliable information to guide decisions on the use and interpretations of PCT test results in the management of neonates with EONS. PMID:26222858

The impact of new trends in POCTs for companion diagnostics, non-invasive testing and molecular diagnostics.

PubMed

Huckle, David

2015-06-01

Point-of-care diagnostics have been slowly developing over several decades and have taken on a new importance in current healthcare delivery for both diagnostics and development of new drugs. Molecular diagnostics have become a key driver of technology change and opened up new areas in companion diagnostics for use alongside pharmaceuticals and in new clinical approaches such as non-invasive testing. Future areas involving smartphone and other information technology advances, together with new developments in molecular biology, microfluidics and surface chemistry are adding to advances in the market. The focus for point-of-care tests with molecular diagnostic technologies is focused on advancing effective applications.

System theory in medical diagnostic devices: an overview.

PubMed

Baura, Gail D

2006-01-01

Medical diagnostics refers to testing conducted either in vitro or in vivo to provide critical health care information for risk assessment, early diagnosis, treatment, or disease management. Typical in vivo diagnostic tests include the computed tomography scan, magnetic resonance imaging, and blood pressure screening. Typical in vitro diagnostic tests include cholesterol, Papanicolaou smear, and conventional glucose monitoring tests. Historically, devices associated with both types of diagnostics have used heuristic curve fitting during signal analysis. However, since the early 1990s, a few enterprising engineers and physicians have used system theory to improve their core processing for feature detection and system identification. Current applications include automated Pap smear screening for detection of cervical cancer and diagnosis of Alzheimer's disease. Future applications, such as disease prediction before symptom onset and drug treatment customization, have been catalyzed by the Human Genome Project.

Assessing Diagnostic Tests II: Grading on a Curve.

PubMed

Jupiter, Daniel C

2015-01-01

In this Investigators' Corner, I continue discussing how to introduce and assess new diagnostic tests to replace older tests that are considered gold standards. Specifically, I talk about how to assess a "family" of diagnostics, and how to choose an optimal "family member." Copyright © 2015 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Immunochromatographic diagnostic test analysis using Google Glass.

PubMed

Feng, Steve; Caire, Romain; Cortazar, Bingen; Turan, Mehmet; Wong, Andrew; Ozcan, Aydogan

2014-03-25

We demonstrate a Google Glass-based rapid diagnostic test (RDT) reader platform capable of qualitative and quantitative measurements of various lateral flow immunochromatographic assays and similar biomedical diagnostics tests. Using a custom-written Glass application and without any external hardware attachments, one or more RDTs labeled with Quick Response (QR) code identifiers are simultaneously imaged using the built-in camera of the Google Glass that is based on a hands-free and voice-controlled interface and digitally transmitted to a server for digital processing. The acquired JPEG images are automatically processed to locate all the RDTs and, for each RDT, to produce a quantitative diagnostic result, which is returned to the Google Glass (i.e., the user) and also stored on a central server along with the RDT image, QR code, and other related information (e.g., demographic data). The same server also provides a dynamic spatiotemporal map and real-time statistics for uploaded RDT results accessible through Internet browsers. We tested this Google Glass-based diagnostic platform using qualitative (i.e., yes/no) human immunodeficiency virus (HIV) and quantitative prostate-specific antigen (PSA) tests. For the quantitative RDTs, we measured activated tests at various concentrations ranging from 0 to 200 ng/mL for free and total PSA. This wearable RDT reader platform running on Google Glass combines a hands-free sensing and image capture interface with powerful servers running our custom image processing codes, and it can be quite useful for real-time spatiotemporal tracking of various diseases and personal medical conditions, providing a valuable tool for epidemiology and mobile health.

How to Use the DX SYSTEM of Diagnostic Testing. Methodology Project.

ERIC Educational Resources Information Center

McArthur, David; Cabello, Beverly

The DX SYSTEM of Diagnostic Testing is an easy-to-use computerized system for developing and administering diagnostic tests. A diagnostic test measures a student's mastery of a specific domain (skill or content area). It examines the necessary subskills hierarchically from the most to the least complex. The DX SYSTEM features tailored testing with…

Clinical usefulness of a biomarker-based diagnostic test for acute stroke: the Biomarker Rapid Assessment in Ischemic Injury (BRAIN) study.

PubMed

Laskowitz, Daniel T; Kasner, Scott E; Saver, Jeffrey; Remmel, Kerri S; Jauch, Edward C

2009-01-01

One of the significant limitations in the evaluation and management of patients with suspected acute cerebral ischemia is the absence of a widely available, rapid, and sensitive diagnostic test. The objective of the current study was to assess whether a test using a panel of biomarkers might provide useful diagnostic information in the early evaluation of stroke by differentiating patients with cerebral ischemia from other causes of acute neurological deficit. A total of 1146 patients presenting with neurological symptoms consistent with possible stroke were prospectively enrolled at 17 different sites. Timed blood samples were assayed for matrix metalloproteinase 9, brain natriuretic factor, d-dimer, and protein S100beta. A separate cohort of 343 patients was independently enrolled to validate the multiple biomarker model approach. A diagnostic tool incorporating the values of matrix metalloproteinase 9, brain natriuretic factor, d-dimer, and S-100beta into a composite score was sensitive for acute cerebral ischemia. The multivariate model demonstrated modest discriminative capabilities with an area under the receiver operating characteristic curve of 0.76 for hemorrhagic stroke and 0.69 for all stroke (likelihood test P<0.001). When the threshold for the logistic model was set at the first quartile, this resulted in a sensitivity of 86% for detecting all stroke and a sensitivity of 94% for detecting hemorrhagic stroke. Moreover, results were reproducible in a separate cohort tested on a point-of-care platform. These results suggest that a biomarker panel may add valuable and time-sensitive diagnostic information in the early evaluation of stroke. Such an approach is feasible on a point-of-care platform. The rapid identification of patients with suspected stroke would expand the availability of time-limited treatment strategies. Although the diagnostic accuracy of the current panel is clearly imperfect, this study demonstrates the feasibility of incorporating a

Dilution testing using rapid diagnostic tests in a HIV diagnostic algorithm: a novel alternative for confirmation testing in resource limited settings.

PubMed

Shanks, Leslie; Siddiqui, M Ruby; Abebe, Almaz; Piriou, Erwan; Pearce, Neil; Ariti, Cono; Masiga, Johnson; Muluneh, Libsework; Wazome, Joseph; Ritmeijer, Koert; Klarkowski, Derryck

2015-05-14

Current WHO testing guidelines for resource limited settings diagnose HIV on the basis of screening tests without a confirmation test due to cost constraints. This leads to a potential risk of false positive HIV diagnosis. In this paper, we evaluate the dilution test, a novel method for confirmation testing, which is simple, rapid, and low cost. The principle of the dilution test is to alter the sensitivity of a rapid diagnostic test (RDT) by dilution of the sample, in order to screen out the cross reacting antibodies responsible for falsely positive RDT results. Participants were recruited from two testing centres in Ethiopia where a tiebreaker algorithm using 3 different RDTs in series is used to diagnose HIV. All samples positive on the initial screening RDT and every 10th negative sample underwent testing with the gold standard and dilution test. Dilution testing was performed using Determine™ rapid diagnostic test at 6 different dilutions. Results were compared to the gold standard of Western Blot; where Western Blot was indeterminate, PCR testing determined the final result. 2895 samples were recruited to the study. 247 were positive for a prevalence of 8.5 % (247/2895). A total of 495 samples underwent dilution testing. The RDT diagnostic algorithm misclassified 18 samples as positive. Dilution at the level of 1/160 was able to correctly identify all these 18 false positives, but at a cost of a single false negative result (sensitivity 99.6 %, 95 % CI 97.8-100; specificity 100 %, 95 % CI: 98.5-100). Concordance between the gold standard and the 1/160 dilution strength was 99.8 %. This study provides proof of concept for a new, low cost method of confirming HIV diagnosis in resource-limited settings. It has potential for use as a supplementary test in a confirmatory algorithm, whereby double positive RDT results undergo dilution testing, with positive results confirming HIV infection. Negative results require nucleic acid testing to rule out false

Promoting the hydrostatic conceptual change test (HCCT) with four-tier diagnostic test item

NASA Astrophysics Data System (ADS)

Purwanto, M. G.; Nurliani, R.; Kaniawati, I.; Samsudin, A.

2018-05-01

Hydrostatic Conceptual Change Test (HCCT) is a diagnostic test instrument to identify students’ conception on Hydrostatic field. It is very important to support the learning process in the classroom. Based on that point of view, the researcher decided to develop HCCT instrument test into four-tier test diagnostic items. The resolve of this research is planned as the first step of four-tier test-formatted HCCT development as one of investigative test instrument on Hydrostatic. The research method used the 4D model which has four comprehensive steps: 1) defining, 2) designing, 3) developing and 4) disseminating. The instrument developed has been tried to 30 students in one of senior high schools. The data showed that four-tier- test-formatted HCCT is able to identify student’s conception level of Hydrostatic. In conclusion, the development of four-tier test-formatted HCCT is one of potential diagnostic test instrument that able to classify the category of students who misconception, no understanding, understanding, partial understanding and no codeable about concept of Hydrostatic.

Immunochromatographic Diagnostic Test Analysis Using Google Glass

PubMed Central

2014-01-01

We demonstrate a Google Glass-based rapid diagnostic test (RDT) reader platform capable of qualitative and quantitative measurements of various lateral flow immunochromatographic assays and similar biomedical diagnostics tests. Using a custom-written Glass application and without any external hardware attachments, one or more RDTs labeled with Quick Response (QR) code identifiers are simultaneously imaged using the built-in camera of the Google Glass that is based on a hands-free and voice-controlled interface and digitally transmitted to a server for digital processing. The acquired JPEG images are automatically processed to locate all the RDTs and, for each RDT, to produce a quantitative diagnostic result, which is returned to the Google Glass (i.e., the user) and also stored on a central server along with the RDT image, QR code, and other related information (e.g., demographic data). The same server also provides a dynamic spatiotemporal map and real-time statistics for uploaded RDT results accessible through Internet browsers. We tested this Google Glass-based diagnostic platform using qualitative (i.e., yes/no) human immunodeficiency virus (HIV) and quantitative prostate-specific antigen (PSA) tests. For the quantitative RDTs, we measured activated tests at various concentrations ranging from 0 to 200 ng/mL for free and total PSA. This wearable RDT reader platform running on Google Glass combines a hands-free sensing and image capture interface with powerful servers running our custom image processing codes, and it can be quite useful for real-time spatiotemporal tracking of various diseases and personal medical conditions, providing a valuable tool for epidemiology and mobile health. PMID:24571349

42 CFR 414.508 - Payment for a new clinical diagnostic laboratory test.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 3 2010-10-01 2010-10-01 false Payment for a new clinical diagnostic laboratory... SERVICES Payment for New Clinical Diagnostic Laboratory Tests § 414.508 Payment for a new clinical diagnostic laboratory test. For a new clinical diagnostic laboratory test that is assigned a new or...

42 CFR 414.508 - Payment for a new clinical diagnostic laboratory test.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 42 Public Health 3 2011-10-01 2011-10-01 false Payment for a new clinical diagnostic laboratory... SERVICES Payment for New Clinical Diagnostic Laboratory Tests § 414.508 Payment for a new clinical diagnostic laboratory test. For a new clinical diagnostic laboratory test that is assigned a new or...

Whole Genome Sequencing Increases Molecular Diagnostic Yield Compared with Current Diagnostic Testing for Inherited Retinal Disease.

PubMed

Ellingford, Jamie M; Barton, Stephanie; Bhaskar, Sanjeev; Williams, Simon G; Sergouniotis, Panagiotis I; O'Sullivan, James; Lamb, Janine A; Perveen, Rahat; Hall, Georgina; Newman, William G; Bishop, Paul N; Roberts, Stephen A; Leach, Rick; Tearle, Rick; Bayliss, Stuart; Ramsden, Simon C; Nemeth, Andrea H; Black, Graeme C M

2016-05-01

To compare the efficacy of whole genome sequencing (WGS) with targeted next-generation sequencing (NGS) in the diagnosis of inherited retinal disease (IRD). Case series. A total of 562 patients diagnosed with IRD. We performed a direct comparative analysis of current molecular diagnostics with WGS. We retrospectively reviewed the findings from a diagnostic NGS DNA test for 562 patients with IRD. A subset of 46 of 562 patients (encompassing potential clinical outcomes of diagnostic analysis) also underwent WGS, and we compared mutation detection rates and molecular diagnostic yields. In addition, we compared the sensitivity and specificity of the 2 techniques to identify known single nucleotide variants (SNVs) using 6 control samples with publically available genotype data. Diagnostic yield of genomic testing. Across known disease-causing genes, targeted NGS and WGS achieved similar levels of sensitivity and specificity for SNV detection. However, WGS also identified 14 clinically relevant genetic variants through WGS that had not been identified by NGS diagnostic testing for the 46 individuals with IRD. These variants included large deletions and variants in noncoding regions of the genome. Identification of these variants confirmed a molecular diagnosis of IRD for 11 of the 33 individuals referred for WGS who had not obtained a molecular diagnosis through targeted NGS testing. Weighted estimates, accounting for population structure, suggest that WGS methods could result in an overall 29% (95% confidence interval, 15-45) uplift in diagnostic yield. We show that WGS methods can detect disease-causing genetic variants missed by current NGS diagnostic methodologies for IRD and thereby demonstrate the clinical utility and additional value of WGS. Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Diagnostic Testing at UK Universities: An E-Mail Survey

ERIC Educational Resources Information Center

Gillard, Jonathan; Levi, Margaret; Wilson, Robert

2010-01-01

In July 2009, an e-mail survey was sent to various UK universities to gain information regarding current practices concerning mathematics diagnostic testing, and to provide an update from the review "Diagnostic Testing for Mathematics" published by the LTSN MathsTEAM Project in 2003. A total of 38 university departments were contacted…

Management of early renal anaemia: diagnostic work-up, iron therapy, epoetin therapy.

PubMed

Van Wyck, D B

2000-01-01

Effective management of early anaemia in the course of chronic renal insufficiency requires the following: (i) implementing an efficient diagnostic strategy to exclude common contributing factors; (ii) initiating epoetin therapy for the majority of patients; for and (iii) ensuring adequate iron supply erythropoiesis. Diagnostic inquiry is warranted whenever the haemoglobin concentration is below the normal range adjusted for age and gender. The most efficient diagnostic approach is to assume erythropoietin deficiency, exclude iron deficiency, and pursue further diagnostic tests only when red-cell indices are abnormal or when leukopenia or thrombocytopenia are also present. Macrocytosis should prompt an inquiry into alcoholism, B12 deficiency, or folate deficiency. Microcytosis suggests iron deficiency or thalassaemia. Associated cytopenias raise the possibility of alcohol toxicity, pernicious anaemia, malignancy, or myelodysplastic syndrome. Epoetin therapy is warranted whenever the haemoglobin concentration has fallen below 10.0 g/dl. To initiate therapy prior to dialysis, epoetin should be administered at an average dose of 100 IU/kg/week (80-120 IU/kg/week, 50-150 IU/kg/ week) by subcutaneous injection. Haemoglobin concentration should be monitored every 2 weeks and the epoetin dose adjusted by increments or decrements of 25% to maintain a rate of rise of haemoglobin concentration of 0.2-0.6 g/dl (0.3 0.6 g/dl/week, 0.2-0.5 g/dl/week). When the target range is achieved, the dose of epoetin should be continually adjusted to maintain a stable haemoglobin concentration. Transferrin saturation and ferritin concentration should be monitored monthly, and sufficient iron provided to maintain transferrin saturation above 20%. The lower the haemoglobin concentration, the greater the likelihood that future intravenous iron will be required. Oral iron supplements should be avoided, since they are costly, ineffective, and troublesome to patients. Finally, a blunted

A diagnostic approach to hemochromatosis

PubMed Central

Tavill, Anthony S; Adams, Paul C

2006-01-01

In the present clinical review, a diagnostic approach to hemochromatosis is discussed from the perspective of two clinicians with extensive experience in this area. The introduction of genetic testing and large-scale population screening studies have broadened our understanding of the clinical expression of disease and the utility of biochemical iron tests for the detection of disease and for the assessment of disease severity. Liver biopsy has become more of a prognostic test than a diagnostic test. The authors offer a stepwise, diagnostic algorithm based on current evidence-based data, that they regard as most cost-effective. An early diagnosis can lead to phlebotomy therapy to prevent the development of cirrhosis. PMID:16955151

Preliminary assessment of the diagnostic performances of a new rapid diagnostic test for the serodiagnosis of human cystic echinococcosis.

PubMed

Vola, Ambra; Tamarozzi, Francesca; Noordin, Rahmah; Yunus, Muhammad Hafiznur; Khanbabaie, Sam; De Silvestri, Annalisa; Brunetti, Enrico; Mariconti, Mara

2018-04-14

Rapid diagnostic tests for cystic echinococcosis (CE) are convenient to support ultrasound diagnosis in uncertain cases, especially in resource-limited settings. We found comparable diagnostic performances of the experimental Hyd Rapid Test and the commercial VIRapid HYDATIDOSIS Test, used in our diagnostic laboratory, using samples from well-characterized hepatic CE cases. Copyright © 2018 Elsevier Inc. All rights reserved.

Changes in laboratory test results and diagnostic imaging presentation before the detection of occupational cholangiocarcinoma.

PubMed

Kubo, Shoji; Takemura, Shigekazu; Sakata, Chikaharu; Urata, Yorihisa; Nishioka, Takayoshi; Nozawa, Akinori; Kinoshita, Masahiko; Hamano, Genya; Nakanuma, Yasuni; Endo, Ginji

2014-01-01

A cholangiocarcinoma outbreak among workers of an offset color proof-printing department in a printing company was recently reported. It is important to understand the clinical course leading to occupational cholangiocarcinoma development for investigation of the carcinogenesis process and for surveillance and early detection. We evaluated the changes in laboratory test results and diagnostic imaging presentation before the detection of cholangiocarcinoma. We investigated the changes in laboratory test results and diagnostic imaging presentation before the detection of cholangiocarcinoma in 2 patients because the data were available. Results The clinical courses observed in the 2 participating patients showed persistent elevation of serum γ-glutamyl transpeptidase levels with or without elevated serum levels of alanine aminotransferase and/or aspartate aminotransferase before cholangiocarcinoma detection. Dilatation of the bile ducts without tumor-induced stenosis was observed several years before cholangiocarcinoma detection and progressed gradually in both patients. The serum concentration of carbohydrate 19-9 also increased prior to cholangiocarcinoma detection in both patients. Eventually, observation of stenosis of the bile duct and a space-occupying lesion strongly suggested cholangiocarcinoma. Pathological examination of the resected specimens showed chronic bile duct injury and neoplastic lesions, such as "biliary intraepithelial neoplasia" and "intraductal papillary neoplasm of the bile duct" in various sites of the bile ducts, particularly in the dilated bile ducts. The changes in laboratory test results and diagnostic imaging might be related to the development of cholangiocarcinoma. It is important to monitor diagnostic imaging presentation and laboratory test results in workers with extended exposure to organic solvents.

When is diagnostic testing inappropriate or irrational? Acceptable regret approach.

PubMed

Hozo, Iztok; Djulbegovic, Benjamin

2008-01-01

The authors provide a new model within the framework of theories of bounded rationality for the observed physicians' behavior that their ordering of diagnostic tests may not be rational. Contrary to the prevailing thinking, the authors find that physicians do not act irrationally or inappropriately when they order diagnostic tests in usual clinical practice. When acceptable regret (i.e., regret that a decision maker finds tolerable upon making a wrong decision) is taken into account, the authors show that physicians tend to order diagnostic tests at a higher level of pretest probability of disease than predicted by expected utility theory. They also show why physicians tend to overtest when regret about erroneous decisions is extremely small. Finally, they explain variations in the practice of medicine. They demonstrate that in the same clinical situation, different decision makers might have different acceptable regret thresholds for withholding treatment, for ordering a diagnostic test, or for administering treatment. This in turn means that for some decision makers, the most rational strategy is to do nothing, whereas for others, it may be to order a diagnostic test, and still for others, choosing treatment may be the most rational course of action.

Juvenile retinoschisis: a model for molecular diagnostic testing of X-linked ophthalmic disease.

PubMed Central

Sieving, P A; Yashar, B M; Ayyagari, R

1999-01-01

BACKGROUND AND PURPOSE: X-linked juvenile retinoschisis (RS) provides a starting point to define clinical paradigms and understand the limitations of diagnostic molecular testing. The RS phenotype is specific, but the broad severity range is clinically confusing. Molecular diagnostic testing obviates unnecessary examinations for boys at-risk and identifies carrier females who otherwise show no clinical signs. METHODS: The XLRS1 gene has 6 exons of 26-196 base-pair size. Each exon is amplified by a single polymerase chain reaction and then sequenced, starting with exons 4 through 6, which contain mutation "hot spots." RESULTS: The 6 XLRS1 exons are sequenced serially. If alterations are found, they are compared with mutations in our > 120 XLRS families and with the > 300 mutations reported worldwide. Point mutations, small deletions, or rearrangements are identified in nearly 90% of males with a clinical diagnosis of RS. XLRS1 has very few sequence polymorphisms. Carrier-state testing produces 1 of 3 results: (1) positive, in which the woman has the same mutation as an affected male relative or known in other RS families; (2) negative, in which she lacks the mutation of her affected male relative; and (3) uninformative, in which no known mutation is identified or no information exists about the familial mutation. CONCLUSIONS: Molecular RS screening is an effective diagnostic tool that complements the clinician's skills for early detection of at-risk males. Useful outcomes of carrier testing depend on several factors: (1) a male relative with a clear clinical diagnosis; (2) a well-defined inheritance pattern; (3) high disease penetrance; (4) size and organization of the gene; and (5) the types of disease-associated mutations. Ethical questions include molecular diagnostic testing of young at-risk females before the age of consent, the impact of this information on the emotional health of the patient and family, and issues of employability and insurance coverage

Epidemiology of meningitis with a negative CSF Gram stain: under-utilization of available diagnostic tests.

PubMed

Nesher, L; Hadi, C M; Salazar, L; Wootton, S H; Garey, K W; Lasco, T; Luce, A M; Hasbun, R

2016-01-01

Meningitis with a negative cerebrospinal fluid Gram stain (CSF-GS) poses a diagnostic challenge as more than 50% of patients remain without an aetiology. The introduction of polymerase chain reaction (PCR) and arboviral serologies have increased diagnostic capabilities, yet large scale epidemiological studies evaluating their use in clinical practice are lacking. We conducted a prospective observational study in New Orleans between November 1999 and September 2008 (early era) when PCR was not widely available, and in Houston between November 2008 and June 2013 (modern era), when PCR was commonly used. Patients presenting with meningitis and negative CSF-GS were followed for 4 weeks. All investigations, PCR used, and results were recorded as they became available. In 323 patients enrolled, PCR provided the highest diagnostic yield (24·2%) but was ordered for 128 (39·6%) patients; followed by serology for arboviruses (15%) that was ordered for 100 (31%) of all patients. The yield of blood cultures was (10·3%) and that of CSF cultures was 4%; the yield for all other tests was <10%. Overall, 65% of the patients remained without a diagnosis at 4 weeks: 72·1% in early era vs. 53·4% (P < 0·01) in modern era; this change was attributed to diagnosing more viral pathogens, 8·3% and 26·3% (P < 0·01), respectively. The introduction of PCR and arboviral serologies has improved the yield of diagnosing patients with meningitis and a negative CSF-GS, but both tests are being under-utilized.

Validation of the Lollipop Test: A Diagnostic Screening Test of School Readiness.

ERIC Educational Resources Information Center

Chew, Alex L.; Morris, John D.

1984-01-01

The validity of the Lollipop Test: A Diagnostic Screening Test of School Readiness was examined using the Metropolitan Readiness Test (MRT), Level I, Form Q, as the criterion. Appreciable concurrent validity was found across test batteries. Implications for school readiness screening are discussed. (Author/BS)

Reporting Diagnostic Scores in Educational Testing: Temptations, Pitfalls, and Some Solutions

ERIC Educational Resources Information Center

Sinharay, Sandip; Puhan, Gautam; Haberman, Shelby J.

2010-01-01

Diagnostic scores are of increasing interest in educational testing due to their potential remedial and instructional benefit. Naturally, the number of educational tests that report diagnostic scores is on the rise, as are the number of research publications on such scores. This article provides a critical evaluation of diagnostic score reporting…

Automation of diagnostic genetic testing: mutation detection by cyclic minisequencing.

PubMed

Alagrund, Katariina; Orpana, Arto K

2014-01-01

The rising role of nucleic acid testing in clinical decision making is creating a need for efficient and automated diagnostic nucleic acid test platforms. Clinical use of nucleic acid testing sets demands for shorter turnaround times (TATs), lower production costs and robust, reliable methods that can easily adopt new test panels and is able to run rare tests in random access principle. Here we present a novel home-brew laboratory automation platform for diagnostic mutation testing. This platform is based on the cyclic minisequecing (cMS) and two color near-infrared (NIR) detection. Pipetting is automated using Tecan Freedom EVO pipetting robots and all assays are performed in 384-well micro plate format. The automation platform includes a data processing system, controlling all procedures, and automated patient result reporting to the hospital information system. We have found automated cMS a reliable, inexpensive and robust method for nucleic acid testing for a wide variety of diagnostic tests. The platform is currently in clinical use for over 80 mutations or polymorphisms. Additionally to tests performed from blood samples, the system performs also epigenetic test for the methylation of the MGMT gene promoter, and companion diagnostic tests for analysis of KRAS and BRAF gene mutations from formalin fixed and paraffin embedded tumor samples. Automation of genetic test reporting is found reliable and efficient decreasing the work load of academic personnel.

Predictors of Inappropriate Use of Diagnostic Tests and Management of Bronchiolitis

PubMed Central

Sarmiento, Lorena; Rojas-Soto, Gladys E.

2017-01-01

Background The aim of the present study was to determine predictors of inappropriate use of diagnostic tests and management of bronchiolitis in a population of hospitalized infants. Methods In an analytical cross-sectional study, we determined independent predictors of the inappropriate use of diagnostic tests and management of bronchiolitis in a population of hospitalized infants. We defined a composite outcome score as the main outcome variable. Results Of the 303 included patients, 216 (71.3%) experienced an inappropriate use of diagnostic tests and treatment of bronchiolitis. After controlling for potential confounders, it was found that atopic dermatitis (OR 5.30; CI 95% 1.14–24.79; p = 0.034), length of hospital stay (OR 1.48; CI 95% 1.08–2.03; p = 0.015), and the number of siblings (OR 1.92; CI 95% 1.13–3.26; p = 0.015) were independent predictors of an inappropriate use of diagnostic tests and treatment of the disease. Conclusions Inappropriate use of diagnostic tests and treatment of bronchiolitis was a highly prevalent outcome in our population of study. Participants with atopic dermatitis, a longer hospital stay, and a greater number of siblings were at increased risk for inappropriate use of diagnostic tests and management of the disease. PMID:28758127

Molecular diagnostic testing for primary biliary cholangitis.

PubMed

Gatselis, Nikolaos K; Dalekos, George N

2016-09-01

A reliable liver autoimmune serology for the diagnosis of primary biliary cholangitis (PBC) is of particular importance. Recognition of patients at early stages and prompt treatment initiation may alter the outcome, slow progression, delays liver failure, and improves survival. In this review, we summarize and discuss the published data obtained from literature searches from PubMed and The National Library of Medicine (USA) and our own experience on the current and potential molecular based approaches to the diagnosis of PBC. Expert commentary: Standardization of liver diagnostic serology and clinical governance are two major points as antimitochondrial antibodies are the diagnostic hallmark of the disease and PBC-specific antinuclear antibodies could assist in the diagnosis and estimation of prognosis. New biomarkers such as novel autoantibodies, genetic polymorphisms, metabolomic profiling, micro-RNA and epigenetics may assist to the understanding, diagnosis and management of the disease.

The Monosyllable Imitation Test for Toddlers: influence of stimulus characteristics on imitation, compliance and diagnostic accuracy.

PubMed

Hodges, Rosemary; Munro, Natalie; Baker, Elise; McGregor, Karla; Heard, Rob

2017-01-01

Although verbal imitation can provide a valuable window into the developing language abilities of toddlers, some toddlers find verbal imitation challenging and will not comply with tests that involve elicited verbal imitation. The characteristics of stimuli that are offered to toddlers for imitation may influence how easy or hard it is for them to imitate. This study presents a new test of elicited imitation-the Monosyllable Imitation Test for Toddlers (MITT)-comprising stimuli of varying characteristics and test features designed to optimize compliance. To investigate whether the stimulus characteristics of neighbourhood density and consonant complexity have independent and/or convergent influences on imitation accuracy; and to examine non-compliance rates and diagnostic accuracy of the MITT and an existing test, the Test of Early Nonword Repetition (TENR) (Stokes and Klee 2009a). Fifty-two toddlers (25-35 months) participated. Twenty-six had typically developing language (TDs) and 26 were defined as late talkers (LTs) based on parent-reported vocabulary. The MITT stimuli were created by manipulating both neighbourhood density (dense or sparse) and consonant complexity (early- or late-developing initial consonant). The MITT was designed to maximize compliance by: (1) using eight monosyllabic stimuli, (2) providing three exposures to stimuli and (3) embedding imitation in a motivating context: a computer animation with reasons for imitation. Stimulus characteristics influenced imitation accuracy in TDs and LTs. For TDs, neighbourhood density had an independent influence, whereas for LTs consonant complexity had an independent influence. These characteristics also had convergent influences. For TDs, stimuli were all equally easy to imitate, except those that were both sparse and contained a late-developing consonant which were harder to imitate. For LTs, stimuli that were both dense and contained an early-developing consonant were easier to imitate than any other

Diagnostic and prognostic value of procalcitonin for early intracranial infection after craniotomy

PubMed Central

Yu, Y.; Li, H.J.

2017-01-01

Intracranial infection is a common clinical complication after craniotomy. We aimed to explore the diagnostic and prognostic value of dynamic changing procalcitonin (PCT) in early intracranial infection after craniotomy. A prospective study was performed on 93 patients suspected of intracranial infection after craniotomy. Routine peripheral venous blood was collected on the day of admission, and C reactive protein (CRP) and PCT levels were measured. Cerebrospinal fluid (CSF) was collected for routine biochemical, PCT and culture assessment. Serum and CSF analysis continued on days 1, 2, 3, 5, 7, 9, and 11. The patients were divided into intracranial infection group and non-intracranial infection group; intracranial infection group was further divided into infection controlled group and infection uncontrolled group. Thirty-five patients were confirmed with intracranial infection after craniotomy according to the diagnostic criteria. The serum and cerebrospinal fluid PCT levels in the infected group were significantly higher than the non-infected group on day 1 (P<0.05, P<0.01). The area under curve of receiver operating characteristics was 0.803 for CSF PCT in diagnosing intracranial infection. The diagnostic sensitivity and specificity of CSF PCT was superior to other indicators. The serum and CSF PCT levels have potential value in the early diagnosis of intracranial infection after craniotomy. Since CSF PCT levels have higher sensitivity and specificity, dynamic changes in this parameter could be used for early detection of intracranial infection after craniotomy, combined with other biochemical indicators. PMID:28443989

Optimal Combinations of Diagnostic Tests Based on AUC.

PubMed

Huang, Xin; Qin, Gengsheng; Fang, Yixin

2011-06-01

When several diagnostic tests are available, one can combine them to achieve better diagnostic accuracy. This article considers the optimal linear combination that maximizes the area under the receiver operating characteristic curve (AUC); the estimates of the combination's coefficients can be obtained via a nonparametric procedure. However, for estimating the AUC associated with the estimated coefficients, the apparent estimation by re-substitution is too optimistic. To adjust for the upward bias, several methods are proposed. Among them the cross-validation approach is especially advocated, and an approximated cross-validation is developed to reduce the computational cost. Furthermore, these proposed methods can be applied for variable selection to select important diagnostic tests. The proposed methods are examined through simulation studies and applications to three real examples. © 2010, The International Biometric Society.

Increased Diagnostic Accuracy of Digital vs. Conventional Clock Drawing Test for Discrimination of Patients in the Early Course of Alzheimer's Disease from Cognitively Healthy Individuals.

PubMed

Müller, Stephan; Preische, Oliver; Heymann, Petra; Elbing, Ulrich; Laske, Christoph

2017-01-01

The conventional Clock Drawing Test (cCDT) is a rapid and inexpensive screening tool for detection of moderate and severe dementia. However, its usage is limited due to poor diagnostic accuracy especially in patients with mild cognitive impairment (MCI). The diagnostic value of a newly developed digital Clock Drawing Test (dCDT) was evaluated and compared with the cCDT in 20 patients with early dementia due to AD (eDAT), 30 patients with amnestic MCI (aMCI) and 20 cognitively healthy controls (HCs). Parameters assessed by dCDT were time while transitioning the stylus from one stroke to the next above the surface (i.e., time-in-air), time the stylus produced a visible stroke (i.e., time-on-surface) and total-time during clock drawing. Receiver-operating characteristic (ROC) curves were calculated and logistic regression analyses have been conducted for statistical analysis. Using dCDT, time-in-air was significantly increased in eDAT (70965.8 ms) compared to aMCI (54073.7 ms; p = 0.027) and HC (32315.6 ms; p < 0.001). In addition, time-in-air was significantly longer in patients with aMCI compared to HC ( p = 0.003), even in the aMCI group with normal cCDT score (54141.8 ms; p < 0.001). Time-in-air using dCDT allowed discrimination of patients with aMCI from HCs with a sensitivity of 81.3% and a specificity of 72.2% while cCDT scoring revealed a sensitivity of 62.5% and a specificity of 83.3%. Most interestingly, time-in-air allowed even discrimination of aMCI patients with normal cCDT scores (80% from all aMCI patients) from HCs with a clinically relevant sensitivity of 80.8% and a specificity of 77.8%. A combination of dCDT variables and cCDT scores did not improve the discrimination of patients with aMCI from HC. In conclusion, assessment of time-in-air using dCDT yielded a higher diagnostic accuracy for discrimination of aMCI patients from HCs than the use of cCDT even in those aMCI patients with normal cCDT scores. Modern digitizing devices offer the opportunity

Early-onset dementias: diagnostic and etiological considerations

PubMed Central

2013-01-01

This paper summarizes the body of literature about early-onset dementia (EOD) that led to recommendations from the Fourth Canadian Consensus Conference on the Diagnosis and Treatment of Dementia. A broader differential diagnosis is required for EOD compared with late-onset dementia. Delays in diagnosis are common, and the social impact of EOD requires special care teams. The etiologies underlying EOD syndromes should take into account family history and comorbid diseases, such as cerebrovascular risk factors, that may influence the clinical presentation and age at onset. For example, although many EODs are more likely to have Mendelian genetic and/or metabolic causes, the presence of comorbidities may drive the individual at risk for late-onset dementia to manifest the symptoms at an earlier age, which contributes further to the observed heterogeneity and may confound diagnostic investigation. A personalized medicine approach to diagnosis should therefore be considered depending on the age at onset, clinical presentation, and comorbidities. Genetic counseling and testing as well as specialized biochemical screening are often required, especially in those under the age of 40 and in those with a family history of autosomal dominant or recessive disease. Novel treatments in the drug development pipeline for EOD, such as genetic forms of Alzheimer's disease, should target the specific pathogenic cascade implicated by the mutation or biochemical defect. PMID:24565469

Drug sensitivity testing platforms for gastric cancer diagnostics.

PubMed

Lau, Vianne; Wong, Andrea Li-Ann; Ng, Christopher; Mok, Yingting; Lakshmanan, Manikandan; Yan, Benedict

2016-02-01

Gastric cancer diagnostics has traditionally been histomorphological and primarily the domain of surgical pathologists. Although there is an increasing usage of molecular and genomic techniques for clinical diagnostics, there is an emerging field of personalised drug sensitivity testing. In this review, we describe the various personalised drug sensitivity testing platforms and discuss the challenges facing clinical adoption of these assays for gastric cancer. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Google glass based immunochromatographic diagnostic test analysis

NASA Astrophysics Data System (ADS)

Feng, Steve; Caire, Romain; Cortazar, Bingen; Turan, Mehmet; Wong, Andrew; Ozcan, Aydogan

2015-03-01

Integration of optical imagers and sensors into recently emerging wearable computational devices allows for simpler and more intuitive methods of integrating biomedical imaging and medical diagnostics tasks into existing infrastructures. Here we demonstrate the ability of one such device, the Google Glass, to perform qualitative and quantitative analysis of immunochromatographic rapid diagnostic tests (RDTs) using a voice-commandable hands-free software-only interface, as an alternative to larger and more bulky desktop or handheld units. Using the built-in camera of Glass to image one or more RDTs (labeled with Quick Response (QR) codes), our Glass software application uploads the captured image and related information (e.g., user name, GPS, etc.) to our servers for remote analysis and storage. After digital analysis of the RDT images, the results are transmitted back to the originating Glass device, and made available through a website in geospatial and tabular representations. We tested this system on qualitative human immunodeficiency virus (HIV) and quantitative prostate-specific antigen (PSA) RDTs. For qualitative HIV tests, we demonstrate successful detection and labeling (i.e., yes/no decisions) for up to 6-fold dilution of HIV samples. For quantitative measurements, we activated and imaged PSA concentrations ranging from 0 to 200 ng/mL and generated calibration curves relating the RDT line intensity values to PSA concentration. By providing automated digitization of both qualitative and quantitative test results, this wearable colorimetric diagnostic test reader platform on Google Glass can reduce operator errors caused by poor training, provide real-time spatiotemporal mapping of test results, and assist with remote monitoring of various biomedical conditions.

Chronic pancreatitis: A diagnostic dilemma

PubMed Central

Duggan, Sinead N; Ní Chonchubhair, Hazel M; Lawal, Oladapo; O’Connor, Donal B; Conlon, Kevin C

2016-01-01

Typical clinical symptoms of chronic pancreatitis are vague and non-specific and therefore diagnostic tests are required, none of which provide absolute diagnostic certainly, especially in the early stages of disease. Recently-published guidelines bring much needed structure to the diagnostic work-up of patients with suspected chronic pancreatitis. In addition, novel diagnostic modalities bring promise for the future. The assessment and diagnosis of pancreatic exocrine insufficiency remains challenging and this review contests the accepted perspective that steatorrhea only occurs with > 90% destruction of the gland. PMID:26900292

Assessing Diagnostic Tests I: You Can't Be Too Sensitive.

PubMed

Jupiter, Daniel C

2015-01-01

Clinicians and patients are always interested in less invasive, cheaper, and faster diagnostic tests. When introducing such a test, physicians must ensure that it is reliable in its diagnoses and does not commit errors. In this article, I discuss several ways that new tests are compared against gold standard diagnostics. Copyright © 2015 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Low clinical diagnostic accuracy of early vs advanced Parkinson disease: clinicopathologic study.

PubMed

Adler, Charles H; Beach, Thomas G; Hentz, Joseph G; Shill, Holly A; Caviness, John N; Driver-Dunckley, Erika; Sabbagh, Marwan N; Sue, Lucia I; Jacobson, Sandra A; Belden, Christine M; Dugger, Brittany N

2014-07-29

Determine diagnostic accuracy of a clinical diagnosis of Parkinson disease (PD) using neuropathologic diagnosis as the gold standard. Data from the Arizona Study of Aging and Neurodegenerative Disorders were used to determine the predictive value of a clinical PD diagnosis, using 2 clinical diagnostic confidence levels, PossPD (never treated or not clearly responsive) and ProbPD (responsive to medications). Neuropathologic diagnosis was the gold standard. Based on first visit, 9 of 34 (26%) PossPD cases had neuropathologically confirmed PD while 80 of 97 (82%) ProbPD cases had confirmed PD. PD was confirmed in 8 of 15 (53%) ProbPD cases with <5 years of disease duration and 72 of 82 (88%) with ≥5 years of disease duration. Using final diagnosis at time of death, 91 of 107 (85%) ProbPD cases had confirmed PD. Clinical variables that improved diagnostic accuracy were medication response, motor fluctuations, dyskinesias, and hyposmia. Using neuropathologic findings of PD as the gold standard, this study establishes the novel findings of only 26% accuracy for a clinical diagnosis of PD in untreated or not clearly responsive subjects, 53% accuracy in early PD responsive to medication (<5 years' duration), and >85% diagnostic accuracy of longer duration, medication-responsive PD. Caution is needed when interpreting clinical studies of PD, especially studies of early disease that do not have autopsy confirmation. The need for a tissue or other diagnostic biomarker is reinforced. This study provides Class II evidence that a clinical diagnosis of PD identifies patients who will have pathologically confirmed PD with a sensitivity of 88% and specificity of 68%. © 2014 American Academy of Neurology.

Nonparametric predictive inference for combining diagnostic tests with parametric copula

NASA Astrophysics Data System (ADS)

Muhammad, Noryanti; Coolen, F. P. A.; Coolen-Maturi, T.

2017-09-01

Measuring the accuracy of diagnostic tests is crucial in many application areas including medicine and health care. The Receiver Operating Characteristic (ROC) curve is a popular statistical tool for describing the performance of diagnostic tests. The area under the ROC curve (AUC) is often used as a measure of the overall performance of the diagnostic test. In this paper, we interest in developing strategies for combining test results in order to increase the diagnostic accuracy. We introduce nonparametric predictive inference (NPI) for combining two diagnostic test results with considering dependence structure using parametric copula. NPI is a frequentist statistical framework for inference on a future observation based on past data observations. NPI uses lower and upper probabilities to quantify uncertainty and is based on only a few modelling assumptions. While copula is a well-known statistical concept for modelling dependence of random variables. A copula is a joint distribution function whose marginals are all uniformly distributed and it can be used to model the dependence separately from the marginal distributions. In this research, we estimate the copula density using a parametric method which is maximum likelihood estimator (MLE). We investigate the performance of this proposed method via data sets from the literature and discuss results to show how our method performs for different family of copulas. Finally, we briefly outline related challenges and opportunities for future research.

Diagnostic reliability of MMPI-2 computer-based test interpretations.

PubMed

Pant, Hina; McCabe, Brian J; Deskovitz, Mark A; Weed, Nathan C; Williams, John E

2014-09-01

Reflecting the common use of the MMPI-2 to provide diagnostic considerations, computer-based test interpretations (CBTIs) also typically offer diagnostic suggestions. However, these diagnostic suggestions can sometimes be shown to vary widely across different CBTI programs even for identical MMPI-2 profiles. The present study evaluated the diagnostic reliability of 6 commercially available CBTIs using a 20-item Q-sort task developed for this study. Four raters each sorted diagnostic classifications based on these 6 CBTI reports for 20 MMPI-2 profiles. Two questions were addressed. First, do users of CBTIs understand the diagnostic information contained within the reports similarly? Overall, diagnostic sorts of the CBTIs showed moderate inter-interpreter diagnostic reliability (mean r = .56), with sorts for the 1/2/3 profile showing the highest inter-interpreter diagnostic reliability (mean r = .67). Second, do different CBTIs programs vary with respect to diagnostic suggestions? It was found that diagnostic sorts of the CBTIs had a mean inter-CBTI diagnostic reliability of r = .56, indicating moderate but not strong agreement across CBTIs in terms of diagnostic suggestions. The strongest inter-CBTI diagnostic agreement was found for sorts of the 1/2/3 profile CBTIs (mean r = .71). Limitations and future directions are discussed. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Analysis of the Astronomy Diagnostic Test

ERIC Educational Resources Information Center

Brogt, Erik; Sabers, Darrell; Prather, Edward E.; Deming, Grace L.; Hufnagel, Beth; Slater, Timothy F.

2007-01-01

Seventy undergraduate class sections were examined from the database of Astronomy Diagnostic Test (ADT) results of Deming and Hufnagel to determine if course format correlated with ADT normalized gain scores. Normalized gains were calculated for four different classroom scenarios: lecture, lecture with discussion, lecture with lab, and lecture…

Development of companion diagnostics

DOE PAGES

Mankoff, David A.; Edmonds, Christine E.; Farwell, Michael D.; ...

2015-12-12

The goal of individualized and targeted treatment and precision medicine requires the assessment of potential therapeutic targets to direct treatment selection. The biomarkers used to direct precision medicine, often termed companion diagnostics, for highly targeted drugs have thus far been almost entirely based on in vitro assay of biopsy material. Molecular imaging companion diagnostics offer a number of features complementary to those from in vitro assay, including the ability to measure the heterogeneity of each patient’s cancer across the entire disease burden and to measure early changes in response to treatment. We discuss the use of molecular imaging methods asmore » companion diagnostics for cancer therapy with the goal of predicting response to targeted therapy and measuring early (pharmacodynamic) response as an indication of whether the treatment has “hit” the target. We also discuss considerations for probe development for molecular imaging companion diagnostics, including both small-molecule probes and larger molecules such as labeled antibodies and related constructs. We then describe two examples where both predictive and pharmacodynamic molecular imaging markers have been tested in humans: endocrine therapy for breast cancer and human epidermal growth factor receptor type 2–targeted therapy. Lastly, the review closes with a summary of the items needed to move molecular imaging companion diagnostics from early studies into multicenter trials and into the clinic.« less

Development of companion diagnostics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mankoff, David A.; Edmonds, Christine E.; Farwell, Michael D.

The goal of individualized and targeted treatment and precision medicine requires the assessment of potential therapeutic targets to direct treatment selection. The biomarkers used to direct precision medicine, often termed companion diagnostics, for highly targeted drugs have thus far been almost entirely based on in vitro assay of biopsy material. Molecular imaging companion diagnostics offer a number of features complementary to those from in vitro assay, including the ability to measure the heterogeneity of each patient’s cancer across the entire disease burden and to measure early changes in response to treatment. We discuss the use of molecular imaging methods asmore » companion diagnostics for cancer therapy with the goal of predicting response to targeted therapy and measuring early (pharmacodynamic) response as an indication of whether the treatment has “hit” the target. We also discuss considerations for probe development for molecular imaging companion diagnostics, including both small-molecule probes and larger molecules such as labeled antibodies and related constructs. We then describe two examples where both predictive and pharmacodynamic molecular imaging markers have been tested in humans: endocrine therapy for breast cancer and human epidermal growth factor receptor type 2–targeted therapy. Lastly, the review closes with a summary of the items needed to move molecular imaging companion diagnostics from early studies into multicenter trials and into the clinic.« less

Development of Companion Diagnostics

PubMed Central

Mankoff, David A.; Edmonds, Christine E.; Farwell, Michael D.; Pryma, Daniel A.

2016-01-01

The goal of individualized and targeted treatment and precision medicine requires the assessment of potential therapeutic targets to direct treatment selection. The biomarkers used to direct precision medicine, often termed companion diagnostics, for highly targeted drugs have thus far been almost entirely based on in vitro assay of biopsy material. Molecular imaging companion diagnostics offer a number of features complementary to those from in vitro assay, including the ability to measure the heterogeneity of each patient’s cancer across the entire disease burden and to measure early changes in response to treatment. We discuss the use of molecular imaging methods as companion diagnostics for cancer therapy with the goal of predicting response to targeted therapy and measuring early (pharmacodynamic) response as an indication of whether the treatment has “hit” the target. We also discuss considerations for probe development for molecular imaging companion diagnostics, including both small-molecule probes and larger molecules such as labeled antibodies and related constructs. We then describe two examples where both predictive and pharmacodynamic molecular imaging markers have been tested in humans: endocrine therapy for breast cancer and human epidermal growth factor receptor type 2–targeted therapy. The review closes with a summary of the items needed to move molecular imaging companion diagnostics from early studies into multicenter trials and into the clinic. PMID:26687857

Increased Diagnostic Accuracy of Digital vs. Conventional Clock Drawing Test for Discrimination of Patients in the Early Course of Alzheimer’s Disease from Cognitively Healthy Individuals

PubMed Central

Müller, Stephan; Preische, Oliver; Heymann, Petra; Elbing, Ulrich; Laske, Christoph

2017-01-01

The conventional Clock Drawing Test (cCDT) is a rapid and inexpensive screening tool for detection of moderate and severe dementia. However, its usage is limited due to poor diagnostic accuracy especially in patients with mild cognitive impairment (MCI). The diagnostic value of a newly developed digital Clock Drawing Test (dCDT) was evaluated and compared with the cCDT in 20 patients with early dementia due to AD (eDAT), 30 patients with amnestic MCI (aMCI) and 20 cognitively healthy controls (HCs). Parameters assessed by dCDT were time while transitioning the stylus from one stroke to the next above the surface (i.e., time-in-air), time the stylus produced a visible stroke (i.e., time-on-surface) and total-time during clock drawing. Receiver-operating characteristic (ROC) curves were calculated and logistic regression analyses have been conducted for statistical analysis. Using dCDT, time-in-air was significantly increased in eDAT (70965.8 ms) compared to aMCI (54073.7 ms; p = 0.027) and HC (32315.6 ms; p < 0.001). In addition, time-in-air was significantly longer in patients with aMCI compared to HC (p = 0.003), even in the aMCI group with normal cCDT score (54141.8 ms; p < 0.001). Time-in-air using dCDT allowed discrimination of patients with aMCI from HCs with a sensitivity of 81.3% and a specificity of 72.2% while cCDT scoring revealed a sensitivity of 62.5% and a specificity of 83.3%. Most interestingly, time-in-air allowed even discrimination of aMCI patients with normal cCDT scores (80% from all aMCI patients) from HCs with a clinically relevant sensitivity of 80.8% and a specificity of 77.8%. A combination of dCDT variables and cCDT scores did not improve the discrimination of patients with aMCI from HC. In conclusion, assessment of time-in-air using dCDT yielded a higher diagnostic accuracy for discrimination of aMCI patients from HCs than the use of cCDT even in those aMCI patients with normal cCDT scores. Modern digitizing devices offer the opportunity

A Novel Field-Deployable Point-of-Care Diagnostic Test for Cutaneous Leishmaniasis

DTIC Science & Technology

2017-10-01

AWARD NUMBER: W81XWH-14-2-0195 TITLE: A Novel Field-Deployable Point-of-Care Diagnostic Test for Cutaneous Leishmaniasis PRINCIPAL INVESTIGATOR...Field-Deployable Point-of-Care Diagnostic Test for Cutaneous Leishmaniasis 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S...Month % completion Aim 1: To use simulated field conditions to optimize and produce the established RPA lateral flow diagnostic test for POC

Further statistics in dentistry, Part 5: Diagnostic tests for oral conditions.

PubMed

Petrie, A; Bulman, J S; Osborn, J F

2002-12-07

A diagnostic test is a simple test, sometimes based on a clinical measurement, which is used when the gold-standard test providing a definitive diagnosis of a given condition is too expensive, invasive or time-consuming to perform. The diagnostic test can be used to diagnose a dental condition in an individual patient or as a screening device in a population of apparently healthy individuals.

More Than Just Accuracy: A Novel Method to Incorporate Multiple Test Attributes in Evaluating Diagnostic Tests Including Point of Care Tests.

PubMed

Thompson, Matthew; Weigl, Bernhard; Fitzpatrick, Annette; Ide, Nicole

2016-01-01

Current frameworks for evaluating diagnostic tests are constrained by a focus on diagnostic accuracy, and assume that all aspects of the testing process and test attributes are discrete and equally important. Determining the balance between the benefits and harms associated with new or existing tests has been overlooked. Yet, this is critically important information for stakeholders involved in developing, testing, and implementing tests. This is particularly important for point of care tests (POCTs) where tradeoffs exist between numerous aspects of the testing process and test attributes. We developed a new model that multiple stakeholders (e.g., clinicians, patients, researchers, test developers, industry, regulators, and health care funders) can use to visualize the multiple attributes of tests, the interactions that occur between these attributes, and their impacts on health outcomes. We use multiple examples to illustrate interactions between test attributes (test availability, test experience, and test results) and outcomes, including several POCTs. The model could be used to prioritize research and development efforts, and inform regulatory submissions for new diagnostics. It could potentially provide a way to incorporate the relative weights that various subgroups or clinical settings might place on different test attributes. Our model provides a novel way that multiple stakeholders can use to visualize test attributes, their interactions, and impacts on individual and population outcomes. We anticipate that this will facilitate more informed decision making around diagnostic tests.

20 CFR 404.1519m - Diagnostic tests or procedures.

Code of Federal Regulations, 2010 CFR

2010-04-01

... DISABILITY INSURANCE (1950- ) Determining Disability and Blindness Standards for the Type of Referral and for Report Content § 404.1519m Diagnostic tests or procedures. We will request the results of any diagnostic..., arteriograms, or cardiac catheterizations for the evaluation of disability under the Social Security program. A...

Computerized Diagnostic Testing: Problems and Possibilities.

ERIC Educational Resources Information Center

McArthur, David L.

The use of computers to build diagnostic inferences is explored in two contexts. In computerized monitoring of liquid oxygen systems for the space shuttle, diagnoses are exact because they can be derived within a world which is closed. In computerized classroom testing of reading comprehension, programs deliver a constrained form of adaptive…

Uptake of prenatal diagnostic testing and the effectiveness of prenatal screening for Down syndrome.

PubMed

Jaques, Alice M; Collins, Veronica R; Muggli, Evelyne E; Amor, David J; Francis, Ivan; Sheffield, Leslie J; Halliday, Jane L

2010-06-01

To map prenatal screening and diagnostic testing pathways in Victorian pregnant women during 2003 to 2004; measure the impact of prenatal diagnostic testing uptake on the effectiveness of prenatal screening for Down syndrome; and assess factors influencing uptake of diagnostic testing following screening. State-wide data collections of prenatal screening and diagnostic tests were linked to all Victorian births and pregnancy terminations for birth defects. Overall, 52% of women had a prenatal test (65 692/126 305); screening (44.9%), diagnostic testing (3.9%), or both (3.2%). Uptake of diagnostic testing was 71.4% (2390/3349) after an increased risk screen result, and 2.5% (1381/54 286) after a low risk result. Variation in uptake of diagnostic testing reduced the effectiveness of the screening program by 11.2%: from 87.4% (sensitivity - 125/143) to 76.2% (prenatal diagnoses of Down syndrome - 109/143). In both the increased and low risk groups, uptake was influenced by absolute numerical risk, as well as by the change in numerical risk from a priori risk. This comprehensive follow-up demonstrates clearly that numerical risk is being used to aid in decision making about confirmatory diagnostic testing. Collectively, these fundamental individual decisions will impact on the overall effectiveness of screening programmes for Down syndrome.

An embedded barcode for "connected" malaria rapid diagnostic tests.

PubMed

Scherr, Thomas F; Gupta, Sparsh; Wright, David W; Haselton, Frederick R

2017-03-29

Many countries are shifting their efforts from malaria control to disease elimination. New technologies will be necessary to meet the more stringent demands of elimination campaigns, including improved quality control of malaria diagnostic tests, as well as an improved means for communicating test results among field healthcare workers, test manufacturers, and national ministries of health. In this report, we describe and evaluate an embedded barcode within standard rapid diagnostic tests as one potential solution. This information-augmented diagnostic test operates on the familiar principles of traditional lateral flow assays and simply replaces the control line with a control grid patterned in the shape of a QR (quick response) code. After the test is processed, the QR code appears on both positive or negative tests. In this report we demonstrate how this multipurpose code can be used not only to fulfill the control line role of test validation, but also to embed test manufacturing details, serve as a trigger for image capture, enable registration for image analysis, and correct for lighting effects. An accompanying mobile phone application automatically captures an image of the test when the QR code is recognized, decodes the QR code, performs image processing to determine the concentration of the malarial biomarker histidine-rich protein 2 at the test line, and transmits the test results and QR code payload to a secure web portal. This approach blends automated, sub-nanomolar biomarker detection, with near real-time reporting to provide quality assurance data that will help to achieve malaria elimination.

Efficient strategies to find diagnostic test accuracy studies in kidney journals.

PubMed

Rogerson, Thomas E; Ladhani, Maleeka; Mitchell, Ruth; Craig, Jonathan C; Webster, Angela C

2015-08-01

Nephrologists looking for quick answers to diagnostic clinical questions in MEDLINE can use a range of published search strategies or Clinical Query limits to improve the precision of their searches. We aimed to evaluate existing search strategies for finding diagnostic test accuracy studies in nephrology journals. We assessed the accuracy of 14 search strategies for retrieving diagnostic test accuracy studies from three nephrology journals indexed in MEDLINE. Two investigators hand searched the same journals to create a reference set of diagnostic test accuracy studies to compare search strategy results against. We identified 103 diagnostic test accuracy studies, accounting for 2.1% of all studies published. The most specific search strategy was the Narrow Clinical Queries limit (sensitivity: 0.20, 95% CI 0.13-0.29; specificity: 0.99, 95% CI 0.99-0.99). Using the Narrow Clinical Queries limit, a searcher would need to screen three (95% CI 2-6) articles to find one diagnostic study. The most sensitive search strategy was van der Weijden 1999 Extended (sensitivity: 0.95; 95% CI 0.89-0.98; specificity 0.55, 95% CI 0.53-0.56) but required a searcher to screen 24 (95% CI 23-26) articles to find one diagnostic study. Bachmann 2002 was the best balanced search strategy, which was sensitive (0.88, 95% CI 0.81-0.94), but also specific (0.74, 95% CI 0.73-0.75), with a number needed to screen of 15 (95% CI 14-17). Diagnostic studies are infrequently published in nephrology journals. The addition of a strategy for diagnostic studies to a subject search strategy in MEDLINE may reduce the records needed to screen while preserving adequate search sensitivity for routine clinical use. © 2015 Asian Pacific Society of Nephrology.

Interactive visualisation for interpreting diagnostic test accuracy study results.

PubMed

Fanshawe, Thomas R; Power, Michael; Graziadio, Sara; Ordóñez-Mena, José M; Simpson, John; Allen, Joy

2018-02-01

Information about the performance of diagnostic tests is typically presented in the form of measures of test accuracy such as sensitivity and specificity. These measures may be difficult to translate directly into decisions about patient treatment, for which information presented in the form of probabilities of disease after a positive or a negative test result may be more useful. These probabilities depend on the prevalence of the disease, which is likely to vary between populations. This article aims to clarify the relationship between pre-test (prevalence) and post-test probabilities of disease, and presents two free, online interactive tools to illustrate this relationship. These tools allow probabilities of disease to be compared with decision thresholds above and below which different treatment decisions may be indicated. They are intended to help those involved in communicating information about diagnostic test performance and are likely to be of benefit when teaching these concepts. A substantive example is presented using C reactive protein as a diagnostic marker for bacterial infection in the older adult population. The tools may also be useful for manufacturers of clinical tests in planning product development, for authors of test evaluation studies to improve reporting and for users of test evaluations to facilitate interpretation and application of the results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Does Diagnostic Classification of Early-Onset Psychosis Change over Follow-Up?

ERIC Educational Resources Information Center

Fraguas, David; de Castro, Maria J.; Medina, Oscar; Parellada, Mara; Moreno, Dolores; Graell, Montserrat; Merchan-Naranjo, Jessica; Arango, Celso

2008-01-01

Objective: To examine the diagnostic stability and the functional outcome of patients with early-onset psychosis (EOP) over a 2-year follow-up period. Methods: A total of 24 patients (18 males (75%) and 6 females (25%), mean age [plus or minus] SD: 15.7 [plus or minus] 1.6 years) with a first episode of EOP formed the sample. Psychotic symptoms…

Network meta-analysis of diagnostic test accuracy studies identifies and ranks the optimal diagnostic tests and thresholds for health care policy and decision-making.

PubMed

Owen, Rhiannon K; Cooper, Nicola J; Quinn, Terence J; Lees, Rosalind; Sutton, Alex J

2018-07-01

Network meta-analyses (NMA) have extensively been used to compare the effectiveness of multiple interventions for health care policy and decision-making. However, methods for evaluating the performance of multiple diagnostic tests are less established. In a decision-making context, we are often interested in comparing and ranking the performance of multiple diagnostic tests, at varying levels of test thresholds, in one simultaneous analysis. Motivated by an example of cognitive impairment diagnosis following stroke, we synthesized data from 13 studies assessing the efficiency of two diagnostic tests: Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA), at two test thresholds: MMSE <25/30 and <27/30, and MoCA <22/30 and <26/30. Using Markov chain Monte Carlo (MCMC) methods, we fitted a bivariate network meta-analysis model incorporating constraints on increasing test threshold, and accounting for the correlations between multiple test accuracy measures from the same study. We developed and successfully fitted a model comparing multiple tests/threshold combinations while imposing threshold constraints. Using this model, we found that MoCA at threshold <26/30 appeared to have the best true positive rate, whereas MMSE at threshold <25/30 appeared to have the best true negative rate. The combined analysis of multiple tests at multiple thresholds allowed for more rigorous comparisons between competing diagnostics tests for decision making. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Characterization of the Goubau line for testing beam diagnostic instruments

NASA Astrophysics Data System (ADS)

Kim, S. Y.; Stulle, F.; Sung, C. K.; Yoo, K. H.; Seok, J.; Moon, K. J.; Choi, C. U.; Chung, Y.; Kim, G.; Woo, H. J.; Kwon, J.; Lee, I. G.; Choi, E. M.; Chung, M.

2017-12-01

One of the main characteristics of the Goubau line is that it supports a low-loss, non-radiated surface wave guided by a dielectric-coated metal wire. The dominant mode of the surface wave along the Goubau line is a TM01 mode, which resembles the pattern of the electromagnetic fields induced in the metallic beam pipe when the charged particle beam passes through it. Therefore, the Goubau line can be used for the preliminary bench test and performance optimization of the beam diagnostic instruments without requiring charged particle beams from the accelerators. In this paper, we discuss the basic properties of the Goubau line for testing beam diagnostic instruments and present the initial test results for button-type beam position monitors (BPMs). The experimental results are consistent with the theoretical estimations, which indicates that Goubau line allows effective testing of beam diagnostic equipment.

Better Tests, Better Care: Improved Diagnostics for Infectious Diseases

PubMed Central

Caliendo, Angela M.; Gilbert, David N.; Ginocchio, Christine C.; Hanson, Kimberly E.; May, Larissa; Quinn, Thomas C.; Tenover, Fred C.; Alland, David; Blaschke, Anne J.; Bonomo, Robert A.; Carroll, Karen C.; Ferraro, Mary Jane; Hirschhorn, Lisa R.; Joseph, W. Patrick; Karchmer, Tobi; MacIntyre, Ann T.; Reller, L. Barth; Jackson, Audrey F.

2013-01-01

In this IDSA policy paper, we review the current diagnostic landscape, including unmet needs and emerging technologies, and assess the challenges to the development and clinical integration of improved tests. To fulfill the promise of emerging diagnostics, IDSA presents recommendations that address a host of identified barriers. Achieving these goals will require the engagement and coordination of a number of stakeholders, including Congress, funding and regulatory bodies, public health agencies, the diagnostics industry, healthcare systems, professional societies, and individual clinicians. PMID:24200831

Diagnostic value of the plasmatic ADM level for early ectopic pregnancy.

PubMed

Yan, Qi; Lu, Qi; Tao, Yu; Wang, Yu-Dong; Zhao, Wen-Xia

2015-01-01

To analyze the plasmatic ADM level in early pregnancy and to investigate the diagnostic value of ADM in early ectopic pregnancy (EP). 70 patients with EP who had menopause for 5~8 weeks were included as study group, while 155 women with normal intrauterine pregnancy were also included as control group. The correlation between ADM level and menopause weeks was statistically analyzed and ROC curve was used to identify the diagnostic value of ADM. (1) In 155 cases of normal intrauterine pregnancy, the plasmatic ADM level was increased with menopause weeks in linear relationship, and the correlation coefficient (R) was 0.991 (P<0.05). In 70 patients with EP, no significant increase was found with menopause weeks and no linear relationship can be found between ADM level and menopause weeks in EP group. The correlation coefficient (R) was 0.744 (P>0.05). (2) The multiple of median of plasmatic ADM level in EP group of menopause for 8 weeks was obviously lower than the intrauterine control group (P<0.01). (3) ROC curve was used to analyze the cut-off value of ADM level in the diagnosis of EP, and the area under the ROC curve was 0.523 (P>0.05) regardless of menopause weeks, however, the area under the ROC curve was 0.702 (P<0.05) at 8 weeks after menopause with sensitivity of 53.50% and specificity of 85.00%. Different from normal intrauterine pregnancy, plasmatic ADM level in early EP was relatively lower and no significant increase was found with menopause weeks; further studies are still needed for plasmatic ADM level as an indicator in the early diagnosis of EP.

Rapid antigen detection test for respiratory syncytial virus diagnosis as a diagnostic tool.

PubMed

Mesquita, Flávio da Silva; Oliveira, Danielle Bruna Leal de; Crema, Daniela; Pinez, Célia Miranda Nunes; Colmanetti, Thaís Cristina; Thomazelli, Luciano Matsumia; Gilio, Alfredo Elias; Vieira, Sandra Elisabeth; Martinez, Marina Baquerizo; Botosso, Viviane Fongaro; Durigon, Edison Luiz

The aim of this study was to evaluate the QuickVue ® RSV Test Kit (QUIDEL Corp, CA, USA) as a screening tool for respiratory syncytial virus in children with acute respiratory disease in comparison with the indirect immunofluorescence assay as gold standard. In Brazil, rapid antigen detection tests for respiratory syncytial virus are not routinely utilized as a diagnostic tool, except for the diagnosis of dengue and influenza. The authors retrospectively analyzed 486 nasopharyngeal aspirate samples from children under age 5 with acute respiratory infection, between December 2013 and August 2014, the samples were analyzed by indirect immunofluorescence assay and QuickVue ® RSV Test kit. Samples with discordant results were analyzed by real time PCR and nucleotide sequencing. From 313 positive samples by immunofluorescence assays, 282 (90%) were also positive by the rapid antigen detection test, two were positive only by rapid antigen detection test, 33 were positive only by immunofluorescence assays, and 171 were positive by both methods. The 35 samples with discordant results were analyzed by real time PCR; the two samples positive only by rapid antigen detection test and the five positive only by immunofluorescence assays were also positive by real time PCR. There was no relation between the negativity by QuickVue ® RSV Test and viral load or specific strain. The QuickVue ® RSV Test showed sensitivity of 90%, specificity of 98.8%, predictive positive value of 99.3%, and negative predictive value of 94.6%, with accuracy of 93.2% and agreement κ index of 0.85 in comparison to immunofluorescence assay. This study demonstrated that the QuickVue ® RSV Test Kit can be effective in early detection of Respiratory syncytial virus in nasopharyngeal aspirate and is reliable for use as a diagnostic tool in pediatrics. Copyright © 2016 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

Combination of fluorescence imaging and local spectrophotometry in fluorescence diagnostics of early cancer of larynx and bronchi

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sokolov, Vladimir V; Filonenko, E V; Telegina, L V

2002-11-30

The results of comparative studies of autofluorescence and 5-ALA-induced fluorescence of protoporphyrin IX, used in the diagnostics of early cancer of larynx and bronchi, are presented. The autofluorescence and 5-ALA-induced fluorescence images of larynx and bronchial tissues are analysed during the endoscopic study. The method of local spectrophotometry is used to verify findings obtained from fluorescence images. It is shown that such a combined approach can be efficiently used to improve the diagnostics of precancer and early cancer, to detect a primary multiple tumours, as well as for the diagnostics of a residual tumour or an early recurrence after themore » endoscopic, surgery or X-ray treatment. The developed approach allows one to minimise the number of false-positive results and to reduce the number of biopsies, which are commonly used in the white-light bronchoscopy search for occult cancerous loci. (laser biology and medicine)« less

Diagnostic Testing Package DX v 2.0 Technical Specification. Methodology Project.

ERIC Educational Resources Information Center

McArthur, David

This paper contains the technical specifications, schematic diagrams, and program printout for a computer software package for the development and administration of diagnostic tests. The second version of the Diagnostic Testing Package DX consists of a PASCAL-based set of modules located in two main programs: (1) EDITTEST creates, modifies, and…

Using Standardized Diagnostic Instruments to Classify Children with Autism in the Study to Explore Early Development

ERIC Educational Resources Information Center

Wiggins, Lisa D.; Reynolds, Ann; Rice, Catherine E.; Moody, Eric J.; Bernal, Pilar; Blaskey, Lisa; Rosenberg, Steven A.; Lee, Li-Ching; Levy, Susan E.

2015-01-01

The Study to Explore Early Development (SEED) is a multi-site case-control study designed to explore the relationship between autism spectrum disorder (ASD) phenotypes and etiologies. The goals of this paper are to (1) describe the SEED algorithm that uses the Autism Diagnostic Interview-Revised (ADI-R) and Autism Diagnostic Observation Schedule…

Development of diagnostic test instruments to reveal level student conception in kinematic and dynamics

NASA Astrophysics Data System (ADS)

Handhika, J.; Cari, C.; Suparmi, A.; Sunarno, W.; Purwandari, P.

2018-03-01

The purpose of this research was to develop a diagnostic test instrument to reveal students' conceptions in kinematics and dynamics. The diagnostic test was developed based on the content indicator the concept of (1) displacement and distance, (2) instantaneous and average velocity, (3) zero and constant acceleration, (4) gravitational acceleration (5) Newton's first Law, (6) and Newton's third Law. The diagnostic test development model includes: Diagnostic test requirement analysis, formulating test-making objectives, developing tests, checking the validity of the content and the performance of reliability, and application of tests. The Content Validation Index (CVI) results in the category are highly relevant, with a value of 0.85. Three questions get negative Content Validation Ratio CVR) (-0.6), after revised distractors and clarify visual presentation; the CVR become 1 (highly relevant). This test was applied, obtained 16 valid test items, with Cronbach Alpha value of 0.80. It can conclude that diagnostic test can be used to reveal the level of students conception in kinematics and dynamics.

Rapid diagnostic tests for typhoid and paratyphoid (enteric) fever

PubMed Central

Wijedoru, Lalith; Mallett, Sue; Parry, Christopher M

2017-01-01

Background Differentiating both typhoid (Salmonella Typhi) and paratyphoid (Salmonella Paratyphi A) infection from other causes of fever in endemic areas is a diagnostic challenge. Although commercial point-of-care rapid diagnostic tests (RDTs) for enteric fever are available as alternatives to the current reference standard test of blood or bone marrow culture, or to the widely used Widal Test, their diagnostic accuracy is unclear. If accurate, they could potentially replace blood culture as the World Health Organization (WHO)-recommended main diagnostic test for enteric fever. Objectives To assess the diagnostic accuracy of commercially available rapid diagnostic tests (RDTs) and prototypes for detecting Salmonella Typhi or Paratyphi A infection in symptomatic persons living in endemic areas. Search methods We searched the Cochrane Infectious Diseases Group Specialized Register, MEDLINE, Embase, Science Citation Index, IndMED, African Index Medicus, LILACS, ClinicalTrials.gov, and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) up to 4 March 2016. We manually searched WHO reports, and papers from international conferences on Salmonella infections. We also contacted test manufacturers to identify studies. Selection criteria We included diagnostic accuracy studies of enteric fever RDTs in patients with fever or with symptoms suggestive of enteric fever living in endemic areas. We classified the reference standard used as either Grade 1 (result from a blood culture and a bone marrow culture) or Grade 2 (result from blood culture and blood polymerase chain reaction, or from blood culture alone). Data collection and analysis Two review authors independently extracted the test result data. We used a modified QUADAS-2 extraction form to assess methodological quality. We performed a meta-analysis when there were sufficient studies for the test and heterogeneity was reasonable. Main results Thirty-seven studies met the inclusion

Compare diagnostic tests using transformation-invariant smoothed ROC curves⋆

PubMed Central

Tang, Liansheng; Du, Pang; Wu, Chengqing

2012-01-01

Receiver operating characteristic (ROC) curve, plotting true positive rates against false positive rates as threshold varies, is an important tool for evaluating biomarkers in diagnostic medicine studies. By definition, ROC curve is monotone increasing from 0 to 1 and is invariant to any monotone transformation of test results. And it is often a curve with certain level of smoothness when test results from the diseased and non-diseased subjects follow continuous distributions. Most existing ROC curve estimation methods do not guarantee all of these properties. One of the exceptions is Du and Tang (2009) which applies certain monotone spline regression procedure to empirical ROC estimates. However, their method does not consider the inherent correlations between empirical ROC estimates. This makes the derivation of the asymptotic properties very difficult. In this paper we propose a penalized weighted least square estimation method, which incorporates the covariance between empirical ROC estimates as a weight matrix. The resulting estimator satisfies all the aforementioned properties, and we show that it is also consistent. Then a resampling approach is used to extend our method for comparisons of two or more diagnostic tests. Our simulations show a significantly improved performance over the existing method, especially for steep ROC curves. We then apply the proposed method to a cancer diagnostic study that compares several newly developed diagnostic biomarkers to a traditional one. PMID:22639484

A comparison of early diagnostic utility of Alzheimer disease biomarkers in brain magnetic resonance and cerebrospinal fluid.

PubMed

Monge Argilés, J A; Blanco Cantó, M A; Leiva Salinas, C; Flors, L; Muñoz Ruiz, C; Sánchez Payá, J; Gasparini Berenguer, R; Leiva Santana, C

2014-09-01

The goals of this study were to compare the early diagnostic utility of Alzheimer disease biomarkers in the CSF with those in brain MRI in conditions found in our clinical practice, and to ascertain the diagnostic accuracy of both techniques used together. Between 2008 and 2009, we included 30 patients with mild cognitive impairment (MCI) who were examined using 1.5 Tesla brain MRI and AD biomarker analysis in CSF. MRI studies were evaluated by 2 radiologists according to the Korf́s visual scale. CSF biomarkers were analysed using INNOTEST reagents for Aβ1-42, total-tau and phospho-tau181p. We evaluated clinical changes 2 years after inclusion. By 2 years after inclusion, 15 of the original 30 patients (50%) had developed AD (NINCDS-ADRA criteria). The predictive utility of AD biomarkers in CSF (RR 2.7; 95% CI, 1.1-6.7; P<.01) was greater than that of MRI (RR 1.5; 95% CI 95%, 0.7-3.4; P<.2); using both techniques together yielded a sensitivity and a negative predictive value of 100%. Normal results on both complementary tests ruled out progression to AD (100%) within 2 years of inclusion. Our results show that the diagnostic accuracy of biomarkers in CSF is higher than that of biomarkers in MRI. Combined use of both techniques is highly accurate for either early diagnosis or exclusion of AD in patients with MCI. Copyright © 2013 Sociedad Española de Neurología. Published by Elsevier Espana. All rights reserved.

Comprehensive Carrier Screening and Molecular Diagnostic Testing for Recessive Childhood Diseases

PubMed Central

Kingsmore, Stephen

2012-01-01

Of 7,028 disorders with suspected Mendelian inheritance, 1,139 are recessive and have an established molecular basis. Although individually uncommon, Mendelian diseases collectively account for ~20% of infant mortality and ~18% of pediatric hospitalizations. Molecular diagnostic testing is currently available for only ~300 recessive disorders. Preconception screening, together with genetic counseling of carriers, has resulted in remarkable declines in the incidence of several severe recessive diseases including Tay-Sachs disease and cystic fibrosis. However, extension of preconception screening and molecular diagnostic testing to most recessive disease genes has hitherto been impractical. Recently, we reported a preconception carrier screen / molecular diagnostic test for 448 recessive childhood diseases. The current status of this test is reviewed here. Currently, this reports analytical validity of the comprehensive carrier test. As the clinical validity and clinical utility in the contexts described is ascertained, this article will be updated. PMID:22872815

30 CFR 250.525 - What do I submit if my casing diagnostic test requires action?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 2 2011-07-01 2011-07-01 false What do I submit if my casing diagnostic test... if my casing diagnostic test requires action? Within 14 days after you perform a casing diagnostic... Corrective Action Plan within 30 days of the diagnostic test. (b) a casing pressure request, Regional...

Diagnostic methods for CW laser damage testing

NASA Astrophysics Data System (ADS)

Stewart, Alan F.; Shah, Rashmi S.

2004-06-01

High performance optical coatings are an enabling technology for many applications - navigation systems, telecom, fusion, advanced measurement systems of many types as well as directed energy weapons. The results of recent testing of superior optical coatings conducted at high flux levels will be presented. The diagnostics used in this type of nondestructive testing and the analysis of the data demonstrates the evolution of test methodology. Comparison of performance data under load to the predictions of thermal and optical models shows excellent agreement. These tests serve to anchor the models and validate the performance of the materials and coatings.

Diagnostic efficacy of microscopy, rapid diagnostic test and polymerase chain reaction for malaria using bayesian latent class analysis.

PubMed

Saha, Sreemanti; Narang, Rahul; Deshmukh, Pradeep; Pote, Kiran; Anvikar, Anup; Narang, Pratibha

2017-01-01

The diagnostic techniques for malaria are undergoing a change depending on the availability of newer diagnostics and annual parasite index of infection in a particular area. At the country level, guidelines are available for selection of diagnostic tests; however, at the local level, this decision is made based on malaria situation in the area. The tests are evaluated against the gold standard, and if that standard has limitations, it becomes difficult to compare other available tests. Bayesian latent class analysis computes its internal standard rather than using the conventional gold standard and helps comparison of various tests including the conventional gold standard. In a cross-sectional study conducted in a tertiary care hospital setting, we have evaluated smear microscopy, rapid diagnostic test (RDT), and polymerase chain reaction (PCR) for diagnosis of malaria using Bayesian latent class analysis. We found the magnitude of malaria to be 17.7% (95% confidence interval: 12.5%-23.9%) among the study subjects. In the present study, the sensitivity of microscopy was 63%, but it had very high specificity (99.4%). Sensitivity and specificity of RDT and PCR were high with RDT having a marginally higher sensitivity (94% vs. 90%) and specificity (99% vs. 95%). On comparison of likelihood ratios (LRs), RDT had the highest LR for positive test result (175) and the lowest LR for negative test result (0.058) among the three tests. In settings like ours conventional smear microscopy may be replaced with RDT and as we move toward elimination and facilities become available PCR may be roped into detect cases with lower parasitaemia.

Endoscopic fluorescent diagnostics and PDT of early malignancies of lung and esophagus

NASA Astrophysics Data System (ADS)

Sokolov, Victor V.; Chissov, Valery I.; Trakhtenberg, A. K.; Mamontov, A. S.; Frank, George A.; Filonenko, E. V.; Telegina, L. V.; Gladunov, V. K.; Belous, T. A.; Aristarkhova, E. I.; Zharkova, Natalia N.; Smirnov, V. V.; Kozlov, Dmitrij N.

1996-01-01

In this paper the results of fluorescence diagnostics and photodynamic therapy of early stage malignancies of lung (17 patients) and esophagus (8 patients) are presented. 13 patients had multiple primary tumors. As photosensitizers the new drugs Photoheme and Photosense were used. Complete remission was obtained in 92%. The patients are followed up without relapses to 2,5 years.

42 CFR 410.32 - Diagnostic x-ray tests, diagnostic laboratory tests, and other diagnostic tests: Conditions.

Code of Federal Regulations, 2014 CFR

2014-10-01

.... Nonphysician practitioners (that is, clinical nurse specialists, clinical psychologists, clinical social... that do not involve the use of contrast media; and (iii) Diagnostic mammograms if the approved portable...

Background review for diagnostic test development for Zika virus infection.

PubMed

Charrel, Rémi N; Leparc-Goffart, Isabelle; Pas, Suzan; de Lamballerie, Xavier; Koopmans, Marion; Reusken, Chantal

2016-08-01

To review the state of knowledge about diagnostic testing for Zika virus infection and identify areas of research needed to address the current gaps in knowledge. We made a non-systematic review of the published literature about Zika virus and supplemented this with information from commercial diagnostic test kits and personal communications with researchers in European preparedness networks. The review covered current knowledge about the geographical spread, pathogen characteristics, life cycle and infection kinetics of the virus. The available molecular and serological tests and biosafety issues are described and discussed in the context of the current outbreak strain. We identified the following areas of research to address current knowledge gaps: (i) an urgent assessment of the laboratory capacity and capability of countries to detect Zika virus; (ii) rapid and extensive field validation of the available molecular and serological tests in areas with and without Zika virus transmission, with a focus on pregnant women; (iii) monitoring the genomic diversity of circulating Zika virus strains; (iv) prospective studies into the virus infection kinetics, focusing on diagnostic sampling (specimen types, combinations and timings); and (v) developing external quality assessments for molecular and serological testing, including differential diagnosis for similar viruses and symptom clusters. The availability of reagents for diagnostic development (virus strains and antigens, quantified viral ribonucleic acid) needs to be facilitated. An international laboratory response is needed, including preparation of protocols for prospective studies to address the most pressing information needs.

Simple Sample Processing Enhances Malaria Rapid Diagnostic Test Performance

PubMed Central

Davis, K. M.; Gibson, L. E.; Haselton, F. R.; Wright, D. W.

2016-01-01

Lateral flow immunochromatographic rapid diagnostic tests (RDTs) are the primary form of medical diagnostic used for malaria in underdeveloped nations. Unfortunately, many of these tests do not detect asymptomatic malaria carriers. In order for eradication of the disease to be achieved, this problem must be solved. In this study, we demonstrate enhancement in the performance of six RDT brands when a simple sample-processing step is added to the front of the diagnostic process. Greater than a 4-fold RDT signal enhancement was observed as a result of the sample processing step. This lowered the limit of detection for RDT brands to submicroscopic parasitemias. For the best performing RDTs the limits of detection were found to be as low as 3 parasites/μL. Finally, through individual donor samples, the correlations between donor source, WHO panel detection scores and RDT signal intensities were explored. PMID:24787948

Simple sample processing enhances malaria rapid diagnostic test performance.

PubMed

Davis, K M; Gibson, L E; Haselton, F R; Wright, D W

2014-06-21

Lateral flow immunochromatographic rapid diagnostic tests (RDTs) are the primary form of medical diagnostic used for malaria in underdeveloped nations. Unfortunately, many of these tests do not detect asymptomatic malaria carriers. In order for eradication of the disease to be achieved, this problem must be solved. In this study, we demonstrate enhancement in the performance of six RDT brands when a simple sample-processing step is added to the front of the diagnostic process. Greater than a 4-fold RDT signal enhancement was observed as a result of the sample processing step. This lowered the limit of detection for RDT brands to submicroscopic parasitemias. For the best performing RDTs the limits of detection were found to be as low as 3 parasites per μL. Finally, through individual donor samples, the correlations between donor source, WHO panel detection scores and RDT signal intensities were explored.

Plasma levels and diagnostic utility of VEGF, MMP-2 and TIMP-2 in the diagnostics of breast cancer patients.

PubMed

Ławicki, Sławomir; Zajkowska, Monika; Głażewska, Edyta Katarzyna; Będkowska, Grażyna Ewa; Szmitkowski, Maciej

2017-03-01

We investigated plasma levels and diagnostic utility of vascular endothelial growth factor VEGF, matrix metalloproteinase-2 (MMP-2) and tissue inhibitors of metalloproteinase-2 (TIMP-2) in comparison to cancer antigen 15-3 (CA 15-3). Plasma levels of tested parameters were determined using enzyme-linked immunosorbent assay (ELISA) while CA 15-3 with chemiluminescent microparticle immunoassay (CMIA). The plasma levels of VEGF, TIMP-2 showed significantly higher than CA 15-3 values of the diagnostic sensitivity, the predictive values of positive and negative test results (PPV, NPV) and the area under the receiver-operating characteristics (ROC) curve (AUC) in early stages of breast cancer (BC). The combined use of the tested parameters with CA 15-3 resulted in the increase in sensitivity, NPV and AUC, especially in the combination with VEGF (83%; 72%; 0.888) and TIMP-2 (83%; 72%; 0.894). The highest values were obtained for combination of all three parameters (93%; 85%; 0.923). These findings suggest the usefulness of the tested parameters in the diagnosis of BC, especially VEGF and TIMP-2 with CA 15-3 in early stages of BC, which could be a new diagnostic panel.

Laboratory development and testing of spacecraft diagnostics

NASA Astrophysics Data System (ADS)

Amatucci, William; Tejero, Erik; Blackwell, Dave; Walker, Dave; Gatling, George; Enloe, Lon; Gillman, Eric

2017-10-01

The Naval Research Laboratory's Space Chamber experiment is a large-scale laboratory device dedicated to the creation of large-volume plasmas with parameters scaled to realistic space plasmas. Such devices make valuable contributions to the investigation of space plasma phenomena under controlled, reproducible conditions, allowing for the validation of theoretical models being applied to space data. However, in addition to investigations such as plasma wave and instability studies, such devices can also make valuable contributions to the development and testing of space plasma diagnostics. One example is the plasma impedance probe developed at NRL. Originally developed as a laboratory diagnostic, the sensor has now been flown on a sounding rocket, is included on a CubeSat experiment, and will be included on the DoD Space Test Program's STP-H6 experiment on the International Space Station. In this talk, we will describe how the laboratory simulation of space plasmas made this development path possible. Work sponsored by the US Naval Research Laboratory Base Program.

Sweat conductivity: an accurate diagnostic test for cystic fibrosis?

PubMed

Mattar, Ana Claudia Veras; Leone, Claudio; Rodrigues, Joaquim Carlos; Adde, Fabíola Villac

2014-09-01

Sweat chloride test is the gold standard test for cystic fibrosis (CF) diagnosis. Sweat conductivity is widely used although still considered a screening test. This was a prospective, cross-sectional, diagnostic research conducted at the laboratory of the Instituto da Criança of the Hospital das Clínicas, São Paulo, Brazil. Sweat chloride (quantitative pilocarpine iontophoresis) and sweat conductivity tests were simultaneously performed in patients referred for a sweat test between March 2007 and October 2008. Conductivity and chloride cut-off values used to rule out or diagnose CF were <75 and ≥90 mmol/L and <60 and ≥60 mmol/L, respectively. The ROC curve method was used to calculate the sensitivity, specificity, positive (PPV) and negative predictive value (NPV), as well as the respective 95% confidence intervals and to calculate the area under the curve for both tests. The kappa coefficient was used to evaluate agreement between the tests. Both tests were performed in 738 children, and CF was ruled out in 714 subjects; the median sweat chloride and conductivity values were 11 and 25 mmol/L in these populations, respectively. Twenty-four patients who had received a diagnosis of CF presented median sweat chloride and conductivity values of 87 and 103 mmol/L, respectively. Conductivity values above 90 mmol/L had 83.3% sensitivity, 99.7% specificity, 90.9% PPV and 99.4% NPV to diagnose CF. The best conductivity cut-off value to exclude CF was <75 mmol/L. Good agreement was observed between the tests (kappa: 0.934). The sweat conductivity test yielded a high degree of diagnostic accuracy and it showed good agreement with sweat chloride. We suggest that it should play a role as a diagnostic test for CF in the near future. Copyright © 2014 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

The demand for pregnancy testing: The Aschheim–Zondek reaction, diagnostic versatility, and laboratory services in 1930s Britain

PubMed Central

Olszynko-Gryn, Jesse

2014-01-01

The Aschheim–Zondek reaction is generally regarded as the first reliable hormone test for pregnancy and as a major product of the ‘heroic age’ of reproductive endocrinology. Invented in Berlin in the late 1920s, by the mid 1930s a diagnostic laboratory in Edinburgh was performing thousands of tests every year for doctors around Britain. In her classic history of antenatal care, sociologist Ann Oakley claimed that the Aschheim–Zondek test launched a ‘modern era’ of obstetric knowledge, which asserted its superiority over that of pregnant women. This article reconsiders Oakley’s claim by examining how pregnancy testing worked in practice. It explains the British adoption of the test in terms less of the medicalisation of pregnancy than of clinicians’ increasing general reliance on laboratory services for differential diagnosis. Crucially, the Aschheim–Zondek reaction was a test not directly for the fetus, but for placental tissue. It was used, less as a yes-or-no test for ordinary pregnancy, than as a versatile diagnostic tool for the early detection of malignant tumours and hormonal deficiencies believed to cause miscarriage. This test was as much a product of oncology and the little-explored world of laboratory services as of reproductive medicine. PMID:24388014

Clinical features of pathologic childhood aerophagia: early recognition and essential diagnostic criteria.

PubMed

Hwang, Jin-Bok; Choi, Won Joung; Kim, Jun Sik; Lee, Sang Yun; Jung, Chul-Ho; Lee, Young Hwan; Kam, Sin

2005-11-01

This study investigated the early recognition and diagnosis of pathologic childhood aerophagia to avoid unnecessary diagnostic approaches and serious complications. Between 1995 and 2003, data from 42 consecutive patients with pathologic childhood aerophagia, aged 2 to 16 years, were reviewed. An esophageal air sign was defined as an abnormal air shadow on the proximal esophagus adjacent to the trachea on a full-inflated chest radiograph. Of the 42 patients, the chief complaints were abdominal distention (52.4%), recurrent abdominal pain syndrome (21.4%), chronic diarrhea (11.9%), acute abdominal pain (7.1%) and others (7.2%). Mean symptom duration before diagnosis was 10.6 months (range, 1 to 60 months), and it exceeded 12 months for 16 (38.1%) patients. The clinical features common to all patients were abdominal distention that increased progressively during the day, increased flatus on sleep, increased bowel sound on auscultation and an air-distended stomach with increased gas in the small and large bowel by radiography. Visible or audible air swallowing (26.2%) and repetitive belching (9.5%) were also noted. Esophageal air sign was observed in 76.2% of the patients and in 9.7% of the controls (P=0.0001). The subgroups of pathologic childhood aerophagia divided by underlying associations were pathologic childhood aerophagia without severe mental retardation (76.2%), which consisted of psychological stresses and uncertain condition, and pathologic childhood aerophagia with severe mental retardation (23.8%). The common manifestations of pathologic childhood aerophagia may be its essential diagnostic criteria, and esophageal air sign may be useful for the early recognition of pathologic childhood aerophagia. Our observations show that the diagnostic clinical profiles suggested by Rome II criteria should be detailed and made clearer if they are to serve as diagnostic criteria for pathologic childhood aerophagia.

Unirhinal Olfactory Testing for the Diagnostic Workup of Mild Cognitive Impairment.

PubMed

Huart, Caroline; Rombaux, Philippe; Gérard, Thomas; Hanseeuw, Bernard; Lhommel, Renaud; Quenon, Lisa; Ivanoiu, Adrian; Mouraux, André

2015-01-01

Olfactory dysfunction is associated with Alzheimer's disease (AD), and already present at pre-dementia stage. Based on the assumption that early neurodegeneration in AD is asymmetrical and that olfactory input is primarily processed in the ipsilateral hemisphere, we assessed whether unirhinal psychophysical and electrophysiological assessment of olfactory function can contribute to the diagnostic workup of mild cognitive impairment (MCI). Olfactory function of 13 MCI patients with positive amyloid PET, 13 aged-matched controls (AC) with negative amyloid PET and 13 patients with post-infectious olfactory loss (OD) was assessed unirhinally using (1) psychophysical testing of olfactory detection, discrimination and identification performance and (2) the recording of olfactory event-related brain potentials. Time-frequency analysis was used to enhance the signal-to-noise ratio of the electrophysiological responses. Psychophysical and electrophysiological assessment of auditory and trigeminal chemosensory function served as controls. As compared to AC and OD, MCI patients exhibited a significant asymmetry of olfactory performance. This asymmetry efficiently discriminated between MCI and AC (sensitivity: 85% , specificity: 77% ), as well as MCI and OD (sensitivity: 85% , specificity: 70% ). There was also an asymmetry of the electrophysiological responses, but not specific for MCI. In both MCI and OD, olfactory stimulation of the best nostril elicited significantly more activity than stimulation of the worse nostril, between 3-7.5 Hz and 1.2-2.0 s after stimulus onset. Trigeminal and auditory psychophysical testing did not show any difference between groups. MCI patients exhibit a marked asymmetry of behavioral olfactory function, which could be useful for the diagnostic workup of MCI.

Assessment of demand for prenatal diagnostic testing using willingness to pay.

PubMed

Caughey, Aaron B; Washington, A Eugene; Gildengorin, Virginia; Kuppermann, Miriam

2004-03-01

To investigate the demand for invasive prenatal diagnostic testing (amniocentesis and chorionic villous sampling) in a racially/ethnically diverse group of pregnant women of all ages in the San Francisco Bay Area by using estimates of willingness to pay for these procedures. We surveyed 447 women of varying ages, ethnicity, and socioeconomic levels to assess their desire to undergo and willingness to pay for invasive prenatal testing for chromosomal disorders. Each woman was asked what she would be willing to pay for invasive diagnostic testing up to the full cost of the procedure. We also asked several demographic and attitudinal questions. Overall, 49% of the women indicated an interest in undergoing invasive prenatal diagnostic testing. Women aged 35 years and older were more likely to desire testing as compared with women aged less than 35 years (72% versus 36%, P <.001). Of the women aged less than 35 years who desired testing, 31% indicated that they would be willing to pay the full price of $1,300, whereas 73% were willing to pay a portion of the cost. Maternal age of 35 years or greater (odds ratio [OR] 3.3; 95% confidence interval [CI] 2.0, 5.6) and willingness to have an elective abortion (OR 2.8; 95% CI 1.6, 4.9) were significant predictors of desire to undergo prenatal diagnostic testing after controlling for income, race/ethnicity, and education. Maternal age of 35 years or greater (OR 3.5; 95% CI 1.59, 7.88) and having an income greater than $35,000 (OR 2.3; 95% CI 1.02, 5.26) were significant predictors of willingness to pay the full price of testing. A substantial proportion of women of all ages indicate a desire to undergo and a willingness to pay for prenatal diagnostic testing. Variations in willingness to pay are correlated with both socioeconomic and attitudinal differences in addition to age. Guidelines regarding use of prenatal genetic diagnosis should be expanded to offer testing to all women, not just those deemed at increased risk. II-2

Diagnostic performance of a rapid in-clinic test for the detection of Canine Parvovirus under different storage conditions and vaccination status.

PubMed

Kantere, Maria C; Athanasiou, Labrini V; Spyrou, Vassiliki; Kyriakis, Constantinos S; Kontos, Vassilios; Chatzopoulos, Dimitrios C; Tsokana, Constantina N; Billinis, Charalambos

2015-04-01

Canine parvovirus (CPV) is one of the most common causes of acute haemorrhagic enteritis in young dogs, while clinical diagnosis is often indecisive. The aim of our study was to evaluate the diagnostic accuracy of an in-clinic rapid test in the detection of CPV infection in dogs. To this end, we compared the Rapid Diagnostic Kit of Canine Parvovirus, Coronavirus and Rotavirus antigen (Quicking(®)) to PCR, which is considered as the most reliable diagnostic method. A total of 78 duplicated faecal samples were collected from diarrhoeic dogs. Vaccination history within a month prior to the onset of diarrhoea was reported for 12 of the sampled dogs. The rapid diagnostic test was performed in 23 of the faecal samples directly, while the rest were placed into a sterile cotton tipped swab suitable for collection and transportation of viruses (Sigma Σ-VCM(®)) and stored at -20 °C. The sensitivity of the Quicking rapid diagnostic test compared to PCR in the total number of samples, in samples from non-vaccinated dogs and in samples tested directly after collection were 22.22% (95% CI: 13.27-33.57%), 26.67% (95% CI: 16.08-39.66%) and 76.47% (95% CI: 50.10-93.04%) respectively, while the specificity of the test was 100% in any case. In conclusion, negative results do not exclude parvoenteritis from the differential diagnosis, especially in dogs with early vaccination history, but a positive result almost certainly indicates CPV infection. An improved sensitivity may be expected when the test is performed immediately. Copyright © 2015 Elsevier B.V. All rights reserved.

Aerospike Engine Post-Test Diagnostic System Delivered to Rocketdyne

NASA Technical Reports Server (NTRS)

Meyer, Claudia M.

2000-01-01

The NASA Glenn Research Center at Lewis Field, in cooperation with Rocketdyne, has designed, developed, and implemented an automated Post-Test Diagnostic System (PTDS) for the X-33 linear aerospike engine. The PTDS was developed to reduce analysis time and to increase the accuracy and repeatability of rocket engine ground test fire and flight data analysis. This diagnostic system provides a fast, consistent, first-pass data analysis, thereby aiding engineers who are responsible for detecting and diagnosing engine anomalies from sensor data. It uses analytical methods modeled after the analysis strategies used by engineers. Glenn delivered the first version of PTDS in September of 1998 to support testing of the engine s power pack assembly. The system was used to analyze all 17 power pack tests and assisted Rocketdyne engineers in troubleshooting both data acquisition and test article anomalies. The engine version of PTDS, which was delivered in June of 1999, will support all single-engine, dual-engine, and flight firings of the aerospike engine.

Developing energy and momentum conceptual survey (EMCS) with four-tier diagnostic test items

NASA Astrophysics Data System (ADS)

Afif, Nur Faadhilah; Nugraha, Muhammad Gina; Samsudin, Achmad

2017-05-01

Students' conceptions of work and energy are important to support the learning process in the classroom. For that reason, a diagnostic test instrument is needed to diagnose students' conception of work and energy. As a result, the researcher decided to develop Energy and Momentum Conceptual Survey (EMCS) instrument test into four-tier test diagnostic items. The purpose of this research is organized as the first step of four-tier test-formatted EMCS development as one of diagnostic test instruments on work and Energy. The research method used the 4D model (Defining, Designing, Developing and Disseminating). The instrument developed has been tested to 39 students in one of Senior High Schools. The resulting research showed that four-tier test-formatted EMCS is able to diagnose students' conception level of work and energy concept. It can be concluded that the development of four-tier test-formatted EMCS is one of potential diagnostic test instruments that able to obtain the category of students who understand concepts, misconceptions and do not understand about Work and Energy concept at all.

Aquifer test interpretation using derivative analysis and diagnostic plots

NASA Astrophysics Data System (ADS)

Hernández-Espriú, Antonio; Real-Rangel, Roberto; Cortés-Salazar, Iván; Castro-Herrera, Israel; Luna-Izazaga, Gabriela; Sánchez-León, Emilio

2017-04-01

Pumping tests remain a method of choice to deduce fundamental aquifer properties and to assess well condition. In the oil and gas (O&G) industry, well testing has been the core technique in examining reservoir behavior over the last 50 years. The pressure derivative by Bourdet, it is perhaps, the most significant single development in the history of well test analysis. Recently, the so-called diagnostics plots (e.g. drawdown and drawdown derivative in a log-log plot) have been successfully tested in aquifers. However, this procedure is still underutilized by groundwater professionals. This research illustrates the applicability range, advantages and drawbacks (e.g. smoothing procedures) of diagnostic plots using field examples from a wide spectrum of tests (short/long tests, constant/variable flow rates, drawdown/buildup stages, pumping well/observation well) in dissimilar geological conditions. We analyze new and pre-existent aquifer tests in Mexico, USA, Canada, Germany, France and Saudi Arabia. In constant flow rate tests, our results show that derivative analysis is an easy, robust and powerful tool to assess near-borehole damage effects, formation heterogeneity, boundaries, flow regimes, infinite-acting radial stages, i.e., valid Theisian framework, and fracture-driven flow. In step tests, the effectiveness relies on high-frequency drawdown measurements. Moreover, we adapt O&G analytical solutions to cater for the conditions in groundwater systems. In this context, further parameters can be computed analytically from the plots, such as skin factor, head losses, wellbore storage, distance to the boundary, channel-aquifer and/or fracture zone width, among others. Therefore, diagnostic plots should be considered a mandatory tool for pumping tests analysis among hydrogeologists. This project has been supported by DGAPA (UNAM) under the research project PAPIIT IN-112815.

Variability in the diagnostic performance of a bedside rapid diagnostic influenza test over four epidemic seasons in a pediatric emergency department.

PubMed

Avril, E; Lacroix, S; Vrignaud, B; Moreau-Klein, A; Coste-Burel, M; Launay, E; Gras-Le Guen, C

2016-07-01

We wanted to determine the diagnostic performance of a rapid influenza diagnostic test (RIDT) used bedside in a pediatric emergency department (PED). This was a prospective study over four consecutive winters (2009-2013), comparing the results of a RIDT (QuickVue®) with RT-PCR in children admitted to a PED. Among the 764 children included, we did not observe any significant differences in the diagnostic performance of RIDT except during the H1N1 pandemic. The overall sensitivity of the test was 0.82; the specificity 0.98; the positive and negative likelihood ratios 37.8 and 0.19. The positive and negative post-test probabilities of infection were 98% and 17%. The diagnostic performance was increased for influenza B cases (P = 0.03). RIDTs are suitable for use every winter with few differences in its diagnostic value, except during specific pandemic periods. This test could limit unnecessary complementary exams and guide the prescription of antivirals during influenza epidemic periods in PEDs. Copyright © 2016. Published by Elsevier Inc.

Assessing Old and New Diagnostic Tests for Gastroesophageal Reflux Disease.

PubMed

Vaezi, Michael F; Sifrim, Daniel

2018-01-01

A detailed critique of objective measurements of gastroesophageal reflux disease (GERD) would improve management of patients suspecting of having reflux, leading to rational selection of treatment and better outcomes. Many diagnostic tests for GERD have been developed over the past decades. We analyze their development, positive- and negative-predictive values, and ability to predict response to treatment. These features are important for development of medical, surgical, and endoscopic therapies for GERD. We discuss the value of available diagnostic tests and review their role in management of patients with persistent reflux symptoms despite adequate medical or surgical treatment. This is becoming a significant health economic problem, due to the widespread use of proton pump inhibitors. GERD is believed to cause nonesophageal symptoms, such as those provoked by ear, nose, throat, or respiratory disorders. We analyze the value of GERD diagnostic tests in evaluation of these troublesome, nonesophageal symptoms. Copyright © 2018 AGA Institute. Published by Elsevier Inc. All rights reserved.

Rapid non-invasive tests for diagnostics of infectious diseases

NASA Astrophysics Data System (ADS)

Malamud, Daniel

2014-06-01

A rapid test for an infectious disease that can be used at point-of-care at a physician's office, a pharmacy, or in the field is critical for the prompt and appropriate therapeutic intervention. Ultimately by treating infections early on will decrease transmission of the pathogen. In contrast to metabolic diseases or cancer where multiple biomarkers are required, infectious disease targets (e.g. antigen, antibody, nucleic acid) are simple and specific for the pathogen causing the disease. Our laboratory has focused on three major infectious disease; HIV, Tuberculosis, and Malaria. These diseases are pandemic in much of the world thus putting natives, tourists and military personnel at risk for becoming infected, and upon returning to the U.S., transmitting these diseases to their contacts. Our devices are designed to detect antigens, antibodies or nucleic acids in blood or saliva samples in less than 30 minutes. An overview describing the current status of each of the three diagnostic platforms is presented. These microfluidic point-of-care devices will be relatively inexpensive, disposable, and user friendly.

[Rapid diagnostic test for malaria].

PubMed

Houzé, S

2017-02-01

The rapid diagnostic tests (RDTs) whose main interest lies in their implementation without special equipment by unskilled personnel have grown significantly over the past fifteen years to diagnose malaria. They rely on the detection of specific Plasmodium proteins, PfHRP2, pLDH and aldolase. If the detection of PfHRP2 has very good sensitivity for the diagnosis of Plasmodium falciparum malaria, the detection of pLDH or aldolase is less efficient for other species, leaving its place to the reference microscopic diagnosis. RDT could not generally be used to monitor therapeutic efficacy because they can remain positive after clinical and parasitological cure. Furthermore, the development of the use of these tests has highlighted the need for quality assurance programs to monitor their production as their use.

Background review for diagnostic test development for Zika virus infection

PubMed Central

Charrel, Rémi N; Leparc-Goffart, Isabelle; Pas, Suzan; de Lamballerie, Xavier; Koopmans, Marion; Reusken, Chantal

2016-01-01

Abstract Objective To review the state of knowledge about diagnostic testing for Zika virus infection and identify areas of research needed to address the current gaps in knowledge. Methods We made a non-systematic review of the published literature about Zika virus and supplemented this with information from commercial diagnostic test kits and personal communications with researchers in European preparedness networks. The review covered current knowledge about the geographical spread, pathogen characteristics, life cycle and infection kinetics of the virus. The available molecular and serological tests and biosafety issues are described and discussed in the context of the current outbreak strain. Findings We identified the following areas of research to address current knowledge gaps: (i) an urgent assessment of the laboratory capacity and capability of countries to detect Zika virus; (ii) rapid and extensive field validation of the available molecular and serological tests in areas with and without Zika virus transmission, with a focus on pregnant women; (iii) monitoring the genomic diversity of circulating Zika virus strains; (iv) prospective studies into the virus infection kinetics, focusing on diagnostic sampling (specimen types, combinations and timings); and (v) developing external quality assessments for molecular and serological testing, including differential diagnosis for similar viruses and symptom clusters. The availability of reagents for diagnostic development (virus strains and antigens, quantified viral ribonucleic acid) needs to be facilitated. Conclusion An international laboratory response is needed, including preparation of protocols for prospective studies to address the most pressing information needs. PMID:27516635

Performance of Dengue Diagnostic Tests in a Single-Specimen Diagnostic Algorithm.

PubMed

Hunsperger, Elizabeth A; Muñoz-Jordán, Jorge; Beltran, Manuela; Colón, Candimar; Carrión, Jessica; Vazquez, Jesus; Acosta, Luz Nereida; Medina-Izquierdo, Juan F; Horiuchi, Kalanthe; Biggerstaff, Brad J; Margolis, Harold S

2016-09-15

Anti-dengue virus (DENV) immunoglobulin M (IgM) seroconversion has been the reference standard for dengue diagnosis. However, paired specimens are rarely obtained, and the interval for this testing negates its usefulness in guiding clinical case management. The presence of DENV viremia and appearance of IgM during the febrile phase of dengue provides the framework for dengue laboratory diagnosis by using a single serum specimen. Archived paired serum specimens (n = 1234) from patients with laboratory-confirmed dengue from 2005 through 2011 were used to determine the diagnostic performance of real-time reverse transcription polymerase chain reaction (RT-PCR), for detection of DENV serotypes 1-4, and enzyme-linked immunosorbent assays (ELISAs), for detection of DENV nonstructural protein 1 (NS1) antigen and anti-DENV IgM. During 1-3 days after illness onset, real-time RT-PCR and NS1 antigen testing detected 82%-69% and 90%-84% of cases, respectively, as viremia levels declined, while anti-DENV IgM ELISA detected 5%-41% of cases as antibody appeared. Over the 10-day period of the febrile phase of dengue, the cumulative effect of using these 3 types of tests in a diagnostic algorithm confirmed ≥90% of dengue cases. The use of molecular or NS1 antigen tests to detect DENV and one to detect anti-DENV IgM in a single serum specimen collected during the first 10 days of illness accurately identified ≥90% of dengue primary and secondary cases. Published by Oxford University Press for the Infectious Diseases Society of America 2016. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Dry Eye Disease: Concordance Between the Diagnostic Tests in African Eyes.

PubMed

Onwubiko, Stella N; Eze, Boniface I; Udeh, Nnenma N; Onwasigwe, Ernest N; Umeh, Rich E

2016-11-01

To assess the concordance between the diagnostic tests for dry eye disease (DED) in a Nigerian hospital population. The study was a hospital-based cross-sectional survey of adults (≥18 years) presenting at the eye clinic of the University of Nigeria Teaching Hospital (UNTH), Enugu; September-December, 2011. Participants' socio-demographic data were collected. Each subject was assessed for DED using the "Ocular Surface Disease Index" (OSDI) questionnaire, tear-film breakup time (TBUT), and Schirmer test. The intertest concordance was assessed using kappa statistic, correlation, and regression coefficients. The participants (n=402; men: 193) were aged 50.1±19.1 standard deviation years (range: 18-94 years). Dry eye disease was diagnosed in 203 by TBUT, 170 by Schirmer test, and 295 by OSDI; the concordance between the tests were OSDI versus TBUT (Kappa, κ=-0.194); OSDI versus Schirmer (κ=-0.276); and TBUT versus Schirmer (κ=0.082). Ocular Surface Disease Index was inversely correlated with Schirmer test (Spearman ρ=-0.231, P<0.001) and TBUT (ρ=-0.237, P<0.001). In the linear regression model, OSDI was poorly predicted by TBUT (β=-0.09; 95% confidence interval (CI): -0.26 to -0.03, P=0.14) and Schirmer test (β=-0.35, 95% CI: -0.53 to -0.18, P=0.18). At UNTH, there is poor agreement, and almost equal correlation, between the subjective and objective tests for DED. Therefore, the selection of diagnostic test for DED should be informed by cost-effectiveness and diagnostic resource availability, not diagnostic efficiency or utility.

Diagnostic value of ganglion cell-inner plexiform layer for early detection of ethambutol-induced optic neuropathy.

PubMed

Lee, Ju-Yeun; Han, Jinu; Seo, Jeong Gi; Park, Kyung-Ah; Oh, Sei Yeul

2018-04-26

To evaluate the diagnostic value of macular ganglion cell-inner plexiform layer (mGCIPL) thickness versus peripapillary retinal nerve fibre layer (pRNFL) thickness for the early detection of ethambutol-induced optic neuropathy (EON). Twenty-eight eyes of 15 patients in the EON group and 100 eyes of 53 healthy subjects in the control group were included. All patients with EON demonstrated the onset of visual symptoms within 3 weeks. Diagnostic power for pRNFL and mGCIPL thicknesses measured by Cirrus spectral-domain optical coherence tomography was assessed by area under the receiver operating characteristic (AUROC) curves and sensitivity. All of the mGCIPL thickness measurements were thinner in the EON group than in the control group in early EON (p<0.001). All of pRNFL thicknesses except inferior RNFL showed AUROC curves above 0.5, and all of the mGCIPL thicknesses showed AUROC curves above 0.5. The AUROC of the average mGCIPL (0.812) thickness was significantly greater than that of the average pRNFL (0.507) thickness (p<0.001). Of all the mGCIPL-related parameters considered, the minimum thickness showed the greatest AUROC value (0.863). The average mGCIPL thickness showed a weak correlation with visual field pattern standard deviations (r 2 =0.158, p<0.001). In challenging cases of EON, the mGCIPL thickness has better diagnostic performance in detecting early-onset EON as compared with using pRNFL thickness. Among the early detection ability of mGCIPL thickness, minimum GCIPL thickness has high diagnostic ability. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Diffusion of Molecular Diagnostic Lung Cancer Tests: A Survey of German Oncologists

PubMed Central

Steffen, Julius Alexander

2014-01-01

This study was aimed at examining the diffusion of diagnostic lung cancer tests in Germany. It was motivated by the high potential of detecting and targeting oncogenic drivers. Recognizing that the diffusion of diagnostic tests is a conditio sine qua non for the success of personalized lung cancer therapies, this study analyzed the diffusion of epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) tests in Germany. Qualitative and quantitative research strategies were combined in a mixed-method design. A literature review and subsequent Key Opinion Leader interviews identified a set of qualitative factors driving the diffusion process, which were then translated into an online survey. The survey was conducted among a sample of 961 oncologists (11.34% response rate). The responses were analyzed in a multiple linear regression which identified six statistically significant factors driving the diffusion of molecular diagnostic lung cancer tests: reimbursement, attitude towards R&D, information self-assessment, perceived attitudes of colleagues, age and test-pathway strategies. Besides the important role of adequate reimbursement and relevant guidelines, the results of this study suggest that an increasing usage of test-pathway strategies, especially in an office-based setting, can increase the diffusion of molecular diagnostic lung cancer tests in the future. PMID:25562146

Diagnostic delays in children with early-onset epilepsy: impact, reasons, and opportunities to improve care

PubMed Central

Berg, Anne T.; Loddenkemper, Tobias; Baca, Christine B.

2014-01-01

Purpose Delayed diagnosis of early-onset epilepsy is a potentially important and avoidable complication in epilepsy care. We examined the frequency of diagnostic delays in young children with newly presenting epilepsy, their developmental impact, and reasons for delays. Methods Children who developed epilepsy before their third birthday were identified in a prospective community-based cohort. An interval ≥1 month from second seizure to diagnosis was considered a delay. Testing of development at baseline and for up to three years after and of IQ 8–9 years later was performed. Detailed parental baseline interview accounts and medical records were reviewed to identify potential reasons for delays. Factors associated with delays included the parent, child, pediatrician, neurologist, and scheduling. Results Diagnostic delays occurred in 70/172 (41%) children. Delays occurred less often if children had received medical attention for the first seizure (p<0.0001), previously had neonatal or febrile seizures (p=0.02), had only convulsions before diagnosis (p=0.005) or had a college-educated parent (p=0.01). A ≥1 month diagnostic delay was associated with an average 7.4 point drop (p=0.02) in the Vineland Scales of Adaptive Behavior motor score. The effect was present at diagnosis, persisted for at least three years, and was also apparent in IQ scores 8–9 years later which were lower in association with a diagnostic delay by 8.4 points (p=0.06) for processing speed up to 14.5 points (p=0.004) for full scale IQ, after adjustment for parental education and other epilepsy-related clinical factors. Factors associated with delayed diagnosis included parents not recognizing events as seizures (N=47), pediatricians missing or deferring diagnosis (N=15), neurologists deferring diagnosis (N=7), and scheduling problems (N=11). Significance Diagnostic delays occur in many young children with epilepsy. They are associated with substantial decrements in development and IQ later

An accelerated diagnostic protocol for the early, safe discharge of low-risk chest pain patients.

PubMed

Altherwi, Tawfeeq; Grad, Willis B

2015-07-01

Can an accelerated 2-hour diagnostic protocol using the cardiac troponin I (cTnI) measurement as the only biomarker be implemented to allow an earlier and safe discharge of low-risk chest pain patients? Than M, Cullen L, Aldous S, et al. 2-Hour accelerated diagnostic protocol to assess patients with chest pain symptoms using contemporary troponins as the only biomarker: the ADAPT trial. J Am Coll Cardiol 2012;59(23):2091-8. To determine whether an accelerated diagnostic protocol (ADP) for possible cardiac chest pain could identify low-risk patients suitable for early discharge using cTnI as the sole biomarker.

Diagnostic performance characteristics of a rapid field test for anthrax in cattle.

PubMed

Muller, Janine; Gwozdz, Jacek; Hodgeman, Rachel; Ainsworth, Catherine; Kluver, Patrick; Czarnecki, Jill; Warner, Simone; Fegan, Mark

2015-07-01

Although diagnosis of anthrax can be made in the field with a peripheral blood smear, and in the laboratory with bacterial culture or molecular based tests, these tests require either considerable experience or specialised equipment. Here we report on the evaluation of the diagnostic sensitivity and specificity of a simple and rapid in-field diagnostic test for anthrax, the anthrax immunochromatographic test (AICT). The AICT detects the protective antigen (PA) component of the anthrax toxin present within the blood of an animal that has died from anthrax. The test provides a result in 15min and offers the advantage of avoiding the necessity for on-site necropsy and subsequent occupational risks and environmental contamination. The specificity of the test was determined by testing samples taken from 622 animals, not infected with Bacillus anthracis. Diagnostic sensitivity was estimated on samples taken from 58 animals, naturally infected with B. anthracis collected over a 10-year period. All samples used to estimate the diagnostic sensitivity and specificity of the AICT were also tested using the gold standard of bacterial culture. The diagnostic specificity of the test was estimated to be 100% (99.4-100%; 95% CI) and the diagnostic sensitivity was estimated to be 93.1% (83.3-98.1%; 95% CI) (Clopper-Pearson method). Four samples produced false negative AICT results. These were among 9 samples, all of which tested positive for B. anthracis by culture, where there was a time delay between collection and testing of >48h and/or the samples were collected from animals that were >48h post-mortem. A statistically significant difference (P<0.001; Fishers exact test) was found between the ability of the AICT to detect PA in samples from culture positive animals <48h post-mortem, 49 of 49, Se=100% (92.8-100%; 95% CI) compared with samples tested >48h post-mortem 5 of 9 Se=56% (21-86.3%; 95% CI) (Clopper-Pearson method). Based upon these results a post hoc cut-off for use of

Compounding diagnostic delays: a qualitative study of point-of-care testing in South Africa.

PubMed

Engel, Nora; Davids, Malika; Blankvoort, Nadine; Pai, Nitika Pant; Dheda, Keertan; Pai, Madhukar

2015-04-01

Successful point-of-care (POC) testing (completion of test-and-treat cycle in one patient encounter) has immense potential to reduce diagnostic and treatment delays, and improve patient and public health outcomes. We explored what tests are done and how in public/private, rural/urban hospitals and clinics in South Africa and whether they can ensure successful POC testing. This qualitative research study examined POC testing across major diseases in Cape Town, Durban and Eastern Cape. We conducted 101 semi-structured interviews and seven focus group discussions with doctors, nurses, community health workers, patients, laboratory technicians, policymakers, hospital managers and diagnostic manufacturers. In South Africa, diagnostics are characterised by a centralised system. Most tests conducted on the spot can be made to work successfully as POC tests. The majority of public/private clinics and smaller hospitals send samples via couriers to centralised laboratories and retrieve results the same way, via internet, fax or phone. The main challenge to POC testing lies in transporting samples and results, while delays risk patient loss from diagnostic/treatment pathways. Strategies to deal with associated delays create new problems, such as artificially prolonged turnaround times, strains on human resources and quality of testing, compounding additional diagnostic and treatment delays. For POC testing to succeed, particular characteristics of diagnostic ecosystems and adaptations of professional practices to overcome associated challenges must be taken into account. © 2014 John Wiley & Sons Ltd.

Effects of Training on the Test of Diagnostic Skills. Publication No. 30.

ERIC Educational Resources Information Center

Haley, John V.

This report summarizes research performed on the Test of Diagnostic Skills, used to evaluate the clinical diagnostic skills of medical students. Forms of the test were administered to groups at different levels of medical experience to ascertain the effect of training on performance. A cross-sectional study was conducted with approximately 90…

Diagnostic Testing in Mathematics: An Extension of the PIAT?

ERIC Educational Resources Information Center

Algozzine, Bob; McGraw, Karen

1980-01-01

The article addresses the usefulness of the Peabody Individual Achievement Test (PIAT) in assessing various levels of arithmetic performance. The mathematics subtest of the PIAT is considered in terms of purpose; mathematical abilities subsections (foundations, basic facts, applications); diagnostic testing (the error analysis matrix); and poor…

[Comparative diagnostic value of Helicobacter pylori infection testing methods].

PubMed

Girdalidze, A M; Elisabedashvili, G V; Sharvadze, L G; Dzhorbenadze, T A

2013-12-01

In 213 patients with gastric and duodenal pathology, including received surgery, comparative estimation of results of Helicobacter pylori (Hp) infection testing with invasive and noninvasive methods, were performed. Material for invasive endoscopic biopsy test (EBT), including rapid urease test (RUT) for rapid Hp identification by determination of urease activity, smear cytology and histology was extracted on endoscopy or intraoperationally. RUT was carried out with the help of URE-HP test kit. Serological test for Hp antibodies IgG and IgA class was performed by IFA using kit ELISA. 13С urea breath test (UBT) was made by determination of 13/12CO2 in breath samples on infrared spectroscope. Based on 5 different methods of Hp infection testing Hp positivity in 172 (80,8%) and Hp negativity in 41 (19,2%) from 213 examined patients was revealed. 13С-UBT revealed the highest diagnostic value (accuracy-97,5%, sensibility-97,0%, specificity-100%) in Hp infection diagnostics. In treatment efficiency control this parameters of 13С-UBT are also much high (96,7%, 90,0% and 100% respectively). In spite of high sensitivity of serological test (100%), it had comparative low specificity (71,0%) with high probability of false positive results in treated patients (antibodies titer to Hp after eradication retains for a long time). Thought, this test may be successfully used only in primary patients and in epidemiological studies. Among three methods of EBT, Hp infection detection with RUT revealed the best results (accuracy-94,8%, sensibility-95,0%, specificity-100%). Correlation of RUT and UBT results and much higher diagnostic value of UBT, necessitate RUT with histological study of stomach body mucosa to perform in patients over 45 year, with prolonged anamnesis and dangerous symptoms of disease. In Hp positive patients correlation of index DOB‰ of breath test with results of RUT was revealed. This can serve the index DOB‰ of 13С-UBT as a marker of Hp infection rate. The

Autism in the Faroe Islands: Diagnostic Stability from Childhood to Early Adult Life

PubMed Central

Kočovská, Eva; Billstedt, Eva; Ellefsen, Asa; Kampmann, Hanna; Gillberg, I. Carina; Biskupstø, Rannvá; Andorsdóttir, Guðrið; Stóra, Tormóður; Minnis, Helen; Gillberg, Christopher

2013-01-01

Childhood autism or autism spectrum disorder (ASD) has been regarded as one of the most stable diagnostic categories applied to young children with psychiatric/developmental disorders. The stability over time of a diagnosis of ASD is theoretically interesting and important for various diagnostic and clinical reasons. We studied the diagnostic stability of ASD from childhood to early adulthood in the Faroe Islands: a total school age population sample (8–17-year-olds) was screened and diagnostically assessed for AD in 2002 and 2009. This paper compares both independent clinical diagnosis and Diagnostic Interview for Social and Communication Disorders (DISCO) algorithm diagnosis at two time points, separated by seven years. The stability of clinical ASD diagnosis was perfect for AD, good for “atypical autism”/PDD-NOS, and less than perfect for Asperger syndrome (AS). Stability of the DISCO algorithm subcategory diagnoses was more variable but still good for AD. Both systems showed excellent stability over the seven-year period for “any ASD” diagnosis, although a number of clear cases had been missed at the original screening in 2002. The findings support the notion that subcategories of ASD should be collapsed into one overarching diagnostic entity with subgrouping achieved on other “non-autism” variables, such as IQ and language levels and overall adaptive functioning. PMID:23476144

Cost Implications of Value-Based Pricing for Companion Diagnostic Tests in Precision Medicine.

PubMed

Zaric, Gregory S

2016-07-01

Many interpretations of personalized medicine, also referred to as precision medicine, include discussions of companion diagnostic tests that allow drugs to be targeted to those individuals who are most likely to benefit or that allow treatment to be designed in a way such that individuals who are unlikely to benefit do not receive treatment. Many authors have commented on the clinical and competitive implications of companion diagnostics, but there has been relatively little formal analysis of the cost implications of companion diagnostics, although cost reduction is often cited as a significant benefit of precision medicine. We investigate the potential impact on costs of precision medicine implemented through the use of companion diagnostics. We develop a framework in which the costs of companion diagnostic tests are determined by considerations of profit maximization and cost effectiveness. We analyze four scenarios that are defined by the incremental cost-effectiveness ratio of the new drug in the absence of a companion diagnostic test. We find that, in most scenarios, precision medicine strategies based on companion diagnostics should be expected to lead to increases in costs in the short term and that costs would fall only in a limited number of situations.

Systematic reviews of diagnostic tests in endocrinology: an audit of methods, reporting, and performance.

PubMed

Spencer-Bonilla, Gabriela; Singh Ospina, Naykky; Rodriguez-Gutierrez, Rene; Brito, Juan P; Iñiguez-Ariza, Nicole; Tamhane, Shrikant; Erwin, Patricia J; Murad, M Hassan; Montori, Victor M

2017-07-01

Systematic reviews provide clinicians and policymakers estimates of diagnostic test accuracy and their usefulness in clinical practice. We identified all available systematic reviews of diagnosis in endocrinology, summarized the diagnostic accuracy of the tests included, and assessed the credibility and clinical usefulness of the methods and reporting. We searched Ovid MEDLINE, EMBASE, and Cochrane CENTRAL from inception to December 2015 for systematic reviews and meta-analyses reporting accuracy measures of diagnostic tests in endocrinology. Experienced reviewers independently screened for eligible studies and collected data. We summarized the results, methods, and reporting of the reviews. We performed subgroup analyses to categorize diagnostic tests as most useful based on their accuracy. We identified 84 systematic reviews; half of the tests included were classified as helpful when positive, one-fourth as helpful when negative. Most authors adequately reported how studies were identified and selected and how their trustworthiness (risk of bias) was judged. Only one in three reviews, however, reported an overall judgment about trustworthiness and one in five reported using adequate meta-analytic methods. One in four reported contacting authors for further information and about half included only patients with diagnostic uncertainty. Up to half of the diagnostic endocrine tests in which the likelihood ratio was calculated or provided are likely to be helpful in practice when positive as are one-quarter when negative. Most diagnostic systematic reviews in endocrine lack methodological rigor, protection against bias, and offer limited credibility. Substantial efforts, therefore, seem necessary to improve the quality of diagnostic systematic reviews in endocrinology.

Early diagnosis in glaucoma.

PubMed

Garway-Heath, David F

2008-01-01

This chapter reviews the evidence for the clinical application of vision function tests and imaging devices to identify early glaucoma, and sets out a scheme for the appropriate use and interpretation of test results in screening/case-finding and clinic settings. In early glaucoma, signs may be equivocal and the diagnosis is often uncertain. Either structural damage or vision function loss may be the first sign of glaucoma; neither one is consistently apparent before the other. Quantitative tests of visual function and measurements of optic-nerve head and retinal nerve fiber layer anatomy are useful to either raise or lower the probability that glaucoma is present. The posttest probability for glaucoma may be calculated from the pretest probability and the likelihood ratio of the diagnostic criterion, and the output of several diagnostic devices may be combined to achieve a final probability. However, clinicians need to understand how these diagnostic devices make their measurements, so that the validity of each test result can be adequately assessed. Only then should the result be used, together with the patient history and clinical examination, to derive a diagnosis.

A general diagnostic model applied to language testing data.

PubMed

von Davier, Matthias

2008-11-01

Probabilistic models with one or more latent variables are designed to report on a corresponding number of skills or cognitive attributes. Multidimensional skill profiles offer additional information beyond what a single test score can provide, if the reported skills can be identified and distinguished reliably. Many recent approaches to skill profile models are limited to dichotomous data and have made use of computationally intensive estimation methods such as Markov chain Monte Carlo, since standard maximum likelihood (ML) estimation techniques were deemed infeasible. This paper presents a general diagnostic model (GDM) that can be estimated with standard ML techniques and applies to polytomous response variables as well as to skills with two or more proficiency levels. The paper uses one member of a larger class of diagnostic models, a compensatory diagnostic model for dichotomous and partial credit data. Many well-known models, such as univariate and multivariate versions of the Rasch model and the two-parameter logistic item response theory model, the generalized partial credit model, as well as a variety of skill profile models, are special cases of this GDM. In addition to an introduction to this model, the paper presents a parameter recovery study using simulated data and an application to real data from the field test for TOEFL Internet-based testing.

Common pitfalls in statistical analysis: Understanding the properties of diagnostic tests - Part 1.

PubMed

Ranganathan, Priya; Aggarwal, Rakesh

2018-01-01

In this article in our series on common pitfalls in statistical analysis, we look at some of the attributes of diagnostic tests (i.e., tests which are used to determine whether an individual does or does not have disease). The next article in this series will focus on further issues related to diagnostic tests.

Diagnostic testing for coagulopathies in patients with ischemic stroke.

PubMed

Bushnell, C D; Goldstein, L B

2000-12-01

Hypercoagulable states are a recognized, albeit uncommon, etiology of ischemic stroke. It is unclear how often the results of specialized coagulation tests affect management. Using data compiled from a systematic review of available studies, we employed quantitative methodology to assess the diagnostic yield of coagulation tests for identification of coagulopathies in ischemic stroke patients. We performed a MEDLINE search to identify controlled studies published during 1966-1999 that reported the prevalence of deficiencies of protein C, protein S, antithrombin III, plasminogen, activated protein C resistance (APCR)/factor V Leiden mutation (FVL), anticardiolipin antibodies (ACL), or lupus anticoagulant (LA) in patients with ischemic stroke. The cumulative prevalence rates (pretest probabilities) and positive likelihood ratios for all studies and for those including only patients aged diagnostic yield. The cumulative pretest probabilities of coagulation defects in ischemic stroke patients are as follows: LA, 3% (8% for those aged tests, and features of the patients' history and clinical presentation. The pretest probabilities of coagulation defects in ischemic stroke patients are low. The diagnostic yield of coagulation tests may be increased by using tests with the highest specificities and by targeting patients with clinical or historical features that increase pretest probability. Consideration of these data might lead to more rational ordering of tests and an associated cost savings.

Diagnostics of the ITER neutral beam test facility.

PubMed

Pasqualotto, R; Serianni, G; Sonato, P; Agostini, M; Brombin, M; Croci, G; Dalla Palma, M; De Muri, M; Gazza, E; Gorini, G; Pomaro, N; Rizzolo, A; Spolaore, M; Zaniol, B

2012-02-01

The ITER heating neutral beam (HNB) injector, based on negative ions accelerated at 1 MV, will be tested and optimized in the SPIDER source and MITICA full injector prototypes, using a set of diagnostics not available on the ITER HNB. The RF source, where the H(-)∕D(-) production is enhanced by cesium evaporation, will be monitored with thermocouples, electrostatic probes, optical emission spectroscopy, cavity ring down, and laser absorption spectroscopy. The beam is analyzed by cooling water calorimetry, a short pulse instrumented calorimeter, beam emission spectroscopy, visible tomography, and neutron imaging. Design of the diagnostic systems is presented.

A comparison of diagnostic tests for lactose malabsorption - which one is the best?

PubMed Central

2009-01-01

Background Perceived milk intolerance is a common complaint, and tests for lactose malabsorption (LM) are unreliable. This study assesses the agreement between diagnostic tests for LM and describes the diagnostic properties of the tests. Methods Patients above 18 years of age with suspected LM were included. After oral intake of 25 g lactose, a combined test with measurement of serum glucose (s-glucose) and hydrogen (H2) and methane (CH4) in expired air was performed and symptoms were recorded. In patients with discrepancies between the results, the combined test was repeated and a gene test for lactose non-persistence was added. The diagnosis of LM was based on an evaluation of all tests. The following tests were compared: Increase in H2, CH4, H2+CH4 and H2+CH4x2 in expired air, increase in s-glucose, and symptoms. The agreement was calculated and the diagnostic properties described. Results Sixty patients were included, seven (12%) had LM. The agreement (kappa-values) between the methods varied from 0.25 to 0.91. The best test was the lactose breath test with measurement of the increase in H2 + CH4x2 in expired air. With a cut-off level < 18 ppm, the area under the ROC-curve was 0.967 and sensitivity was 100%. This shows that measurement of CH4 in addition to H2 improves the diagnostic properties of the breath test. Conclusion The agreement between commonly used methods for the diagnosis of LM was unsatisfactory. A lactose breath test with measurement of H2 + CH4x2 in expired air had the best diagnostic properties. PMID:19878587

The glucose breath test: a diagnostic test for small bowel stricture(s) in Crohn's disease.

PubMed

Mishkin, Daniel; Boston, Francis M; Blank, David; Yalovsky, Morty; Mishkin, Seymour

2002-03-01

The aim of this study was to determine whether an indirect noninvasive indicator of proximal bacterial overgrowth, the glucose breath test, was of diagnostic value in inflammatory bowel disease. Twenty four of 71 Crohn's disease patients tested had a positive glucose breath test. No statistical conclusions could be drawn between the Crohn's disease activity index and glucose breath test status. Of patients with radiologic evidence of small bowel stricture(s), 96.0% had a positive glucose breath test, while only one of 46 negative glucose breath test patients had a stricture. The positive and negative predictive values for a positive glucose breath test as an indicator of stricture formation were 96.0% and 97.8%, respectively. This correlation was not altered in Crohn's disease patients with fistulae or status postresection of the terminal ileum. The data in ulcerative colitis were nondiagnostic. In conclusion, the glucose breath test appears to be an accurate noninvasive inexpensive diagnostic test for small bowel stricture(s) and secondary bacterial overgrowth in Crohn's disease.

Identification of early diagnostic antigens from major excretory-secretory proteins of Trichinella spiralis muscle larvae using immunoproteomics.

PubMed

Wang, Li; Cui, Jing; Hu, Dan Dan; Liu, Ruo Dan; Wang, Zhong Quan

2014-01-22

The excretory-secretory (ES) proteins of Trichinella spiralis muscle larvae (ML) come mainly from the excretory granules of the stichosome and the cuticles (membrane proteins), are directly exposed to the host's immune system, and are the main target antigens, which induce the immune responses. Although the ES proteins are the most commonly used diagnostic antigens for trichinellosis, their main disadvantage are the false negative results during the early stage of infection. The aim of this study was to identify early specific diagnostic antigens from the main components of T. spiralis muscle larval ES proteins. Two-dimensional electrophoresis (2-DE) combined with Western blot were used to screen the early diagnostic antigens from the main components of T. spiralis muscle larval ES proteins. The protein spots recognized by the sera from BALB/c mice infected with T. spiralis at 18 days post-infection (dpi) were identified by MALDI-TOF/TOF-MS and putatively annotated using GO terms obtained from the InterPro databases. The ES proteins were analyzed by 2-DE, and more than 33 protein spots were detected with molecular weight varying from 40 to 60 kDa and isoelectric point (pI) from 4 to 7. When probed with the sera from infected mice at 18 dpi, 21 protein spots were recognized and then identified, and they were characterized to correlate with five different proteins of T. spiralis, including two serine proteases, one deoxyribonuclease (DNase) II, and two kinds of trypsin. The five proteins were functionally categorized into molecular function and biological process according to GO hierarchy. 2-DE and Western blot combined with MALDI-TOF/TOF-MS were used to screen the diagnostic antigens from the main components of T. spiralis muscle larval ES proteins. The five proteins of T. spiralis identified (two serine proteases, DNase II and two kinds of trypsin) might be the early specific diagnostic antigens of trichinellosis.

Malaria rapid diagnostic tests in endemic settings.

PubMed

Maltha, J; Gillet, P; Jacobs, J

2013-05-01

Malaria rapid diagnostic tests (RDTs) are instrument-free tests that provide results within 20 min and can be used by community health workers. RDTs detect antigens produced by the Plasmodium parasite such as Plasmodium falciparum histidine-rich protein-2 (PfHPR2) and Plasmodium lactate dehydrogenase (pLDH). The accuracy of RDTs for the diagnosis of uncomplicated P. falciparum infection is equal or superior to routine microscopy (but inferior to expert microscopy). Sensitivity for Plasmodium vivax is 75-100%; for Plasmodium ovale and Plasmodium malariae, diagnostic performance is poor. Design limitations of RDTs include poor sensitivity at low parasite densities, susceptibility to the prozone effect (PfHRP2-detecting RDTs), false-negative results due to PfHRP2 deficiency in the case of pfhrp2 gene deletions (PfHRP2-detecting RDTs), cross-reactions between Plasmodium antigens and detection antibodies, false-positive results by other infections and susceptibility to heat and humidity. End-user's errors relate to safety, procedure (delayed reading, incorrect sample and buffer volumes) and interpretation (not recognizing invalid test results, disregarding faint test lines). Withholding antimalarial treatment in the case of negative RDT results tends to be infrequent and tendencies towards over-prescription of antibiotics have been noted. Numerous shortcomings in RDT kits' labelling, instructions for use (correctness and readability) and contents have been observed. The World Health Organization and partners actively address quality assurance of RDTs by comparative testing of RDTs, inspections of manufacturing sites, lot testing and training tools but no formal external quality assessment programme of end-user performance exists. Elimination of malaria requires RDTs with lower detection limits, for which nucleic acid amplification tests are under development. © 2013 The Authors Clinical Microbiology and Infection © 2013 European Society of Clinical Microbiology and

[Pathogenic Mechanism and Diagnostic Testing for Drug Allergies].

PubMed

Uno, Katsuji

2018-01-01

　Three stages of the pathogenic mechanism of drug allergies can be considered: antigen formation, immune reaction and inflammation/disorder reaction. Drugs are thought to form 4 types of antigens: drug only, polymers, drug-carrier conjugates, and metabolite-carrier complexes. Antigens are recognized by B cell receptors and T cell receptors. Helper T cells (Th) are differentiated into four subsets, namely, Th1, Th2, Th17 and regulatory T cells (Treg). Th1 produces interleukin (IL)-2 and interferon (IFN)-γ, and activates macrophages and cytotoxic T cells (Tc). Macrophages induce type IV allergies, and Tc lead to serious type IV allergies. On the other hand, Th2 produces IL-4, IL-5, and IL-6, etc., and activates B cells. B cells produce IgE antibodies, and the IgE antibody affects mast cells and induces type I allergies. Activated eosinophil leads to the chronic state of type I allergy. Diagnostic testing for allergenic drugs is necessary for patients with drug allergies. Because in vivo diagnostic tests for allergenic drugs are associated with a risk and burden to the patient, in vitro allergy tests are recommended to identify allergenic drugs. In allergy tests performed in vitro, cytological tests are more effective than serological tests, and the leukocyte migration test (LMT) presently has the highest efficacy. An LMT-chamber is better than LMT-agarose in terms of usability and sensitivity, and it can detect about 80% of allergenic drugs.

Get the Diagnosis: an evidence-based medicine collaborative Wiki for diagnostic test accuracy.

PubMed

Hammer, Mark M; Kohlberg, Gavriel D

2017-04-01

Despite widespread calls for its use, there are challenges to the implementation of evidence-based medicine (EBM) in clinical practice. In response to the challenges of finding timely, pertinent information on diagnostic test accuracy, we developed an online, crowd-sourced Wiki on diagnostic test accuracy called Get the Diagnosis (GTD, http://www.getthediagnosis.org). Since its launch in November 2008 till October 2015, GTD has accumulated information on 300 diagnoses, with 1617 total diagnostic entries. There are a total of 1097 unique diagnostic tests with a mean of 5.4 tests (range 0-38) per diagnosis. 73% of entries (1182 of 1617) have an associated sensitivity and specificity and 89% of entries (1432 of 1617) have associated peer-reviewed literature citations. Altogether, GTD contains 474 unique literature citations. For a sample of three diagnoses, the search precision (percentage of relevant results in the first 30 entries) in GTD was 100% as compared with a range of 13.3%-63.3% for PubMed and between 6.7% and 76.7% for Google Scholar. GTD offers a fast, precise and efficient way to look up diagnostic test accuracy. On three selected examples, GTD had a greater precision rate compared with PubMed and Google Scholar in identifying diagnostic test information. GTD is a free resource that complements other currently available resources. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Diagnostic Tests to Support Late-Stage Control Programs for Schistosomiasis and Soil-Transmitted Helminthiases.

PubMed

Hawkins, Kenneth R; Cantera, Jason L; Storey, Helen L; Leader, Brandon T; de Los Santos, Tala

2016-12-01

Global efforts to address schistosomiasis and soil-transmitted helminthiases (STH) include deworming programs for school-aged children that are made possible by large-scale drug donations. Decisions on these mass drug administration (MDA) programs currently rely on microscopic examination of clinical specimens to determine the presence of parasite eggs. However, microscopy-based methods are not sensitive to the low-intensity infections that characterize populations that have undergone MDA. Thus, there has been increasing recognition within the schistosomiasis and STH communities of the need for improved diagnostic tools to support late-stage control program decisions, such as when to stop or reduce MDA. Failure to adequately address the need for new diagnostics could jeopardize achievement of the 2020 London Declaration goals. In this report, we assess diagnostic needs and landscape potential solutions and determine appropriate strategies to improve diagnostic testing to support control and elimination programs. Based upon literature reviews and previous input from experts in the schistosomiasis and STH communities, we prioritized two diagnostic use cases for further exploration: to inform MDA-stopping decisions and post-MDA surveillance. To this end, PATH has refined target product profiles (TPPs) for schistosomiasis and STH diagnostics that are applicable to these use cases. We evaluated the limitations of current diagnostic methods with regards to these use cases and identified candidate biomarkers and diagnostics with potential application as new tools. Based on this analysis, there is a need to develop antigen-detecting rapid diagnostic tests (RDTs) with simplified, field-deployable sample preparation for schistosomiasis. Additionally, there is a need for diagnostic tests that are more sensitive than the current methods for STH, which may include either a field-deployable molecular test or a simple, low-cost, rapid antigen-detecting test.

Early Diagnosis of Fibrodysplasia Ossificans Progressiva

PubMed Central

Kaplan, Frederick S.; Xu, Meiqi; Glaser, David L.; Collins, Felicity; Connor, Michael; Kitterman, Joseph; Sillence, David; Zackai, Elaine; Ravitsky, Vardit; Zasloff, Michael; Ganguly, Arupa; Shore, Eileen M.

2012-01-01

BACKGROUND Fibrodysplasia ossificans progressiva is a rare and disabling genetic condition characterized by congenital malformation of the great toes and by progressive heterotopic ossification in specific anatomic patterns. Most patients with fibrodys-plasia ossificans progressiva are misdiagnosed early in life before the appearance of heterotopic ossification and undergo diagnostic procedures that can cause lifelong disability. Recently, the genetic cause of fibrodysplasia ossificans progressiva was identified, and definitive genetic testing for fibrodysplasia ossificans progressiva is now available before the appearance of heterotopic ossification. METHODS We recently evaluated 7 children for diagnosis of fibrodysplasia ossificans progressiva before the onset of heterotopic ossification. A medical history, physical examination, and skeletal survey were obtained on all of the patients, as well as clinical genetic testing for the canonical fibrodysplasia ossificans progressiva mutation. RESULTS All 7 of the children (4 girls and 3 boys; ages 3 months to 6 years) had congenital malformations of the great toes, but none had radiographic evidence of heterotopic ossification at the time of evaluation. Five of the 7 children had soft tissue lesions of the neck and back, suggestive of early fibrodysplasia ossificans progressiva flare-ups, 3 of whom had undergone invasive diagnostic procedures that exacerbated their condition. Two children had no history or signs of soft tissue swelling or flare-ups. DNA sequence analysis found that all 7 of the children had the recurrent fibrodysplasia ossificans progressiva missense mutation, a single nucleotide substitution (c.617G>A) at codon 206 in the glycine-serine activation domain of activin receptor IA, a bone morphogenetic protein type 1 receptor. CONCLUSION Clinical suspicion of fibrodysplasia ossificans progressiva early in life on the basis of malformed great toes can lead to early clinical diagnosis, confirmatory

Triple diagnostics for early detection of ambivalent necrotizing fasciitis.

PubMed

Hietbrink, Falco; Bode, Lonneke G; Riddez, Louis; Leenen, Luke P H; van Dijk, Marijke R

2016-01-01

Necrotizing fasciitis is an uncommon, rapidly progressive and potential lethal condition. Over the last decade time to surgery decreased and outcome improved, most likely due to increased awareness and more timely referral. Early recognition is key to improve mortality and morbidity. However, early referral frequently makes it a challenge to recognize this heterogeneous disease in its initial stages. Signs and symptoms might be misleading or absent, while the most prominent skin marks might be in discrepancy with the position of the fascial necrosis. Gram staining and especially fresh frozen section histology might be a useful adjunct. Retrospective analysis of 3 year period. Non-transferred patients who presented with suspected necrotizing fasciitis are included. ASA classification was determined. Mortality was documented. In total, 21 patients are included. Most patients suffered from severe comorbidities. In 11 patients, diagnoses was confirmed based on intra-operative macroscopic findings. Histology and/or microbiotic findings resulted in 6/10 remaining patients in a change in treatment strategy. In total, 17 patients proved to suffer necrotizing fasciitis. In the cohort series 2 patients died due to necrotizing fasciitis. In the early phases of necrotizing fasciitis, clinical presentation can be ambivalent. In the present cohort, triple diagnostics consisting of an incisional biopsy with macroscopic, histologic and microbiotic findings was helpful in timely identification of necrotizing fasciitis.

The role of neurologists and diagnostic tests in the management of distal symmetric polyneuropathy

PubMed Central

Callaghan, Brian C.; Kerber, Kevin A.; Lisabeth, Lynda L.; Morgenstern, Lewis B.; Longoria, Ruth; Rodgers, Ann; Longwell, Paxton; Feldman, Eva L.

2014-01-01

Importance Distal symmetric polyneuropathy (DSP) is a prevalent condition resulting in high costs from diagnostic testing. However, the role of neurologists and diagnostic tests on patient care is unknown. Objective To determine how often neurologists and diagnostic tests influence the diagnosis and management of DSP patients in a community setting. Design We utilized a validated case-capture method (ICD-9 screening technique with subsequent medical chart abstraction) to identify patients with a new DSP diagnosis (retrospective cohort). Using a structured data abstraction process, diagnostic testing, diagnoses rendered (before and after testing), and subsequent management were recorded. Setting Community neurologist’s outpatient offices in Corpus Christi, Texas. Participants Patients meeting the Toronto consensus criteria for probable DSP. Main Outcome Measure Changes in etiology and management after diagnostic testing by neurologists. Results Between 1/1/2010–3/31/2011, we identified 458 DSP patients followed for mean (SD) 435.3 (44.1) days. Neurologists identified a cause of DSP in 63.5% of cases prior to their diagnostic testing. Seventy-one patients (15.5%) had a new DSP cause discovered after testing by neurologists. The most common new diagnoses were pre-diabetes (N=28), B12 deficiency (N=20), diabetes (N=8), and thyroid disease (N=8). Management changes were common (63.1%), usually related to neuropathic pain management (77.5%). Disease modifying management changes occurred in 24.7% with diabetes management (N=45), starting vitamins (N=39), advising diet/exercise (N=33), and adjusting thyroid medications (N=10) the most common. Electrodiagnostic testing and MRIs of the neuroaxis rarely led to management changes. Conclusions and Relevance Neurologists diagnosed the cause of DSP in almost two-thirds of patients prior to their diagnostic testing. Inexpensive blood tests for diabetes, thyroid dysfunction, and B12 deficiency, allowed neurologists to identify

Diagnostic Tools for Acute Anterior Cruciate Ligament Injury: GNRB, Lachman Test, and Telos.

PubMed

Ryu, Seung Min; Na, Ho Dong; Shon, Oog Jin

2018-06-01

The purpose of this study is to compare the accuracy of the GNRB arthrometer (Genourob), Lachman test, and Telos device (GmbH) in acute anterior cruciate ligament (ACL) injuries and to evaluate the accuracy of each diagnostic tool according to the length of time from injury to examination. From September 2015 to September 2016, 40 cases of complete ACL rupture were reviewed. We divided the time from injury to examination into three periods of 10 days each and analyzed the diagnostic tools according to the time frame. An analysis of the area under the curve (AUC) of a receiver operating characteristic curve showed that all diagnostic tools were fairly informative. The GNRB showed a higher AUC than other diagnostic tools. In 10 cases assessed within 10 days after injury, the GNRB showed statistically significant side-to-side difference in laxity (p＜0.001), whereas the Telos test and Lachman test did not show significantly different laxity (p=0.541 and p=0.413, respectively). All diagnostic values of the GNRB were better than other diagnostic tools in acute ACL injuries. The GNRB was more effective in acute ACL injuries examined within 10 days of injury. The GNRB arthrometer can be a useful diagnostic tool for acute ACL injuries.

Diagnostic and prognostic utility of an inexpensive rapid on site malaria diagnostic test (ParaHIT f) among ethnic tribal population in areas of high, low and no transmission in central India.

PubMed

Singh, Neeru; Mishra, A K; Shukla, M M; Chand, S K; Bharti, Praveen Kumar

2005-06-21

Malaria presents a diagnostic challenge in most tropical countries. Rapid detection of the malaria parasite and early treatment of infection still remain the most important goals of disease management. Therefore, performance characteristics of the new indigenous ParaHIT f test (Span diagnostic Ltd, Surat, India) was determined among ethnic tribal population in four districts of different transmission potential in central India to assess whether this rapid diagnostic test (RDT) could be widely applied as a diagnostic tool to control malaria. Beyond diagnosis, the logical utilization of RDTs is to monitor treatment outcome. A finger prick blood sample was collected from each clinically suspected case of malaria to prepare blood smear and for testing with the RDT after taking informed consent. The blood smears were read by an experienced technician blinded to the RDT results and clinical status of the subjects. The figures for specificity, sensitivity, accuracy and predictive values were calculated using microscopy as gold standard. The prevalence of malaria infection estimated by RDT in parallel with microscopy provide evidence of the type of high, low or no transmission in the study area. Analysis revealed (pooled data of all four epidemiological settings) that overall sensitivity, specificity and accuracy of the RDT were >90% in areas of different endemicity. While, RDT is useful to confirm the diagnosis of new symptomatic cases of suspected P. falciparum infection, the persistence of parasite antigen leading to false positives even after clearance of asexual parasitaemia has limited its utility as a prognostic tool. The study showed that the ParaHIT f test was easy to use, reliable and cheap. Thus this RDT is an appropriate test for the use in the field by paramedical staff when laboratory facilities are not available and thus likely to contribute greatly to an effective control of malaria in resource poor countries.

76 FR 49491 - Medicare Program; Section 3113: The Treatment of Certain Complex Diagnostic Laboratory Tests...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-10

...] Medicare Program; Section 3113: The Treatment of Certain Complex Diagnostic Laboratory Tests Demonstration... code under the Treatment of Certain Complex Diagnostic Laboratory Tests Demonstration. The deadline for... interested parties of an opportunity to participate in the Treatment of Certain Complex Diagnostic Laboratory...

Role of non-Invasive Tests for the Early Detection of Cancer

Cancer.gov

Dr. Nickolas Papadopoulos is Professor of Oncology & Pathology and Director of Translational Genetics at the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins. He is internationally known as a co-discoverer of the genetic basis of the predisposition to hereditary nonpolyposis colon cancer (HNPCC), one of the most common hereditary forms of cancer, earlier in his career. He is known for the development of diagnostic tests and is considered an expert in cancer genetics and diagnostics. He was part of the interdisciplinary team that was first to sequence all of the protein coding genes, determine genetic alterations, and construct expression profiles of four common tumor types. Later, he was involved in the identification of genetic alterations that drive tumorigenesis in multiple tumor types. Noteworthy discoveries made by Dr. Papadopoulos include the identification of novel mutations in chromatin remodeling genes in ovarian clear cell carcinomas and pancreatic neuroendocrine tumors. He is a co-developer of sensitive methods for the detection of tumor DNA in liquid biopsy, and also the co-founder of two companies that develop diagnostics for cancer. Currently, he is focused on translating the genetic information derived from cancer genome analyses to clinical applications in early detection, diagnosis and monitoring of cancer. Dr. Papadopoulos received his PhD from the University of Texas McGovern Medical School in Houston.

DIAGNOSTIC CLASSIFICATION OF MENTAL HEALTH AND DEVELOPMENTAL DISORDERS OF INFANCY AND EARLY CHILDHOOD DC:0-5: SELECTIVE REVIEWS FROM A NEW NOSOLOGY FOR EARLY CHILDHOOD PSYCHOPATHOLOGY.

PubMed

Zeanah, Charles H; Carter, Alice S; Cohen, Julie; Egger, Helen; Gleason, Mary Margaret; Keren, Miri; Lieberman, Alicia; Mulrooney, Kathleen; Oser, Cindy

2016-09-01

The Diagnostic Classification of Mental Health and Developmental Disorders of Infancy and Early Childhood: Revised Edition (DC:0-5; ZERO TO THREE) is scheduled to be published in 2016. The articles in this section are selective reviews that have been undertaken as part of the process of refining and updating the nosology. They provide the rationales for new disorders, for disorders that had not been included previously in the Diagnostic Classification of Mental Health and Developmental Disorders of Infancy and Early Childhood: Revised Edition (DC:0-3R; ZERO TO THREE, 2005), and for changes in how certain types of disorders are conceptualized. © 2016 Michigan Association for Infant Mental Health.

Laboratory Diagnostics Market in East Africa: A Survey of Test Types, Test Availability, and Test Prices in Kampala, Uganda.

PubMed

Schroeder, Lee F; Elbireer, Ali; Jackson, J Brooks; Amukele, Timothy K

2015-01-01

Diagnostic laboratory tests are routinely defined in terms of their sensitivity, specificity, and ease of use. But the actual clinical impact of a diagnostic test also depends on its availability and price. This is especially true in resource-limited settings such as sub-Saharan Africa. We present a first-of-its-kind report of diagnostic test types, availability, and prices in Kampala, Uganda. Test types (identity) and availability were based on menus and volumes obtained from clinical laboratories in late 2011 in Kampala using a standard questionnaire. As a measure of test availability, we used the Availability Index (AI). AI is the combined daily testing volumes of laboratories offering a given test, divided by the combined daily testing volumes of all laboratories in Kampala. Test prices were based on a sampling of prices collected in person and via telephone surveys in 2015. Test volumes and menus were obtained for 95% (907/954) of laboratories in Kampala city. These 907 laboratories offered 100 different test types. The ten most commonly offered tests in decreasing order were Malaria, HCG, HIV serology, Syphilis, Typhoid, Urinalysis, Brucellosis, Stool Analysis, Glucose, and ABO/Rh. In terms of AI, the 100 tests clustered into three groups: high (12 tests), moderate (33 tests), and minimal (55 tests) availability. 50% and 36% of overall availability was provided through private and public laboratories, respectively. Point-of-care laboratories contributed 35% to the AI of high availability tests, but only 6% to the AI of the other tests. The mean price of the most commonly offered test types was $2.62 (range $1.83-$3.46). One hundred different laboratory test types were in use in Kampala in late 2011. Both public and private laboratories were critical to test availability. The tests offered in point-of-care laboratories tended to be the most available tests. Prices of the most common tests ranged from $1.83-$3.46.

Diagnostic methods of TSH in thyroid screening tests.

PubMed

Matyjaszek-Matuszek, Beata; Pyzik, Aleksandra; Nowakowski, Andrzej; Jarosz, Mirosław J

2013-01-01

Reliable and quick thyreologic diagnostics, as well as verification of the effectiveness of the therapy undertaken, is of great importance for the state of health of society. The measurement of plasma TSH is the commonly accepted and most sensitive screening test for primary thyroid disorders, which are the most frequent diseases related to the endocrine glands. At present, the available methods for the determination of TSH are characterized by high sensitivity ≤0.01 µIU/ml and lack of cross-reactivity. However, many drugs and substances, as well as pathological conditions, may affect the TSH level. evaluation of contemporary laboratory methods for the determination of TSH and the principles of interpretation of screening tests. In many countries, the TSH test is the only test performed in the diagnostics of thyroid function; nevertheless, it seems that for genuine and objective assessment of thyroid status the TSH level, together with FT4 level, should be absolutely determined, which allows the differentiation and assessment of the intensity of thyroid function disorders and foresee its consequences. The interpretation of TSH results in screening tests is different in such population groups as: children aged under 14, pregnant women, the elderly, and patients with non-thyroidal illnesses. From among currently used laboratory methods for determination of TSH levels, third generation non-isotopic methods are most frequently recommended, especially the method of immunochemiluminescence.

SELDI-TOF-based serum proteomic pattern diagnostics for early detection of cancer.

PubMed

Petricoin, Emanuel F; Liotta, Lance A

2004-02-01

Proteomics is more than just generating lists of proteins that increase or decrease in expression as a cause or consequence of pathology. The goal should be to characterize the information flow through the intercellular protein circuitry that communicates with the extracellular microenvironment and then ultimately to the serum/plasma macroenvironment. The nature of this information can be a cause, or a consequence, of disease and toxicity-based processes. Serum proteomic pattern diagnostics is a new type of proteomic platform in which patterns of proteomic signatures from high dimensional mass spectrometry data are used as a diagnostic classifier. This approach has recently shown tremendous promise in the detection of early-stage cancers. The biomarkers found by SELDI-TOF-based pattern recognition analysis are mostly low molecular weight fragments produced at the specific tumor microenvironment.

Special Educator's Complete Guide to 109 Diagnostic Tests: How To Select & Interpret Tests, Use Results in IEPs, and Remediate Specific Difficulties.

ERIC Educational Resources Information Center

Pierangelo, Roger; Giuliani, George

This manual is a guide to the special education diagnostic process and covers the various stages of evaluation, interpretation, diagnosis, prescription, and remediation. Test information includes: explanations of the most commonly used diagnostic tests, coverage of the areas measured by each test, interpretation of test patterns for commonly used…

Meta-analyses of the sensitivity and specificity of ante-mortem and post-mortem diagnostic tests for bovine tuberculosis in the UK and Ireland.

PubMed

Nuñez-Garcia, Javier; Downs, Sara H; Parry, Jessica E; Abernethy, Darrell A; Broughan, Jennifer M; Cameron, Angus R; Cook, Alasdair J; de la Rua-Domenech, Ricardo; Goodchild, Anthony V; Gunn, Jane; More, Simon J; Rhodes, Shelley; Rolfe, Simon; Sharp, Michael; Upton, Paul A; Vordermeier, H Martin; Watson, Eamon; Welsh, Michael; Whelan, Adam O; Woolliams, John A; Clifton-Hadley, Richard S; Greiner, Matthias

2018-05-01

Bovine Tuberculosis (bTB) in cattle is a global health problem and eradication of the disease requires accurate estimates of diagnostic test performance to optimize their efficiency. The objective of this study was, through statistical meta-analyses, to obtain estimates of sensitivity (Se) and specificity (Sp), for 14 different ante-mortem and post-mortem diagnostic tests for bTB in cattle. Using data from a systematic review of the scientific literature (published 1934-2009) diagnostic Se and Sp were estimated using Bayesian logistic regression models adjusting for confounding factors. Random effect terms were used to account for unexplained heterogeneity. Parameters in the models were implemented using Markov Chain Monte Carlo (MCMC), and posterior distributions for the diagnostic parameters with adjustment for covariates (confounding factors) were obtained using the inverse logit function. Estimates for Se and/or Sp of the tuberculin skin tests and the IFN-γ blood test were compared with estimates published 2010-2015. Median Se for the single intradermal comparative cervical tuberculin skin (SICCT) test (standard interpretation) was 0.50 and Bayesian credible intervals (CrI) were wide (95% CrI 0.26, 0.78). Median Sp for the SICCT test was 1.00 (95% CrI 0.99, 1.00). Estimates for the IFN-γ blood test Bovine Purified Protein Derivative (PPD)-Avian PPD and Early Secreted Antigen target 6 and Culture Filtrate Protein 10 (ESAT-6/CFP10) ESAT6/CFP10 were 0.67 (95% CrI 0.49, 0.82) and 0.78 (95% CrI 0.60, 0.90) respectively for Se, and 0.98 (95% CrI 0.96, 0.99) and 0.99 (95% CrI 0.99, 1.00) for Sp. The study provides an overview of the accuracy of a range of contemporary diagnostic tests for bTB in cattle. Better understanding of diagnostic test performance is essential for the design of effective control strategies and their evaluation. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

Bovine paratuberculosis: a review of the advantages and disadvantages of different diagnostic tests.

PubMed

Gilardoni, Liliana R; Paolicchi, Fernando A; Mundo, Silvia L

2012-01-01

Paratuberculosis (PTB), or Johne's disease, is a chronic infectious granulomatous enteritis of ruminants, caused by Mycobacterium avium subspecies paratuberculosis (Map). It is characterized by diarrhea and progressive cachexia, which may cause the death of the animal. Calves are the most susceptible to infection. Infected animals excrete Map mainly by the feces. PTB is endemic worldwide, with high prevalence levels, strong economic impact and public health relevance because of its possible association with Crohn's disease. Although the current reference diagnostic test is identification of Map in the bacterial culture, there are different diagnostic tests to identify infected individuals and/or herds. The sensitivity and specificity of these tests vary according to the stage of the disease in the animals to be evaluated. The correct choice and application of each of these diagnostic tests will ensure their success and may allow to establish a control program. The aim of this work is to review and discuss the different diagnostic tests used in the detection of Map-infected animals, focusing on their advantages and disadvantages.

Diagnostic Accuracy of the Neck Tornado Test as a New Screening Test in Cervical Radiculopathy.

PubMed

Park, Juyeon; Park, Woo Young; Hong, Seungbae; An, Jiwon; Koh, Jae Chul; Lee, Youn-Woo; Kim, Yong Chan; Choi, Jong Bum

2017-01-01

The Spurling test, although a highly specific provocative test of the cervical spine in cervical radiculopathy (CR), has low to moderate sensitivity. Thus, we introduced the neck tornado test (NTT) to examine the neck and the cervical spine in CR. The aim of this study was to introduce a new provocative test, the NTT, and compare the diagnostic accuracy with a widely accepted provocative test, the Spurling test. Retrospective study. Medical records of 135 subjects with neck pain (CR, n = 67; without CR, n = 68) who had undergone cervical spine magnetic resonance imaging and been referred to the pain clinic between September 2014 and August 2015 were reviewed. Both the Spurling test and NTT were performed in all patients by expert examiners. Sensitivity, specificity, and accuracy were compared for both the Spurling test and the NTT. The sensitivity of the Spurling test and the NTT was 55.22% and 85.07% ( P < 0.0001); specificity, 98.53% and 86.76% ( P = 0.0026); accuracy, 77.04% and 85.93% ( P = 0.0423), respectively. The NTT is more sensitive with superior diagnostic accuracy for CR diagnosed by magnetic resonance imaging than the Spurling test.

Audit of the autoantibody test, EarlyCDT®-lung, in 1600 patients: an evaluation of its performance in routine clinical practice.

PubMed

Jett, James R; Peek, Laura J; Fredericks, Lynn; Jewell, William; Pingleton, William W; Robertson, John F R

2014-01-01

EarlyCDT(®)-Lung may enhance detection of early stage lung cancer by aiding physicians in assessing high-risk patients through measurement of biological markers (i.e., autoantibodies). The test's performance characteristics in routine clinical practice were evaluated by auditing clinical outcomes of 1613 US patients deemed at high risk for lung cancer by their physician, who ordered the EarlyCDT-Lung test for their patient. Clinical outcomes for all 1613 patients who provided HIPAA authorization are reported. Clinical data were collected from each patient's treating physician. Pathology reports when available were reviewed for diagnostic classification. Staging was assessed on histology, otherwise on imaging. Six month follow-up for the positives/negatives was 99%/93%. Sixty-one patients (4%) were identified with lung cancer, 25 of whom tested positive by EarlyCDT-Lung (sensitivity=41%). A positive EarlyCDT-Lung test on the current panel was associated with a 5.4-fold increase in lung cancer incidence versus a negative. Importantly, 57% (8/14) of non-small cell lung cancers detected as positive (where stage was known) were stage I or II. EarlyCDT-Lung has been extensively tested and validated in case-control settings and has now been shown in this audit to perform in routine clinical practice as predicted. EarlyCDT-Lung may be a complementary tool to CT for detection of early lung cancer. Copyright © 2013 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

[Diagnostic performance of surface electrocardiogram in early detection of chagasic cardiomyopathy].

PubMed

Bochard-Villanueva, Bruno; Estornell-Erill, Jordi; Fabregat-Andrés, Óscar; García-González, Pilar; Morell-Cabedo, Salvador; Ridocci-Soriano, Francisco

2015-03-15

Contrast-enhanced cardiac magnetic resonance imaging (CMR) allows early detection of myocardial involvement by Trypanosoma cruzi infection. The aim of our study was to assess the diagnostic performance of the surface electrocardiogram (ECG) in the early detection of Chagas' cardiomyopathy (CCM) compared with CMR. We included 43 asymptomatic patients (30 women, 42 ± 9.8 years), diagnosed of Chagas disease. The sample was divided into 2 groups according to the presence (n=17) or absence (n=26) of electrocardiographic abnormalities. All patients underwent CMR and late gadolinium enhancement (LGE) was used as a marker of early myocardial involvement. Six (14%) patients had a LGE significantly higher in the group who had electrocardiographic abnormalities (29 vs. 4%, P<.05). With CMR as the method of reference, the ECG had a sensitivity of 83% and a negative predictive value of 96% to detect CCM. ECG is a useful, inexpensive and globally available tool for the screening of CCM in asymptomatic patients but with proven myocardial involvement in CMR. Copyright © 2013 Elsevier España, S.L.U. All rights reserved.

Diagnostic validation of selected serological tests for detecting scrub typhus.

PubMed

Koraluru, Munegowda; Bairy, Indira; Varma, Muralidhar; Vidyasagar, Sudha

2015-07-01

Clinical diagnosis of scrub typhus is often difficult because the symptoms are very similar to those of other febrile illness such as dengue, leptospirosis, malaria and other viral hemorrhagic fevers. Though better diagnostic tests are available for rickettsial diseases and scrub typhus elsewhere, the Weil-Felix test is still commonly used in India, mainly because microimmunofluorescence assays (M-IFA) were not available in India till recently and relevant staff had insufficient training. The present study was performed to investigate the performance of M-IFA, IgM ELISA, and Weil-Felix test on 546 non-repeated serum samples from subjects suspected of having scrub typhus. One hundred and forty-three of these 546 samples were positive by M-IFA; these cases were also confirmed clinically to have scrub typhus based on their dramatic responses to doxycycline therapy. IgM ELISA was positive in 122 of the 143 M-IFA positive cases and the Weil-Felix test in 96. Though the Weil-Felix test is a heterophile agglutination test, it was found in this study to have good specificity but far too little sensitivity to use as a routine diagnostic test. IgM ELISA can be a good substitute for M-IFA. Incorporation of multiple prototype antigens on M-IFA slides is likely one of the reasons for its superior performance. As newer and better diagnostic assays become available for scrub typhus diagnosis in developed countries, it will be imperative to also use such tests in other endemic countries to prevent over- or under-diagnosis of scrub typhus. © 2015 The Societies and Wiley Publishing Asia Pty Ltd.

Development and Validation of Diagnostic Economics Test for Secondary Schools

ERIC Educational Resources Information Center

Eleje, Lydia I.; Esomonu, Nkechi P. M.; Agu, Ngozi N.; Okoye, Romy O.; Obasi, Emma; Onah, Frederick E.

2016-01-01

A diagnostic test in economics to aid the teachers determine student's specific weak content areas was developed and validated. Five research questions guided the study. Preliminary validation was done by two experienced teachers in the content area of secondary economics and two experts in test construction. The pilot testing was conducted for…

Diagnostic accuracy of physical examination tests of the ankle/foot complex: a systematic review.

PubMed

Schwieterman, Braun; Haas, Deniele; Columber, Kirby; Knupp, Darren; Cook, Chad

2013-08-01

Orthopedic special tests of the ankle/foot complex are routinely used during the physical examination process in order to help diagnose ankle/lower leg pathologies. The purpose of this systematic review was to investigate the diagnostic accuracy of ankle/lower leg special tests. A search of the current literature was conducted using PubMed, CINAHL, SPORTDiscus, ProQuest Nursing and Allied Health Sources, Scopus, and Cochrane Library. Studies were eligible if they included the following: 1) a diagnostic clinical test of musculoskeletal pathology in the ankle/foot complex, 2) description of the clinical test or tests, 3) a report of the diagnostic accuracy of the clinical test (e.g. sensitivity and specificity), and 4) an acceptable reference standard for comparison. The quality of included studies was determined by two independent reviewers using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool. Nine diagnostic accuracy studies met the inclusion criteria for this systematic review; analyzing a total of 16 special tests of the ankle/foot complex. After assessment using the QUADAS-2, only one study had low risk of bias and low concerns regarding applicability. Most ankle/lower leg orthopedic special tests are confirmatory in nature and are best utilized at the end of the physical examination. Most of the studies included in this systematic review demonstrate notable biases, which suggest that results and recommendations in this review should be taken as a guide rather than an outright standard. There is need for future research with more stringent study design criteria so that more accurate diagnostic power of ankle/lower leg special tests can be determined. 3a.

DIAGNOSTIC ACCURACY OF PHYSICAL EXAMINATION TESTS OF THE ANKLE/FOOT COMPLEX: A SYSTEMATIC REVIEW

PubMed Central

Schwieterman, Braun; Haas, Deniele; Columber, Kirby; Knupp, Darren

2013-01-01

Background: Orthopedic special tests of the ankle/foot complex are routinely used during the physical examination process in order to help diagnose ankle/lower leg pathologies. Purpose: The purpose of this systematic review was to investigate the diagnostic accuracy of ankle/lower leg special tests. Methods: A search of the current literature was conducted using PubMed, CINAHL, SPORTDiscus, ProQuest Nursing and Allied Health Sources, Scopus, and Cochrane Library. Studies were eligible if they included the following: 1) a diagnostic clinical test of musculoskeletal pathology in the ankle/foot complex, 2) description of the clinical test or tests, 3) a report of the diagnostic accuracy of the clinical test (e.g. sensitivity and specificity), and 4) an acceptable reference standard for comparison. The quality of included studies was determined by two independent reviewers using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool. Results: Nine diagnostic accuracy studies met the inclusion criteria for this systematic review; analyzing a total of 16 special tests of the ankle/foot complex. After assessment using the QUADAS-2, only one study had low risk of bias and low concerns regarding applicability. Conclusion: Most ankle/lower leg orthopedic special tests are confirmatory in nature and are best utilized at the end of the physical examination. Most of the studies included in this systematic review demonstrate notable biases, which suggest that results and recommendations in this review should be taken as a guide rather than an outright standard. There is need for future research with more stringent study design criteria so that more accurate diagnostic power of ankle/lower leg special tests can be determined. Level of Evidence: 3a PMID:24175128

9 CFR 147.8 - Procedures for preparing egg yolk samples for diagnostic tests.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Procedures for preparing egg yolk samples for diagnostic tests. 147.8 Section 147.8 Animals and Animal Products ANIMAL AND PLANT HEALTH... IMPROVEMENT PLAN Blood Testing Procedures § 147.8 Procedures for preparing egg yolk samples for diagnostic...

9 CFR 147.8 - Procedures for preparing egg yolk samples for diagnostic tests.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Procedures for preparing egg yolk samples for diagnostic tests. 147.8 Section 147.8 Animals and Animal Products ANIMAL AND PLANT HEALTH... IMPROVEMENT PLAN Blood Testing Procedures § 147.8 Procedures for preparing egg yolk samples for diagnostic...

9 CFR 147.8 - Procedures for preparing egg yolk samples for diagnostic tests.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Procedures for preparing egg yolk samples for diagnostic tests. 147.8 Section 147.8 Animals and Animal Products ANIMAL AND PLANT HEALTH... IMPROVEMENT PLAN Blood Testing Procedures § 147.8 Procedures for preparing egg yolk samples for diagnostic...

9 CFR 147.8 - Procedures for preparing egg yolk samples for diagnostic tests.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Procedures for preparing egg yolk samples for diagnostic tests. 147.8 Section 147.8 Animals and Animal Products ANIMAL AND PLANT HEALTH... IMPROVEMENT PLAN Blood Testing Procedures § 147.8 Procedures for preparing egg yolk samples for diagnostic...

Integrated Rapid-Diagnostic-Test Reader Platform on a Cellphone

PubMed Central

Mudanyali, Onur; Dimitrov, Stoyan; Sikora, Uzair; Padmanabhan, Swati; Navruz, Isa; Ozcan, Aydogan

2012-01-01

We demonstrate a cellphone based Rapid-Diagnostic-Test (RDT) reader platform that can work with various lateral flow immuno-chromatographic assays and similar tests to sense the presence of a target analyte in a sample. This compact and cost-effective digital RDT reader, weighing only ~65 grams, mechanically attaches to the existing camera unit of a cellphone, where various types of RDTs can be inserted to be imaged in reflection or transmission modes under light-emitting-diode (LED) based illumination. Captured raw images of these tests are then digitally processed (within less than 0.2 sec/image) through a smart application running on the cellphone for validation of the RDT as well as for automated reading of its diagnostic result. The same smart application running on the cellphone then transmits the resulting data, together with the RDT images and other related information (e.g., demographic data) to a central server, which presents the diagnostic results on a world-map through geo-tagging. This dynamic spatio-temporal map of various RDT results can then be viewed and shared using internet browsers or through the same cellphone application. We tested this platform using malaria, tuberculosis (TB) as well as HIV RDTs by installing it on both Android based smart-phones as well as an iPhone. Providing real-time spatio-temporal statistics for the prevalence of various infectious diseases, this smart RDT reader platform running on cellphones might assist health-care professionals and policy makers to track emerging epidemics worldwide and help epidemic preparedness. PMID:22596243

The Accuracy of Diagnostic Tests for Lyme Disease in Humans, A Systematic Review and Meta-Analysis of North American Research.

PubMed

Waddell, Lisa A; Greig, Judy; Mascarenhas, Mariola; Harding, Shannon; Lindsay, Robbin; Ogden, Nicholas

2016-01-01

There has been an increasing incidence of Lyme disease (LD) in Canada and the United States corresponding to the expanding range of the Ixodes tick vector and Lyme disease agent (Borrelia burgdorferi sensu stricto). There are many diagnostic tests for LD available in North America, all of which have some performance issues, and physicians are concerned about the appropriate use and interpretation of these tests. The objective of this systematic review is to summarize the North American evidence on the accuracy of diagnostic tests and test regimes at various stages of LD. Included in the review are 48 studies on diagnostic tests used in North America published since 1995. Thirteen studies examined a two-tier serological test protocol vs. clinical diagnosis, 24 studies examined single assays vs. clinical diagnosis, 9 studies examined single immunoblot vs. clinical diagnosis, 7 studies compared culture or PCR direct detection methods vs. clinical diagnosis, 22 studies compared two or more tests with each other and 8 studies compared a two-tiered serological test protocol to another test. Recent studies examining the sensitivity and specificity of various test protocols noted that the Immunetics® C6 B. burgdorferi ELISA™ and the two tier approach have superior specificity compared to proposed replacements, and the CDC recommended western blot algorithm has equivalent or superior specificity over other proposed test algorithms. There is a dramatic increase in test sensitivity with progression of B. burgdorferi infection from early to late LD. Direct detection methods, culture and PCR of tissue or blood samples were not as sensitive or timely compared to serological testing. It was also noted that there are a large number of both commercial (n = 42) and in-house developed tests used by private laboratories which have not been evaluated in the primary literature.

The Accuracy of Diagnostic Tests for Lyme Disease in Humans, A Systematic Review and Meta-Analysis of North American Research

PubMed Central

Lindsay, Robbin; Ogden, Nicholas

2016-01-01

There has been an increasing incidence of Lyme disease (LD) in Canada and the United States corresponding to the expanding range of the Ixodes tick vector and Lyme disease agent (Borrelia burgdorferi sensu stricto). There are many diagnostic tests for LD available in North America, all of which have some performance issues, and physicians are concerned about the appropriate use and interpretation of these tests. The objective of this systematic review is to summarize the North American evidence on the accuracy of diagnostic tests and test regimes at various stages of LD. Included in the review are 48 studies on diagnostic tests used in North America published since 1995. Thirteen studies examined a two-tier serological test protocol vs. clinical diagnosis, 24 studies examined single assays vs. clinical diagnosis, 9 studies examined single immunoblot vs. clinical diagnosis, 7 studies compared culture or PCR direct detection methods vs. clinical diagnosis, 22 studies compared two or more tests with each other and 8 studies compared a two-tiered serological test protocol to another test. Recent studies examining the sensitivity and specificity of various test protocols noted that the Immunetics® C6 B. burgdorferi ELISA™ and the two tier approach have superior specificity compared to proposed replacements, and the CDC recommended western blot algorithm has equivalent or superior specificity over other proposed test algorithms. There is a dramatic increase in test sensitivity with progression of B. burgdorferi infection from early to late LD. Direct detection methods, culture and PCR of tissue or blood samples were not as sensitive or timely compared to serological testing. It was also noted that there are a large number of both commercial (n = 42) and in-house developed tests used by private laboratories which have not been evaluated in the primary literature. PMID:28002488

The role of molecular diagnostic testing in the management of thyroid nodules.

PubMed

Moore, Maureen D; Panjwani, Suraj; Gray, Katherine D; Finnerty, Brendan M; Zarnegar, Rasa; Fahey, Thomas J

2017-06-01

Fine needle aspiration (FNA) with cytologic examination remains the standard of care for investigation of thyroid nodules. However, as many as 30% of FNA samples are cytologically indeterminate for malignancy, which confounds clinical management. To reduce the burden of repeat diagnostic testing and unnecessary surgery, there has been extensive investigation into molecular markers that can be detected on FNA specimens to more accurately stratify a patient's risk of malignancy. Areas covered: In this review, the authors discuss recent evidence and progress in molecular markers used in the diagnosis of thyroid cancer highlighting somatic gene alterations, molecular technologies and microRNA analysis. Expert commentary: The goal of molecular markers is to improve diagnostic accuracy and aid clinicians in the preoperative management of thyroid lesions. Modalities such as direct mutation analysis, mRNA gene expression profiling, next-generation sequencing, and miRNA expression profiling have been explored to improve the diagnostic accuracy of thyroid nodule FNA. Although no perfect test has been discovered, molecular diagnostic testing has revolutionized the management of thyroid nodules.

Concordance in diagnostic testing for respiratory pathogens of bighorn sheep

USGS Publications Warehouse

Walsh, Daniel P.; Cassirer, E. Frances; Bonds, Michael D.; Brown, Daniel R.; Edwards, William H.; Weiser, Glen C.; Drew, Mark L.; Briggs, Robert E.; Fox, Karen A.; Miller, Michael W.; Shanthalingam, Sudarvili; Srikumaran, Subramaniam; Besser, Thomas E.

2016-01-01

Reliable diagnostic tests are essential for disease investigation and management. This is particularly true for diseases of free-ranging wildlife where sampling is logistically difficult precluding retesting. Clinical assays for wildlife diseases frequently vary among laboratories because of lack of appropriate standardized commercial kits. Results of diagnostic testing may also be called into question when investigators report different etiologies for disease outbreaks, despite similar clinical and pathologic findings. To evaluate reliability of diagnostic testing for respiratory pathogens of bighorn sheep (Ovis canadensis), we conducted a series of ring tests across 6 laboratories routinely involved in detection of Mycoplasma ovipneumoniae, Pasteurellaceae, lktA (the Pasteurellaceae gene encoding leukotoxin), and 3 reference laboratories. Consistency of results for replicate samples within laboratories was high (median agreement = 1.0). Agreement between laboratories was high for polymerase chain reaction (PCR) detection of M. ovipneumoniae and culture isolation of Mannheimia spp. and Bibersteinia trehalosi(median agreement = 0.89–0.95, Kappa = 0.65–0.74), and lower for PCR detection of Mannheimiaspp. lktA (median agreement = 0.58, Kappa = 0.12). Most errors on defined status samples were false negatives, suggesting test sensitivity was a greater problem than specificity. However, tests for M. haemolytica and lktA yielded some false positive results. Despite differences in testing protocols, median agreement among laboratories and correct classification of controls for most agents was ≥0.80, meeting or exceeding the standard required by federal proficiency testing programs. This information is valuable for interpreting test results, laboratory quality assessments, and advancing diagnosis of respiratory disease in wild sheep. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Technology diffusion and diagnostic testing for prostate cancer

PubMed Central

Schroeck, Florian R.; Kaufman, Samuel R.; Jacobs, Bruce L.; Skolarus, Ted A.; Miller, David C.; Weizer, Alon Z.; Montgomery, Jeffrey S.; Wei, John T.; Shahinian, Vahakn B.; Hollenbeck, Brent K.

2013-01-01

Purpose While the dissemination of robotic prostatectomy and intensity-modulated radiotherapy (IMRT) may fuel increased use of prostatectomy and radiotherapy, these new technologies may also have spillover effects related to diagnostic testing for prostate cancer. Therefore, we examined the association of regional technology penetration with receipt of prostate specific antigen (PSA) testing and prostate biopsy. Methods In this retrospective cohort study, we included 117,857 men age 66 and older from the 5% sample of Medicare beneficiaries living in the Surveillance Epidemiology and End Results (SEER) areas from 2003 – 2007. Regional technology penetration was measured as the number of providers performing robotic prostatectomy or IMRT per population in a healthcare market (i.e., hospital referral region). We assessed the association of technology penetration with rates of PSA testing and prostate biopsy with generalized estimating equations. Results High technology penetration was associated with increased rates of PSA testing (442 versus 425 per 1,000 person-years, p<0.01) and similar rates of prostate biopsy (10.1 versus 9.9 per 1,000 person-years, p=0.69). The impact of technology penetration on PSA testing and prostate biopsy was much smaller than the effect of age, race, and comorbidity (e.g., PSA testing rate per 1,000 person-years: 485 versus 373 for men with only one versus 3+ co-morbid conditions, p<0.01). Conclusions Increased technology penetration was associated with slightly higher rates of PSA testing and no change in prostate biopsy rates. Collectively, our findings temper concerns that adoption of new technology accelerates diagnostic testing for prostate cancer. PMID:23669564

Diagnostic accuracy of clinical tests for assessment of hamstring injury: a systematic review.

PubMed

Reiman, Michael P; Loudon, Janice K; Goode, Adam P

2013-04-01

Systematic literature review. The diagnosis of a hamstring injury has traditionally relied on various clinical measures (eg, palpation, swelling, manual resistance), as well as the use of diagnostic imaging. But a few studies have suggested the use of specific clinical tests that may be helpful for the diagnostic process. To summarize the current literature on the diagnostic accuracy of orthopaedic special tests for hamstring injuries and to determine their clinical utility. A computer-assisted literature search of the MEDLINE, CINAHL, and Embase databases (along with a manual search of grey literature) was conducted using key words related to diagnostic accuracy of hamstring injuries. To be considered for inclusion in the review, the study required (1) patients with hamstring or posterior thigh pain; (2) a cohort, case-control, or cross-sectional design; (3) inclusion of at least 1 clinical examination test used to evaluate hamstring pathology; (4) comparison against an acceptable reference standard; (5) reporting of diagnostic accuracy of the measures (sensitivity [SN], specificity [SP], or likelihood ratios); and (6) publication in English. SN, SP, and positive and negative likelihood ratios were calculated for each diagnostic test. The search strategy identified 602 potential articles, of which only 3 articles met the inclusion criteria, with only 1 of these 3 articles being of high quality. Two of the studies investigated a single special test, whereas the third article examined a composite clinical assessment employing various special tests. The SN values ranged from 0.55 (95% confidence interval [CI]: 0.46, 0.69) for the active range-of-motion test to 1.00 (95% CI: 0.97, 1.00) for the taking-off-the-shoe test. The SP values ranged from 0.03 (95% CI: 0.00, 0.22) for the composite clinical assessment to 1.00 (95% CI: 0.97, 1.00) for the taking-off-the-shoe test, active range-of-motion test, passive range-of-motion test, and resisted range-of-motion test. The

30 CFR 250.523 - How long do I keep records of casing pressure and diagnostic tests?

Code of Federal Regulations, 2011 CFR

2011-07-01

... and diagnostic tests? 250.523 Section 250.523 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT... long do I keep records of casing pressure and diagnostic tests? Records of casing pressure and diagnostic tests must be kept at the field office nearest the well for a minimum of 2 years. The last casing...

Evidence of the preferential use of disease prototypes over case exemplars among early year one medical students prior to and following diagnostic training.

PubMed

Papa, Frank J; Li, Feiming

2015-12-01

Two core dual processing theory (DPT) System I constructs (Exemplars and Prototypes) were used to: 1) formulate a training exercise designed to improve diagnostic performance in year one medical students, and 2) explore whether any observed performance improvements were associated with preferential use of exemplars or prototypes. With IRB approval, 117 year one medical students participated in an acute chest pain diagnostic training exercise. A pre- and post-training test containing the same 27 case vignettes was used to determine if the subjects' diagnostic performance improved via training in both exemplars and prototypes. Exemplar and Prototype theory was also used to generate a unique typicality estimate for each case vignette. Because these estimates produce different performance predictions, differences in the subjects' observed performance would make it possible to infer whether subjects were preferentially using Exemplars or Prototypes. Pre- vs. post-training comparison revealed a significant performance improvement; t=14.04, p<0.001, Cohen's d=1.32. Pre-training, paired t-testing demonstrated that performance against the most typical vignettes>mid typical vignettes: t=4.94, p<0.001; and mid typical>least typical: t=5.16, p<0.001. Post-training, paired t-testing again demonstrated that performance against the most typical vignettes>mid typical: t=2.94, p<0.01; and mid typical>least typical: t=6.64, p<0.001. These findings are more consistent with the performance predictions generated via Prototype theory than Exemplar theory. DPT is useful in designing and evaluating the utility of new approaches to diagnostic training, and, investigating the cognitive factors driving diagnostic capabilities among early medical students.

A systematic review of the diagnostic performance of orthopedic physical examination tests of the hip.

PubMed

Rahman, Labib Ataur; Adie, Sam; Naylor, Justine Maree; Mittal, Rajat; So, Sarah; Harris, Ian Andrew

2013-08-30

Previous reviews of the diagnostic performances of physical tests of the hip in orthopedics have drawn limited conclusions because of the low to moderate quality of primary studies published in the literature. This systematic review aims to build on these reviews by assessing a broad range of hip pathologies, and employing a more selective approach to the inclusion of studies in order to accurately gauge diagnostic performance for the purposes of making recommendations for clinical practice and future research. It specifically identifies tests which demonstrate strong and moderate diagnostic performance. A systematic search of Medline, Embase, Embase Classic and CINAHL was conducted to identify studies of hip tests. Our selection criteria included an analysis of internal and external validity. We reported diagnostic performance in terms of sensitivity, specificity, predictive values and likelihood ratios. Likelihood ratios were used to identify tests with strong and moderate diagnostic utility. Only a small proportion of tests reported in the literature have been assessed in methodologically valid primary studies. 16 studies were included in our review, producing 56 independent test-pathology combinations. Two tests demonstrated strong clinical utility, the patellar-pubic percussion test for excluding radiologically occult hip fractures (negative LR 0.05, 95% Confidence Interval [CI] 0.03-0.08) and the hip abduction sign for diagnosing sarcoglycanopathies in patients with known muscular dystrophies (positive LR 34.29, 95% CI 10.97-122.30). Fifteen tests demonstrated moderate diagnostic utility for diagnosing and/or excluding hip fractures, symptomatic osteoarthritis and loosening of components post-total hip arthroplasty. We have identified a number of tests demonstrating strong and moderate diagnostic performance. These findings must be viewed with caution as there are concerns over the methodological quality of the primary studies from which we have extracted our

Testing the robustness of the diagnostic overshadowing bias.

PubMed

Spengler, P M; Strohmer, D C; Prout, H T

1990-09-01

The robustness of the diagnostic overshadowing bias was examined by (a) testing the relation of overshadowing to level of mental retardation, (b) reexamining the effect of clinical experience in a more sensitive analysis, and (c) extending previous results to rehabilitation counselors. Diagnostic overshadowing was found with individuals with an IQ of 58, but did not generalize to those with IQs 70 or 80. This finding does not support the saliency hypothesis proposed by Reiss and his colleagues. In contrast to earlier studies, experience was related to overshadowing, although results were mixed. Experience measured by number of clients seen was not significant, whereas longevity in the field of mental retardation was associated with increased overshadowing.

Diagnostic Accuracy of the Neck Tornado Test as a New Screening Test in Cervical Radiculopathy

PubMed Central

Park, Juyeon; Park, Woo Young; Hong, Seungbae; An, Jiwon; Koh, Jae Chul; Lee, Youn-Woo; Kim, Yong Chan; Choi, Jong Bum

2017-01-01

Background: The Spurling test, although a highly specific provocative test of the cervical spine in cervical radiculopathy (CR), has low to moderate sensitivity. Thus, we introduced the neck tornado test (NTT) to examine the neck and the cervical spine in CR. Objectives: The aim of this study was to introduce a new provocative test, the NTT, and compare the diagnostic accuracy with a widely accepted provocative test, the Spurling test. Design: Retrospective study. Methods: Medical records of 135 subjects with neck pain (CR, n = 67; without CR, n = 68) who had undergone cervical spine magnetic resonance imaging and been referred to the pain clinic between September 2014 and August 2015 were reviewed. Both the Spurling test and NTT were performed in all patients by expert examiners. Sensitivity, specificity, and accuracy were compared for both the Spurling test and the NTT. Results: The sensitivity of the Spurling test and the NTT was 55.22% and 85.07% (P < 0.0001); specificity, 98.53% and 86.76% (P = 0.0026); accuracy, 77.04% and 85.93% (P = 0.0423), respectively. Conclusions: The NTT is more sensitive with superior diagnostic accuracy for CR diagnosed by magnetic resonance imaging than the Spurling test. PMID:28824298

Diagnostic test accuracy of nutritional tools used to identify undernutrition in patients with colorectal cancer: a systematic review.

PubMed

Håkonsen, Sasja Jul; Pedersen, Preben Ulrich; Bath-Hextall, Fiona; Kirkpatrick, Pamela

2015-05-15

Effective nutritional screening, nutritional care planning and nutritional support are essential in all settings, and there is no doubt that a health service seeking to increase safety and clinical effectiveness must take nutritional care seriously. Screening and early detection of malnutrition is crucial in identifying patients at nutritional risk. There is a high prevalence of malnutrition in hospitalized patients undergoing treatment for colorectal cancer. To synthesize the best available evidence regarding the diagnostic test accuracy of nutritional tools (sensitivity and specificity) used to identify malnutrition (specifically undernutrition) in patients with colorectal cancer (such as the Malnutrition Screening Tool and Nutritional Risk Index) compared to reference tests (such as the Subjective Global Assessment or Patient Generated Subjective Global Assessment). Patients with colorectal cancer requiring either (or all) surgery, chemotherapy and/or radiotherapy in secondary care. Focus of the review: The diagnostic test accuracy of validated assessment tools/instruments (such as the Malnutrition Screening Tool and Nutritional Risk Index) in the diagnosis of malnutrition (specifically under-nutrition) in patients with colorectal cancer, relative to reference tests (Subjective Global Assessment or Patient Generated Subjective Global Assessment). Types of studies: Diagnostic test accuracy studies regardless of study design. Studies published in English, German, Danish, Swedish and Norwegian were considered for inclusion in this review. Databases were searched from their inception to April 2014. Methodological quality was determined using the Quality Assessment of Diagnostic Accuracy Studies checklist. Data was collected using the data extraction form: the Standards for Reporting Studies of Diagnostic Accuracy checklist for the reporting of studies of diagnostic accuracy. The accuracy of diagnostic tests is presented in terms of sensitivity, specificity, positive

Small business development for molecular diagnostics.

PubMed

Anagostou, Anthanasia; Liotta, Lance A

2012-01-01

Molecular profiling, which is the application of molecular diagnostics technology to tissue and blood -specimens, is an integral element in the new era of molecular medicine and individualized therapy. Molecular diagnostics is a fertile ground for small business development because it can generate products that meet immediate demands in the health-care sector: (a) Detection of disease risk, or early-stage disease, with a higher specificity and sensitivity compared to previous testing methods, and (b) "Companion diagnostics" for stratifying patients to receive a treatment choice optimized to their individual disease. This chapter reviews the promise and challenges of business development in this field. Guidelines are provided for the creation of a business model and the generation of a marketing plan around a candidate molecular diagnostic product. Steps to commercialization are outlined using existing molecular diagnostics companies as learning examples.

The business of genomic testing: a survey of early adopters.

PubMed

Crawford, James M; Bry, Lynn; Pfeifer, John; Caughron, Samuel K; Black-Schaffer, Stephen; Kant, Jeffrey A; Kaufman, Jill H

2014-12-01

The practice of "genomic" (or "personalized") medicine requires the availability of appropriate diagnostic testing. Our study objective was to identify the reasons for health systems to bring next-generation sequencing into their clinical laboratories and to understand the process by which such decisions were made. Such information may be of value to other health systems seeking to provide next-generation sequencing testing to their patient populations. A standardized open-ended interview was conducted with the laboratory medical directors and/or department of pathology chairs of 13 different academic institutions in 10 different states. Genomic testing for cancer dominated the institutional decision making, with three primary reasons: more effective delivery of cancer care, the perceived need for institutional leadership in the field of genomics, and the premise that genomics will eventually be cost-effective. Barriers to implementation included implementation cost; the time and effort needed to maintain this newer testing; challenges in interpreting genetic variants; establishing the bioinformatics infrastructure; and curating data from medical, ethical, and legal standpoints. Ultimate success depended on alignment with institutional strengths and priorities and working closely with institutional clinical programs. These early adopters uniformly viewed genomic analysis as an imperative for developing their expertise in the implementation and practice of genomic medicine.

9 CFR 93.404 - Import permits for ruminants and for ruminant test specimens for diagnostic purposes; and...

Code of Federal Regulations, 2012 CFR

2012-01-01

... ruminant test specimens for diagnostic purposes; and reservation fees for space at quarantine facilities... for ruminants and for ruminant test specimens for diagnostic purposes; and reservation fees for space...) For ruminants and ruminant test specimens for diagnostic screening purposes intended for importation...

9 CFR 93.404 - Import permits for ruminants and for ruminant test specimens for diagnostic purposes; and...

Code of Federal Regulations, 2013 CFR

2013-01-01

... ruminant test specimens for diagnostic purposes; and reservation fees for space at quarantine facilities... for ruminants and for ruminant test specimens for diagnostic purposes; and reservation fees for space...) For ruminants and ruminant test specimens for diagnostic screening purposes intended for importation...

9 CFR 93.404 - Import permits for ruminants and for ruminant test specimens for diagnostic purposes; and...

Code of Federal Regulations, 2014 CFR

2014-01-01

... ruminant test specimens for diagnostic purposes; and reservation fees for space at quarantine facilities... for ruminants and for ruminant test specimens for diagnostic purposes; and reservation fees for space...) For ruminants and ruminant test specimens for diagnostic screening purposes intended for importation...

9 CFR 93.404 - Import permits for ruminants and for ruminant test specimens for diagnostic purposes; and...

Code of Federal Regulations, 2010 CFR

2010-01-01

... ruminant test specimens for diagnostic purposes; and reservation fees for space at quarantine facilities... for ruminants and for ruminant test specimens for diagnostic purposes; and reservation fees for space...) For ruminants and ruminant test specimens for diagnostic screening purposes intended for importation...

9 CFR 93.404 - Import permits for ruminants and for ruminant test specimens for diagnostic purposes; and...

Code of Federal Regulations, 2011 CFR

2011-01-01

... ruminant test specimens for diagnostic purposes; and reservation fees for space at quarantine facilities... for ruminants and for ruminant test specimens for diagnostic purposes; and reservation fees for space...) For ruminants and ruminant test specimens for diagnostic screening purposes intended for importation...

Quality of information accompanying on-line marketing of home diagnostic tests.

PubMed

Datta, Adrija K; Selman, Tara J; Kwok, Tony; Tang, Teresa; Khan, Khalid S

2008-01-01

To assess the quality of information provided to consumers by websites marketing medical home diagnostic tests. A cross-sectional analysis of a database developed from searching targeted websites. Data sources were websites written in English which marketed medical home diagnostic tests. A meta-search engine was used to identify the first 20 citations for each type of home diagnostic medical test. Relevant websites limited to those written in English were reviewed independently and in triplicate, with disputes resolved by two further reviewers. Information on the quality of these sites was extracted using a pre-piloted performer. 168 websites were suitable for inclusion in the review. The quality of these sites showed marked variation. Only 24 of 168 (14.2%) complied with at least three-quarters of the quality items and just over half (95 of 168, 56.5%) reported official approval or certification of the test. Information on accuracy of the test marketed was reported by 87 of 168 (51.7%) websites, with 15 of 168 (8.9%) providing a scientific reference. Instructions for use of the product were found in 97 of 168 (57.9%). However, the course of action to be taken after obtaining the test result was stated in only 63 of 168 (37.5%) for a positive result and 43 of 168 (25.5%) for a negative result. The quality of information posted on commercial websites marketing home tests online is unsatisfactory and potentially misleading for consumers.

Combining computer adaptive testing technology with cognitively diagnostic assessment.

PubMed

McGlohen, Meghan; Chang, Hua-Hua

2008-08-01

A major advantage of computerized adaptive testing (CAT) is that it allows the test to home in on an examinee's ability level in an interactive manner. The aim of the new area of cognitive diagnosis is to provide information about specific content areas in which an examinee needs help. The goal of this study was to combine the benefit of specific feedback from cognitively diagnostic assessment with the advantages of CAT. In this study, three approaches to combining these were investigated: (1) item selection based on the traditional ability level estimate (theta), (2) item selection based on the attribute mastery feedback provided by cognitively diagnostic assessment (alpha), and (3) item selection based on both the traditional ability level estimate (theta) and the attribute mastery feedback provided by cognitively diagnostic assessment (alpha). The results from these three approaches were compared for theta estimation accuracy, attribute mastery estimation accuracy, and item exposure control. The theta- and alpha-based condition outperformed the alpha-based condition regarding theta estimation, attribute mastery pattern estimation, and item exposure control. Both the theta-based condition and the theta- and alpha-based condition performed similarly with regard to theta estimation, attribute mastery estimation, and item exposure control, but the theta- and alpha-based condition has an additional advantage in that it uses the shadow test method, which allows the administrator to incorporate additional constraints in the item selection process, such as content balancing, item type constraints, and so forth, and also to select items on the basis of both the current theta and alpha estimates, which can be built on top of existing 3PL testing programs.

LASER BIOLOGY AND MEDICINE: Combination of fluorescence imaging and local spectrophotometry in fluorescence diagnostics of early cancer of larynx and bronchi

NASA Astrophysics Data System (ADS)

Sokolov, Vladimir V.; Filonenko, E. V.; Telegina, L. V.; Boulgakova, N. N.; Smirnov, V. V.

2002-11-01

The results of comparative studies of autofluorescence and 5-ALA-induced fluorescence of protoporphyrin IX, used in the diagnostics of early cancer of larynx and bronchi, are presented. The autofluorescence and 5-ALA-induced fluorescence images of larynx and bronchial tissues are analysed during the endoscopic study. The method of local spectrophotometry is used to verify findings obtained from fluorescence images. It is shown that such a combined approach can be efficiently used to improve the diagnostics of precancer and early cancer, to detect a primary multiple tumours, as well as for the diagnostics of a residual tumour or an early recurrence after the endoscopic, surgery or X-ray treatment. The developed approach allows one to minimise the number of false-positive results and to reduce the number of biopsies, which are commonly used in the white-light bronchoscopy search for occult cancerous loci.

[Rapid diagnostic tests for the serodiagnosis of human cystic echinococcosis].

PubMed

Tamarozzi, F; Mariconti, M; Covini, I; Brunetti, E

2017-02-01

Cystic echinococcosis (CE) is a parasitic zoonosis especially affecting resource-poor populations in livestock raising areas. Imaging, in particular ultrasound (US), is crucial for the diagnosis, staging, and clinical management of abdominal CE in humans. Serology is a valuable complement to imaging, especially when ultrasound features of CE are absent or unclear. In rural endemic areas, where expertise in US is scant, and conventional serology techniques are unavailable due to lack of laboratory equipment, rapid diagnostic tests (RDTs) may be very useful. Several reports have described the performance of commercial and experimental RDTs in the diagnosis of CE, including a recent study by our group that compared the diagnostic performances of three commercial RDTs for the diagnosis of hepatic CE. To put RDTs for CE in context, we reviewed the available literature in English on this topic. Overall, RDTs appear to be useful in resourcepoor settings where they may replace conventional serodiagnostic tests. However, like other serodiagnostic tests, RDTs lack standardization and show unsatisfactory sensitivity and specificity. An important issue that needs to be addressed is that studies on the diagnostic performance of RDTs fail to take into account the variables known to influence results such as anatomical location and cyst stage.

The dilemma of diagnostic testing for Prader-Willi syndrome

PubMed Central

Hung, Dorothy

2017-01-01

Although Prader-Willi syndrome (PWS) is a well-described clinical dysmorphic syndrome, DNA testing is required for a definitive diagnosis. A definitive diagnosis can be made in approximately 99% of cases using DNA testing; there are a number of DNA tests that can be used for this purpose, although there is no set standard algorithm of testing. The dilemma arises because of the complex genetic mechanisms at the basis of PWS, which need to be elucidated. To establish the molecular mechanism with a complete work up, involves at least 2 tests. Here we discuss the commonly used tests currently available and suggest a cost—effective approach to diagnostic testing. PMID:28164030

Technology diffusion and diagnostic testing for prostate cancer.

PubMed

Schroeck, Florian R; Kaufman, Samuel R; Jacobs, Bruce L; Skolarus, Ted A; Miller, David C; Weizer, Alon Z; Montgomery, Jeffrey S; Wei, John T; Shahinian, Vahakn B; Hollenbeck, Brent K

2013-11-01

While the dissemination of robotic prostatectomy and intensity modulated radiotherapy may fuel the increased use of prostatectomy and radiotherapy, these new technologies may also have spillover effects related to diagnostic testing for prostate cancer. Therefore, we examined the association of regional technology penetration with the receipt of prostate specific antigen testing and prostate biopsy. In this retrospective cohort study we included 117,857 men 66 years old or older from the 5% sample of Medicare beneficiaries living in Surveillance, Epidemiology and End Results (SEER) areas from 2003 to 2007. Regional technology penetration was measured as the number of providers performing robotic prostatectomy or intensity modulated radiotherapy per population in a health care market, ie hospital referral region. We assessed the association of technology penetration with the prostate specific antigen testing rate and prostate biopsy using generalized estimating equations. High technology penetration was associated with an increased rate of prostate specific antigen testing (442 vs 425/1,000 person-years, p<0.01) and a similar rate of prostate biopsy (10.1 vs 9.9/1,000 person-years, p=0.69). The impact of technology penetration on prostate specific antigen testing and prostate biopsy was much less than the effect of age, race and comorbidity, eg the prostate specific antigen testing rate per 1,000 person-years was 485 vs 373 for men with only 1 vs 3+ comorbid conditions (p<0.01). Increased technology penetration is associated with a slightly higher rate of prostate specific antigen testing and no change in the prostate biopsy rate. Collectively, our findings temper concerns that adopting new technology accelerates diagnostic testing for prostate cancer. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Diagnostic capability of Pulsar perimetry in pre-perimetric and early glaucoma.

PubMed

Hirasawa, Kazunori; Takahashi, Natsumi; Matsumura, Kazuhiro; Kasahara, Masayuki; Shoji, Nobuyuki

2017-06-12

This study aimed to compare the diagnostic capability of Pulsar perimetry (Pulsar) in pre-perimetric glaucoma (PPG) and early glaucoma (EG) with that of Flicker perimetry (Flicker) and spectral-domain optical conference tomography (SD-OCT). This prospective cross-sectional study included 25 eyes of 25 PPG patients, 35 eyes of 35 EG patients, and 42 eyes of 42 healthy participants. The diagnostic capability using the area under the curve (AUC) of the best parameter and agreement of detectability between structural and functional measurements were compared. For PPG patients, the AUC of Pulsar, Flicker, OCT-disc, and OCT-macular was 0.733, 0.663, 0.842, and 0.780, respectively. The AUC of Flicker was significantly lower than that of OCT-disc (p = 0.016). For EG patients, the AUC of Pulsar, Flicker, OCT-disc, and OCT-macular were 0.851, 0.869, 0.907, and 0.861, respectively. There was no significant difference in AUC among these methods. The agreement between structural and functional measurements expressed by kappa value ranged from -0.16 to 0.07 for PPG and from 0.01 to 0.25 for EG. Although the diagnostic capability of Pulsar in the PPG and EG groups was equal to that of Flicker and SD-OCT, the agreements between structural and functional measurements for both PPG and EG were poor.

Tourniquet Test for Dengue Diagnosis: Systematic Review and Meta-analysis of Diagnostic Test Accuracy.

PubMed

Grande, Antonio Jose; Reid, Hamish; Thomas, Emma; Foster, Charlie; Darton, Thomas C

2016-08-01

Dengue fever is a ubiquitous arboviral infection in tropical and sub-tropical regions, whose incidence has increased over recent decades. In the absence of a rapid point of care test, the clinical diagnosis of dengue is complex. The World Health Organisation has outlined diagnostic criteria for making the diagnosis of dengue infection, which includes the use of the tourniquet test (TT). To assess the quality of the evidence supporting the use of the TT and perform a diagnostic accuracy meta-analysis comparing the TT to antibody response measured by ELISA. A comprehensive literature search was conducted in the following databases to April, 2016: MEDLINE (PubMed), EMBASE, Cochrane Central Register of Controlled Trials, BIOSIS, Web of Science, SCOPUS. Studies comparing the diagnostic accuracy of the tourniquet test with ELISA for the diagnosis of dengue were included. Two independent authors extracted data using a standardized form. A total of 16 studies with 28,739 participants were included in the meta-analysis. Pooled sensitivity for dengue diagnosis by TT was 58% (95% Confidence Interval (CI), 43%-71%) and the specificity was 71% (95% CI, 60%-80%). In the subgroup analysis sensitivity for non-severe dengue diagnosis was 55% (95% CI, 52%-59%) and the specificity was 63% (95% CI, 60%-66%), whilst sensitivity for dengue hemorrhagic fever diagnosis was 62% (95% CI, 53%-71%) and the specificity was 60% (95% CI, 48%-70%). Receiver-operator characteristics demonstrated a test accuracy (AUC) of 0.70 (95% CI, 0.66-0.74). The tourniquet test is widely used in resource poor settings despite currently available evidence demonstrating only a marginal benefit in making a diagnosis of dengue infection alone. The protocol for this systematic review was registered at CRD42015020323.

Generalized likelihood ratios for quantitative diagnostic test scores.

PubMed

Tandberg, D; Deely, J J; O'Malley, A J

1997-11-01

The reduction of quantitative diagnostic test scores to the dichotomous case is a wasteful and unnecessary simplification in the era of high-speed computing. Physicians could make better use of the information embedded in quantitative test results if modern generalized curve estimation techniques were applied to the likelihood functions of Bayes' theorem. Hand calculations could be completely avoided and computed graphical summaries provided instead. Graphs showing posttest probability of disease as a function of pretest probability with confidence intervals (POD plots) would enhance acceptance of these techniques if they were immediately available at the computer terminal when test results were retrieved. Such constructs would also provide immediate feedback to physicians when a valueless test had been ordered.

42 CFR 414.506 - Procedures for public consultation for payment for a new clinical diagnostic laboratory test.

Code of Federal Regulations, 2010 CFR

2010-10-01

... a new clinical diagnostic laboratory test. 414.506 Section 414.506 Public Health CENTERS FOR... FOR PART B MEDICAL AND OTHER HEALTH SERVICES Payment for New Clinical Diagnostic Laboratory Tests § 414.506 Procedures for public consultation for payment for a new clinical diagnostic laboratory test...

42 CFR 414.506 - Procedures for public consultation for payment for a new clinical diagnostic laboratory test.

Code of Federal Regulations, 2011 CFR

2011-10-01

... a new clinical diagnostic laboratory test. 414.506 Section 414.506 Public Health CENTERS FOR... FOR PART B MEDICAL AND OTHER HEALTH SERVICES Payment for New Clinical Diagnostic Laboratory Tests § 414.506 Procedures for public consultation for payment for a new clinical diagnostic laboratory test...

Psychoacoustic Assessment of Speech Communication Systems. The Diagnostic Discrimination Test.

ERIC Educational Resources Information Center

Grether, Craig Blaine

The present report traces the rationale, development and experimental evaluation of the Diagnostic Discrimination Test (DDT). The DDT is a three-choice test of consonant discriminability of the perceptual/acoustic dimensions of consonant phonemes within specific vowel contexts. The DDT was created and developed in an attempt to provide a…

Power calculation for comparing diagnostic accuracies in a multi-reader, multi-test design.

PubMed

Kim, Eunhee; Zhang, Zheng; Wang, Youdan; Zeng, Donglin

2014-12-01

Receiver operating characteristic (ROC) analysis is widely used to evaluate the performance of diagnostic tests with continuous or ordinal responses. A popular study design for assessing the accuracy of diagnostic tests involves multiple readers interpreting multiple diagnostic test results, called the multi-reader, multi-test design. Although several different approaches to analyzing data from this design exist, few methods have discussed the sample size and power issues. In this article, we develop a power formula to compare the correlated areas under the ROC curves (AUC) in a multi-reader, multi-test design. We present a nonparametric approach to estimate and compare the correlated AUCs by extending DeLong et al.'s (1988, Biometrics 44, 837-845) approach. A power formula is derived based on the asymptotic distribution of the nonparametric AUCs. Simulation studies are conducted to demonstrate the performance of the proposed power formula and an example is provided to illustrate the proposed procedure. © 2014, The International Biometric Society.

Introducing malaria rapid diagnostic tests at registered drug shops in Uganda: Limitations of diagnostic testing in the reality of diagnosis.

PubMed Central

Hall-Clifford, Rachel; Asaph, Turinde; Magnussen, Pascal; Clarke, Siân; Mbonye, Anthony K

2014-01-01

In Uganda, around two thirds of medicines are procured from the private sector, mostly from drug shops. The introduction of malaria rapid diagnostic tests (RDTs) at drug shops therefore has the potential to make a significant contribution to targeting antimalarial drugs to those with malaria parasites. We undertook formative research in a district in Uganda in preparation for a randomised trial of RDTs in drug shops. In May to July 2009, we interviewed 9 drug shop workers, 5 health workers and 4 district health officials and carried out 10 focus group discussions with a total of 75 community members to investigate the role of drug shops and the potential for implementation of RDTs at these health care outlets. Drug shops were seen to provide an important service to community members, the nature of which is determined by responsiveness to client demands. However, drug shops hold a liminal status: in the eyes of different actors, these outlets are at once a shop and clinic; legitimate and illegitimate; and trusted and distrusted. Malaria treatment was found to be synonymous with diagnosis. Diagnostic testing was deemed useful in theory, and community members were curious about the results, with the expectation that a test would decrease uncertainty and help secure an end to illness. However, whether testing would be sought as a routine step in treatment decisions in practice is uncertain, since the appeal of the tests waned in light of their costs and potential for results to conflict with presumed diagnosis. Interventions that increase awareness of multiple causes and management of malaria-like illness will be needed to support the new rationalisation for malaria treatment represented by parasitological diagnosis. PMID:21349623

Artificial receptors in serologic tests for the early diagnosis of dengue virus infection.

PubMed

Tai, Dar-Fu; Lin, Chung-Yin; Wu, Tzong-Zeng; Huang, Jyh-Hsiung; Shu, Pei-Yun

2006-08-01

Because of the range and nonspecificity of clinical presentations of dengue virus infections, we felt there was a need to create diagnostic tests. We used artificial receptors for the virus to develop serologic assays to detect dengue virus infection. We coated a quartz crystal microbalance (QCM) with molecularly imprinted polymers specific for nonstructural protein 1 of flavivirus. These artificial receptors were specifically created on a QCM chip by polymerization of monomers and were cross-linked in the presence of the epitope site of nonstructural protein 1. We tested serum samples from patients with confirmed cases of dengue reported to the Center for Disease Control in Taipei. Samples were diluted 100-fold; no other sample pretreatment was used. The QCM response was compared with results of monoclonal ELISA. QCM signals were >15 Hz in 18 of 21 (86%) of dengue samples and in 0 of 16 control samples. The correlation (r2) of the QCM response and the ELISA result was 0.73. Within-run and run-to-run imprecisions (CV) were 4%-28% and 10%-32%, respectively. The described assay offers a serologic technique for diagnosis of early viremia. The results illustrate the potential of well-organized polymers on the highly sensitive sensor system for diagnostic and biotechnological applications.

Diagnostic Tests for Entering and Departing Undergraduate Students

NASA Astrophysics Data System (ADS)

Waltham, Chris; Kotlicki, A.

2006-12-01

A diagnostic test administered at the start of a class should test basic concepts which are recognized as course prerequisites. The questions should not be over-packaged: e.g. students should be required to create models, rather than this being done for them each time. Students should be allowed great latitude in their answers, so we can discover what they are thinking. When administered at the end of a class the goals should be similar: testing concepts taught in the class itself and the retention of necessary concepts from previous classes. Great care has to be taken to avoid teaching to the test. In assessing an entire program, for example an undergraduate majors degree in physics, then one looks for very general skills and knowledge not specific to any one course. The purpose of an undergraduate degree in physics (or indeed any science) is to equip the students with a set of problem-solving skills and basic knowledge which can be applied in a large variety of workplace settings and to allow that student to contribute to civic society as a science-literate person. The creator of any diagnostic test should always have these big goals in mind. We have developed a set of questions which we think fulfill these criteria, yet are not specific to any particular level of science education. They have been administered to students in secondary schools across Canada, incoming first-year science students and final-year physics students at the University of British Columbia. The results will be presented.

Rocket engine exhaust plume diagnostics and health monitoring/management during ground testing

NASA Technical Reports Server (NTRS)

Chenevert, D. J.; Meeks, G. R.; Woods, E. G.; Huseonica, H. F.

1992-01-01

The current status of a rocket exhaust plume diagnostics program sponsored by NASA is reviewed. The near-term objective of the program is to enhance test operation efficiency and to provide for safe cutoff of rocket engines prior to incipient failure, thereby avoiding the destruction of the engine and the test complex and preventing delays in the national space program. NASA programs that will benefit from the nonintrusive remote sensed rocket plume diagnostics and related vehicle health management and nonintrusive measurement program are Space Shuttle Main Engine, National Launch System, National Aero-Space Plane, Space Exploration Initiative, Advanced Solid Rocket Motor, and Space Station Freedom. The role of emission spectrometry and other types of remote sensing in rocket plume diagnostics is discussed.

A systematic review of the diagnostic performance of orthopedic physical examination tests of the hip

PubMed Central

2013-01-01

Background Previous reviews of the diagnostic performances of physical tests of the hip in orthopedics have drawn limited conclusions because of the low to moderate quality of primary studies published in the literature. This systematic review aims to build on these reviews by assessing a broad range of hip pathologies, and employing a more selective approach to the inclusion of studies in order to accurately gauge diagnostic performance for the purposes of making recommendations for clinical practice and future research. It specifically identifies tests which demonstrate strong and moderate diagnostic performance. Methods A systematic search of Medline, Embase, Embase Classic and CINAHL was conducted to identify studies of hip tests. Our selection criteria included an analysis of internal and external validity. We reported diagnostic performance in terms of sensitivity, specificity, predictive values and likelihood ratios. Likelihood ratios were used to identify tests with strong and moderate diagnostic utility. Results Only a small proportion of tests reported in the literature have been assessed in methodologically valid primary studies. 16 studies were included in our review, producing 56 independent test-pathology combinations. Two tests demonstrated strong clinical utility, the patellar-pubic percussion test for excluding radiologically occult hip fractures (negative LR 0.05, 95% Confidence Interval [CI] 0.03-0.08) and the hip abduction sign for diagnosing sarcoglycanopathies in patients with known muscular dystrophies (positive LR 34.29, 95% CI 10.97-122.30). Fifteen tests demonstrated moderate diagnostic utility for diagnosing and/or excluding hip fractures, symptomatic osteoarthritis and loosening of components post-total hip arthroplasty. Conclusions We have identified a number of tests demonstrating strong and moderate diagnostic performance. These findings must be viewed with caution as there are concerns over the methodological quality of the primary

Identification student’s misconception of heat and temperature using three-tier diagnostic test

NASA Astrophysics Data System (ADS)

Suliyanah; Putri, H. N. P. A.; Rohmawati, L.

2018-03-01

The objective of this research is to develop a Three-Tier Diagnostic Test (TTDT) to identify the student's misconception of heat and temperature. Stages of development include: analysis, planning, design, development, evaluation and revise. The results of this study show that (1) the quality of the three-tier type diagnostic test instrument developed has been expressed well with the following details: (a) Internal validity of 88.19% belonging to the valid category. (b) External validity of empirical construct validity test using Pearson Product Moment obtained 0.43 is classified and result of empirical construct validity test obtained false positives 6.1% and false negatives 5.9% then the instrument was valid. (c) Test reliability by using Cronbach’s Alpha of 0.98 which means acceptable. (d) The 80% difficulty level test is quite difficult. (2) Student misconceptions on the temperature of heat and displacement materials based on the II test the highest (84%), the lowest (21%), and the non-misconceptions (7%). (3) The highest cause of misconception among students is associative thinking (22%) and the lowest is caused by incomplete or incomplete reasoning (11%). Three-Tier Diagnostic Test (TTDT) could identify the student's misconception of heat and temperature.

[Clinical Application of Non-invasive Diagnostic Tests for Liver Fibrosis].

PubMed

Shin, Jung Woo; Park, Neung Hwa

2016-07-25

The diagnostic assessment of liver fibrosis is an important step in the management of patients with chronic liver diseases. Liver biopsy is considered the gold standard to assess necroinflammation and fibrosis. However, recent technical advances have introduced numerous serum biomarkers and imaging tools using elastography as noninvasive alternatives to biopsy. Serum markers can be direct or indirect markers of the fibrosis process. The elastography-based studies include transient elastography, acoustic radiation force imaging, supersonic shear wave imaging and magnetic resonance elastography. As accumulation of clinical data shows that noninvasive tests provide prognostic information of clinical relevance, non-invasive diagnostic tools have been incorporated into clinical guidelines and practice. Here, the authors review noninvasive tests for the diagnosis of liver fibrosis.

Quality of information accompanying on-line marketing of home diagnostic tests

PubMed Central

Datta, Adrija K; Selman, Tara J; Kwok, Tony; Tang, Teresa; Khan, Khalid S

2008-01-01

Objective To assess the quality of information provided to consumers by websites marketing medical home diagnostic tests. Design A cross-sectional analysis of a database developed from searching targeted websites. Setting Data sources were websites written in English which marketed medical home diagnostic tests. Main outcome measures A meta-search engine was used to identify the first 20 citations for each type of home diagnostic medical test. Relevant websites limited to those written in English were reviewed independently and in triplicate, with disputes resolved by two further reviewers. Information on the quality of these sites was extracted using a pre-piloted performer. Results 168 websites were suitable for inclusion in the review. The quality of these sites showed marked variation. Only 24 of 168 (14.2%) complied with at least three-quarters of the quality items and just over half (95 of 168, 56.5%) reported official approval or certification of the test. Information on accuracy of the test marketed was reported by 87 of 168 (51.7%) websites, with 15 of 168 (8.9%) providing a scientific reference. Instructions for use of the product were found in 97 of 168 (57.9%). However, the course of action to be taken after obtaining the test result was stated in only 63 of 168 (37.5%) for a positive result and 43 of 168 (25.5%) for a negative result. Conclusions The quality of information posted on commercial websites marketing home tests online is unsatisfactory and potentially misleading for consumers. PMID:18263912

Diagnostic accuracy of apparent diffusion coefficient and 123I-metaiodobenzylguanidine for differentiation of multiple system atrophy and Parkinson's disease.

PubMed

Umemura, Atsushi; Oeda, Tomoko; Hayashi, Ryutaro; Tomita, Satoshi; Kohsaka, Masayuki; Yamamoto, Kenji; Sawada, Hideyuki

2013-01-01

It is often hard to differentiate Parkinson's disease (PD) and parkinsonian variant of multiple system atrophy (MSA-P), especially in the early stages. Cardiac sympathetic denervation and putaminal rarefaction are specific findings for PD and MSA-P, respectively. We investigated diagnostic accuracy of putaminal apparent diffusion coefficient (ADC) test for MSA-P and (123)I-metaiodobenzylguanidine (MIBG) scintigram for PD, especially in early-stage patients. The referral standard diagnosis of PD and MSA-P were the diagnostic criteria of the United Kingdom Parkinson's Disease Society Brain Bank Criteria and the second consensus criteria, respectively. Based on the referral standard criteria, diagnostic accuracy [area under the receiver-operator characteristic curve (AUC), sensitivity and specificity] of the ADC and MIBG tests was estimated retrospectively. Diagnostic accuracy of these tests performed within 3 years of symptom onset was also investigated. ADC and MIBG tests were performed on 138 patients (20 MSA and 118 PD). AUC was 0.95 and 0.83 for the ADC and MIBG tests, respectively. Sensitivity and specificity were 85.0% and 89.0% for MSA-P diagnosis by ADC test and 67.0% and 80.0% for PD diagnosis by MIBG test. When these tests were restricted to patients with disease duration ≤ 3 years, the sensitivity and specificity were 75.0% and 91.4% for the ADC test (MSA-P diagnosis) and 47.7% and 92.3% for the MIBG test (PD diagnosis). Both tests were useful in differentiating between PD and MSA-P, even in the early stages. In early-stage patients, elevated putaminal ADC was a diagnostic marker for MSA-P. Despite high specificity of the MIBG test, careful neurological history and examinations were required for PD diagnosis because of possible false-negative results.

Decision making about healthcare-related tests and diagnostic test strategies. Paper 2: a review of methodological and practical challenges.

PubMed

Mustafa, Reem A; Wiercioch, Wojtek; Cheung, Adrienne; Prediger, Barbara; Brozek, Jan; Bossuyt, Patrick; Garg, Amit X; Lelgemann, Monika; Büehler, Diedrich; Schünemann, Holger J

2017-12-01

In this first of a series of five articles, we provide an overview of how and why healthcare-related tests and diagnostic strategies are currently applied. We also describe how our findings can be integrated with existing frameworks for making decisions that guide the use of healthcare-related tests and diagnostic strategies. We searched MEDLINE, references of identified articles, chapters in relevant textbooks, and identified articles citing classic literature on this topic. We provide updated frameworks for the potential roles and applications of tests with suggested definitions and practical examples. We also discuss study designs that are commonly used to assess tests' performance and the effects of tests on people's health. These designs include diagnostic randomized controlled trials and retrospective validation. We describe the utility of these and other currently suggested designs, which questions they can answer and which ones they cannot. In addition, we summarize the challenges unique to decision-making resulting from the use of tests. This overview highlights current challenges in the application of tests in decision-making in healthcare, provides clarifications, and informs the proposed solutions. Copyright © 2017 Elsevier Inc. All rights reserved.

Diagnostic accuracy of clinical tests of the hip: a systematic review with meta-analysis.

PubMed

Reiman, Michael P; Goode, Adam P; Hegedus, Eric J; Cook, Chad E; Wright, Alexis A

2013-09-01

Hip Physical Examination (HPE) tests have long been used to diagnose a myriad of intra-and extra-articular pathologies of the hip joint. Useful clinical utility is necessary to support diagnostic imaging and subsequent surgical decision making. Summarise and evaluate the current research and utility on the diagnostic accuracy of HPE tests for the hip joint germane to sports related injuries and pathology. A computer-assisted literature search of MEDLINE, CINHAL and EMBASE databases (January 1966 to January 2012) using keywords related to diagnostic accuracy of the hip joint. This systematic review with meta-analysis utilised the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for the search and reporting phases of the study. Der-Simonian and Laird random effects models were used to summarise sensitivities (SN), specificities (SP), likelihood ratios and diagnostic OR. The employed search strategy revealed 25 potential articles, with 10 demonstrating high quality. Fourteen articles qualified for meta-analysis. The meta-analysis demonstrated that most tests possess weak diagnostic properties with the exception of the patellar-pubic percussion test, which had excellent pooled SN 95 (95% CI 92 to 97%) and good specificity 86 (95% CI 78 to 92%). Several studies have investigated pathology in the hip. Few of the current studies are of substantial quality to dictate clinical decision-making. Currently, only the patellar-pubic percussion test is supported by the data as a stand-alone HPE test. Further studies involving high quality designs are needed to fully assess the value of HPE tests for patients with intra- and extra-articular hip dysfunction.

Diagnostic and laboratory test ordering in Northern Portuguese Primary Health Care: a cross-sectional study

PubMed Central

Sá, Luísa; Teixeira, Andreia Sofia Costa; Tavares, Fernando; Costa-Santos, Cristina; Couto, Luciana; Costa-Pereira, Altamiro; Hespanhol, Alberto Pinto; Santos, Paulo

2017-01-01

Objectives To characterise the test ordering pattern in Northern Portugal and to investigate the influence of context-related factors, analysing the test ordered at the level of geographical groups of family physicians and at the level of different healthcare organisations. Design Cross-sectional study. Setting Northern Primary Health Care, Portugal. Participants Records about diagnostic and laboratory tests ordered from 2035 family physicians working at the Northern Regional Health Administration, who served approximately 3.5 million Portuguese patients, in 2014. Outcomes To determine the 20 most ordered diagnostic and laboratory tests in the Northern Regional Health Administration; to identify the presence and extent of variations in the 20 most ordered diagnostic and laboratory tests between the Groups of Primary Care Centres and between health units; and to study factors that may explain these variations. Results The 20 most ordered diagnostic and laboratory tests almost entirely comprise laboratory tests and account for 70.9% of the total tests requested. We can trace a major pattern of test ordering for haemogram, glucose, lipid profile, creatinine and urinalysis. There was a significant difference (P<0.001) in test orders for all tests between Groups of Primary Care Centres and for all tests, except glycated haemoglobin (P=0.06), between health units. Generally, the Personalised Healthcare Units ordered more than Family Health Units. Conclusions The results from this study show that the most commonly ordered tests in Portugal are laboratory tests, that there is a tendency for overtesting and that there is a large variability in diagnostic and laboratory test ordering in different geographical and organisational Portuguese primary care practices, suggesting that there may be considerable potential for the rationalisation of test ordering. The existence of Family Health Units seems to be a strong determinant in decreasing test ordering by Portuguese family

Early detection: the impact of genomics.

PubMed

van Lanschot, M C J; Bosch, L J W; de Wit, M; Carvalho, B; Meijer, G A

2017-08-01

The field of genomics has shifted our view on disease development by providing insights in the molecular and functional processes encoded in the genome. In the case of cancer, many alterations in the DNA accumulate that enable tumor growth or even metastatic dissemination. Identification of molecular signatures that define different stages of progression towards cancer can enable early tumor detection. In this review, the impact of genomics will be addressed using early detection of colorectal cancer (CRC) as an example. Increased understanding of the adenoma-to-carcinoma progression has led to the discovery of several diagnostic biomarkers. This combined with technical advancements, has facilitated the development of molecular tests for non-invasive early CRC detection in stool and blood samples. Even though several tests have already made it to clinical practice, sensitivity and specificity for the detection of precancerous lesions still need improvement. Besides the diagnostic qualities, also the accuracy of the intermediate endpoint is an important issue on how the effectiveness of a novel test is perceived. Here, progression biomarkers may provide a more precise measure than the currently used morphologically based features. Similar developments in biomarker use for early detection have taken place in other cancer types.

An electronic thesaurus of Evidence Based Laboratory Medicine hematological and biochemical diagnostic tests.

PubMed

Dorizzi, R M; Maconi, M; Giavarina, D; Loza, G; Aman, M; Moreira, J; Bisoffi, Z; Gennuso, C

2009-10-01

The adoption of Evidence Based Laboratory Medicine (EBLM) has been hampered until today by the lack of effective tools. The SIMeL EBLM e-Thesaurus (on-line Repertoire of the diagnostic effectiveness of the laboratory, radiology and cardiology test) provides a useful support to clinical laboratory professionals and to clinicians for the interpretation of the diagnostic tests. The e-Thesaurus is an application developed using Microsoft Active Server Pages technology and carried out with Web Server Microsoft Internet Information Server and is available at the SIMeL website using a browser running JavaScript scripts (Internet Explorer is recommended). It contains a database (in Italian, English and Spanish) of the sensitivity and specificity (including the 95% confidence interval), the positive and negative likelihood ratios, the Diagnostic Odds Ratio and the Number Needed to Diagnose of more than 2000 diagnostic (most laboratory but also cardiology and radiology) tests. The e-Thesaurus improves the previous SIMeL paper and CD Thesaurus; its main features are a three languages search and a continuous and an easy updating capability.

Collection and Characterization of Samples for Establishment of a Serum Repository for Lyme Disease Diagnostic Test Development and Evaluation

PubMed Central

Molins, Claudia R.; Sexton, Christopher; Young, John W.; Ashton, Laura V.; Pappert, Ryan; Beard, Charles B.

2014-01-01

Serological assays and a two-tiered test algorithm are recommended for laboratory confirmation of Lyme disease. In the United States, the sensitivity of two-tiered testing using commercially available serology-based assays is dependent on the stage of infection and ranges from 30% in the early localized disease stage to near 100% in late-stage disease. Other variables, including subjectivity in reading Western blots, compliance with two-tiered recommendations, use of different first- and second-tier test combinations, and use of different test samples, all contribute to variation in two-tiered test performance. The availability and use of sample sets from well-characterized Lyme disease patients and controls are needed to better assess the performance of existing tests and for development of improved assays. To address this need, the Centers for Disease Control and Prevention and the National Institutes of Health prospectively collected sera from patients at all stages of Lyme disease, as well as healthy donors and patients with look-alike diseases. Patients and healthy controls were recruited using strict inclusion and exclusion criteria. Samples from all included patients were retrospectively characterized by two-tiered testing. The results from two-tiered testing corroborated the need for novel and improved diagnostics, particularly for laboratory diagnosis of earlier stages of infection. Furthermore, the two-tiered results provide a baseline with samples from well-characterized patients that can be used in comparing the sensitivity and specificity of novel diagnostics. Panels of sera and accompanying clinical and laboratory testing results are now available to Lyme disease serological test users and researchers developing novel tests. PMID:25122862

Development of a molecular diagnostic test for Retinitis Pigmentosa in the Japanese population.

PubMed

Maeda, Akiko; Yoshida, Akiko; Kawai, Kanako; Arai, Yuki; Akiba, Ryutaro; Inaba, Akira; Takagi, Seiji; Fujiki, Ryoji; Hirami, Yasuhiko; Kurimoto, Yasuo; Ohara, Osamu; Takahashi, Masayo

2018-05-21

Retinitis Pigmentosa (RP) is the most common form of inherited retinal dystrophy caused by different genetic variants. More than 60 causative genes have been identified to date. The establishment of cost-effective molecular diagnostic tests with high sensitivity and specificity can be beneficial for patients and clinicians. Here, we developed a clinical diagnostic test for RP in the Japanese population. Evaluation of diagnostic technology, Prospective, Clinical and experimental study. A panel of 39 genes reported to cause RP in Japanese patients was established. Next generation sequence (NGS) technology was applied for the analyses of 94 probands with RP and RP-related diseases. After interpretation of detected genetic variants, molecular diagnosis based on a study of the genetic variants and a clinical phenotype was made by a multidisciplinary team including clinicians, researchers and genetic counselors. NGS analyses found 14,343 variants from 94 probands. Among them, 189 variants in 83 probands (88.3% of all cases) were selected as pathogenic variants and 64 probands (68.1%) have variants which can cause diseases. After the deliberation of these 64 cases, molecular diagnosis was made in 43 probands (45.7%). The final molecular diagnostic rate with the current system combining supplemental Sanger sequencing was 47.9% (45 of 94 cases). The RP panel provides the significant advantage of detecting genetic variants with a high molecular diagnostic rate. This type of race-specific high-throughput genotyping allows us to conduct a cost-effective and clinically useful genetic diagnostic test.

Identifying Students' Mathematical Skills from a Multiple-Choice Diagnostic Test Using an Iterative Technique to Minimise False Positives

ERIC Educational Resources Information Center

Manning, S.; Dix, A.

2008-01-01

There is anecdotal evidence that a significant number of students studying computing related courses at degree level have difficulty with sub-GCE mathematics. Testing of students' skills is often performed using diagnostic tests and a number of computer-based diagnostic tests exist, which work, essentially, by testing one specific diagnostic skill…

Inventions leading to the development of the diagnostic test kit industry--from the modern pregnancy test to the sandwich assays.

PubMed

Wide, Leif

2005-01-01

The universities are encouraged by the government nowadays to stimulate innovations and also to provide the proper machinery for assisting the protection and commercialisation of innovations. A better understanding of the innovation process may help to create an atmosphere suitable for inventions at the university. Examples can be taken from successful innovations previously made at the university. During the 1960's I made a series of inventions, which ultimately led to the development of the diagnostic test kit industry. The first, which I made as an undergraduate, was a simple and reliable test kit for diagnosis of pregnancy. This was followed by the solid phase radioimmunoassay and a solid phase assay for vitamin B12; next, the dual specific non-competitive sandwich assay and the in-vitro test for diagnosis of allergy, called RAST (Radioallergosorbent test). Organon in Holland with the pregnancy test kit, and Pharmacia in Sweden with test kits for radioimmunoassay, became pioneers among the diagnostic test kit industries. Pharmacia Diagnostics later became one of the leading diagnostic test kit companies in the world and has continued to be so in the field of allergy diagnosis. Each one of these inventions started with a few unique observations leading to a technical development. The pregnancy test as well as the allergy test emerged from the development of assay methods with unique qualities with the subsequent search for appropriate applications. The foreseeing of a commercial value on a future market was a very important step. This was followed by the search for a suitable industry interested to exploit the invention with its new business opportunity i.e. apply for a patent, produce and market the products, which in my case consisted of the necessary reagents and equipments for particular diagnostic tests. Finally, an agreement had to be settled between the entrepreneur and the inventors. This report describes these inventions and particularly discusses some

Pre-examination factors affecting molecular diagnostic test results and interpretation: A case-based approach.

PubMed

Payne, Deborah A; Baluchova, Katarina; Peoc'h, Katell H; van Schaik, Ron H N; Chan, K C Allen; Maekawa, Masato; Mamotte, Cyril; Russomando, Graciela; Rousseau, François; Ahmad-Nejad, Parviz

2017-04-01

Multiple organizations produce guidance documents that provide opportunities to harmonize quality practices for diagnostic testing. The International Organization for Standardization ISO 15189 standard addresses requirements for quality in management and technical aspects of the clinical laboratory. One technical aspect addresses the complexities of the pre-examination phase prior to diagnostic testing. The Committee for Molecular Diagnostics of the International Federation for Clinical Chemistry and Laboratory Medicine (also known as, IFCC C-MD) conducted a survey of international molecular laboratories and determined ISO 15189 to be the most referenced guidance document. In this review, the IFCC C-MD provides case-based examples illustrating the value of select pre-examination processes as these processes relate to molecular diagnostic testing. Case-based examples in infectious disease, oncology, inherited disease and pharmacogenomics address the utility of: 1) providing information to patients and users, 2) designing requisition forms, 3) obtaining informed consent and 4) maintaining sample integrity prior to testing. The pre-examination phase requires extensive and consistent communication between the laboratory, the healthcare provider and the end user. The clinical vignettes presented in this paper illustrate the value of applying select ISO 15189 recommendations for general laboratory to the more specialized area of Molecular Diagnostics. Copyright © 2016 Elsevier B.V. All rights reserved.

Human organ-on-a-chip BioMEMS devices for testing new diagnostic and therapeutic strategies

NASA Astrophysics Data System (ADS)

Leary, James F.; Key, Jaehong; Vidi, Pierre-Alexandre; Cooper, Christy L.; Kole, Ayeeshik; Reece, Lisa M.; Lelièvre, Sophie A.

2013-03-01

MEMS human "organs-on-a-chip" can be used to create model human organ systems for developing new diagnostic and therapeutic strategies. They represent a promising new strategy for rapid testing of new diagnostic and therapeutic approaches without the need for involving risks to human subjects. We are developing multicomponent, superparamagnetic and fluorescent nanoparticles as X-ray and MRI contrast agents for noninvasive multimodal imaging and for antibody- or peptide-targeted drug delivery to tumor and precancerous cells inside these artificial organ MEMS devices. Magnetic fields can be used to move the nanoparticles "upstream" to find their target cells in an organs-on-achip model of human ductal breast cancer. Theoretically, unbound nanoparticles can then be removed by reversing the magnetic field to give a greatly enhanced image of tumor cells within these artificial organ structures. Using branched PDMS microchannels and 3D tissue engineering of normal and malignant human breast cancer cells inside those MEMS channels, we can mimic the early stages of human ductal breast cancer with the goal to improve the sensitivity and resolution of mammography and MRI of very small tumors and test new strategies for treatments. Nanomedical systems can easily be imaged by multicolor confocal microscopy inside the artificial organs to test targeting and therapeutic responses including the differential viability of normal and tumor cells during treatments. Currently we are using 2-dimensional MEMS structures, but these studies can be extended to more complex 3D structures using new 3D printing technologies.

Evaluation of the diagnostic value of serologic microagglutination testing and a polymerase chain reaction assay for diagnosis of acute leptospirosis in dogs in a referral center.

PubMed

Fraune, Claudia Kümmerle; Schweighauser, Ariane; Francey, Thierry

2013-05-15

To determine the diagnostic value of a serologic microagglutination test (MAT) and a PCR assay on urine and blood for the diagnosis of leptospirosis in dogs with acute kidney injury (AKI). Cross-sectional study. Animals-76 dogs with AKI in a referral hospital (2008 to 2009). Dogs' leptospirosis status was defined with a paired serologic MAT against a panel of 11 Leptospira serovars as leptospirosis-associated (n = 30) or nonleptospirosis-associated AKI (12). In 34 dogs, convalescent serologic testing was not possible, and leptospirosis status was classified as undetermined. The diagnostic value of the MAT single acute or convalescent blood sample was determined in dogs in which leptospirosis status could be classified. The diagnostic value of a commercially available genus-specific PCR assay was evaluated by use of 36 blood samples and 20 urine samples. Serologic acute testing of an acute blood sample had a specificity of 100% (95% CI, 76% to 100%), a sensitivity of 50% (33% to 67%), and an accuracy of 64% (49% to 77%). Serologic testing of a convalescent blood sample had a specificity of 92% (65% to 99%), a sensitivity of 100% (87% to 100%), and an accuracy of 98% (88% to 100%). Results of the Leptospira PCR assay were negative for all samples from dogs for which leptospirosis status could be classified. Serologic MAT results were highly accurate for diagnosis of leptospirosis in dogs, despite a low sensitivity for early diagnosis. In this referral setting of dogs pretreated with antimicrobials, testing of blood and urine samples with a commercially available genus-specific PCR assay did not improve early diagnosis.

20 CFR 416.919m - Diagnostic tests or procedures.

Code of Federal Regulations, 2010 CFR

2010-04-01

... AGED, BLIND, AND DISABLED Determining Disability and Blindness Standards for the Type of Referral and for Report Content § 416.919m Diagnostic tests or procedures. We will request the results of any..., arteriograms, or cardiac catheterizations for the evaluation of disability under the Supplemental Security...

Diagnostic Testing and Hospital Outcomes of Children with Neurologic Impairment and Bacterial Pneumonia.

PubMed

Thomson, Joanna; Hall, Matt; Berry, Jay G; Stone, Bryan; Ambroggio, Lilliam; Srivastava, Rajendu; Shah, Samir S

2016-11-01

To assess hospital-level variability in diagnostic testing and outcomes for children with neurologic impairment hospitalized with pneumonia. A retrospective cohort study of 27 455 children ages 1-18 years with neurologic impairment hospitalized with pneumonia at 39 children's hospitals. K-means clustering was used to assign each hospital to 1 of 3 groups (termed A, B, and C) based on similar diagnostic testing patterns. Outcomes of hospital-level median length of stay (LOS), 30-day readmissions, and pneumonia-associated complications were compared while controlling for patient differences. Overall, 48.5% had comorbid complex chronic conditions, and 25.4% were assisted with medical technology. Outcomes and diagnostic testing varied across hospitals: median hospital-level LOS, 3.2 days (IQR 2.8-3.8); median readmission, 8.4% (IQR 6.8,-10.0); and median pneumonia-associated complication rate, 23.1% (IQR 18.7-26.8). Despite similar populations, hospitals in group A tended to perform fewer tests than those in groups B and C. Across hospital groups, there was a significant difference in adjusted readmission rates (group A 7.2%, group B 9.0%, group C 7.7%, P = .003). There was no significant difference in adjusted median LOS (group A 3.4 days, group B 3.2 days, group C 3.3 days, P = .3) or adjusted pneumonia-associated complication rates (group A 22.5%, group B 22.5%, group C 25.0%, P = .6). For children with neurologic impairment hospitalized with pneumonia, across hospital differences in diagnostic testing were not associated with clinically meaningful differences in outcomes. High-utilizing hospitals may be able to decrease diagnostic testing for children with neurologic impairment hospitalized with pneumonia without adversely impacting outcomes. Copyright © 2016 Elsevier Inc. All rights reserved.

Privacy and equality in diagnostic genetic testing.

PubMed

Nyrhinen, Tarja; Hietala, Marja; Puukka, Pauli; Leino-Kilpi, Helena

2007-05-01

This study aimed to determine the extent to which the principles of privacy and equality were observed during diagnostic genetic testing according to views held by patients or child patients' parents (n = 106) and by staff (n = 162) from three Finnish university hospitals. The data were collected through a structured questionnaire and analysed using the SAS 8.1 statistical software. In general, the two principles were observed relatively satisfactorily in clinical practice. According to patients/parents, equality in the post-analytic phase and, according to staff, privacy in the pre-analytic phase, involved the greatest ethical problems. The two groups differed in their views concerning pre-analytic privacy. Although there were no major problems regarding the two principles, the differences between the testing phases require further clarification. To enhance privacy protection and equality, professionals need to be given more genetics/ethics training, and patients individual counselling by genetics units staff, giving more consideration to patients' world-view, the purpose of the test and the test result.

Diagnostic accuracy of scapular physical examination tests for shoulder disorders: a systematic review.

PubMed

Wright, Alexis A; Wassinger, Craig A; Frank, Mason; Michener, Lori A; Hegedus, Eric J

2013-09-01

To systematically review and critique the evidence regarding the diagnostic accuracy of physical examination tests for the scapula in patients with shoulder disorders. A systematic, computerised literature search of PubMED, EMBASE, CINAHL and the Cochrane Library databases (from database inception through January 2012) using keywords related to diagnostic accuracy of physical examination tests of the scapula. The Quality Assessment of Diagnostic Accuracy Studies tool was used to critique the quality of each paper. Eight articles met the inclusion criteria; three were considered to be of high quality. Of the three high-quality studies, two were in reference to a 'diagnosis' of shoulder pain. Only one high-quality article referenced specific shoulder pathology of acromioclavicular dislocation with reported sensitivity of 71% and 41% for the scapular dyskinesis and SICK scapula test, respectively. Overall, no physical examination test of the scapula was found to be useful in differentially diagnosing pathologies of the shoulder.

Introducing malaria rapid diagnostic tests at registered drug shops in Uganda: limitations of diagnostic testing in the reality of diagnosis.

PubMed

Chandler, Clare I R; Hall-Clifford, Rachel; Asaph, Turinde; Pascal, Magnussen; Clarke, Siân; Mbonye, Anthony K

2011-03-01

In Uganda, around two thirds of medicines are procured from the private sector, mostly from drug shops. The introduction of malaria rapid diagnostic tests (RDTs) at drug shops therefore has the potential to make a significant contribution to targeting antimalarial drugs to those with malaria parasites. We undertook formative research in a district in Uganda in preparation for a randomised trial of RDTs in drug shops. In May to July 2009, we interviewed 9 drug shop workers, 5 health workers and 4 district health officials and carried out 10 focus group discussions with a total of 75 community members to investigate the role of drug shops and the potential for implementation of RDTs at these health care outlets. Drug shops were seen to provide an important service to community members, the nature of which is determined by responsiveness to client demands. However, drug shops hold a liminal status: in the eyes of different actors, these outlets are at once a shop and clinic; legitimate and illegitimate; and trusted and distrusted. Malaria treatment was found to be synonymous with diagnosis. Diagnostic testing was deemed useful in theory, and community members were curious about the results, with the expectation that a test would decrease uncertainty and help secure an end to illness. However, whether testing would be sought as a routine step in treatment decisions in practice is uncertain, since the appeal of the tests waned in light of their costs and potential for results to conflict with presumed diagnosis. Interventions that increase awareness of multiple causes and management of malaria-like illness will be needed to support the new rationalisation for malaria treatment represented by parasitological diagnosis. Copyright © 2011 Elsevier Ltd. All rights reserved.

The traveling salesman problem as a new screening test in early Alzheimer's disease: an exploratory study. Visual problem-solving in AD.

PubMed

De Vreese, Luc Pieter; Pradelli, Samantha; Massini, Giulia; Buscema, Massimo; Savarè, Rita; Grossi, Enzo

2005-12-01

In the clinical setting, brief general mental status tests tend to detect early-stage Alzheimer's disease (AD) less well than more specific cognitive tests. Some preliminary information was collected on the diagnostic accuracy of the Traveling Salesman Problem (TSP) compared with the Mini-Mental State Examination (MMSE) in recognizing early AD from normal aging. Fifteen AD outpatients (mean +/- SD MMSE: 24.45 +/- 2.61) and 30 age- and education-matched controls were submitted in a single blind protocol to a paper-and-pencil visually-presented version of the TSP, containing a random array of 30 points (TSP30). The task consisted of drawing the shortest continuous path, passing through each point once and only once, and returning to the starting point. Path lengths for subjects' solutions were computed and compared with the optimal solution given by a specific evolutionary algorithm called GenD. TP30 discriminated significantly better between AD subjects and controls (ROC curve AUC = 0.976; 95% CI 0.94-1.01) compared with the MMSE corrected for age and education (ROC curve AUC = 0.877; 95% CI 0.74-1.005). A path length of 478.2354, taken as "cut-off point", classified correctly subjects with a sensitivity of 93.3% and a specificity of 99.3%, whereas a score corrected for age and education of 25.85 on the MMSE had a sensitivity of 73.3% and a specificity of 96.7%. The TSP seems to be particularly sensitive to early AD and independent of patient's age and educational level. The high diagnostic ability, simplicity, and independence of age and education make the TSP promising as a screening test for early AD.

Clonality Testing in Veterinary Medicine: A Review With Diagnostic Guidelines.

PubMed

Keller, S M; Vernau, W; Moore, P F

2016-07-01

The accurate distinction of reactive and neoplastic lymphoid proliferations can present challenges. Given the different prognoses and treatment strategies, a correct diagnosis is crucial. Molecular clonality assays assess rearranged lymphocyte antigen receptor gene diversity and can help differentiate reactive from neoplastic lymphoid proliferations. Molecular clonality assays are commonly used to assess atypical, mixed, or mature lymphoid proliferations; small tissue fragments that lack architecture; and fluid samples. In addition, clonality testing can be utilized to track neoplastic clones over time or across anatomic sites. Molecular clonality assays are not stand-alone tests but useful adjuncts that follow clinical, morphologic, and immunophenotypic assessment. Even though clonality testing provides valuable information in a variety of situations, the complexities and pitfalls of this method, as well as its dependency on the experience of the interpreter, are often understated. In addition, a lack of standardized terminology, laboratory practices, and interpretational guidelines hinders the reproducibility of clonality testing across laboratories in veterinary medicine. The objectives of this review are twofold. First, the review is intended to familiarize the diagnostic pathologist or interested clinician with the concepts, potential pitfalls, and limitations of clonality testing. Second, the review strives to provide a basis for future harmonization of clonality testing in veterinary medicine by providing diagnostic guidelines. © The Author(s) 2016.

75 FR 15443 - Advancing the Development of Diagnostic Tests and Biomarkers for Tuberculosis; Public Workshop...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-29

...] Advancing the Development of Diagnostic Tests and Biomarkers for Tuberculosis; Public Workshop; Request for... workshop entitled ``Advancing the Development of Diagnostic Tests and Biomarkers for Tuberculosis (TB... Tuberculosis in the United States, Committee on the Elimination of Tuberculosis in the United States, Division...

Development, Evaluation, and Integration of a Quantitative Reverse-Transcription Polymerase Chain Reaction Diagnostic Test for Ebola Virus on a Molecular Diagnostics Platform

PubMed Central

Cnops, Lieselotte; Van den Eede, Peter; Pettitt, James; Heyndrickx, Leo; De Smet, Birgit; Coppens, Sandra; Andries, Ilse; Pattery, Theresa; Van Hove, Luc; Meersseman, Geert; Van Den Herrewegen, Sari; Vergauwe, Nicolas; Thijs, Rein; Jahrling, Peter B.; Nauwelaers, David; Ariën, Kevin K.

2016-01-01

Background. The 2013–2016 Ebola epidemic in West Africa resulted in accelerated development of rapid diagnostic tests for emergency outbreak preparedness. We describe the development and evaluation of the Idylla™ prototype Ebola virus test, a fully automated sample-to-result molecular diagnostic test for rapid detection of Zaire ebolavirus (EBOV) and Sudan ebolavirus (SUDV). Methods. The Idylla™ prototype Ebola virus test can simultaneously detect EBOV and SUDV in 200 µL of whole blood. The sample is directly added to a disposable cartridge containing all reagents for sample preparation, RNA extraction, and amplification by reverse-transcription polymerase chain reaction analysis. The performance was evaluated with a variety of sample types, including synthetic constructs and whole blood samples from healthy volunteers spiked with viral RNA, inactivated virus, and infectious virus. Results. The 95% limits of detection for EBOV and SUDV were 465 plaque-forming units (PFU)/mL (1010 copies/mL) and 324 PFU/mL (8204 copies/mL), respectively. In silico and in vitro analyses demonstrated 100% correct reactivity for EBOV and SUDV and no cross-reactivity with relevant pathogens. The diagnostic sensitivity was 97.4% (for EBOV) and 91.7% (for SUDV), the specificity was 100%, and the diagnostic accuracy was 95.9%. Conclusions. The Idylla™ prototype Ebola virus test is a fast, safe, easy-to-use, and near-patient test that meets the performance criteria to detect EBOV in patients with suspected Ebola. PMID:27247341

Inventing a new diagnostic test for vaginal infection.

PubMed Central

O'Dowd, T. C.; Bourne, N.

1994-01-01

Bacterial vaginosis, which is underdiagnosed in clinical practice, has a characteristic fishy smell because of production of diamines. This smell is the basis of a visual rapid diagnostic test that is technically simple to perform. The test has been patented in Europe and America, and a licence agreement has been negotiated. This paper describes the process from idea to invention to patenting and licensing. The combined costs of research and patenting were met by a multinational company in return for rights to exploit the patent invention. The process has taken nine years and has needed clinical, scientific, legal, and commercial input to get the test to the marketplace. Images p41-a PMID:8044068

Does McNemar's test compare the sensitivities and specificities of two diagnostic tests?

PubMed

Kim, Soeun; Lee, Woojoo

2017-02-01

McNemar's test is often used in practice to compare the sensitivities and specificities for the evaluation of two diagnostic tests. For correct evaluation of accuracy, an intuitive recommendation is to test the diseased and the non-diseased groups separately so that the sensitivities can be compared among the diseased, and specificities can be compared among the healthy group of people. This paper provides a rigorous theoretical framework for this argument and study the validity of McNemar's test regardless of the conditional independence assumption. We derive McNemar's test statistic under the null hypothesis considering both assumptions of conditional independence and conditional dependence. We then perform power analyses to show how the result is affected by the amount of the conditional dependence under alternative hypothesis.

Preliminary report on aerotoxic syndrome (AS) and the need for diagnostic neurophysiological tests.

PubMed

Hale, Margaret A; Al-Seffar, Judith A

2009-09-01

Researchers have found, in studies carried out over several years, that many passengers and crew, following their recent flights in commercial jet aeroplanes, have become unwell, with a range of symptoms in common. This condition, which has not yet been officially recognised, is called Aerotoxic Syndrome (AS). It seems to be caused, primarily, by neurotoxic organophosphates contaminating the air circulating in jet cabins. Patients with such symptoms may visit their GPs, who then arrange diagnostic tests. Some of their symptoms fall within the jurisdiction of diagnostic neurophysiological investigations, but neurophysiology practitioners may be unaware of this syndrome. Until AS is officially recognised as an illness, and guidelines for diagnostic procedures established, patients requiring specific investigations may not be appropriately referred, or tests may be performed unnecessarily. This report seeks to stimulate debate within the field, and facilitate studies, if needed, to help define the diagnostic criteria.

Decision analysis to complete diagnostic research by closing the gap between test characteristics and cost-effectiveness.

PubMed

Schaafsma, Joanna D; van der Graaf, Yolanda; Rinkel, Gabriel J E; Buskens, Erik

2009-12-01

The lack of a standard methodology in diagnostic research impedes adequate evaluation before implementation of constantly developing diagnostic techniques. We discuss the methodology of diagnostic research and underscore the relevance of decision analysis in the process of evaluation of diagnostic tests. Overview and conceptual discussion. Diagnostic research requires a stepwise approach comprising assessment of test characteristics followed by evaluation of added value, clinical outcome, and cost-effectiveness. These multiple goals are generally incompatible with a randomized design. Decision-analytic models provide an important alternative through integration of the best available evidence. Thus, critical assessment of clinical value and efficient use of resources can be achieved. Decision-analytic models should be considered part of the standard methodology in diagnostic research. They can serve as a valid alternative to diagnostic randomized clinical trials (RCTs).

Can electronic medical images replace hard-copy film? Defining and testing the equivalence of diagnostic tests.

PubMed

Obuchowski, N A

2001-10-15

Electronic medical images are an efficient and convenient format in which to display, store and transmit radiographic information. Before electronic images can be used routinely to screen and diagnose patients, however, it must be shown that readers have the same diagnostic performance with this new format as traditional hard-copy film. Currently, there exist no suitable definitions of diagnostic equivalence. In this paper we propose two criteria for diagnostic equivalence. The first criterion ('population equivalence') considers the variability between and within readers, as well as the mean reader performance. This criterion is useful for most applications. The second criterion ('individual equivalence') involves a comparison of the test results for individual patients and is necessary when patients are followed radiographically over time. We present methods for testing both individual and population equivalence. The properties of the proposed methods are assessed in a Monte Carlo simulation study. Data from a mammography screening study is used to illustrate the proposed methods and compare them with results from more conventional methods of assessing equivalence and inter-procedure agreement. Copyright 2001 John Wiley & Sons, Ltd.

The impact of communication barriers on diagnostic confidence and ancillary testing in the emergency department.

PubMed

Garra, Gregory; Albino, Hiram; Chapman, Heather; Singer, Adam J; Thode, Henry C

2010-06-01

Communication barriers (CBs) compromise the diagnostic power of the medical interview and may result in increased reliance on diagnostic tests or incorrect test ordering. The prevalence and degree to which these barriers affect diagnosis, testing, and treatment are unknown. To quantify and characterize CBs encountered in the Emergency Department (ED), and assess the effect of CBs on initial diagnosis and perceived reliance on ancillary testing. This was a prospective survey completed by emergency physicians after initial adult patient encounters. CB severity, diagnostic confidence, and reliance on ancillary testing were quantified on a 100-mm Visual Analog Scale (VAS) from least (0) to most (100). Data were collected on 417 ED patient encounters. CBs were reported in 46%; with a mean severity of 50 mm on a 100-mm VAS with endpoints of "perfect communication and "no communication." Language was the most commonly reported form of CB (28%). More than one CB was identified in 6%. The 100-mm VAS rating of diagnostic confidence was lower in patients with perceived CBs (64 mm) vs. those without CBs (80 mm), p < 0.001. VAS ratings of physician reliance on ancillary testing was higher in patients with perceived CBs (50 mm) vs. patients without a perceived CB (38 mm), p < 0.001. Communication barriers in our ED setting were common, and resulted in lower diagnostic confidence and increased perception that ancillary tests are needed to narrow the diagnosis. Copyright 2010 Elsevier Inc. All rights reserved.

SYMPTOM PRESENTATIONS AND CLASSIFICATION OF AUTISM SPECTRUM DISORDER IN EARLY CHILDHOOD: APPLICATION TO THE DIAGNOSTIC CLASSIFICATION OF MENTAL HEALTH AND DEVELOPMENTAL DISORDERS OF INFANCY AND EARLY CHILDHOOD (DC:0-5).

PubMed

Soto, Timothy; Giserman Kiss, Ivy; Carter, Alice S

2016-09-01

Over the past 5 years, a great deal of information about the early course of autism spectrum disorder (ASD) has emerged from longitudinal prospective studies of infants at high risk for developing ASD based on a previously diagnosed older sibling. The current article describes early ASD symptom presentations and outlines the rationale for defining a new disorder, Early Atypical Autism Spectrum Disorder (EA-ASD) to accompany ASD in the new revision of the ZERO TO THREE Diagnostic Classification of Mental Health and Developmental Disorders of Infancy and Early Childhood (DC:0-5) (in press) alternative diagnostic classification manual. EA-ASD is designed to identify children who are 9 to 36 months of age presenting with a minimum of (a) two social-communication symptoms and (b) one repetitive and restricted behavior symptom as well as (c) evidence of impairment, with the intention of providing these children with appropriately tailored services and improving the likelihood of optimizing their development. © 2016 Michigan Association for Infant Mental Health.

Luminescent diagnostics of skin defects in the near-infrared range

NASA Astrophysics Data System (ADS)

Alekseev, Yuriy V.; Rumyantseva, Valentina D.; Gorshkova, Anastasiya S.; Shchelkunova, Anastasiya E.; Shilov, Igor P.; Ivanov, Andrey V.

2017-09-01

Photodynamic therapy becomes a widely spread method due to cancer growth in the world. However, to detect tumors at early stages, it is necessary to carry out diagnostic measures in a timely manner. Our aim was to test the developed pharmaceutical composition, which can be used for external application in early fluorescent diagnostics even in the absence of visual changes, as well as for therapy effectiveness control. Pharmacokinetic studies on laboratory animals and volunteers were carried out. The results have shown that the dipotassium salt of Yb3+-dimethoxyhematoporphyrin IX, which is highly soluble in water and stable in storage, is a promising marker for earlier diagnostics of tumors and can be used in dermatology, dentistry, gynecology, cosmetology, ear, nose, and throat diseases, veterinary, and in other areas of medicine.

Practical diagnostic testing for human immunodeficiency virus.

PubMed Central

Jackson, J B; Balfour, H H

1988-01-01

Since the discovery of human immunodeficiency virus (HIV) as the causative agent of acquired immunodeficiency syndrome in 1983, there has been a proliferation of diagnostic tests. These assays can be used to detect the presence of HIV antibody, HIV antigen, HIV ribonucleic and deoxyribonucleic acids, and HIV reverse transcriptase. Enzyme-linked immunosorbent assays, Western blot, radioimmunoprecipitation assays, indirect immunofluorescence assays, reverse transcriptase assays, and several molecular hybridization techniques are currently available. Enzyme-linked immunosorbent, Western blot, and indirect immunofluorescence assays for HIV antibody are very sensitive, specific, and adaptable to most laboratories. An enzyme-linked immunosorbent assay for HIV antigen is also readily adaptable to most laboratories and will be commercially available soon. While the other assays are more tedious, they are valuable confirmatory tests and are suitable for reference laboratories. The biohazards of performing HIV testing can be minimized with proper biosafety measures. Images PMID:3060241

Estimation of diagnostic test accuracy without full verification: a review of latent class methods

PubMed Central

Collins, John; Huynh, Minh

2014-01-01

The performance of a diagnostic test is best evaluated against a reference test that is without error. For many diseases, this is not possible, and an imperfect reference test must be used. However, diagnostic accuracy estimates may be biased if inaccurately verified status is used as the truth. Statistical models have been developed to handle this situation by treating disease as a latent variable. In this paper, we conduct a systematized review of statistical methods using latent class models for estimating test accuracy and disease prevalence in the absence of complete verification. PMID:24910172

Diagnostic Ability of Wide-field Retinal Nerve Fiber Layer Maps Using Swept-Source Optical Coherence Tomography for Detection of Preperimetric and Early Perimetric Glaucoma.

PubMed

Lee, Won June; Na, Kyeong Ik; Kim, Young Kook; Jeoung, Jin Wook; Park, Ki Ho

2017-06-01

To evaluate the diagnostic ability of wide-field retinal nerve fiber layer (RNFL) maps with swept-source optical coherence tomography (SS-OCT) for detection of preperimetric (PPG) and early perimetric glaucoma (EG). One hundred eighty-four eyes, including 67 healthy eyes, 43 eyes with PPG, and 74 eyes with EG, were analyzed. Patients underwent a comprehensive ocular examination including red-free RNFL photography, visual field testing and wide-field SS-OCT scanning (DRI-OCT-1 Atlantis; Topcon, Tokyo, Japan). SS-OCT provides a wide-field RNFL thickness map and a SuperPixel map, which are composed of the RNFL deviation map of the peripapillary area and the deviation map of the composition of the ganglion cell layer with the inner plexiform layer and RNFL (GC-IPL+RNFL) in the macular area. The ability to discriminate PPG and EG from healthy eyes was assessed using sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) for all parameters and criteria provided by the wide-field SS-OCT scan. The wide-field RNFL thickness map using SS-OCT showed the highest sensitivity of PPG-diagnostic and EG-diagnostic performance compared with the other SS-OCT criteria based on the internal normative base (93.0 and 97.3%, respectively). Among the SS-OCT continuous parameters, the RFNL thickness of the 7 clock-hour, inferior and inferotemporal macular ganglion cell analyses showed the largest AUC of PPG-diagnostic and EG-diagnostic performance (AUC=0.809 to 0.865). The wide-field RNFL thickness map using SS-OCT performed well in distinguishing eyes with PPG and EG from healthy eyes. In the clinical setting, wide-field RNFL maps of SS-OCT can be useful tools for detection of early-stage glaucoma.

Validation of the Argentine version of the Memory Binding Test (MBT) for Early Detection of Mild Cognitive Impairment

PubMed Central

Roman, Fabian; Iturry, Mónica; Rojas, Galeno; Barceló, Ernesto; Buschke, Herman; Allegri, Ricardo F.

2016-01-01

ABSTRACT Background: "Forgetfulness" is frequent in normal aging and characteristic of the early stages of dementia syndromes. The episodic memory test is central for detecting amnestic mild cognitive impairment (MCI). The Memory Binding Test (MBT) is a simple, easy and brief memory test to detect the early stage of episodic memory impairment. Objective: To validate the Argentine version of the MBT in a Latin American population and to estimate the diagnostic accuracy as a tool for early detection of MCI. Methods: 88 subjects (46 healthy controls and 42 patients with amnestic MCI) matched for age and educational level were evaluated by an extensive neuropsychological battery and the memory binding test. Results: A significantly better performance was detected in the control group; all MBT scales were predictive of MCI diagnosis (p<.01). The MBT showed high sensitivity (69%) and high specificity (88%), with a PPV of 93% and a NPV of 55% for associative paired recall. A statistically significant difference (c2=14,164, p<.001) was obtained when comparing the area under the curve (AUC) of the MBT (0.88) and the MMSE (0.70). Conclusion: The Argentine version of the MBT correlated significantly with the MMSE and the memory battery and is a useful tool in the detection of MCI. The operating characteristics of the MBT are well suited, surpassing other tests commonly used for detecting MCI. PMID:29213458

[Variations in the diagnostic confirmation process between breast cancer mass screening units].

PubMed

Natal, Carmen; Fernández-Somoano, Ana; Torá-Rocamora, Isabel; Tardón, Adonina; Castells, Xavier

2016-01-01

To analyse variations in the diagnostic confirmation process between screening units, variations in the outcome of each episode and the relationship between the use of the different diagnostic confirmation tests and the lesion detection rate. Observational study of variability of the standardised use of diagnostic and lesion detection tests in 34 breast cancer mass screening units participating in early-detection programmes in three Spanish regions from 2002-2011. The diagnostic test variation ratio in percentiles 25-75 ranged from 1.68 (further appointments) to 3.39 (fine-needle aspiration). The variation ratio in detection rates of benign lesions, ductal carcinoma in situ and invasive cancer were 2.79, 1.99 and 1.36, respectively. A positive relationship between rates of testing and detection rates was found with fine-needle aspiration-benign lesions (R(2): 0.53), fine-needle aspiration-invasive carcinoma (R(2): 0 28), core biopsy-benign lesions (R(2): 0.64), core biopsy-ductal carcinoma in situ (R(2): 0.61) and core biopsy-invasive carcinoma (R(2): 0.48). Variation in the use of invasive tests between the breast cancer screening units participating in early-detection programmes was found to be significantly higher than variations in lesion detection. Units which conducted more fine-needle aspiration tests had higher benign lesion detection rates, while units that conducted more core biopsies detected more benign lesions and cancer. Copyright © 2016 SESPAS. Published by Elsevier Espana. All rights reserved.

Concordance in diagnostic testing for respiratory pathogens of Bighorn Sheep

USDA-ARS?s Scientific Manuscript database

Reliable diagnostic tests are essential for disease investigation and management. This is particularly true for diseases of free-ranging wildlife where sampling is logistically difficult precluding retesting. Clinical assays for wildlife diseases frequently vary among laboratories because of lack ...

Diagnostic Accuracy of the Slump Test for Identifying Neuropathic Pain in the Lower Limb.

PubMed

Urban, Lawrence M; MacNeil, Brian J

2015-08-01

Diagnostic accuracy study with nonconsecutive enrollment. To assess the diagnostic accuracy of the slump test for neuropathic pain (NeP) in those with low to moderate levels of chronic low back pain (LBP), and to determine whether accuracy of the slump test improves by adding anatomical or qualitative pain descriptors. Neuropathic pain has been linked with poor outcomes, likely due to inadequate diagnosis, which precludes treatment specific for NeP. Current diagnostic approaches are time consuming or lack accuracy. A convenience sample of 21 individuals with LBP, with or without radiating leg pain, was recruited. A standardized neurosensory examination was used to determine the reference diagnosis for NeP. Afterward, the slump test was administered to all participants. Reports of pain location and quality produced during the slump test were recorded. The neurosensory examination designated 11 of the 21 participants with LBP/sciatica as having NeP. The slump test displayed high sensitivity (0.91), moderate specificity (0.70), a positive likelihood ratio of 3.03, and a negative likelihood ratio of 0.13. Adding the criterion of pain below the knee significantly increased specificity to 1.00 (positive likelihood ratio = 11.9). Pain-quality descriptors did not improve diagnostic accuracy. The slump test was highly sensitive in identifying NeP within the study sample. Adding a pain-location criterion improved specificity. Combining the diagnostic outcomes was very effective in identifying all those without NeP and half of those with NeP. Limitations arising from the small and narrow spectrum of participants with LBP/sciatica sampled within the study prevent application of the findings to a wider population. Diagnosis, level 4-.

Preferred Reporting Items for a Systematic Review and Meta-analysis of Diagnostic Test Accuracy Studies: The PRISMA-DTA Statement.

PubMed

McInnes, Matthew D F; Moher, David; Thombs, Brett D; McGrath, Trevor A; Bossuyt, Patrick M; Clifford, Tammy; Cohen, Jérémie F; Deeks, Jonathan J; Gatsonis, Constantine; Hooft, Lotty; Hunt, Harriet A; Hyde, Christopher J; Korevaar, Daniël A; Leeflang, Mariska M G; Macaskill, Petra; Reitsma, Johannes B; Rodin, Rachel; Rutjes, Anne W S; Salameh, Jean-Paul; Stevens, Adrienne; Takwoingi, Yemisi; Tonelli, Marcello; Weeks, Laura; Whiting, Penny; Willis, Brian H

2018-01-23

Systematic reviews of diagnostic test accuracy synthesize data from primary diagnostic studies that have evaluated the accuracy of 1 or more index tests against a reference standard, provide estimates of test performance, allow comparisons of the accuracy of different tests, and facilitate the identification of sources of variability in test accuracy. To develop the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) diagnostic test accuracy guideline as a stand-alone extension of the PRISMA statement. Modifications to the PRISMA statement reflect the specific requirements for reporting of systematic reviews and meta-analyses of diagnostic test accuracy studies and the abstracts for these reviews. Established standards from the Enhancing the Quality and Transparency of Health Research (EQUATOR) Network were followed for the development of the guideline. The original PRISMA statement was used as a framework on which to modify and add items. A group of 24 multidisciplinary experts used a systematic review of articles on existing reporting guidelines and methods, a 3-round Delphi process, a consensus meeting, pilot testing, and iterative refinement to develop the PRISMA diagnostic test accuracy guideline. The final version of the PRISMA diagnostic test accuracy guideline checklist was approved by the group. The systematic review (produced 64 items) and the Delphi process (provided feedback on 7 proposed items; 1 item was later split into 2 items) identified 71 potentially relevant items for consideration. The Delphi process reduced these to 60 items that were discussed at the consensus meeting. Following the meeting, pilot testing and iterative feedback were used to generate the 27-item PRISMA diagnostic test accuracy checklist. To reflect specific or optimal contemporary systematic review methods for diagnostic test accuracy, 8 of the 27 original PRISMA items were left unchanged, 17 were modified, 2 were added, and 2 were omitted. The 27-item

Meta-analysis of diagnostic test data: a bivariate Bayesian modeling approach.

PubMed

Verde, Pablo E

2010-12-30

In the last decades, the amount of published results on clinical diagnostic tests has expanded very rapidly. The counterpart to this development has been the formal evaluation and synthesis of diagnostic results. However, published results present substantial heterogeneity and they can be regarded as so far removed from the classical domain of meta-analysis, that they can provide a rather severe test of classical statistical methods. Recently, bivariate random effects meta-analytic methods, which model the pairs of sensitivities and specificities, have been presented from the classical point of view. In this work a bivariate Bayesian modeling approach is presented. This approach substantially extends the scope of classical bivariate methods by allowing the structural distribution of the random effects to depend on multiple sources of variability. Meta-analysis is summarized by the predictive posterior distributions for sensitivity and specificity. This new approach allows, also, to perform substantial model checking, model diagnostic and model selection. Statistical computations are implemented in the public domain statistical software (WinBUGS and R) and illustrated with real data examples. Copyright © 2010 John Wiley & Sons, Ltd.

Anti-CD74 antibodies have no diagnostic value in early axial spondyloarthritis: data from the spondyloarthritis caught early (SPACE) cohort.

PubMed

de Winter, Janneke J; van de Sande, Marleen G; Baerlecken, Niklas; Berg, Inger; Ramonda, Roberta; van der Heijde, Désirée; van Gaalen, Floris A; Witte, Torsten; Baeten, Dominique L

2018-03-01

Anti-CD74 IgG antibodies are reported to be elevated in patients with axial spondyloarthritis (axSpA). This study assessed the diagnostic value of anti-CD74 antibodies in patients with early axSpA. Anti-CD74 IgG and IgA antibodies were first measured in an exploratory cohort of patients with radiographic axSpA (138 patients with ankylosing spondyloarthritis (AS)) and 57 healthy controls and then were measured in patients with early axSpA (n = 274) and with non-SpA chronic back pain (CBP) (n = 319), participating in the spondyloarthritis caught early (SPACE) prospective cohort study of patients under 45 years old with early back pain (for ≥ 3 months, but ≤ 2 years). In the exploratory cohort, anti-CD74 IgG antibodies were present in 79.7% of patients with AS vs. 43.9% of healthy controls (p < 0.001). Anti-CD74 IgA antibodies were present in 28.5% of patients with AS vs. 5.3% of healthy controls (p < 0.001). In the SPACE cohort, anti-CD74 IgG antibody levels were present in 46.4% of the patients with axSpA vs. 47.9% of the patients with CBP (p = 0.71). Anti-CD74 IgA antibodies were present in 54.7% of the patients with axSpA and 37.0% of the patients with CBP (p < 0.001). This resulted in a positive predictive value of 58.8% (compared to a prior probability of 46.2%) and a negative predictive value of 59.1% (compared to a prior probability of 53.8%). In a regression model, total serum IgA was associated with axSpA odds ratio (OR) 1.19, p < 0.001) whereas anti-CD74 IgA was not (OR) 1.01, p = 0.33). Furthermore, anti-CD74 IgA was associated with sacroiliitis on magnetic resonance imaging (MRI) (OR) = 2.50, p = 0.005) and heel enthesitis (OR) = 2.56, p = 0.002). Albeit anti-CD74 IgA is elevated in patients with early axSpA, this elevation is not sufficiently specific to yield significant diagnostic value in patients under 45 years old presenting with early back pain.

Saliva as a diagnostic tool for oral and systemic diseases

PubMed Central

Javaid, Mohammad A.; Ahmed, Ahad S.; Durand, Robert; Tran, Simon D.

2015-01-01

Early disease detection is not only vital to reduce disease severity and prevent complications, but also critical to increase success rate of therapy. Saliva has been studied extensively as a potential diagnostic tool over the last decade due to its ease and non-invasive accessibility along with its abundance of biomarkers, such as genetic material and proteins. This review will update the clinician on recent advances in salivary biomarkers to diagnose autoimmune diseases (Sjogren's syndrome, cystic fibrosis), cardiovascular diseases, diabetes, HIV, oral cancer, caries and periodontal diseases. Considering their accuracy, efficacy, ease of use and cost effectiveness, salivary diagnostic tests will be available in dental offices. It is expected that the advent of sensitive and specific salivary diagnostic tools and the establishment of defined guidelines and results following rigorous testing will allow salivary diagnostics to be used as chair-side tests for several oral and systemic diseases in the near future. PMID:26937373

Appropriate use of screening and diagnostic tests to foster high-value, cost-conscious care.

PubMed

Qaseem, Amir; Alguire, Patrick; Dallas, Paul; Feinberg, Lawrence E; Fitzgerald, Faith T; Horwitch, Carrie; Humphrey, Linda; LeBlond, Richard; Moyer, Darilyn; Wiese, Jeffrey G; Weinberger, Steven

2012-01-17

Unsustainable rising health care costs in the United States have made reducing costs while maintaining high-quality health care a national priority. The overuse of some screening and diagnostic tests is an important component of unnecessary health care costs. More judicious use of such tests will improve quality and reflect responsible awareness of costs. Efforts to control expenditures should focus not only on benefits, harms, and costs but on the value of diagnostic tests-meaning an assessment of whether a test provides health benefits that are worth its costs or harms. To begin to identify ways that practicing clinicians can contribute to the delivery of high-value, cost-conscious health care, the American College of Physicians convened a workgroup of physicians to identify, using a consensus-based process, common clinical situations in which screening and diagnostic tests are used in ways that do not reflect high-value care. The intent of this exercise is to promote thoughtful discussions about these tests and other health care interventions to promote high-value, cost-conscious care.

Diagnostic role of (99)Tc(m)-MDP SPECT/CT combined SPECT/MRI Multi modality imaging for early and atypical bone metastases.

PubMed

Chen, Xiao-Liang; Li, Qian; Cao, Lin; Jiang, Shi-Xi

2014-01-01

The bone metastasis appeared early before the bone imaging for most of the above patients. (99)Tc(m)-MDP ((99)Tc(m) marked methylene diphosphonate) bone imaging could diagnosis the bone metastasis with highly sensitivity, but with lower specificity. The aim of this study is to explore the diagnostic value of (99)Tc(m)-MDP SPECT/CT combined SPECT/MRI Multi modality imaging for the early period atypical bone metastases. 15 to 30 mCi (99)Tc(m)-MDP was intravenously injected to the 34 malignant patients diagnosed as doubtful early bone metastases. SPECT, CT and SPECT/CT images were captured and analyzed consequently. For the patients diagnosed as early period atypical bone metastases by SPECT/CT, combining the SPECT/CT and MRI together as the SPECT/MRI integrated image. The obtained SPECT/MRI image was analyzed and compared with the pathogenic results of patients. The results indicated that 34 early period doubtful metastatic focus, including 34 SPECT positive focus, 17 focus without special changes by using CT method, 11 bone metastases focus by using SPECT/CT method, 23 doubtful bone metastases focus, 8 doubtful bone metastases focus, 14 doubtful bone metastases focus and 2 focus without clear image. Totally, SPECT/CT combined with SPECT/MRI method diagnosed 30 bone metastatic focus and 4 doubtfully metastatic focus. In conclusion, (99)Tc(m)-MDP SPECT/CT combined SPECT/MRI Multi modality imaging shows a higher diagnostic value for the early period bone metastases, which also enhances the diagnostic accuracy rate.

Present-day potentialities of endoscopic diagnostics and treatment of early cancer in respiratory and digestive tracts

NASA Astrophysics Data System (ADS)

Sokolov, Victor V.; Zharkova, Natalia N.; Filonenko, E. V.; Telegina, L. V.; Karpova, E. S.

1999-12-01

The paper presents the latest potentialities of the endoscopic fluorescent diagnostics as well as endoscopic electric-, laser surgery and photodynamic therapy (PDT) of the early cancer in the respiratory and digestive tracts. We present in detail indication and factors determining the application of the endoscopic resection of the tumor. The advantages of the combination application of PDT, electro-, Nd:YAG laser surgery and brachitherapy are stressed. The near and remote results of endoscopic treatment of the early cancer in larynx (37), lung (109), esophagus (39) and stomach (58) are shown.

Plasma diagnostic development and UHV testing for the ALPHA collaboration at Marquette University

NASA Astrophysics Data System (ADS)

Tharp, T. D.; Alpha Collaboration

2017-10-01

At Marquette, we are developing the next generation of nonneutral plasma diagnostics for the ALPHA experiment at CERN. ALPHA is building a new vertical experiment to test the gravitational interaction of antihydrogen with Earth. This expansion requires significant changes to the design of our plasma diagnostic suites: the next generation of tools must be able to measure plasmas from two directions, and must be capable of operating in a horizontal position. The diagnostic suite includes measurements of plasma density, shape, and temperature. The hardware used includes a MicroChannel Plate (MCP), a Faraday Cup, and an electron gun. In addition, we are building a vacuum chamber to test the viability of 3-d printed components for UHV compatibility, with target pressures of 10-10 mbar.

The Development of STAR Early Literacy. Report.

ERIC Educational Resources Information Center

School Renaissance Inst., Inc., Madison, WI.

This report describes the development and testing of a computerized early literacy diagnostic assessment for students in prekindergarten to grade 3 that can measure skills across a variety of preliteracy and reading domains. The STAR Early Literacy assessment was developed by a team of more than 50 people, including literacy experts,…

The Astronomy Diagnostic Test: Comparing Your Class to Others

NASA Astrophysics Data System (ADS)

Hufnagel, B.; Deming, G.

1999-05-01

A standard diagnostic test can be a powerful tool to assess the conceptual understanding of students, as has been proven for undergraduate physics instruction over the last ten years (e.g., E.F. Redish and R.N. Steinberg 1999, Physics Today, 52:1, 24). If you are now using, or are considering adopting, a more interactive teaching style such as that used by Eric Mazur (Peer Instruction: a User's Manual, [Prentice-Hall: 1997]) or Michael Zeilik and his collaborators (1997, AJP, 65:12, 987), you may want to use a standard diagnostic test designed for undergraduate astronomy classes. Details of the validation of the ADT are at Slater et al., also presented in this session. A comparative database of ADT scores, by class and by question, can help the instructor assess student preparedness and the effectiveness of alternative teaching methods. In the spring of 1999, 19 astronomy instructors at 7 state universities, 4 community colleges, 4 liberal arts schools, 1 woman's college and 1 technical university across the USA gave the ADT to their classes once at the beginning of the course, and again at the end of the course. The average pre-course ADT scores by class from these ~ 1000 students show two surprising results: the conceptual understanding of introductory classes is about the same (34%) regardless of type of school, geographic location, or average student age. However, there is a significant gender difference, with females scoring an average of 29% and males 39%, with the standard errors both less than 1%. The Astronomy Diagnostic Test (ADT) and its comparative by-class database will be available at the National Institute for Science Education (NISE) website after 1 June 1999. This research was supported by the National Science Foundation through Grant DGE-9714489, and by the generosity of the participating astronomy instructors.

Study on validity of a rapid diagnostic test kit versus light microscopy for malaria diagnosis in Ahmedabad city, India.

PubMed

Vyas, S; Puwar, B; Patel, V; Bhatt, G; Kulkarni, S; Fancy, M

2014-05-01

Light microscopy of blood smears for diagnosis of malaria in the field has several limitations, notably delays in diagnosis. This study in Ahmedabad in Gujarat State, India, evaluated the diagnostic performance of a rapid diagnostic test for malaria (SD Bioline Malaria Ag P.f/Pan) versus blood smear examination as the gold standard. All fever cases presenting at 13 urban health centres were subjected to rapid diagnostic testing and thick and thin blood smears. A total of 677 cases with fever were examined; 135 (20.0%) tested positive by rapid diagnostic test and 86 (12.7%) by blood smear. The sensitivity of the rapid diagnostic test for malaria was 98.8%, specificity was 91.5%, positive predictive value 63.0% and negative predictive value 99.8%. For detection of Plasmodium falciparum the sensitivity of rapid diagnostic test was 100% and specificity was 97.3%. The results show the acceptability of the rapid test as an alternative to light microscopy in the field setting.

Self-Reported HIV-Positive Status But Subsequent HIV-Negative Test Result Using Rapid Diagnostic Testing Algorithms Among Seven Sub-Saharan African Military Populations

DTIC Science & Technology

2017-07-07

RESEARCH ARTICLE Self-reported HIV-positive status but subsequent HIV-negative test result using rapid diagnostic testing algorithms among seven sub...America * judith.harbertson.ctr@mail.mil Abstract HIV rapid diagnostic tests (RDTs) combined in an algorithm are the current standard for HIV diagnosis...in many sub-Saharan African countries, and extensive laboratory testing has con- firmed HIV RDTs have excellent sensitivity and specificity. However

Transscrotal Near Infrared Spectroscopy as a Diagnostic Test for Testis Torsion in Pediatric Acute Scrotum: A Prospective Comparison to Gold Standard Diagnostic Test Study.

PubMed

Schlomer, Bruce J; Keays, Melise A; Grimsby, Gwen M; Granberg, Candace F; DaJusta, Daniel G; Menon, Vani S; Ostrov, Lauren; Sheth, Kunj R; Hill, Martinez; Sanchez, Emma J; Harrison, Clanton B; Jacobs, Micah A; Huang, Rong; Burgu, Berk; Hennes, Halim; Baker, Linda A

2017-09-01

A rapid test for testicular torsion in children may obviate the delay for testicular ultrasound. In this study we assessed testicular tissue percent oxygen saturation (%StO2) measured by transscrotal near infrared spectroscopy as a diagnostic test for pediatric testicular torsion. This was a prospective comparison to a gold standard diagnostic test study that evaluated near infrared spectroscopy %StO2 readings to diagnose testicular torsion. The gold standard for torsion diagnosis was standard clinical care. From 2013 to 2015 males with acute scrotum for more than 1 month and who were less than 18 years old were recruited. Near infrared spectroscopy %StO2 readings were obtained for affected and unaffected testes. Near infrared spectroscopy Δ%StO2 was calculated as unaffected minus affected reading. The utility of near infrared spectroscopy Δ%StO2 to diagnose testis torsion was described with ROC curves. Of 154 eligible patients 121 had near infrared spectroscopy readings. Median near infrared spectroscopy Δ%StO2 in the 36 patients with torsion was 2.0 (IQR -4.2 to 9.8) vs -1.7 (IQR -8.7 to 2.0) in the 85 without torsion (p=0.004). AUC for near infrared spectroscopy as a diagnostic test was 0.66 (95% CI 0.55-0.78). Near infrared spectroscopy Δ%StO2 of 20 or greater had a positive predictive value of 100% and a sensitivity of 22.2%. Tanner stage 3-5 cases without scrotal edema or with pain for 12 hours or less had an AUC of 0.91 (95% CI 0.86-1.0) and 0.80 (95% CI 0.62-0.99), respectively. In all children near infrared spectroscopy readings had limited utility in diagnosing torsion. However, in Tanner 3-5 cases without scrotal edema or with pain 12 hours or less, near infrared spectroscopy discriminated well between torsion and nontorsion. Copyright © 2017 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Reliability of HIV rapid diagnostic tests for self-testing compared with testing by health-care workers: a systematic review and meta-analysis.

PubMed

Figueroa, Carmen; Johnson, Cheryl; Ford, Nathan; Sands, Anita; Dalal, Shona; Meurant, Robyn; Prat, Irena; Hatzold, Karin; Urassa, Willy; Baggaley, Rachel

2018-06-01

The ability of individuals to use HIV self-tests correctly is debated. To inform the 2016 WHO recommendation on HIV self-testing, we assessed the reliability and performance of HIV rapid diagnostic tests when used by self-testers. In this systematic review and meta-analysis, we searched PubMed, PopLine, and Embase, conference abstracts, and additional grey literature between Jan 1, 1995, and April 30, 2016, for observational and experimental studies reporting on HIV self-testing performance. We excluded studies evaluating home specimen collection because patients did not interpret their own test results. We extracted data independently, using standardised extraction forms. Outcomes of interest were agreement between self-testers and health-care workers, sensitivity, and specificity. We calculated κ to establish the level of agreement and pooled κ estimates using a random-effects model, by approach (directly assisted or unassisted) and type of specimen (blood or oral fluid). We examined heterogeneity with the I 2 statistic. 25 studies met inclusion criteria (22 to 5662 participants). Quality assessment with QUADAS-2 showed studies had low risk of bias and incomplete reporting in accordance with the STARD checklist. Raw proportion of agreement ranged from 85·4% to 100%, and reported κ ranged from fair (κ 0·277, p<0·001) to almost perfect (κ 0·99, n=25). Pooled κ suggested almost perfect agreement for both types of approaches (directly assisted 0·98, 95% CI 0·96-0·99 and unassisted 0·97, 0·96-0·98; I 2 =34·5%, 0-97·8). Excluding two outliers, sensitivity and specificity was higher for blood-based rapid diagnostic tests (4/16) compared with oral fluid rapid diagnostic tests (13/16). The most common error that affected test performance was incorrect specimen collection (oral swab or finger prick). Study limitations included the use of different reference standards and no disaggregation of results by individuals taking antiretrovirals. Self-testers can

Sensitivity of influenza rapid diagnostic tests to H5N1 and 2009 pandemic H1N1 viruses.

PubMed

Sakai-Tagawa, Yuko; Ozawa, Makoto; Tamura, Daisuke; Le, Mai thi Quynh; Nidom, Chairul A; Sugaya, Norio; Kawaoka, Yoshihiro

2010-08-01

Simple and rapid diagnosis of influenza is useful for making treatment decisions in the clinical setting. Although many influenza rapid diagnostic tests (IRDTs) are available for the detection of seasonal influenza virus infections, their sensitivity for other viruses, such as H5N1 viruses and the recently emerged swine origin pandemic (H1N1) 2009 virus, remains largely unknown. Here, we examined the sensitivity of 20 IRDTs to various influenza virus strains, including H5N1 and 2009 pandemic H1N1 viruses. Our results indicate that the detection sensitivity to swine origin H1N1 viruses varies widely among IRDTs, with some tests lacking sufficient sensitivity to detect the early stages of infection when the virus load is low.

Safety of falciparum malaria diagnostic strategy based on rapid diagnostic tests in returning travellers and migrants: a retrospective study

PubMed Central

2012-01-01

Background Rapid diagnostic tests for malaria (RDTs) allow accurate diagnosis and prompt treatment. Validation of their usefulness in travellers with fever was needed. The safety of a strategy to diagnose falciparum malaria based on RDT followed by immediate or delayed microscopy reading at first attendance was evaluated in one referral hospital in Switzerland. Methods A retrospective study was conducted in the outpatient clinic and emergency ward of University Hospital, covering a period of eight years (1999–2007). The study was conducted in the outpatient clinic and emergency ward of University Hospital. All adults suspected of malaria with a diagnostic test performed were included. RDT and microscopy as immediate tests were performed during working hours, and RDT as immediate test and delayed microscopy reading out of laboratory working hours. The main outcome measure was occurrence of specific complications in RDT negative and RDT positive adults. Results 2,139 patients were recruited. 1987 had both initial RDT and blood smear (BS) result negative. Among those, 2/1987 (0.1%) developed uncomplicated malaria with both RDT and BS positive on day 1 and day 6 respectively. Among the 152 patients initially malaria positive, 137 had both RDT and BS positive, four only BS positive and five only RDT positive (PCR confirmed) (six had only one test performed). None of the four initially RDT negative/BS positive and none of the five initially BS negative/RDT positive developed severe malaria while 6/137 of both RDT and BS positive did so. The use of RDT allowed a reduction of a median of 2.1 hours to get a first malaria test result. Conclusions A malaria diagnostic strategy based on RDTs and a delayed BS is safe in non-immune populations, and shortens the time to first malaria test result. PMID:23158019

Molecular malaria diagnostics: A systematic review and meta-analysis.

PubMed

Roth, Johanna M; Korevaar, Daniël A; Leeflang, Mariska M G; Mens, Pètra F

2016-01-01

Accurate diagnosis of malaria is essential for identification and subsequent treatment of the disease. Currently, microscopy and rapid diagnostic tests are the most commonly used diagnostics, next to treatment based on clinical signs only. These tests are easy to deploy, but have a relatively high detection limit. With declining prevalence in many areas, there is an increasing need for more sensitive diagnostics. Molecular tools may be a suitable alternative, although costs and technical requirements currently hamper their implementation in resource limited settings. A range of (near) point-of-care diagnostics is therefore under development, including simplifications in sample preparation, amplification and/or read-out of the test. Accuracy data, in combination with technical characteristics, are essential in determining which molecular test, if any, would be the most promising to be deployed. This review presents a comprehensive overview of the currently available molecular malaria diagnostics, ranging from well-known tests to platforms in early stages of evaluation, and systematically evaluates their published accuracy. No important difference in accuracy was found between the most commonly used PCR-based assays (conventional, nested and real-time PCR), with most of them having high sensitivity and specificity, implying that there are no reasons other than practical ones to choose one technique over the other. Loop-mediated isothermal amplification and other (novel) diagnostics appear to be highly accurate as well, with some offering potential to be used in resource-limited settings.

Flight Test of Propulsion Monitoring and Diagnostic System

NASA Technical Reports Server (NTRS)

Gabel, Steve; Elgersma, Mike

2002-01-01

The objective of this program was to perform flight tests of the propulsion monitoring and diagnostic system (PMDS) technology concept developed by Honeywell under the NASA Advanced General Aviation Transport Experiment (AGATE) program. The PMDS concept is intended to independently monitor the performance of the engine, providing continuous status to the pilot along with warnings if necessary as well as making the data available to ground maintenance personnel via a special interface. These flight tests were intended to demonstrate the ability of the PMDS concept to detect a class of selected sensor hardware failures, and the ability to successfully model the engine for the purpose of engine diagnosis.

Cost-effectiveness of using a molecular diagnostic test to improve preoperative diagnosis of thyroid cancer.

PubMed

Najafzadeh, Mehdi; Marra, Carlo A; Lynd, Larry D; Wiseman, Sam M

2012-12-01

Fine-needle aspiration biopsy (FNAB) is a safe and inexpensive diagnostic procedure for evaluating thyroid nodules.Up to 25% of the results from an FNAB, however, may not be diagnostic or may be indeterminate, leading to a subsequent diagnostic thyroid surgery. A new molecularly based diagnostic test could potentially reduce indeterminate cytological results and, with high accuracy, provide a definitive diagnosis for cancer in thyroid nodules. The aim of the study was to estimate the cost-effectiveness of utilizing a molecular diagnostic (DX) test as an adjunct to FNAB, compared with NoDX, to improve the preoperative diagnosis of thyroid nodules. We constructed a patient-level simulation model to estimate the clinical and economic outcomes of using a DX test compared with current practice (NoDX) for the diagnosis of thyroid nodules. By using a cost-effectiveness framework, we measured incremental clinical benefits in terms of quality-adjusted life-years and incremental costs over a 10-year time horizon. Assuming 95% sensitivity and specificity of the Dx test when used as an adjunct to FNAB, the utilization of the DX test resulted in a gain of 0.046 quality-adjusted life-years (95% confidence interval 0.019-0.078) and a saving of $1087 (95% confidence interval $691-$1533) in direct costs per patient. If the cost of the Dx test is less than $1087 per test, we expect to save quality-adjusted life-years and reduce costs when it is utilized. Sensitivity of the DX test, compared with specificity, had a larger influence on the overall outcomes. Copyright © 2012 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Diagnostic ability of macular ganglion cell asymmetry for glaucoma.

PubMed

Hwang, Young Hoon; Ahn, Sang Il; Ko, Sung Ju

2015-11-01

Using spectral-domain optical coherence tomography (OCT), this study aims to investigate the glaucoma diagnostic ability of macular ganglion cell asymmetry analysis. A cross-sectional study was conducted. This study was performed to investigate glaucoma diagnostic ability of macular ganglion cell asymmetry analysis in eyes with various degrees of glaucoma. We enrolled 181 healthy eyes and 265 glaucomatous eyes. Glaucomatous eyes were subdivided into pre-perimetric, early, moderate and advanced-to-severe glaucoma based on visual field test results. For each eye, macular ganglion cell-inner plexiform layer (GCIPL) thickness was measured using OCT. Average GCIPL thickness, GCIPL thicknesses in superior and inferior hemispheres, absolute difference in GCIPL thickness between superior and inferior hemispheres and GCIPL asymmetry index calculated as the absolute value of log10 (inferior hemisphere thickness/superior hemisphere thickness) were analysed. Areas under the receiver operating characteristics curves (AUCs) of GCIPL parameter were calculated and compared. All of the GCIPL parameters showed good glaucoma diagnostic ability (AUCs ≥ 0.817, P < 0.01). AUCs of average, superior and inferior GCIPL thickness increased as the severity of glaucoma increased. GCIPL thickness difference and asymmetry index showed the highest AUCs in early and moderate glaucoma and lower AUCs in pre-perimetric and advanced-to-severe glaucoma. GCIPL thickness difference and asymmetry index showed better glaucoma diagnostic ability than other GCIPL parameters only in early stage of glaucoma (P < 0.05); in other stages, these parameters had similar to or worse glaucoma diagnostic ability than other GCIPL parameters. Macular ganglion cell asymmetry analysis showed good glaucoma diagnostic ability, especially in early-stage glaucoma. However, it has limited usefulness in other stages of glaucoma. © 2015 Royal Australian and New Zealand College of Ophthalmologists.

SYMPTOM PRESENTATIONS AND CLASSIFICATION OF AUTISM SPECTRUM DISORDER IN EARLY CHILDHOOD: APPLICATION TO THE DIAGNOSTIC CLASSIFICATION OF MENTAL HEALTH AND DEVELOPMENTAL DISORDERS OF INFANCY AND EARLY CHILDHOOD (DC:0–5)

PubMed Central

SOTO, TIMOTHY; KISS, IVY GISERMAN; CARTER, ALICE S.

2018-01-01

Over the past 5 years, a great deal of information about the early course of autism spectrum disorder (ASD) has emerged from longitudinal prospective studies of infants at high risk for developing ASD based on a previously diagnosed older sibling. The current article describes early ASD symptom presentations and outlines the rationale for defining a new disorder, Early Atypical Autism Spectrum Disorder (EA-ASD) to accompany ASD in the new revision of the ZERO TO THREE Diagnostic Classification of Mental Health and Developmental Disorders of Infancy and Early Childhood (DC:0–5) (in press) alternative diagnostic classification manual. EA-ASD is designed to identify children who are 9 to 36 months of age presenting with a minimum of (a) two social-communication symptoms and (b) one repetitive and restricted behavior symptom as well as (c) evidence of impairment, with the intention of providing these children with appropriately tailored services and improving the likelihood of optimizing their development. PMID:27556740

Development and Use of Diagnostic Tests to Evaluate Students' Misconceptions in Science.

ERIC Educational Resources Information Center

Treagust, David F.

1988-01-01

Describes 10 steps for developing a diagnostic test of students' misconceptions and the use of two tests in chemistry (covalent bonding and structure) and in biology (photosynthesis and respiration in plants). Discusses the results and some implications for teaching science. (YP)

30 CFR 250.525 - What do I submit if my casing diagnostic test requires action?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What do I submit if my casing diagnostic test... INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Well-Completion Operations Casing Pressure Management § 250.525 What do I submit if my casing diagnostic test...

Pathways to multidrug-resistant tuberculosis diagnosis and treatment initiation: a qualitative comparison of patients' experiences in the era of rapid molecular diagnostic tests.

PubMed

Naidoo, Pren; van Niekerk, Margaret; du Toit, Elizabeth; Beyers, Nulda; Leon, Natalie

2015-10-28

Although new molecular diagnostic tests such as GenoType MTBDRplus and Xpert® MTB/RIF have reduced multidrug-resistant tuberculosis (MDR-TB) treatment initiation times, patients' experiences of diagnosis and treatment initiation are not known. This study aimed to explore and compare MDR-TB patients' experiences of their diagnostic and treatment initiation pathway in GenoType MTBDRplus and Xpert® MTB/RIF-based diagnostic algorithms. The study was undertaken in Cape Town, South Africa where primary health-care services provided free TB diagnosis and treatment. A smear, culture and GenoType MTBDRplus diagnostic algorithm was used in 2010, with Xpert® MTB/RIF phased in from 2011-2013. Participants diagnosed in each algorithm at four facilities were purposively sampled, stratifying by age, gender and MDR-TB risk profiles. We conducted in-depth qualitative interviews using a semi-structured interview guide. Through constant comparative analysis we induced common and divergent themes related to symptom recognition, health-care access, testing for MDR-TB and treatment initiation within and between groups. Data were triangulated with clinical information and health visit data from a structured questionnaire. We identified both enablers and barriers to early MDR-TB diagnosis and treatment. Half the patients had previously been treated for TB; most recognised recurring symptoms and reported early health-seeking. Those who attributed symptoms to other causes delayed health-seeking. Perceptions of poor public sector services were prevalent and may have contributed both to deferred health-seeking and to patient's use of the private sector, contributing to delays. However, once on treatment, most patients expressed satisfaction with public sector care. Two patients in the Xpert® MTB/RIF-based algorithm exemplified its potential to reduce delays, commencing MDR-TB treatment within a week of their first health contact. However, most patients in both algorithms experienced

Bayesian evaluation of clinical diagnostic test characteristics of visual observations and remote monitoring to diagnose bovine respiratory disease in beef calves.

PubMed

White, Brad J; Goehl, Dan R; Amrine, David E; Booker, Calvin; Wildman, Brian; Perrett, Tye

2016-04-01

Accurate diagnosis of bovine respiratory disease (BRD) in beef cattle is a critical facet of therapeutic programs through promotion of prompt treatment of diseased calves in concert with judicious use of antimicrobials. Despite the known inaccuracies, visual observation (VO) of clinical signs is the conventional diagnostic modality for BRD diagnosis. Objective methods of remotely monitoring cattle wellness could improve diagnostic accuracy; however, little information exists describing the accuracy of this method compared to traditional techniques. The objective of this research is to employ Bayesian methodology to elicit diagnostic characteristics of conventional VO compared to remote early disease identification (REDI) to diagnose BRD. Data from previous literature on the accuracy of VO were combined with trial data consisting of direct comparison between VO and REDI for BRD in two populations. No true gold standard diagnostic test exists for BRD; therefore, estimates of diagnostic characteristics of each test were generated using Bayesian latent class analysis. Results indicate a 90.0% probability that the sensitivity of REDI (median 81.3%; 95% probability interval [PI]: 55.5, 95.8) was higher than VO sensitivity (64.5%; PI: 57.9, 70.8). The specificity of REDI (median 92.9%; PI: 88.2, 96.9) was also higher compared to VO (median 69.1%; PI: 66.3, 71.8). The differences in sensitivity and specificity resulted in REDI exhibiting higher positive and negative predictive values in both high (41.3%) and low (2.6%) prevalence situations. This research illustrates the potential of remote cattle monitoring to augment conventional methods of BRD diagnosis resulting in more accurate identification of diseased cattle. Copyright © 2016 Elsevier B.V. All rights reserved.

Portuguese Family Physicians’ Awareness of Diagnostic and Laboratory Test Costs: A Cross-Sectional Study

PubMed Central

Sá, Luísa; Costa-Santos, Cristina; Teixeira, Andreia; Couto, Luciana; Costa-Pereira, Altamiro; Hespanhol, Alberto; Santos, Paulo; Martins, Carlos

2015-01-01

Background Physicians’ ability to make cost-effective decisions has been shown to be affected by their knowledge of health care costs. This study assessed whether Portuguese family physicians are aware of the costs of the most frequently prescribed diagnostic and laboratory tests. Methods A cross-sectional study was conducted in a representative sample of Portuguese family physicians, using computer-assisted telephone interviews for data collection. A Likert scale was used to assess physician’s level of agreement with four statements about health care costs. Family physicians were also asked to estimate the costs of diagnostic and laboratory tests. Each physician’s cost estimate was compared with the true cost and the absolute error was calculated. Results One-quarter (24%; 95% confidence interval: 23%–25%) of all cost estimates were accurate to within 25% of the true cost, with 55% (95% IC: 53–56) overestimating and 21% (95% IC: 20–22) underestimating the true actual cost. The majority (76%) of family physicians thought they did not have or were uncertain as to whether they had adequate knowledge of diagnostic and laboratory test costs, and only 7% reported receiving adequate education. The majority of the family physicians (82%) said that they had adequate access to information about the diagnostic and laboratory test costs. Thirty-three percent thought that costs did not influence their decision to order tests, while 27% were uncertain. Conclusions Portuguese family physicians have limited awareness of diagnostic and laboratory test costs, and our results demonstrate a need for improved education in this area. Further research should focus on identifying whether interventions in cost knowledge actually change ordering behavior, in identifying optimal methods to disseminate cost information, and on improving the cost-effectiveness of care. PMID:26356625

Diagnostic Accuracy of Obstructive Airway Adult Test for Diagnosis of Obstructive Sleep Apnea.

PubMed

Gasparini, Giulio; Vicini, Claudio; De Benedetto, Michele; Salamanca, Fabrizio; Sorrenti, Giovanni; Romandini, Mario; Bosi, Marcello; Saponaro, Gianmarco; Foresta, Enrico; Laforì, Andreina; Meccariello, Giuseppe; Bianchi, Alessandro; Toraldo, Domenico Maurizio; Campanini, Aldo; Montevecchi, Filippo; Rizzotto, Grazia; Cervelli, Daniele; Moro, Alessandro; Arigliani, Michele; Gobbi, Riccardo; Pelo, Sandro

2015-01-01

The gold standard for the diagnosis of Obstructive Sleep Apnea (OSA) is polysomnography, whose access is however reduced by costs and limited availability, so that additional diagnostic tests are needed. To analyze the diagnostic accuracy of the Obstructive Airway Adult Test (OAAT) compared to polysomnography for the diagnosis of OSA in adult patients. Ninety patients affected by OSA verified with polysomnography (AHI ≥ 5) and ten healthy patients, randomly selected, were included and all were interviewed by one blind examiner with OAAT questions. The Spearman rho, evaluated to measure the correlation between OAAT and polysomnography, was 0.72 (p < 0.01). The area under the ROC curve (95% CI) was the parameter to evaluate the accuracy of the OAAT: it was 0.91 (0.81-1.00) for the diagnosis of OSA (AHI ≥ 5), 0.90 (0.82-0.98) for moderate OSA (AHI ≥ 15), and 0.84 (0.76-0.92) for severe OSA (AHI ≥ 30). The OAAT has shown a high correlation with polysomnography and also a high diagnostic accuracy for the diagnosis of OSA. It has also been shown to be able to discriminate among the different degrees of severity of OSA. Additional large studies aiming to validate this questionnaire as a screening or diagnostic test are needed.

Dual Processing Model for Medical Decision-Making: An Extension to Diagnostic Testing

PubMed Central

Tsalatsanis, Athanasios; Hozo, Iztok; Kumar, Ambuj; Djulbegovic, Benjamin

2015-01-01

Dual Processing Theories (DPT) assume that human cognition is governed by two distinct types of processes typically referred to as type 1 (intuitive) and type 2 (deliberative). Based on DPT we have derived a Dual Processing Model (DPM) to describe and explain therapeutic medical decision-making. The DPM model indicates that doctors decide to treat when treatment benefits outweigh its harms, which occurs when the probability of the disease is greater than the so called “threshold probability” at which treatment benefits are equal to treatment harms. Here we extend our work to include a wider class of decision problems that involve diagnostic testing. We illustrate applicability of the proposed model in a typical clinical scenario considering the management of a patient with prostate cancer. To that end, we calculate and compare two types of decision-thresholds: one that adheres to expected utility theory (EUT) and the second according to DPM. Our results showed that the decisions to administer a diagnostic test could be better explained using the DPM threshold. This is because such decisions depend on objective evidence of test/treatment benefits and harms as well as type 1 cognition of benefits and harms, which are not considered under EUT. Given that type 1 processes are unique to each decision-maker, this means that the DPM threshold will vary among different individuals. We also showed that when type 1 processes exclusively dominate decisions, ordering a diagnostic test does not affect a decision; the decision is based on the assessment of benefits and harms of treatment. These findings could explain variations in the treatment and diagnostic patterns documented in today’s clinical practice. PMID:26244571

Dual Processing Model for Medical Decision-Making: An Extension to Diagnostic Testing.

PubMed

Tsalatsanis, Athanasios; Hozo, Iztok; Kumar, Ambuj; Djulbegovic, Benjamin

2015-01-01

Dual Processing Theories (DPT) assume that human cognition is governed by two distinct types of processes typically referred to as type 1 (intuitive) and type 2 (deliberative). Based on DPT we have derived a Dual Processing Model (DPM) to describe and explain therapeutic medical decision-making. The DPM model indicates that doctors decide to treat when treatment benefits outweigh its harms, which occurs when the probability of the disease is greater than the so called "threshold probability" at which treatment benefits are equal to treatment harms. Here we extend our work to include a wider class of decision problems that involve diagnostic testing. We illustrate applicability of the proposed model in a typical clinical scenario considering the management of a patient with prostate cancer. To that end, we calculate and compare two types of decision-thresholds: one that adheres to expected utility theory (EUT) and the second according to DPM. Our results showed that the decisions to administer a diagnostic test could be better explained using the DPM threshold. This is because such decisions depend on objective evidence of test/treatment benefits and harms as well as type 1 cognition of benefits and harms, which are not considered under EUT. Given that type 1 processes are unique to each decision-maker, this means that the DPM threshold will vary among different individuals. We also showed that when type 1 processes exclusively dominate decisions, ordering a diagnostic test does not affect a decision; the decision is based on the assessment of benefits and harms of treatment. These findings could explain variations in the treatment and diagnostic patterns documented in today's clinical practice.

Early Diagnosis of Pneumonia in Severe Stroke: Clinical Features and the Diagnostic Role of C-Reactive Protein.

PubMed

Warusevitane, Anushka; Karunatilake, Dumin; Sim, Julius; Smith, Craig; Roffe, Christine

2016-01-01

Accurate diagnosis of pneumonia complicating severe stroke is challenging due to difficulties in physical examination, altered immune responses and delayed manifestations of radiological changes. The aims of this study were to describe early clinical features and to examine C-reactive protein (CRP) as a diagnostic marker of post-stroke pneumonia. Patients who required nasogastric feeding and had no evidence of pneumonia within 7 days of stroke onset were included in the study and followed-up for 21 days with a daily clinical examination. Pneumonia was diagnosed using modified British Thoracic Society criteria. 60 patients were recruited (mean age 77 years, mean National Institutes of Health Stroke Scale Score 19.47). Forty-four episodes of pneumonia were identified. Common manifestations on the day of the diagnosis were new onset crackles (43/44, 98%), tachypnoea>25/min (42/44, 95%), and oxygen saturation <90% (41/44, 93%). Cough, purulent sputum, and pyrexia >38°C were observed in 27 (61%), 25 (57%) and 15 (34%) episodes respectively. Leucocytosis (WBC>11,000/ml) and raised CRP (>10 mg/l) were observed in 38 (86%) and 43 (97%) cases of pneumonia respectively. The area under the ROC curve for CRP was 0.827 (95% CI 0.720, 0.933). The diagnostic cut-off for CRP with an acceptable sensitivity (>0.8) was 25.60 mg/L (Youden index (J) 0.515; sensitivity 0.848; specificity 0.667). A cut-off of 64.65 mg/L had the highest diagnostic accuracy (J 0.562; sensitivity 0.636; specificity 0.926). Patients with severe stroke frequently do not manifest key diagnostic features of pneumonia such as pyrexia, cough and purulent sputum early in their illness. The most common signs in this group are new-onset crackles, tachypnoea and hypoxia. Our results suggest that a CRP >25 mg/L should prompt investigations for pneumonia while values >65 mg/L have the highest diagnostic accuracy to justify consideration of this threshold as a diagnostic marker of post-stroke pneumonia.

Development, Evaluation, and Integration of a Quantitative Reverse-Transcription Polymerase Chain Reaction Diagnostic Test for Ebola Virus on a Molecular Diagnostics Platform.

PubMed

Cnops, Lieselotte; Van den Eede, Peter; Pettitt, James; Heyndrickx, Leo; De Smet, Birgit; Coppens, Sandra; Andries, Ilse; Pattery, Theresa; Van Hove, Luc; Meersseman, Geert; Van Den Herrewegen, Sari; Vergauwe, Nicolas; Thijs, Rein; Jahrling, Peter B; Nauwelaers, David; Ariën, Kevin K

2016-10-15

 The 2013-2016 Ebola epidemic in West Africa resulted in accelerated development of rapid diagnostic tests for emergency outbreak preparedness. We describe the development and evaluation of the Idylla™ prototype Ebola virus test, a fully automated sample-to-result molecular diagnostic test for rapid detection of Zaire ebolavirus (EBOV) and Sudan ebolavirus (SUDV).  The Idylla™ prototype Ebola virus test can simultaneously detect EBOV and SUDV in 200 µL of whole blood. The sample is directly added to a disposable cartridge containing all reagents for sample preparation, RNA extraction, and amplification by reverse-transcription polymerase chain reaction analysis. The performance was evaluated with a variety of sample types, including synthetic constructs and whole blood samples from healthy volunteers spiked with viral RNA, inactivated virus, and infectious virus.  The 95% limits of detection for EBOV and SUDV were 465 plaque-forming units (PFU)/mL (1010 copies/mL) and 324 PFU/mL (8204 copies/mL), respectively. In silico and in vitro analyses demonstrated 100% correct reactivity for EBOV and SUDV and no cross-reactivity with relevant pathogens. The diagnostic sensitivity was 97.4% (for EBOV) and 91.7% (for SUDV), the specificity was 100%, and the diagnostic accuracy was 95.9%.  The Idylla™ prototype Ebola virus test is a fast, safe, easy-to-use, and near-patient test that meets the performance criteria to detect EBOV in patients with suspected Ebola. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

The development of a post-test diagnostic system for rocket engines

NASA Technical Reports Server (NTRS)

Zakrajsek, June F.

1991-01-01

An effort was undertaken by NASA to develop an automated post-test, post-flight diagnostic system for rocket engines. The automated system is designed to be generic and to automate the rocket engine data review process. A modular, distributed architecture with a generic software core was chosen to meet the design requirements. The diagnostic system is initially being applied to the Space Shuttle Main Engine data review process. The system modules currently under development are the session/message manager, and portions of the applications section, the component analysis section, and the intelligent knowledge server. An overview is presented of a rocket engine data review process, the design requirements and guidelines, the architecture and modules, and the projected benefits of the automated diagnostic system.

In Search of Optimal Cognitive Diagnostic Model(s) for ESL Grammar Test Data

ERIC Educational Resources Information Center

Yi, Yeon-Sook

2017-01-01

This study compares five cognitive diagnostic models in search of optimal one(s) for English as a Second Language grammar test data. Using a unified modeling framework that can represent specific models with proper constraints, the article first fit the full model (the log-linear cognitive diagnostic model, LCDM) and investigated which model…

Perspectives on Introduction and Implementation of New Point-of-Care Diagnostic Tests

PubMed Central

Palamountain, Kara M.; Baker, Jeff; Cowan, Elliot P.; Essajee, Shaffiq; Mazzola, Laura T.; Metzler, Mutsumi; Schito, Marco; Stevens, Wendy S.; Young, Gloria J.

2012-01-01

In recent years, there has been significant investment from both the private and public sectors in the development of diagnostic technologies to meet the need for human immunodeficiency virus (HIV) and tuberculosis testing in low-resource settings. Future investments should ensure that the most appropriate technologies are adopted in settings where they will have a sustainable impact. Achieving these aims requires the involvement of many stakeholders, as their needs, operational constraints, and priorities are often distinct. Here, we discuss these considerations from different perspectives representing those of various stakeholders involved in the development, introduction, and implementation of diagnostic tests. We also discuss some opportunities to address these considerations. PMID:22402038

Effect of recording duration on the diagnostic performance of multifocal visual-evoked potentials in high-risk ocular hypertension and early glaucoma.

PubMed

Fortune, Brad; Zhang, Xian; Hood, Donald C; Demirel, Shaban; Patterson, Emily; Jamil, Annisa; Mansberger, Steven L; Cioffi, George A; Johnson, Chris A

2008-01-01

To evaluate the effect on diagnostic performance of reducing multifocal visual-evoked potential (mfVEP) recording duration from 16 to 8 minutes per eye. Both eyes of 185 individuals with high-risk ocular hypertension or early glaucoma were studied. Two 8-minute mfVEP recordings were obtained for each eye in an ABBA order using VERIS. The first recording for each eye was compared against single run (1-Run) mfVEP normative data; the average of both recordings for each eye was compared against 2-Run normative data. Visual fields (VFs) were obtained by standard automated perimetry (SAP) within 22.3+/-27.0 days of the mfVEP. Stereo disc photographs and Heidelberg Retina Tomograph images were obtained together, within 24.8+/-50.4 days of the mfVEP and 33.1+/-62.9 days of SAP. Masked experts graded disc photographs as either glaucomatous optic neuropathy or normal. The overall Moorfields Regression Analysis result from the Heidelberg Retina Tomograph was used as a separate diagnostic classification. Thus, 4 diagnostic standards were applied in total, 2 based on optic disc structure alone and 2 others based on disc structure and SAP. Agreement between the 1-Run and 2-Run mfVEP was 90%. Diagnostic performance of the 1-Run mfVEP was similar to that of the 2-Run mfVEP for all 4 diagnostic standards. Sensitivity was slightly higher for the 2-Run mfVEP, whereas specificity was slightly higher for the 1-Run mfVEP. If higher sensitivity is sought, the 2-Run mfVEP will provide better discrimination between groups of eyes with relatively high signal-to-noise ratio (eg, early glaucoma or high-risk suspects). But if higher specificity is a more important goal, the 1-Run mfVEP provides adequate sensitivity and requires only half the test time. Considered alongside prior studies, the present results suggest that the 1-Run mfVEP is an efficient way to confirm (or refute) the extent of VF loss in patients with moderate or advanced glaucoma, particularly in those with unreliable VFs

Effect of Recording Duration on the Diagnostic Performance of Multifocal Visual-evoked Potentials in High-risk Ocular Hypertension and Early Glaucoma

PubMed Central

Fortune, Brad; Zhang, Xian; Hood, Donald C.; Demirel, Shaban; Patterson, Emily; Jamil, Annisa; Mansberger, Steven L.; Cioffi, George A.; Johnson, Chris A.

2010-01-01

Purpose To evaluate the effect on diagnostic performance of reducing multifocal visual-evoked potential (mfVEP) recording duration from 16 to 8 minutes per eye. Methods Both eyes of 185 individuals with high-risk ocular hypertension or early glaucoma were studied. Two 8-minute mfVEP recordings were obtained for each eye in an ABBA order using VERIS. The first recording for each eye was compared against single run (1-Run) mfVEP normative data; the average of both recordings for each eye was compared against 2-Run normative data. Visual fields (VFs) were obtained by standard automated perimetry (SAP) within 22.3±27.0 days of the mfVEP. Stereo disc photographs and Heidelberg Retina Tomograph images were obtained together, within 24.8±50.4 days of the mfVEP and 33.1±62.9 days of SAP. Masked experts graded disc photographs as either glaucomatous optic neuropathy or normal. The overall Moorfields Regression Analysis result from the Heidelberg Retina Tomograph was used as a separate diagnostic classification. Thus, 4 diagnostic standards were applied in total, 2 based on optic disc structure alone and 2 others based on disc structure and SAP. Results Agreement between the 1-Run and 2-Run mfVEP was 90%. Diagnostic performance of the 1-Run mfVEP was similar to that of the 2-Run mfVEP for all 4 diagnostic standards. Sensitivity was slightly higher for the 2-Run mfVEP, whereas specificity was slightly higher for the 1-Run mfVEP. Conclusions If higher sensitivity is sought, the 2-Run mfVEP will provide better discrimination between groups of eyes with relatively high signal-to-noise ratio (eg, early glaucoma or high-risk suspects). But if higher specificity is a more important goal, the 1-Run mfVEP provides adequate sensitivity and requires only half the test time. Considered alongside prior studies, the present results suggest that the 1-Run mfVEP is an efficient way to confirm (or refute) the extent of VF loss in patients with moderate or advanced glaucoma, particularly

Diagnostic molecular microbiology: a 2013 snapshot.

PubMed

Fairfax, Marilynn Ransom; Salimnia, Hossein

2013-12-01

Molecular testing has a large and increasing role in the diagnosis of infectious diseases. It has evolved significantly since the first probe tests were FDA approved in the early 1990s. This article highlights the uses of molecular techniques in diagnostic microbiology, including "older," as well as innovative, probe techniques, qualitative and quantitative RT-PCR, highly multiplexed PCR panels, some of which use sealed microfluidic test cartridges, MALDI TOF, and nuclear magnetic resonance. Tests are grouped together by technique and target. Tests with similar roles for similar analytes are compared with respect to benefits, drawbacks, and possible problems. Copyright © 2013 Elsevier Inc. All rights reserved.

Towards improving diagnosis of memory loss in general practice: TIMeLi diagnostic test accuracy study protocol.

PubMed

Creavin, Sam T; Cullum, Sarah J; Haworth, Judy; Wye, Lesley; Bayer, Antony; Fish, Mark; Purdy, Sarah; Ben-Shlomo, Yoav

2016-07-19

People with cognitive problems, and their families, report distress and uncertainty whilst undergoing evaluation for dementia and perceive that traditional diagnostic evaluation in secondary care is insufficiently patient centred. The James Lind Alliance has prioritised research to investigate the role of primary care in supporting a more effective diagnostic pathway, and the topic is also of interest to health commissioners. However, there are very few studies that investigate the accuracy of diagnostic tests for dementia in primary care. We will conduct a prospective diagnostic test accuracy study to evaluate the accuracy of a range of simple tests for diagnosing all-cause-dementia in symptomatic people aged over 70 years who have consulted with their general practitioner (GP). We will invite eligible people to attend a research clinic where they will undergo a range of index tests that a GP could perform in the surgery and also be assessed by a specialist in memory disorders at the same appointment. Participating GPs will request neuroimaging and blood tests and otherwise manage patients in line with their usual clinical practice. The reference standard will be the consensus judgement of three experts (neurologist, psychiatrist and geriatrician) based on information from the specialist assessment, GP records and investigations, but not including items in the index test battery. The target condition will be all-cause dementia but we will also investigate diagnostic accuracy for sub-types where possible. We will use qualitative interviews with patients and focus groups with clinicians to help us understand the acceptability and feasibility of diagnosing dementia in primary care using the tests that we are investigating. Our results will help clinicians decide on which tests to perform in someone where there is concern about possible dementia and inform commissioning of diagnostic pathways.

Evaluation of Raman spectroscopy in comparison to commonly performed dengue diagnostic tests

NASA Astrophysics Data System (ADS)

Khan, Saranjam; Ullah, Rahat; Khurram, Muhammad; Ali, Hina; Mahmood, Arshad; Khan, Ajmal; Ahmed, Mushtaq

2016-09-01

This study demonstrates the evaluation of Raman spectroscopy as a rapid diagnostic test in comparison to commonly performed tests for an accurate detection of dengue fever in human blood sera. Blood samples of 104 suspected dengue patients collected from Holy Family Hospital, Rawalpindi, Pakistan, have been used in this study. Out of 104 samples, 52 (50%) were positive based on immunoglobulin G (IgG), whereas 54 (52%) were positive based on immunoglobulin M (IgM) antibody tests. For the determination of the diagnostic capabilities of Raman spectroscopy, accuracy, sensitivity, specificity and false positive rate have been calculated in comparison to normally performed IgM and IgG captured enzyme-linked immunosorbent assay tests. Accuracy, precision, specificity, and sensitivity for Raman spectroscopy in comparison to IgM were found to be 66%, 70%, 72%, and 61%, whereas based on IgG they were 47%, 46%, 52%, and 43%, respectively.

Selling biotechnology in the dental medicine marketplace: the OmniGene Diagnostics DNA probe tests for periodontal pathogens.

PubMed

Van Arsdell, S W; DiFronzo, F; Backman, K C; Mahler, P H

1996-09-01

OmniGene Diagnostics, Inc. has applied the principles of genetic engineering to develop species-specific DNA probe tests for eight periodontal pathogens (Porphyromonas gingivalis, Prevotella intermedia, Actinobacillus actinomycetem-comitans, Fusobacterium nucleatum, Eikenella corrodens, Campylobacter rectus, Bacteroides forsythus, and Treponema denticola). The test requires minimal effort on the part of the clinician: subgingival plaque samples are collected from the patient and sent through the mail for analysis by OmniGene Diagnostics' fully licensed clinical reference laboratory. Results are transmitted to the practitioner by phone, fax, or mail. The use of diagnostic tests for periodontal pathogens is a relatively new concept in dentistry and acceptance of the OmniGene Diagnostics tests by the dental marketplace has been slower than anticipated. OmniGene Diagnostics' challenge for the future is to persuade the dental community that monitoring periodontal pathogen levels, as well as other clinical indicators of disease, is essential to providing optimal care to the periodontitis patient.

Diagnostic performance of optical coherence tomography ganglion cell--inner plexiform layer thickness measurements in early glaucoma.

PubMed

Mwanza, Jean-Claude; Budenz, Donald L; Godfrey, David G; Neelakantan, Arvind; Sayyad, Fouad E; Chang, Robert T; Lee, Richard K

2014-04-01

To evaluate the glaucoma diagnostic performance of ganglion cell inner-plexiform layer (GCIPL) parameters used individually and in combination with retinal nerve fiber layer (RNFL) or optic nerve head (ONH) parameters measured with Cirrus HD-OCT (Carl Zeiss Meditec, Inc, Dublin, CA). Prospective cross-sectional study. Fifty patients with early perimetric glaucoma and 49 age-matched healthy subjects. Three peripapillary RNFL and 3 macular GCIPL scans were obtained in 1 eye of each participant. A patient was considered glaucomatous if at least 2 of the 3 RNFL or GCIPL scans had the average or at least 1 sector measurement flagged at 1% to 5% or less than 1%. The diagnostic performance was determined for each GCIPL, RNFL, and ONH parameter as well as for binary or-logic and and-logic combinations of GCIPL with RNFL or ONH parameters. Sensitivity, specificity, positive likelihood ratio (PLR), and negative likelihood ratio (NLR). Among GCIPL parameters, the minimum had the best diagnostic performance (sensitivity, 82.0%; specificity, 87.8%; PLR, 6.69; and NLR, 0.21). Inferior quadrant was the best RNFL parameter (sensitivity, 74%; specificity, 95.9%; PLR, 18.13; and NLR, 0.27), as was rim area (sensitivity, 68%; specificity, 98%; PLR, 33.3; and NLR, 0.33) among ONH parameters. The or-logic combination of minimum GCIPL and average RNFL provided the overall best diagnostic performance (sensitivity, 94%; specificity, 85.7%; PRL, 6.58; and NLR, 0.07) as compared with the best RNFL, best ONH, and best and-logic combination (minimum GCIPL and inferior quadrant RNFL; sensitivity, 64%; specificity, 100%; PLR, infinity; and NPR, 0.36). The binary or-logic combination of minimum GCIPL and average RNFL or rim area provides better diagnostic performances than those of and-logic combinations or best single GCIPL, RNFL, or ONH parameters. This finding may be clinically valuable for the diagnosis of early glaucoma. Copyright © 2014 American Academy of Ophthalmology. Published by

Convergent and diagnostic validity of STAVUX, a word and pseudoword spelling test for adults.

PubMed

Östberg, Per; Backlund, Charlotte; Lindström, Emma

2016-10-01

Few comprehensive spelling tests are available in Swedish, and none have been validated in adults with reading and writing disorders. The recently developed STAVUX test includes word and pseudoword spelling subtests with high internal consistency and adult norms stratified by education. This study evaluated the convergent and diagnostic validity of STAVUX in adults with dyslexia. Forty-six adults, 23 with dyslexia and 23 controls, took STAVUX together with a standard word-decoding test and a self-rated measure of spelling skills. STAVUX subtest scores showed moderate to strong correlations with word-decoding scores and predicted self-rated spelling skills. Word and pseudoword subtest scores both predicted dyslexia status. Receiver-operating characteristic (ROC) analysis showed excellent diagnostic discriminability. Sensitivity was 91% and specificity 96%. In conclusion, the results of this study support the convergent and diagnostic validity of STAVUX.

A new condition for assessing the clinical efficiency of a diagnostic test.

PubMed

Bokhari, Ehsan; Hubert, Lawrence

2015-09-01

When prediction using a diagnostic test outperforms simple prediction using base rates, the test is said to be "clinically efficient," a term first introduced into the literature by Meehl and Rosen (1955) in Psychological Bulletin. This article provides three equivalent conditions for determining the clinical efficiency of a diagnostic test: (a) Meehl-Rosen (Meehl & Rosen, 1955); (b) Dawes (Dawes, 1962); and (c) the Bokhari-Hubert condition, introduced here for the first time. Clinical efficiency is then generalized to situations where misclassification costs are considered unequal (for example, false negatives are more costly than false positives). As an illustration, the clinical efficiency of an actuarial device for predicting violent and dangerous behavior is examined that was developed as part of the MacArthur Violence Risk Assessment Study. (c) 2015 APA, all rights reserved.

The Clinical Utility and Diagnostic Performance of MRI for Identification of Early and Advanced Knee Osteoarthritis: A Systematic Review

PubMed Central

Quatman, Carmen E.; Hettrich, Carolyn M.; Schmitt, Laura C.; Spindler, Kurt P.

2013-01-01

Background Current diagnostic strategies for detection of structural articular cartilage abnormalities, the earliest structural signs of osteoarthritis, often do not capture the condition until it is too far advanced for the most potential benefit of non-invasive interventions. Purpose Systematically review the literature relative to the following questions: (1) Is MRI a valid, sensitive, specific, accurate and reliable instrument to identify knee articular cartilage abnormalities compared to arthroscopy? (2) Is MRI a sensitive tool that can be utilized to identify early cartilage degeneration? Study Design Systematic Review Methods A systematic search was performed in November 2010 using PubMed MEDLINE (from 1966), CINAHL (from 1982), SPORTDiscus (from 1985), and SCOPUS (from 1996) databases. Results Fourteen level I and 13 level II studies were identified that met inclusion criteria and provided information related to diagnostic performance of MRI compared to arthroscopic evaluation. The diagnostic performance of MRI demonstrated a large range of sensitivities, specificities, and accuracies. The sensitivity for identifying articular cartilage abnormalities in the knee joint was reported between 26–96%. Specificity and accuracy was reported between 50–100% and 49–94%, respectively. The sensitivity, specificity, and accuracy for identifying early osteoarthritis were reported between 0–86%, 48–95%, and 5–94%, respectively. As a result of inconsistencies between imaging techniques and methodological shortcomings of many of the studies, a meta-analysis was not performed and it was difficult to fully synthesize the information to state firm conclusions about the diagnostic performance of MRI. Conclusions There is evidence in some MRI protocols that MRI is a relatively valid, sensitive, specific, accurate, and reliable clinical tool for identifying articular cartilage degeneration. Due to heterogeneity of MRI sequences it is not possible to make definitive

Prevention of sudden death in adolescent athletes: Incremental diagnostic value and cost-effectiveness of diagnostic tests.

PubMed

Grazioli, Gonzalo; Sanz de la Garza, Maria; Vidal, Barbara; Montserrat, Silvia; Sarquella-Brugada, Georgia; Pi, Ramon; Til, Lluis; Gutierrez, Josep; Brugada, Josep; Sitges, Marta

2017-09-01

Introduction Pre-participation screening in athletes attempts to reduce the incidence of sudden death during sports by identifying susceptible individuals. The objective of this study was to evaluate the diagnostic capacity of the different pre-participation screening points in adolescent athletes and the cost effectiveness of the programme. Methods Athletes were studied between 12-18 years old. Pre-participation screening included the American Heart Association questionnaire, electrocardiogram, echocardiogram, and stress test. The cost of test was established by the Catalan public health system. Results Of 1650 athletes included, 57% were men and mean age was 15.09 ± 1.82 years. Positive findings were identified as follows: in American Heart Association questionnaire 5.09% of subjects, in electrocardiogram 3.78%, in echocardiogram 4.96%, and in exercise test 1.75%. Six athletes (0.36%) were disqualified from participation and 10 (0.60%) were referred for interventional treatment. Diagnostic capacity was assessed by the area under the curve for detection of diseases that motivated disqualification for sport practice (American Heart Association questionnaire, 0.55; electrocardiogram, 0.72; echocardiogram, 0.88; stress test, 0.57). The cost for each athlete disqualified from the sport for a disease causing sudden death was €45,578. Conclusion The electrocardiogram and echocardiogram were the most useful studies to detect athletes susceptible to sudden death, and the stress test best diagnosed arrhythmias with specific treatment. In our country, pre-participatory screening was cost effective to detect athletes who might experience sudden death in sports.

2012 HIV Diagnostics Conference: the molecular diagnostics perspective.

PubMed

Branson, Bernard M; Pandori, Mark

2013-04-01

2012 HIV Diagnostic Conference Atlanta, GA, USA, 12-14 December 2012. This report highlights the presentations and discussions from the 2012 National HIV Diagnostic Conference held in Atlanta (GA, USA), on 12-14 December 2012. Reflecting changes in the evolving field of HIV diagnostics, the conference provided a forum for evaluating developments in molecular diagnostics and their role in HIV diagnosis. In 2010, the HIV Diagnostics Conference concluded with the proposal of a new diagnostic algorithm which included nucleic acid testing to resolve discordant screening and supplemental antibody test results. The 2012 meeting, picking up where the 2010 meeting left off, focused on scientific presentations that assessed this new algorithm and the role played by RNA testing and new developments in molecular diagnostics, including detection of total and integrated HIV-1 DNA, detection and quantification of HIV-2 RNA, and rapid formats for detection of HIV-1 RNA.

30 CFR 250.524 - When am I required to take action from my casing diagnostic test?

Code of Federal Regulations, 2010 CFR

2010-07-01

... casing diagnostic test; (c) Any well that has demonstrated tubing/casing, tubing/riser, casing/casing... casing diagnostic test? 250.524 Section 250.524 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT... Gas Well-Completion Operations Casing Pressure Management § 250.524 When am I required to take action...

Culture-independent diagnostic testing: have we opened Pandora's box for good?

PubMed

Janda, J Michael; Abbott, Sharon A

2014-11-01

The ability to accurately and quickly identify microbial agents associated with infectious diseases has been a longstanding and continuous goal of diagnostic microbiology laboratories. Over the course of several decades, technology and testing methodologies in this field have gradually evolved from traditional- or classic-based culture and identification approaches to antigen capture systems and more molecular-oriented applications. Recently, these molecular-based applications have signaled a new era in clinical diagnostic microbiology with the commercial introduction of culture-independent diagnostic testing (CIDT) systems. The first major commercial venture into the CIDT arena involves the detection of acute bacterial gastroenteritis. Several commercial products are now on the market globally with at least 4 Food and Drug Administration approved since January of 2013. These new systems offer the direct detection of a variety of enteropathogens quickly without the need for traditional culture. In Greek mythology, Pandora opened a "jar" or "box" out of curiosity thereby releasing all of humanity's evils most notably diseases and plagues according to Hesiod's Theogony. While not ill-intentioned the only thing left in the box was Hope. Copyright © 2014 Elsevier Inc. All rights reserved.

Assessing value of innovative molecular diagnostic tests in the concept of predictive, preventive, and personalized medicine.

PubMed

Akhmetov, Ildar; Bubnov, Rostyslav V

2015-01-01

Molecular diagnostic tests drive the scientific and technological uplift in the field of predictive, preventive, and personalized medicine offering invaluable clinical and socioeconomic benefits to the key stakeholders. Although the results of diagnostic tests are immensely influential, molecular diagnostic tests (MDx) are still grudgingly reimbursed by payers and amount for less than 5 % of the overall healthcare costs. This paper aims at defining the value of molecular diagnostic test and outlining the most important components of "value" from miscellaneous assessment frameworks, which go beyond accuracy and feasibility and impact the clinical adoption, informing healthcare resource allocation decisions. The authors suggest that the industry should facilitate discussions with various stakeholders throughout the entire assessment process in order to arrive at a consensus about the depth of evidence required for positive marketing authorization or reimbursement decisions. In light of the evolving "value-based healthcare" delivery practices, it is also recommended to account for social and ethical parameters of value, since these are anticipated to become as critical for reimbursement decisions and test acceptance as economic and clinical criteria.

Clinical overlap between malaria and pneumonia: can malaria rapid diagnostic test play a role?

PubMed

Ukwaja, Kingsley Nnanna; Aina, Olufemi B; Talabi, Ademola A

2011-03-21

Malaria and pneumonia account for 40% of mortality among children under five years of age in sub-Saharan Africa. Due to lack of diagnostic facilities, their management is based on the integrated management of childhood illnesses (IMCI) strategy. Symptoms of malaria and pneumonia overlap in African children, necessitating dual IMCI classifications at health centres and treatment with both antibiotics and antimalarials. This study determined the prevalence of malaria-pneumonia symptom overlap and confirmed the diagnosis of malaria in these cases using a rapid diagnostic test. Consecutive consultations of 1,216 children (two months to five years old) were documented over a three-month period in a comprehensive health centre. Malaria rapid diagnostic tests were conducted only for children who had symptom overlap. Of the 1,216 children enrolled, 1,090 (90%) reported cough or fever. Among the children fulfilling the malaria case definition, 284 (30%) also met the pneumonia case definition. Twenty-three percent (284) of all children enrolled met the criteria for both malaria and pneumonia. However, only 130 (46%) of them had a positive result for malaria using a malaria rapid diagnostic test. During a malaria-pneumonia overlap, female children (chi-square 5.9, P = 0.01) and children ≥ one year (chi-square 4.8, P = 0.003) were more likely to seek care within two days of fever. Dual treatment with antimalarials and antibiotics in children with malaria-pneumonia overlap may result in unnecessary over-prescription of antimalarial medications. Use of rapid diagnostic tests in their management can potentially avoid over-prescribing of malaria medications.

An International Comparison Using a Diagnostic Testing Model: Turkish Students' Profile of Mathematical Skills on TIMSS-R

ERIC Educational Resources Information Center

Dogan, Enis; Tatsuoka, Kikumi

2008-01-01

This study illustrates how a diagnostic testing model can be used to make detailed comparisons between student populations participating in international assessments. The performance of Turkish students on the TIMSS-R mathematics test was reanalyzed with a diagnostic testing model called the Rule Space Model. First, mathematical and cognitive…

Diagnostic accuracy of patch test in children with food allergy.

PubMed

Caglayan Sozmen, Sule; Povesi Dascola, Carlotta; Gioia, Edoardo; Mastrorilli, Carla; Rizzuti, Laura; Caffarelli, Carlo

2015-08-01

The gold standard test for confirming whether a child has clinical hypersensitivity reactions to foods is the oral food challenge. Therefore, there is increasing interest in simpler diagnostic markers of food allergy, especially in children, to avoid oral food challenge. The goal of this study was to assess the diagnostic accuracy of atopy patch test in comparison with oral food challenge. We investigated 243 children (mean age, 51 months) referred for evaluation of suspected egg or cow's milk allergy. Skin prick test and atopy patch test were carried out, and after a 2 weeks elimination diet, oral food challenge was performed. Two hundred and forty-three children underwent OFC to the suspected food. We found clinically relevant food allergies in 40 (65%) children to egg and in 22 (35%) to cow's milk. The sensitivity of skin prick test for both milk and egg was 92%, specificity 91%, positive predictive value 35%, and negative predictive value of 93%. Sensitivity, specificity, positive predictive value, and negative predictive value of atopy patch test for both milk and egg were 21%, 73%, 20%, and 74%, respectively. Our study suggests that there is insufficient evidence for the routine use of atopy patch test for the evaluation of egg and cow's milk allergy. OFC remains gold standard for the diagnosis of egg and milk allergy even in the presence of high costs in terms of both time and risks during application. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Early Detection of Lung Cancer Using Nano-Nose - A Review

PubMed Central

Fernandes, M. P.; Venkatesh, S; Sudarshan, B. G

2015-01-01

Lung cancer is one of the malignancies causing deaths worldwide. The yet to be developed non-invasive diagnostic techniques, are a challenge for early detection of cancer before it progresses to its later stages. The currently available diagnostic methods are expensive or invasive, and are not fit for general screening purposes. Early identification not only helps in detecting primary cancer, but also in treating its secondaries; which creates a need for easily applicable tests to screen individuals at risk. A detailed review of the various screening methods, including the latest trend of breath analysis using gold nanoparticles, to identify cancer at its early stage, are studied here. The VOC based breath biomarkers are used to analyze the exhaled breath of the patients. These biomarkers are utilized by Chemiresistors coated with gold nanoparticles, which are found to be the most suited technique for early detection of lung cancer. This technique is highly accurate and is relatively easy to operate and was tested on smokers and non-smokers. This review also gives as an outline of the fabrication and working of the device Na-Nose. The Chemiresistors coated with Gold nanoparticles, show a great potential in being an non-invasive and cost-effective diagnostic technique for early detection of lung cancer. PMID:26628933

Early Detection of Lung Cancer Using Nano-Nose - A Review.

PubMed

Fernandes, M P; Venkatesh, S; Sudarshan, B G

2015-01-01

Lung cancer is one of the malignancies causing deaths worldwide. The yet to be developed non-invasive diagnostic techniques, are a challenge for early detection of cancer before it progresses to its later stages. The currently available diagnostic methods are expensive or invasive, and are not fit for general screening purposes. Early identification not only helps in detecting primary cancer, but also in treating its secondaries; which creates a need for easily applicable tests to screen individuals at risk. A detailed review of the various screening methods, including the latest trend of breath analysis using gold nanoparticles, to identify cancer at its early stage, are studied here. The VOC based breath biomarkers are used to analyze the exhaled breath of the patients. These biomarkers are utilized by Chemiresistors coated with gold nanoparticles, which are found to be the most suited technique for early detection of lung cancer. This technique is highly accurate and is relatively easy to operate and was tested on smokers and non-smokers. This review also gives as an outline of the fabrication and working of the device Na-Nose. The Chemiresistors coated with Gold nanoparticles, show a great potential in being an non-invasive and cost-effective diagnostic technique for early detection of lung cancer.

Toxicoproteomics: serum proteomic pattern diagnostics for early detection of drug induced cardiac toxicities and cardioprotection.

PubMed

Petricoin, Emanuel F; Rajapaske, Vinodh; Herman, Eugene H; Arekani, Ali M; Ross, Sally; Johann, Donald; Knapton, Alan; Zhang, J; Hitt, Ben A; Conrads, Thomas P; Veenstra, Timothy D; Liotta, Lance A; Sistare, Frank D

2004-01-01

Proteomics is more than just generating lists of proteins that increase or decrease in expression as a cause or consequence of pathology. The goal should be to characterize the information flow through the intercellular protein circuitry which communicates with the extracellular microenvironment and then ultimately to the serum/plasma macroenvironment. The nature of this information can be a cause, or a consequence, of disease and toxicity based processes as cascades of reinforcing information percolate through the system and become reflected in changing proteomic information content of the circulation. Serum Proteomic Pattern Diagnostics is a new type of proteomic platform in which patterns of proteomic signatures from high dimensional mass spectrometry data are used as a diagnostic classifier. While this approach has shown tremendous promise in early detection of cancers, detection of drug-induced toxicity may also be possible with this same technology. Analysis of serum from rat models of anthracycline and anthracenedione induced cardiotoxicity indicate the potential clinical utility of diagnostic proteomic patterns where low molecular weight peptides and protein fragments may have higher accuracy than traditional biomarkers of cardiotoxicity such as troponins. These fragments may one day be harvested by circulating nanoparticles designed to absorb, enrich and amplify the diagnostic biomarker repertoire generated even at the critical initial stages of toxicity.

Uncomplicated malaria in children: The place of rapid diagnostic test.

PubMed

Elechi, Hassan Abdullahi; Rabasa, Adamu Ibrahim; Bashir, Muhammad Faruk; Gofama, Mustapha Modu; Ibrahim, Halima Abubakar; Askira, Umoru Muhammed

2015-01-01

Malaria has remained a major cause of morbidity and mortality among the under-five children in Nigeria. Prompt and accurate diagnosis of malaria is necessary in controlling this high burden and preventing unnecessary use of anti-malarial drugs. Malaria rapid diagnostic test (MRDT) offers the hope of achieving this goal. However, the performance of these kits among the most vulnerable age group to malaria is inadequate. In this cross-sectional study, 433 out-patients, aged <5 years with fever or history of fever were enrolled. Each candidate was tested for malaria parasitaemia using ACON; malaria pf. Thick and thin films were also prepared from the same finger prick blood for each candidate. Malaria rapid diagnostic test had sensitivity of 8.3%, specificity of 100%, positive predictive value (PPV) of 100% and negative predictive value (NPV) of 74%. The sensitivity of MRDT increased with increasing age. This effect of age on sensitivity was statistically significant (P = 0.007). Similarly parasite density had significant effect on the sensitivity of MRDT (P = <0.001). Histidine-rich protein-2 based MRDT is not a reliable mean of diagnosing malaria in the under-five age children with acute uncomplicated malaria.

30 CFR 250.523 - How long do I keep records of casing pressure and diagnostic tests?

Code of Federal Regulations, 2010 CFR

2010-07-01

... field office nearest the well for a minimum of 2 years. The last casing diagnostic test for each casing... and diagnostic tests? 250.523 Section 250.523 Mineral Resources MINERALS MANAGEMENT SERVICE... Gas Well-Completion Operations Casing Pressure Management § 250.523 How long do I keep records of...

The Astronomy Diagnostic Test: Past, Present and Future

NASA Astrophysics Data System (ADS)

Deming, G. L.; Hufnagel, B. R.

2000-12-01

During 1998, the Collaboration for Astronomy Education Research (Adams, Adrian, Brick, Deming, Hufnagel, Slater, and Zeilik) developed a content-based diagnostic test for undergraduate non-science majors taking their first introductory level astronomy course. Student interviews and written feedback were used to construct a series of questions reflecting the students' natural language and with distractors (wrong answers) that mirror commonly held misconceptions. Version 1.9 of the Astronomy Diagnostic Test (ADT) was administered during Spring 1999 by volunteers teaching astronomy at 22 institutions across the United States. Minor modifications were made and Version 2.0 was released on June 21, 1999. The ADT 2.0 currently is available to the astronomical community through two websites and we continue to collect pretest/posttest results. Award of an NSF Small Grant for Exploratory Research has enabled us to work with a team of education researchers at the Ontario Institute for Studies in Education. Our database will be subjected to a statistical analysis in order to establish reliability of ADT 2.0. In addition, content, face, and construct validity are being examined. If you are teaching an introductory astronomy course aimed at non-science majors for Spring 2001, your class can be part of this project. We are looking for volunteers! We are also interested in hearing your ideas for a "next-generation" version of the ADT. Funding provided by NSF grant REC-0089239

Cognitive Diagnostic Models for Tests with Multiple-Choice and Constructed-Response Items

ERIC Educational Resources Information Center

Kuo, Bor-Chen; Chen, Chun-Hua; Yang, Chih-Wei; Mok, Magdalena Mo Ching

2016-01-01

Traditionally, teachers evaluate students' abilities via their total test scores. Recently, cognitive diagnostic models (CDMs) have begun to provide information about the presence or absence of students' skills or misconceptions. Nevertheless, CDMs are typically applied to tests with multiple-choice (MC) items, which provide less diagnostic…

Comparison between DOT EIA IgM and Widal Test as early diagnosis of typhoid fever.

PubMed

Begum, Z; Hossain, M A; Musa, A K; Shamsuzzaman, A K; Mahmud, M C; Ahsan, M M; Sumona, A A; Ahmed, S; Jahan, N A; Alam, M; Begum, A

2009-01-01

A recently developed DOT enzyme immunoassay known as "Typhidot" for detecting IgM antibody against 50 KDa OMP antigen of Salmonella typhi, was evaluated on 100 clinically suspected typhoid fever cases and 40 age-sex matched controls, in the Department of Microbiology, Mymensingh Medical College during, the period from June 2006 to July 2007. Blood culture, Widal test, and DOT EIA for IgM test were performed in all patients. Among 100 clinically suspected typhoid fever cases, 35 were subsequently confirmed on the basis of positive blood culture for S. typhi and/or significant rising titre of Widal test. The DOT EIA IgM test could produce results within 1 hour. The result of the DOT EIA IgM test showed a good diagnostic value for typhoid fever. The sensitivity, specificity, positive and negative predictive value of the test was found as 91.42%, 90.00%, 88.88% and 92.30% respectively. On the other hand corresponding values for Widal test were of 42.85%, 85.00%, 71.42% and 62.96% respectively. Thus, The DOT EIA IgM seems to be a practical alternative to Widal test for early diagnosis of typhoid fever.

Discussion of the quality control and performance testing of ultrasound diagnostic equipment

NASA Astrophysics Data System (ADS)

Jiang, Junjie

2018-03-01

In recent years, with the rapid development of ultrasonography, the application and popularization of new technology used in ultrasound equipment, the level of providing diagnostic information for doctors enhances unceasingly, which has become the indispensable diagnostic tool for medical institutions. The performance of equipment is directly related to the doctor’s diagnosis and the patient’s health, therefore, it is very important to choose a good method for quality control and performance testing.

Difference of Diagnostic Rates and Analytical Methods in the Test Positions of Vestibular Evoked Myogenic Potentials

PubMed Central

Park, Jeong Mee; Yong, Sang Yeol; Kim, Jong Heon; Kim, Hee; Park, Sang-Yoo

2014-01-01

Objective To compare the differences of diagnostic rates, of the two widely used test positions, in measuring vestibular evoked myogenic potentials (VEMP) and selecting the most appropriate analytical method for diagnostic criteria for the patients with vertigo. Methods Thirty-two patients with vertigo were tested in two comparative testing positions: turning the head to the opposite side of the evaluating side and bowing while in seated position, and bowing while in supine positions. Abnormalities were determined by prolonged latency of p13 or n23, shortening of the interpeak latency, and absence of VEMP formation. Results Using the three criteria above for determining abnormalities, both the seated and supine positions showed no significant differences in diagnostic rates, however, the concordance correlation of the two positions was low. When using only the prolonged latency of p13 or n23 in the two positions, diagnostic rates were not significantly different and their concordance correlation was high. On the other hand, using only the shortened interpeak latency in both positions showed no significant difference of diagnostic rates, and the degree of agreement between two positions was low. Conclusion Bowing while in seated position with the head turned in the opposite direction to the area being evaluated is found to be the best VEMP test position due to the consistent level of sternocleidomastoid muscle tension and the high level of compliance. Also, among other diagnostic analysis methods, using prolonged latency of p13 or n23 as the criterion is found to be the most appropriate method of analysis for the VEMP test. PMID:24855617

Using Meta-Analysis to Inform the Design of Subsequent Studies of Diagnostic Test Accuracy

ERIC Educational Resources Information Center

Hinchliffe, Sally R.; Crowther, Michael J.; Phillips, Robert S.; Sutton, Alex J.

2013-01-01

An individual diagnostic accuracy study rarely provides enough information to make conclusive recommendations about the accuracy of a diagnostic test; particularly when the study is small. Meta-analysis methods provide a way of combining information from multiple studies, reducing uncertainty in the result and hopefully providing substantial…

Mutual Information Item Selection Method in Cognitive Diagnostic Computerized Adaptive Testing with Short Test Length

ERIC Educational Resources Information Center

Wang, Chun

2013-01-01

Cognitive diagnostic computerized adaptive testing (CD-CAT) purports to combine the strengths of both CAT and cognitive diagnosis. Cognitive diagnosis models aim at classifying examinees into the correct mastery profile group so as to pinpoint the strengths and weakness of each examinee whereas CAT algorithms choose items to determine those…

The diagnostic accuracy of three rapid diagnostic tests for typhoid fever at Chittagong Medical College Hospital, Chittagong, Bangladesh.

PubMed

Maude, Rapeephan R; de Jong, Hanna K; Wijedoru, Lalith; Fukushima, Masako; Ghose, Aniruddha; Samad, Rasheda; Hossain, Mohammed Amir; Karim, Mohammed Rezaul; Faiz, Mohammed Abul; Parry, Christopher M

2015-10-01

To determine the diagnostic accuracy of three rapid diagnostic tests (RDTs) for typhoid fever in febrile hospitalised patients in Bangladesh. Febrile adults and children admitted to Chittagong Medical College Hospital, Bangladesh, were investigated with Bact/Alert(®) blood cultures and real-time PCR to detect Salmonella enterica Typhi and Paratyphi A and assays for Rickettsia, leptospirosis and dengue fever. Acute serum samples were examined with the LifeAssay (LA) Test-it™ Typhoid IgM lateral flow assay detecting IgM antibodies against S. Typhi O antigen, CTKBiotech Onsite Typhoid IgG/IgM Combo Rapid-test cassette lateral flow assay detecting IgG and IgM antibodies against S. Typhi O and H antigens and SD Bioline line assay for IgG and IgM antibodies against S. Typhi proteins. In 300 malaria smear-negative febrile patients [median (IQR) age of 13.5 (5-31) years], 34 (11.3%) had confirmed typhoid fever: 19 positive by blood culture for S. Typhi (three blood PCR positive) and 15 blood culture negative but PCR positive for S. Typhi in blood. The respective sensitivity and specificity of the three RDTs in patients using a composite reference standard of blood culture and/or PCR-confirmed typhoid fever were 59% and 61% for LifeAssay, 59% and 74% for the CTK IgM and/or IgG, and 24% and 96% for the SD Bioline RDT IgM and/or IgG. The LifeAssay RDT had a sensitivity of 63% and a specificity of 91% when modified with a positive cut-off of ≥2+ and analysed using a Bayesian latent class model. These typhoid RDTs demonstrated moderate diagnostic accuracies, and better tests are needed. © 2015 The Authors. Tropical Medicine & International Health Published by John Wiley & Sons Ltd.

Rapid molecular diagnostics for multi-drug resistant tuberculosis in India.

PubMed

Ramachandran, Rajeswari; Muniyandi, M

2018-03-01

Rapid molecular diagnostic methods help in the detection of TB and Rifampicin resistance. These methods detect TB early, are accurate and play a crucial role in reducing the burden of drug resistant tuberculosis. Areas covered: This review analyses rapid molecular diagnostic tools used in the diagnosis of MDR-TB in India, such as the Line Probe Assay and GeneXpert. We have discussed the burden of MDR-TB and the impact of recent diagnostic tools on case detection and treatment outcomes. This review also discusses the costs involved in establishing these new techniques in India. Expert commentary: Molecular methods have considerable advantages for the programmatic management of drug resistant TB. These include speed, standardization of testing, potentially high throughput and reduced laboratory biosafety requirements. There is a desperate need for India to adopt modern, rapid, molecular tools with point-of-care tests being currently evaluated. New molecular diagnostic tests appear to be cost effective and also help in detecting missing cases. There is enough evidence to support the scaling up of these new tools in India.

Analysis of direct-to-consumer marketed Chlamydia trachomatis diagnostic tests in Norway.

PubMed

Reinton, Nils; Hjelmevoll, Stig Ove; Håheim, Håkon; Garstad, Kjersti; Mørch-Reiersen, Lisa Therese; Moghaddam, Amir

2015-08-01

Background In 2014, and for the first time in Norway, a pharmacy chain started selling home sampling kits for Chlamydia trachomatis (C. trachomatis) detection. Direct-to-consumer diagnostic kits for C. trachomatis have been available in Norway from an Internet company since 2005. There has been little assessment of persons who purchase direct-to-consumer diagnostic tests for sexually transmissible infections (STIs) detection and if low-risk populations are being unnecessarily encouraged to buy these tests. The prevalence of C. trachomatis in customers who purchased home sampling kits from the pharmacy chain and from the commercial Internet Co. were compared to that of patients attending STI clinics and other free primary healthcare services. Prevalences of other STIs in pharmacy and Internet customers were also determined. The prevalence of C. trachomatis among pharmacy customers was 11%, almost identical to the prevalence among Internet customers (12%). In comparison, the prevalence among patients attending STI clinics in Oslo was 7.2%, which is similar to the prevalence among patients who have been tested through primary healthcare services. The prevalence of Mycoplasma genitalium was two-fold less than that of C. trachomatis in the STI and primary physician population, and significantly less in the Internet and the pharmacy population. Neisseria gonorrhoeae was not detected in urine samples from pharmacy customers or from Internet customers. Both pharmacy and Internet C. trachomatis home-sampling kits seem to be purchased by the right risk population. Marketing of direct-to-consumer N. gonorrhoeae tests and possibly M. genitalium tests cannot be justified in Norway. Direct-to-consumer diagnostic tests should be actively utilised as part of national programs in preventing the spread of C. trachomatis.

Diagnostic Yield of Routine Enteropathogenic Stool Tests in Pediatric Ulcerative Colitis.

PubMed

Ihekweazu, Faith D; Ajjarapu, Avanthi; Kellermayer, Richard

2015-01-01

It can be important to exclude infectious etiologies prior to adjusting immunosuppressive therapy in patients with ulcerative colitis (UC) exacerbation. We sought to determine the diagnostic yield of routine infectious stool studies in pediatric UC patients. We conducted a retrospective review of 152 pediatric UC patients at Texas Children's Hospital between January 2003 and December 2009. The patient records were followed through July 2014. The number and type of infectious stool studies performed and the results of those were collected. Three hundred fifty-four diagnostic stool tests were conducted for Clostridium difficile; 13.6% were positive. Two hundred twenty stool bacterial cultures were performed, and 1.8% were positive, all growing non-typhoid Salmonella. One of 13 (7.7%) Adenovirus PCR tests was positive. Two of 152 examinations (1.3%) for Ova and Parasites were positive. No stool tests for viral culture, viral particles, Yersinia or Rotavirus were positive. Clostridium difficile infection is common in pediatric UC, and routine screening during flares is strongly recommended. Other bacterial and parasitic infections routinely tested for are uncommon, but Salmonella may be a potentially important attribute to disease exacerbations in select patients. In patients without co-morbid conditions, the utility of performing non-specific fecal viral tests is questionable. © 2015 by the Association of Clinical Scientists, Inc.

Rapid diagnostic tests compared with malaria microscopy for guiding outpatient treatment of febrile illness in Tanzania: randomised trial.

PubMed

Reyburn, Hugh; Mbakilwa, Hilda; Mwangi, Rose; Mwerinde, Ombeni; Olomi, Raimos; Drakeley, Chris; Whitty, Christopher J M

2007-02-24

To compare rapid diagnostic tests (RDTs) for malaria with routine microscopy in guiding treatment decisions for febrile patients. Randomised trial. Outpatient departments in northeast Tanzania at varying levels of malaria transmission. 2416 patients for whom a malaria test was requested. Staff received training on rapid diagnostic tests; patients sent for malaria tests were randomised to rapid diagnostic test or routine microscopy Proportion of patients with a negative test prescribed an antimalarial drug. Of 7589 outpatient consultations, 2425 (32%) had a malaria test requested. Of 1204 patients randomised to microscopy, 1030 (86%) tested negative for malaria; 523 (51%) of these were treated with an antimalarial drug. Of 1193 patients randomised to rapid diagnostic test, 1005 (84%) tested negative; 540 (54%) of these were treated for malaria (odds ratio 1.13, 95% confidence interval 0.95 to 1.34; P=0.18). Children aged under 5 with negative rapid diagnostic tests were more likely to be prescribed an antimalarial drug than were those with negative slides (P=0.003). Patients with a negative test by any method were more likely to be prescribed an antibiotic (odds ratio 6.42, 4.72 to 8.75; P<0.001). More than 90% of prescriptions for antimalarial drugs in low-moderate transmission settings were for patients for whom a test requested by a clinician was negative for malaria. Although many cases of malaria are missed outside the formal sector, within it malaria is massively over-diagnosed. This threatens the sustainability of deployment of artemisinin combination treatment, and treatable bacterial diseases are likely to be missed. Use of rapid diagnostic tests, with basic training for clinical staff, did not in itself lead to any reduction in over-treatment for malaria. Interventions to improve clinicians' management of febrile illness are essential but will not be easy. Clinical trials NCT00146796 [ClinicalTrials.gov].

Systematic Review of Health Economic Evaluations of Diagnostic Tests in Brazil: How accurate are the results?

PubMed

Oliveira, Maria Regina Fernandes; Leandro, Roseli; Decimoni, Tassia Cristina; Rozman, Luciana Martins; Novaes, Hillegonda Maria Dutilh; De Soárez, Patrícia Coelho

2017-08-01

The aim of this study is to identify and characterize the health economic evaluations (HEEs) of diagnostic tests conducted in Brazil, in terms of their adherence to international guidelines for reporting economic studies and specific questions in test accuracy reports. We systematically searched multiple databases, selecting partial and full HEEs of diagnostic tests, published between 1980 and 2013. Two independent reviewers screened articles for relevance and extracted the data. We performed a qualitative narrative synthesis. Forty-three articles were reviewed. The most frequently studied diagnostic tests were laboratory tests (37.2%) and imaging tests (32.6%). Most were non-invasive tests (51.2%) and were performed in the adult population (48.8%). The intended purposes of the technologies evaluated were mostly diagnostic (69.8%), but diagnosis and treatment and screening, diagnosis, and treatment accounted for 25.6% and 4.7%, respectively. Of the reviewed studies, 12.5% described the methods used to estimate the quantities of resources, 33.3% reported the discount rate applied, and 29.2% listed the type of sensitivity analysis performed. Among the 12 cost-effectiveness analyses, only two studies (17%) referred to the application of formal methods to check the quality of the accuracy studies that provided support for the economic model. The existing Brazilian literature on the HEEs of diagnostic tests exhibited reasonably good performance. However, the following points still require improvement: 1) the methods used to estimate resource quantities and unit costs, 2) the discount rate, 3) descriptions of sensitivity analysis methods, 4) reporting of conflicts of interest, 5) evaluations of the quality of the accuracy studies considered in the cost-effectiveness models, and 6) the incorporation of accuracy measures into sensitivity analyses.

Skin-prick testing as a diagnostic aid for childhood asthma.

PubMed

Chan, E Y; Dundas, I; Bridge, P D; Healy, M J R; McKenzie, S A

2005-06-01

Diagnosing asthma is problematic when based solely on reported symptoms. The purpose of this study was to evaluate skin-prick testing as a diagnostic aid for asthma in children. Skin-prick testing (SPT) was undertaken in children aged 2-10 years with either no history of wheeze (n = 149) or recent doctor-observed wheeze which responded to treatment with a bronchodilator, the "gold standard" (n = 164). Children with moderate or severe asthma were excluded. SPT positivity increased sharply at age 5 years in wheezers. Data were therefore divided into two age groups: 2- < 5 years (57 controls, 97 wheezers) and 5-10 years (92 controls, 67 wheezers). The sensitivity, specificity, and likelihood ratios of SPT positivity for wheeze were 32%, 89%, and 2.9, respectively, in the younger children, and 82%, 85%, and 5.5, respectively, in the older children. For a prevalence of 30% for asthma, the positive predictive values of a positive SPT were 55% and 70% for the younger and older age groups, respectively. The test characteristics of SPT for helping diagnose asthma in schoolchildren are good. The prevalence of wheeze in preschool children is high, and so SPT should be helpful even in this group. We suggest that clinicians consider skin-prick testing as a diagnostic aid for asthma. Copyright 2005 Wiley-Liss, Inc.

Girls who masturbate in early infancy: diagnostics, natural course and a long-term follow-up.

PubMed

Rödöö, Peo; Hellberg, Dan

2013-07-01

To evaluate the natural course, onset, diagnostics and long-term follow-up masturbation in infant girls, which up to now has only been described in case reports. Nineteen consecutive healthy, masturbating girls, diagnosed in early infancy between three and 15 months, were followed up for an average of 8 years. All were diagnosed in the same Swedish hospital between May 1996 and June 2010. Ten girls were videotaped and/or directly observed while masturbating. Mean age at onset of masturbation was 10.4 months. The diagnosis was based on history taking and clinical observation. Parents reported that masturbation ranged from a few times a week to two-to-fifty episodes a day. Twelve girls had stopped masturbating when this study was written, after a mean duration of 66 months. Their symptoms and diagnostics are described in detail. This is the first follow-up study of girls who started masturbating in early infancy, with a mean duration of five-and-a-half years. Diagnosis may be difficult, but with awareness and knowledge of the condition, a normal physical and neurological examination, a detailed history from the parents and, in particular, video documentation, it can be settled without extensive investigations and the parents reassured. ©2013 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

40 CFR 797.1600 - Fish early life stage toxicity test.

Code of Federal Regulations, 2014 CFR

2014-07-01

... the test solution concentrations. The test terminates following 60 days of post-hatch exposure (for an... 40 Protection of Environment 32 2014-07-01 2014-07-01 false Fish early life stage toxicity test... Fish early life stage toxicity test. (a) Purpose. This guideline is intended to be used for assessing...

40 CFR 797.1600 - Fish early life stage toxicity test.

Code of Federal Regulations, 2011 CFR

2011-07-01

... the test solution concentrations. The test terminates following 60 days of post-hatch exposure (for an... 40 Protection of Environment 32 2011-07-01 2011-07-01 false Fish early life stage toxicity test... Fish early life stage toxicity test. (a) Purpose. This guideline is intended to be used for assessing...