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...

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...

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 ...

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...

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

[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.

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...

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.

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.

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.

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

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.

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…

University students' perspectives on diagnostic testing in mathematics

NASA Astrophysics Data System (ADS)

fhloinn, Eabhnat Ní; Macan Bhaird, Ciarán; Nolan, Brien

2014-01-01

Many universities issue mathematical diagnostic tests to incoming first-year students, covering a range of the basic concepts with which they should be comfortable from secondary school. As far as many lecturers are concerned, the purpose of this test is to determine the students' mathematical knowledge on entry. It should also provide an early indication of which students are likely to need additional help, and hopefully encourage such students to avail of extra support mechanisms at an early stage. However, it is not clear that students recognize these intentions and there is a fear that students who score poorly in the test will have their confidence further damaged in relation to mathematics and will be reluctant to seek help. To this end, a questionnaire was developed to explore students' perspectives on diagnostic testing. Analysis of responses received to the questionnaire provided an interesting insight into students' perspectives including the optimum time to conduct such a test, their views on the aims of diagnostic testing, whether they feel that testing is a good idea, and their attitudes to the support systems put in place to help those who scored poorly in the test.

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…

Prognostic value of paroxysmal nocturnal haemoglobinuria clone presence in aplastic anaemia patients treated with combined immunosuppression: results of two-centre prospective study.

PubMed

Kulagin, Alexander; Lisukov, Igor; Ivanova, Maria; Golubovskaya, Irina; Kruchkova, Irina; Bondarenko, Sergey; Vavilov, Vladimir; Stancheva, Natalia; Babenko, Elena; Sipol, Alexandra; Pronkina, Natalia; Kozlov, Vladimir; Afanasyev, Boris

2014-02-01

Paroxysmal nocturnal haemoglobinuria (PNH) clones are frequently detected in patients with aplastic anaemia (AA). To evaluate the prognostic role of PNH clone presence we conducted a prospective study in 125 AA patients treated with combined immunosuppressive therapy (IST). Seventy-four patients (59%) had a PNH clone (PNH+ patients) at diagnosis, with a median clone size of 0·60% in granulocytes and 0·15% in red blood cells. The response rate at 6 months was higher in PNH+ patients than that in PNH- patients, both after first- and second-line IST: 68% vs. 45%, P = 0·0164 and 53% vs. 13%, P = 0·0502 respectively. Moreover, 42% of PNH+ patients achieved complete remission compared with only 16% of PNH- patients (P = 0·0029). In multivariate logistic regression analysis, PNH clone presence (odds ratio 2·56, P = 0·0180) and baseline absolute reticulocyte count (ARC) ≥30 × 10(9) /l (odds ratio 5·19, P = 0·0011) were independent predictors of response to treatment. Stratification according to PNH positivity and ARC ≥30 × 10(9) /l showed significant distinctions for cumulative incidence of response, overall and failure-free survival. The results of this prospective study confirmed the favourable prognostic value of PNH clone presence in the setting of IST for AA. © 2013 John Wiley & Sons Ltd.

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.

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.

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

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.

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.

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.

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…

Clinical benefit of eculizumab in patients with no transfusion history in the International Paroxysmal Nocturnal Haemoglobinuria Registry.

PubMed

Almeida, Antonio M; Bedrosian, Camille; Cole, Alexander; Muus, Petra; Schrezenmeier, Hubert; Szer, Jeff; Rosse, Wendell F

2017-09-01

Eculizumab reduces intravascular haemolysis and improves disease symptoms in patients with paroxysmal nocturnal haemoglobinuria (PNH). To characterise, in a real-world setting, the effect of eculizumab in patients with haemolytic PNH (lactase dehydrogenase (LDH) ≥ 1.5 upper limit of normal) and no history of red blood cell transfusion, including those with high disease activity (HDA). Three populations from the International PNH Registry were studied: (i) non-transfused, untreated; (ii) non-transfused, eculizumab-treated and (iii) transfused, eculizumab-treated (≥1 transfusions in 6 months prior to eculizumab initiation). Using multivariate linear regression, the primary outcome was mean absolute change from baseline to 6 months in LDH (U/L) in non-transfused patients who were treated with eculizumab versus those who remained untreated. Secondary outcomes were mean changes in functional assessment of chronic illness therapy (FACIT)-Fatigue and European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC-QLQ)-C30 Fatigue scores from baseline to last available assessment. The study population included (i) 144 non-transfused, untreated patients; (ii) 45 non-transfused, eculizumab-treated patients and (iii) 105 transfused, eculizumab-treated patients. Of these, 136/144, 43/45 and 99/105 had HDA respectively. Compared with untreated patients, non-transfused, treated patients had greater absolute reduction in LDH (-1318.8 vs -39.4; P < 0.001) and greater percentage reduction in LDH (-69.9 vs -1.6%; P < 0.001). Clinically meaningful improvements in FACIT-Fatigue (73.7 vs 24.6%, respectively) and in EORTC-QLQ-C30 (84.2 vs 33.3%, respectively) were observed. Non-transfused, treated patients with HDA had significantly reduced LDH levels (P < 0.001) and clinically meaningful improvements in FACIT-Fatigue (P = 0.003) and EORTC-QLQ-C30 (P = 0.020) versus untreated patients. Significant LDH reduction and

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.

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.

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 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…

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

False positive malaria rapid diagnostic test in returning traveler with typhoid fever.

PubMed

Meatherall, Bonnie; Preston, Keith; Pillai, Dylan R

2014-07-09

Rapid diagnostic tests play a pivotal role in the early diagnosis of malaria where microscopy or polymerase chain reaction are not immediately available. We report the case of a 39 year old traveler to Canada who presented with fever, headache, and abdominal pain after visiting friends and relatives in India. While in India, the individual was not ill and had no signs or symptoms of malaria. Laboratory testing upon his return to Canada identified a false positive malaria rapid diagnostic (BinaxNOW® malaria) result for P. falciparum with coincident Salmonella Typhi bacteraemia without rheumatoid or autoimmune factors. Rapid diagnostic test false positivity for malaria coincided with the presence or absence of Salmonella Typhi in the blood. Clinicians should be aware that Salmonella Typhi infection may result in a false positive malaria rapid diagnostic test. The mechanism of this cross-reactivity is not clear.

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

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.

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.

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.

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

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 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.

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 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

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.

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.

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.

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.

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...

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.

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…

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.

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 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...

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

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.

[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.

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.

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

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

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

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.

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.

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.

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.

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

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.

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.

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 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

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

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.

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...

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.

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

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.

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.

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.

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.

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…

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.

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.

Towards Modernizing the Characterization of Shock and Detonation Physics Performance via Novel Diagnostics and Tests

NASA Astrophysics Data System (ADS)

Salyer, Terry

2017-06-01

For the bulk of detonation performance experiments, a fairly basic set of diagnostic techniques has evolved as the standard for acquiring the necessary measurements. Gold standard techniques such as pin switches and streak cameras still produce the high-quality data required, yet much room remains for improvement with regard to ease of use, cost of fielding, breadth of data, and diagnostic versatility. Over the past several years, an alternate set of diagnostics has been under development to replace many of these traditional techniques. Pulse Correlation Reflectometry (PCR) is a capable substitute for pin switches with the advantage of obtaining orders of magnitude more data at a small fraction of the cost and fielding time. Spectrally Encoded Imaging (SEI) can replace most applications of streak camera with the advantage of imaging surfaces through a single optical fiber that are otherwise optically inaccessible. Such diagnostics advance the measurement state of the art, but even further improvements may come through revamping the standardized tests themselves such as the copper cylinder expansion test. At the core of this modernization, the aforementioned diagnostics play a significant role in revamping and improving the standard test suite for the present era. This research was performed under the auspices of the United States Department of Energy.

External Quality Assessment for Zika Virus Molecular Diagnostic Testing, Brazil.

PubMed

Fischer, Carlo; Pedroso, Celia; Mendrone, Alfredo; Bispo de Filippis, Ana Maria; Vallinoto, Antonio Carlos Rosário; Ribeiro, Bergmann Morais; Durigon, Edison Luiz; Marques, Ernesto T A; Campos, Gubio S; Viana, Isabelle F T; Levi, José Eduardo; Scarpelli, Luciano Cesar; Nogueira, Mauricio Lacerda; Bastos, Michele de Souza; Souza, Nathalia C Santiago; Khouri, Ricardo; Lira, Sanny; Komninakis, Shirley Vasconcelos; Baronti, Cécile; Charrel, Rémi N; Kümmerer, Beate M; Drosten, Christian; Brites, Carlos; de Lamballerie, Xavier; Niedrig, Matthias; Netto, Eduardo Martins; Drexler, Jan Felix

2018-05-01

We conducted an external quality assessment of Zika virus molecular diagnostic tests in Brazil using a new Zika virus standard. Of 15 laboratories, 73% showed limited sensitivity and specificity. Viral load estimates varied significantly. Continuous quality assurance is needed to adequately estimate risk for Zika virus-associated disease and determine patient care.

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.

Statistical analysis of Turbine Engine Diagnostic (TED) field test data

NASA Astrophysics Data System (ADS)

Taylor, Malcolm S.; Monyak, John T.

1994-11-01

During the summer of 1993, a field test of turbine engine diagnostic (TED) software, developed jointly by U.S. Army Research Laboratory and the U.S. Army Ordnance Center and School, was conducted at Fort Stuart, GA. The data were collected in conformance with a cross-over design, some of whose considerations are detailed. The initial analysis of the field test data was exploratory, followed by a more formal investigation. Technical aspects of the data analysis insights that were elicited are reported.

Effects of a Web-Based Decision Aid Regarding Diagnostic Self-Testing. A Single-Blind Randomized Controlled Trial

ERIC Educational Resources Information Center

Ickenroth, Martine H. P.; Grispen, J. E. J.; de Vries, N. K.; Dinant, G. J.; Ronda, G.; van der Weijden, T.

2016-01-01

Currently, there are many diagnostic self-tests on body materials available to consumers. The aim of this study was to assess the effect of an online decision aid on diagnostic self-testing for cholesterol and diabetes on knowledge among consumers with an intention to take these tests. A randomized controlled trial was designed. A total of 1259…

[Companion diagnostics "POTELIGEO TEST IHC/FCM" used with "POTELIGEO" (mogamulizumab) for adult T-cell leukemia-lymphoma (ATL) treatment].

PubMed

Goami, Takeshi

2014-05-01

Personalized medicine offers the best treatment for individual patients, it is important for an IVD manufacturer to develop companion diagnostics in parallel with the development of new drugs through close cooperation with drug companies, and supply diagnostics companies with new drugs for physicians and patients. We received approval for a premarket approval application (PMA) for two in vitro diagnostic ("IVD") reagents, POTELIGEO TEST IHC and POTELIGEO TEST FCM ("POTELIGEO TEST"), in March 2012, and subsequently launched POTELIGEO TEST in May 2012. POTELIGEO TEST is a companion diagnostic used with POTELIGEO for which Kyowa Hakko Kirin has a new drug application (NDA) that was approved in March 2012, and is designed to help physicians identify appropriate subpopulations of adult T-cell leukemia-lymphoma(ATL) patients who are most likely to respond to POTELIGEO 20 mg (mogamulizumab) Injection ("POTELIGEO").

Potential Biases Introduced by Conflating Screening and Diagnostic Testing in Colorectal Cancer Screening Surveillance

PubMed Central

Becker, Elizabeth A.; Griffith, Derek M.; West, Brady T.; Janz, Nancy K.; Resnicow, Ken; Morris, Arden M.

2015-01-01

Background Screening and post-symptomatic diagnostic testing are often conflated in cancer screening surveillance research. We examined the error in estimated colorectal cancer (CRC) screening prevalence due to the conflation of screening and diagnostic testing. Methods Using data from the 2008 National Health Interview Survey, we compared weighted prevalence estimates of the use of all testing (screening and diagnostic) and screening in at-risk adults, and calculated the overestimation of screening prevalence across socio-demographic groups. Results The population screening prevalence was overestimated by 23.3%, and the level of overestimation varied widely across socio-demographic groups (median 22.6%, mean 24.8%). The highest levels of overestimation were in non-Hispanic White females (27.4%), adults ages 50–54 (32.0%), and those with the highest socioeconomic vulnerability (low educational attainment (31.3%), low poverty ratio (32.5%), no usual source of health care (54.4%) and not insured (51.6%)) (all p-values < 0.001). Conclusions When the impetus for testing was not included, CRC screening prevalence was overestimated, and patterns of overestimation often aligned with social and economic vulnerability. These results are of concern to researchers who utilize survey data from the Behavioral Risk Factor Surveillance System (BRFSS) to assess cancer screening behaviors, as it is currently not designed to distinguish diagnostic testing from screening. Impact Surveillance research in cancer screening that does not consider the impetus for testing risks measurement error of screening prevalence, impeding progress toward improving population health. Ultimately, in order to craft relevant screening benchmarks and interventions, we must look beyond ‘what’ and ‘when’ and include ‘why.’ PMID:26491056

Variation in Results Release and Patient Portal Access to Diagnostic Test Results at an Academic Medical Center

PubMed Central

Krasowski, Matthew D.; Grieme, Caleb V.; Cassady, Brian; Dreyer, Nicholas R.; Wanat, Karolyn A.; Hightower, Maia; Nepple, Kenneth G.

2017-01-01

Background: Electronic health records (EHRs) are commonplace in industrialized countries. Many hospitals are granting their patients access to their medical information through online patient portals. In this report, we describe a retrospective analysis of patient access to diagnostic test results released through the patient portal (MyChart; Epic, Inc.) at a state academic medical center. Methods: We analyzed 6 months of data for anatomic pathology, clinical laboratory, and radiology test results to evaluate variations in results release (automated vs. manual) and subsequent patient access to the institutional patient portal. During this period, diagnostic test results were released for all patient encounters including inpatient units, outpatient clinics, and the emergency department. Results: Manual results release by providers before automated release time occurred most commonly in the outpatient setting. The highest rates of access of diagnostic test results occurred for outpatients (about 30% overall view rate), females (two times or more compared to males in nearly every age bracket), and 20–45-year-old. Access rates of diagnostic tests in the emergency department or inpatient units were <10% across all populations. Access of diagnostic test results was very low for 12–17-year-old, likely influenced by institutional policies limiting parental proxy access within this pediatric age range. Approximately 20% of outpatient laboratory results were viewed by patients within 8 h of release from the EHR to the patient portal and 10% within 2 h of release. Conclusions: Patient accessing of diagnostic test results were generally higher for females, outpatients, and 20–45-year-old. Approximately, 20% of outpatient results were viewed quickly by patients after release to the EHR. PMID:29226008

Variation in Results Release and Patient Portal Access to Diagnostic Test Results at an Academic Medical Center.

PubMed

Krasowski, Matthew D; Grieme, Caleb V; Cassady, Brian; Dreyer, Nicholas R; Wanat, Karolyn A; Hightower, Maia; Nepple, Kenneth G

2017-01-01

Electronic health records (EHRs) are commonplace in industrialized countries. Many hospitals are granting their patients access to their medical information through online patient portals. In this report, we describe a retrospective analysis of patient access to diagnostic test results released through the patient portal (MyChart; Epic, Inc.) at a state academic medical center. We analyzed 6 months of data for anatomic pathology, clinical laboratory, and radiology test results to evaluate variations in results release (automated vs. manual) and subsequent patient access to the institutional patient portal. During this period, diagnostic test results were released for all patient encounters including inpatient units, outpatient clinics, and the emergency department. Manual results release by providers before automated release time occurred most commonly in the outpatient setting. The highest rates of access of diagnostic test results occurred for outpatients (about 30% overall view rate), females (two times or more compared to males in nearly every age bracket), and 20-45-year-old. Access rates of diagnostic tests in the emergency department or inpatient units were <10% across all populations. Access of diagnostic test results was very low for 12-17-year-old, likely influenced by institutional policies limiting parental proxy access within this pediatric age range. Approximately 20% of outpatient laboratory results were viewed by patients within 8 h of release from the EHR to the patient portal and 10% within 2 h of release. Patient accessing of diagnostic test results were generally higher for females, outpatients, and 20-45-year-old. Approximately, 20% of outpatient results were viewed quickly by patients after release to the EHR.

European and Mexican vs US diagnostic extracts of Bermuda grass and cat in skin testing.

PubMed

Larenas-Linnemann, Désirée; Cruz, Alfredo Arias; Gutierrez, Isabel Rojo; Rodriguez, Pablo; Shah-Hosseini, Kijawasch; Michels, Alexandra; Mösges, Ralph

2011-05-01

Laboratory testing of various diagnostic extracts has shown lower potencies for several European and Mexican extracts relative to the US Food and Drug Administration (FDA) reference (10,000 BAU/mL). Quantitative skin prick testing (QSPT) with Dermatophagoides pteronyssinus extracts have previously shown a similar picture. To compare European and Mexican Bermuda grass (BG) and cat diagnostic extracts against an FDA-validated extract using QSPT. Six diagnostic BG and cat extracts (1 reference FDA extract, 3 European extracts, 1 imported nonstandardized extract from the United States, and 1 Mexican extract) were tested with quadruplicate QSPT, as a concentrate and as 2 serial 2-fold dilutions, in cat and BG allergic individuals. BG showed good dose response in wheal size for the concentrate (1:2-1:4 dilutions; steep part of the curve). Cat showed poorer dose response. The Wilcoxon test for linked random samples was used to investigate whether the distribution of the reference differed from each of the test extracts to a statistically significant degree (2-sided asymptotic significance, α = .05). All BG and 2 cat extracts were statistically less potent than the 10,000 BAU/mL US reference. European BG extracts were 7,700, 4,100, and 1,600 BAU/mL, and cat extracts were 12,500, 4,400, and 5,100 BAU/mL. The potency of some diagnostic extracts of BG and cat used in Europe, Mexico, and the United States differs, with the US extracts being generally more potent. On the basis of provocation tests, optimal diagnostic concentrations should be determined. Similar comparisons using other manufacturers and therapeutic extracts might be interesting. Copyright © 2011 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

[The Offer of Medical-Diagnostic Self-Tests on German Language Websites: Results of a Systematic Internet Search].

PubMed

Kuecuekbalaban, P; Schmidt, S; Muehlan, H

2018-03-01

The aim of the current study was to provide an overview of medical-diagnostic self-tests which can be purchased without a medical prescription on German language websites. From September 2014 to March 2015, a systematic internet research was conducted with the following search terms: self-test, self-diagnosis, home test, home diagnosis, quick test, rapid test. 513 different self-tests for the diagnostics of 52 diverse diseases or health risks were identified, including chronic diseases (e. g. diabetes, chronic disease of the kidneys, liver, and lungs), sexually transmitted diseases (e. g. HIV, chlamydia, gonorrhea), infectious diseases (e. g. tuberculosis, malaria, Helicobacter pylori), allergies (e. g. house dust, cats, histamine) and cancer as well as tests for the diagnostics of 12 different psychotropic substances. These were sold by 90 companies in Germany and by other foreign companies. The number of medical-diagnostic self-tests which can be bought without a medical prescription on the Internet has increased enormously in the last 10 years. Further studies are needed for the identification of the determinants of the use of self-tests as well as the impact of the application on the experience and behavior of the user. © Georg Thieme Verlag KG Stuttgart · New York.

Homogeneity tests of clustered diagnostic markers with applications to the BioCycle Study

PubMed Central

Tang, Liansheng Larry; Liu, Aiyi; Schisterman, Enrique F.; Zhou, Xiao-Hua; Liu, Catherine Chun-ling

2014-01-01

Diagnostic trials often require the use of a homogeneity test among several markers. Such a test may be necessary to determine the power both during the design phase and in the initial analysis stage. However, no formal method is available for the power and sample size calculation when the number of markers is greater than two and marker measurements are clustered in subjects. This article presents two procedures for testing the accuracy among clustered diagnostic markers. The first procedure is a test of homogeneity among continuous markers based on a global null hypothesis of the same accuracy. The result under the alternative provides the explicit distribution for the power and sample size calculation. The second procedure is a simultaneous pairwise comparison test based on weighted areas under the receiver operating characteristic curves. This test is particularly useful if a global difference among markers is found by the homogeneity test. We apply our procedures to the BioCycle Study designed to assess and compare the accuracy of hormone and oxidative stress markers in distinguishing women with ovulatory menstrual cycles from those without. PMID:22733707

High diagnostic accuracy of subcutaneous Triptorelin test compared with GnRH test for diagnosing central precocious puberty in girls.

PubMed

Freire, Analía Verónica; Escobar, María Eugenia; Gryngarten, Mirta Graciela; Arcari, Andrea Josefina; Ballerini, María Gabriela; Bergadá, Ignacio; Ropelato, María Gabriela

2013-03-01

The GnRH test is the gold standard to confirm the diagnosis of central precocious puberty (CPP); however, this compound is not always readily available. Diagnostic accuracy of subcutaneous GnRH analogues tests compared to classical GnRH test has not been reported. To evaluate the diagnostic accuracy of Triptorelin test (index test) compared to the GnRH test (reference test) in girls with suspicion of CPP. A prospective, case-control, randomized clinical trial was performed. CPP or precocious thelarche (PT) was diagnosed according to maximal LH response to GnRH test and clinical characteristics during follow-up. Forty-six girls with premature breast development randomly underwent two tests: (i) intravenous GnRH 100 μg, (ii) subcutaneous Triptorelin acetate (0.1 mg/m(2), to a maximum of 0.1 mg) with blood sampling at 0, 3 and 24 h for LH, FSH and estradiol ascertainment. Gonadotrophins and estradiol responses to Triptorelin test were measured by ultrasensitive assays. Clinical features were similar between CPP (n = 33) and PT (n = 13) groups. Using receiver operating characteristic curves, maximal LH response (LH-3 h) under Triptorelin test ≥ 7 IU/l by immunofluorometric assay (IFMA) or ≥ 8 IU/l by electrochemiluminescence immunoassay (ECLIA) confirmed the diagnosis of CPP with specificity of 1.00 (95% CI: 0.75-1.00) and sensitivity 0.76 (95% CI: 0.58-0.89). Considering either LH-3 h or maximal estradiol response at 24 h (cut-off value, 295 pm), maintaining the specificity at 1.00, the test sensitivity increased to 0.94 (95% CI: 0.80-0.99) and the diagnostic efficiency to 96%. The Triptorelin test had high accuracy for the differential diagnosis of CPP vs PT in girls providing a valid alternative to the classical GnRH test. This test also allowed a comprehensive evaluation of the pituitary-ovarian axis. © 2012 Blackwell Publishing Ltd.

Web-Based Two-Tier Diagnostic Test and Remedial Learning Experiment

ERIC Educational Resources Information Center

Lai, Ah-Fur; Chen, Deng-Jyi

2010-01-01

Offering a series of diagnosis and individual remedial learning activities for a general class by means of web and multimedia technology can overcome the dilemma of conventional diagnosis and remedial instruction. The study proposes a three-layer conceptual framework and adopts a two-tier diagnostic test theory to develop a web-based two-tier…

Diagnostic value of FIB-4 for liver fibrosis in patients with hepatitis B: a meta-analysis of diagnostic test.

PubMed

Yin, Zhi; Zou, Jin; Li, Qiongxuan; Chen, Lizhang

2017-04-04

This study is aimed at evaluating the diagnostic value of FIB-4 for liver fibrosis in patients with hepatitis B through a meta-analysis of diagnostic test. We conducted a comprehensive search in the Pubmed, Embase, Web of Science, and Chinese National Knowledge Infrastructure before October 31, 2016. Stata 14.0 software was used for calculation and statistical analyses. We used the sensitivity, specificity, positive and negative likelihood ratio (PLR, NLR), diagnostic odds ratio (DOR) and 95% confidence intervals (CIs) to evaluate the diagnostic value of FIB-4 for liver fibrosis in patients with hepatitis B. Twenty-six studies were included in the final analyses, with a total of 8274 individuals. The pooled parameters are calculated from all studies: sensitivity of 0.69 (95%CI:0.63-0.75), specificity of 0.81 (95%CI: 0.73-0.87), PLR of 3.63 (95%CI:2.66-4.94), NLR of 0.38 (95%CI:0.32-0.44), DOR of 9.57 (95%CI: 6.67-13.74), and area under the curve (AUC) of 0.80 (95%CI: 0.76-0.83). We also conducted subgroup based on the range of cut-off values. Results from subgroup analysis showed that cut-off was the source of heterogeneity in the present study. The sensitivity and specificity of cut-off>2 were 0.69 and 0.95 with the AUC of 0.90 (95%CI: 0.87-0.92). The overall diagnostic value of FIB-4 is not very high for liver fibrosis in patients with hepatitis B. However, the diagnostic value is affected by the cut-off value. FIB-4 has relatively high diagnostic value for detecting liver fibrosis in patients with hepatitis B when the diagnostic threshold value is more than 2.0.

Bivariate random-effects meta-analysis models for diagnostic test accuracy studies using arcsine-based transformations.

PubMed

Negeri, Zelalem F; Shaikh, Mateen; Beyene, Joseph

2018-05-11

Diagnostic or screening tests are widely used in medical fields to classify patients according to their disease status. Several statistical models for meta-analysis of diagnostic test accuracy studies have been developed to synthesize test sensitivity and specificity of a diagnostic test of interest. Because of the correlation between test sensitivity and specificity, modeling the two measures using a bivariate model is recommended. In this paper, we extend the current standard bivariate linear mixed model (LMM) by proposing two variance-stabilizing transformations: the arcsine square root and the Freeman-Tukey double arcsine transformation. We compared the performance of the proposed methods with the standard method through simulations using several performance measures. The simulation results showed that our proposed methods performed better than the standard LMM in terms of bias, root mean square error, and coverage probability in most of the scenarios, even when data were generated assuming the standard LMM. We also illustrated the methods using two real data sets. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rubella Surveillance and Diagnostic Testing among a Low-Prevalence Population, New York City, 2012-2013.

PubMed

Isaac, Beth M; Zucker, Jane R; Giancotti, Francesca R; Abernathy, Emily; Icenogle, Joseph; Rakeman, Jennifer L; Rosen, Jennifer B

2017-09-01

The New York City Department of Health and Mental Hygiene (DOHMH) receives clinical and laboratory reports for rubella. Because rubella immunoglobulin M (IgM) assays may produce false-positive results and rubella infections may be asymptomatic, interpretation of positive IgM results can be challenging. Rubella reports received by DOHMH in 2012 to 2013 were reviewed. The rubella IgM testing purpose was determined through case investigation. Results of IgM testing by indirect enzyme-linked immunosorbent assay (ELISA) and capture enzyme immunoassay (EIA) were compared to determine positive predictive value (PPV) and specificity. DOHMH received 199 rubella reports; 2 were true cases. Of all reports, 77.9% were tested for rubella IgM erroneously, 19.6% were tested for diagnostic purposes, 2.0% had unknown test purpose, and 0.5% were not tested. PPV of indirect ELISA was 6% overall, 14% for diagnostic tests, and 0% for tests ordered erroneously. PPV of capture EIA was 29% overall, 50% for diagnostic tests, and 0% for tests ordered erroneously. Overall, specificity was 52% for indirect ELISA and 85% for capture EIA. Limiting rubella IgM testing to patients for whom rubella diagnosis is suspected and using a more specific IgM assay have the potential to reduce false-positive rubella IgM results. Copyright © 2017 American Society for Microbiology.

42 CFR 414.509 - Reconsideration of basis for and amount of payment for a new clinical diagnostic laboratory test.

Code of Federal Regulations, 2010 CFR

2010-10-01

... for a new clinical diagnostic laboratory test. 414.509 Section 414.509 Public Health CENTERS FOR... FOR PART B MEDICAL AND OTHER HEALTH SERVICES Payment for New Clinical Diagnostic Laboratory Tests § 414.509 Reconsideration of basis for and amount of payment for a new clinical diagnostic laboratory...

Neural net diagnostics for VLSI test

NASA Technical Reports Server (NTRS)

Lin, T.; Tseng, H.; Wu, A.; Dogan, N.; Meador, J.

1990-01-01

This paper discusses the application of neural network pattern analysis algorithms to the IC fault diagnosis problem. A fault diagnostic is a decision rule combining what is known about an ideal circuit test response with information about how it is distorted by fabrication variations and measurement noise. The rule is used to detect fault existence in fabricated circuits using real test equipment. Traditional statistical techniques may be used to achieve this goal, but they can employ unrealistic a priori assumptions about measurement data. Our approach to this problem employs an adaptive pattern analysis technique based on feedforward neural networks. During training, a feedforward network automatically captures unknown sample distributions. This is important because distributions arising from the nonlinear effects of process variation can be more complex than is typically assumed. A feedforward network is also able to extract measurement features which contribute significantly to making a correct decision. Traditional feature extraction techniques employ matrix manipulations which can be particularly costly for large measurement vectors. In this paper we discuss a software system which we are developing that uses this approach. We also provide a simple example illustrating the use of the technique for fault detection in an operational amplifier.

A hybrid model for combining case-control and cohort studies in systematic reviews of diagnostic tests

PubMed Central

Chen, Yong; Liu, Yulun; Ning, Jing; Cormier, Janice; Chu, Haitao

2014-01-01

Systematic reviews of diagnostic tests often involve a mixture of case-control and cohort studies. The standard methods for evaluating diagnostic accuracy only focus on sensitivity and specificity and ignore the information on disease prevalence contained in cohort studies. Consequently, such methods cannot provide estimates of measures related to disease prevalence, such as population averaged or overall positive and negative predictive values, which reflect the clinical utility of a diagnostic test. In this paper, we propose a hybrid approach that jointly models the disease prevalence along with the diagnostic test sensitivity and specificity in cohort studies, and the sensitivity and specificity in case-control studies. In order to overcome the potential computational difficulties in the standard full likelihood inference of the proposed hybrid model, we propose an alternative inference procedure based on the composite likelihood. Such composite likelihood based inference does not suffer computational problems and maintains high relative efficiency. In addition, it is more robust to model mis-specifications compared to the standard full likelihood inference. We apply our approach to a review of the performance of contemporary diagnostic imaging modalities for detecting metastases in patients with melanoma. PMID:25897179

Superior Diagnostic Performance of Malaria Rapid Diagnostic Tests as compared to Blood Smears in U.S. Clinical Practice

PubMed Central

Stauffer, William M.; Cartwright, Charles P.; Olson, Douglas; Juni, Billie Anne; Taylor, Charlotte M; Bowers, Susan H.; Hanson, Kevan L.; Rosenblatt, Jon E.; Boulware, David R.

2010-01-01

Background Approximately 4 million U.S. travelers to developing countries are ill enough to seek healthcare with 1,500 malaria cases reported in the U.S. annually. The diagnosis of malaria is frequently delayed due to the time to prepare malaria blood films and lack of technical expertise. An easy, reliable rapid diagnostic test (RDT) with high sensitivity and negative predictive value (NPV), particularly for Plasmodium falciparum, would be clinically useful. The study objective was to determine the diagnostic performance of the FDA-approved NOW® Malaria Test in comparison to traditional thick and thin blood smears for malaria diagnosis. Methods This prospective study tested 852 consecutive blood samples sent for thick and thin smears with blinded, malaria rapid tests at three hospital laboratories during 2003–2006. Polymerase chain reaction (PCR) verified positive tests and discordant results. Results Malaria occurred in 11% (95/852). The rapid test had superior performance than the standard Giemsa thick blood smear (P=.003). The rapid test’s sensitivity for all malaria was 97% (92/95) vs. 85% (81/95) by blood smear, and the RDT had superior NPV of 99.6% vs. 98.2% (P=.001). The P. falciparum performance was excellent with 100% rapid test sensitivity versus only 88% (65/74) by blood smear (P=.003). Conclusions This operational study demonstrates the FDA-approved rapid malaria test is superior to a single set of blood smears performed under routine U.S. clinical laboratory conditions. The most valuable clinical role of the RDT is in the rapid diagnosis or the exclusion of P. falciparum malaria, which is particularly useful in outpatient settings when evaluating febrile travelers. PMID:19686072

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.

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.

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.

Diagnostic testing for Giardia infections.

PubMed

Heyworth, Martin F

2014-03-01

The traditional method for diagnosing Giardia infections involves microscopic examination of faecal specimens for Giardia cysts. This method is subjective and relies on observer experience. From the 1980s onwards, objective techniques have been developed for diagnosing Giardia infections, and are superseding diagnostic techniques reliant on microscopy. Detection of Giardia antigen(s) by immunoassay is the basis of commercially available diagnostic kits. Various nucleic acid amplification techniques (NAATs) can demonstrate DNA of Giardia intestinalis, and have the potential to become standard approaches for diagnosing Giardia infections. Of such techniques, methods involving either fluorescent microspheres (Luminex) or isothermal amplification of DNA (loop-mediated isothermal amplification; LAMP) are especially promising.

Malaria rapid diagnostic tests in elimination settings—can they find the last parasite?

PubMed Central

McMorrow, M. L.; Aidoo, M.; Kachur, S. P.

2016-01-01

Rapid diagnostic tests (RDTs) for malaria have improved the availability of parasite-based diagnosis throughout the malaria-endemic world. Accurate malaria diagnosis is essential for malaria case management, surveillance, and elimination. RDTs are inexpensive, simple to perform, and provide results in 15–20 min. Despite high sensitivity and specificity for Plasmodium falciparum infections, RDTs have several limitations that may reduce their utility in low-transmission settings: they do not reliably detect low-density parasitaemia (≤200 parasites/μL), many are less sensitive for Plasmodium vivax infections, and their ability to detect Plasmodium ovale and Plasmodium malariae is unknown. Therefore, in elimination settings, alternative tools with higher sensitivity for low-density infections (e.g. nucleic acid-based tests) are required to complement field diagnostics, and new highly sensitive and specific field-appropriate tests must be developed to ensure accurate diagnosis of symptomatic and asymptomatic carriers. As malaria transmission declines, the proportion of low-density infections among symptomatic and asymptomatic persons is likely to increase, which may limit the utility of RDTs. Monitoring malaria in elimination settings will probably depend on the use of more than one diagnostic tool in clinical-care and surveillance activities, and the combination of tools utilized will need to be informed by regular monitoring of test performance through effective quality assurance. PMID:21910780

Effect of Accreditation on Accuracy of Diagnostic Tests in Medical Laboratories

PubMed Central

Jang, Mi-Ae; Yoon, Young Ahn; Song, Junghan; Kim, Jeong-Ho; Min, Won-Ki; Lee, Ji Sung

2017-01-01

Background Medical laboratories play a central role in health care. Many laboratories are taking a more focused and stringent approach to quality system management. In Korea, laboratory standardization efforts undertaken by the Korean Laboratory Accreditation Program (KLAP) and the Korean External Quality Assessment Scheme (KEQAS) may have facilitated an improvement in laboratory performance, but there are no fundamental studies demonstrating that laboratory standardization is effective. We analyzed the results of the KEQAS to identify significant differences between laboratories with or without KLAP and to determine the impact of laboratory standardization on the accuracy of diagnostic tests. Methods We analyzed KEQAS participant data on clinical chemistry tests such as albumin, ALT, AST, and glucose from 2010 to 2013. As a statistical parameter to assess performance bias between laboratories, we compared 4-yr variance index score (VIS) between the two groups with or without KLAP. Results Compared with the group without KLAP, the group with KLAP exhibited significantly lower geometric means of 4-yr VIS for all clinical chemistry tests (P<0.0001); this difference justified a high level of confidence in standardized services provided by accredited laboratories. Confidence intervals for the mean of each test in the two groups (accredited and non-accredited) did not overlap, suggesting that the means of the groups are significantly different. Conclusions These results confirmed that practice standardization is strongly associated with the accuracy of test results. Our study emphasizes the necessity of establishing a system for standardization of diagnostic testing. PMID:28224767

Rubella Surveillance and Diagnostic Testing among a Low-Prevalence Population, New York City, 2012–2013

PubMed Central

Zucker, Jane R.; Giancotti, Francesca R.; Abernathy, Emily; Icenogle, Joseph; Rakeman, Jennifer L.; Rosen, Jennifer B.

2017-01-01

ABSTRACT The New York City Department of Health and Mental Hygiene (DOHMH) receives clinical and laboratory reports for rubella. Because rubella immunoglobulin M (IgM) assays may produce false-positive results and rubella infections may be asymptomatic, interpretation of positive IgM results can be challenging. Rubella reports received by DOHMH in 2012 to 2013 were reviewed. The rubella IgM testing purpose was determined through case investigation. Results of IgM testing by indirect enzyme-linked immunosorbent assay (ELISA) and capture enzyme immunoassay (EIA) were compared to determine positive predictive value (PPV) and specificity. DOHMH received 199 rubella reports; 2 were true cases. Of all reports, 77.9% were tested for rubella IgM erroneously, 19.6% were tested for diagnostic purposes, 2.0% had unknown test purpose, and 0.5% were not tested. PPV of indirect ELISA was 6% overall, 14% for diagnostic tests, and 0% for tests ordered erroneously. PPV of capture EIA was 29% overall, 50% for diagnostic tests, and 0% for tests ordered erroneously. Overall, specificity was 52% for indirect ELISA and 85% for capture EIA. Limiting rubella IgM testing to patients for whom rubella diagnosis is suspected and using a more specific IgM assay have the potential to reduce false-positive rubella IgM results. PMID:28701468

Limited-information goodness-of-fit testing of diagnostic classification item response models.

PubMed

Hansen, Mark; Cai, Li; Monroe, Scott; Li, Zhen

2016-11-01

Despite the growing popularity of diagnostic classification models (e.g., Rupp et al., 2010, Diagnostic measurement: theory, methods, and applications, Guilford Press, New York, NY) in educational and psychological measurement, methods for testing their absolute goodness of fit to real data remain relatively underdeveloped. For tests of reasonable length and for realistic sample size, full-information test statistics such as Pearson's X 2 and the likelihood ratio statistic G 2 suffer from sparseness in the underlying contingency table from which they are computed. Recently, limited-information fit statistics such as Maydeu-Olivares and Joe's (2006, Psychometrika, 71, 713) M 2 have been found to be quite useful in testing the overall goodness of fit of item response theory models. In this study, we applied Maydeu-Olivares and Joe's (2006, Psychometrika, 71, 713) M 2 statistic to diagnostic classification models. Through a series of simulation studies, we found that M 2 is well calibrated across a wide range of diagnostic model structures and was sensitive to certain misspecifications of the item model (e.g., fitting disjunctive models to data generated according to a conjunctive model), errors in the Q-matrix (adding or omitting paths, omitting a latent variable), and violations of local item independence due to unmodelled testlet effects. On the other hand, M 2 was largely insensitive to misspecifications in the distribution of higher-order latent dimensions and to the specification of an extraneous attribute. To complement the analyses of the overall model goodness of fit using M 2 , we investigated the utility of the Chen and Thissen (1997, J. Educ. Behav. Stat., 22, 265) local dependence statistic XLD2 for characterizing sources of misfit, an important aspect of model appraisal often overlooked in favour of overall statements. The XLD2 statistic was found to be slightly conservative (with Type I error rates consistently below the nominal level) but still useful

Meta-analysis for the comparison of two diagnostic tests to a common gold standard: A generalized linear mixed model approach.

PubMed

Hoyer, Annika; Kuss, Oliver

2018-05-01

Meta-analysis of diagnostic studies is still a rapidly developing area of biostatistical research. Especially, there is an increasing interest in methods to compare different diagnostic tests to a common gold standard. Restricting to the case of two diagnostic tests, in these meta-analyses the parameters of interest are the differences of sensitivities and specificities (with their corresponding confidence intervals) between the two diagnostic tests while accounting for the various associations across single studies and between the two tests. We propose statistical models with a quadrivariate response (where sensitivity of test 1, specificity of test 1, sensitivity of test 2, and specificity of test 2 are the four responses) as a sensible approach to this task. Using a quadrivariate generalized linear mixed model naturally generalizes the common standard bivariate model of meta-analysis for a single diagnostic test. If information on several thresholds of the tests is available, the quadrivariate model can be further generalized to yield a comparison of full receiver operating characteristic (ROC) curves. We illustrate our model by an example where two screening methods for the diagnosis of type 2 diabetes are compared.

The diagnostic value of skin prick testing in children with food allergy.

PubMed

Hill, David J; Heine, Ralf G; Hosking, Clifford S

2004-10-01

The diagnostic accuracy of the skin prick test (SPT) in food allergy is controversial. We have developed diagnostic cut-off levels for SPT in children with allergy to cow milk, egg and peanut. Based on 555 open food challenges in 467 children (median age 3.0 yr) we defined food-specific SPT weal diameters that were '100% diagnostic' for allergy to cow milk (>or=8 mm), egg (>or=7 mm) and peanut (>or=8 mm). In children < 2 yr of age, the corresponding weal diameters were >or=6 mm, >or=5 mm and >or=4 mm, respectively. These SPT cut-off levels were prospectively validated in 90 consecutive children diagnostic cut-off but reached the diagnostic cut-off at the time of challenge in the second year of life. We assessed the diagnostic agreement between food-specific immunoglobulin E (IgE) antibody levels and SPT in a cohort of 820 infants and children under 2 yr of age (median age 13.1 months) with suspected allergy to cow milk, egg or peanut. When applying published 95%-positive predictive CAP values, the diagnostic accuracy of SPT and IgE antibody levels was similar for cow milk, but SPT was more sensitive in diagnosing allergy to egg (p < 0.0001) and peanut (p < 0.0001). Further studies are required to define age-specific diagnostic IgE antibody and SPT cut-off levels use in infants under 2 yr of age with suspected food allergies.

Impact of clinical awareness and diagnostic tests on the underdiagnosis of Clostridium difficile infection.

PubMed

Alcalá, L; Reigadas, E; Marín, M; Martín, A; Catalán, P; Bouza, E

2015-08-01

A multicenter study of Clostridium difficile infection (CDI) performed during 2008 in Spain revealed that two of every three episodes went undiagnosed or were misdiagnosed owing to nonsensitive diagnostic tests or lack of clinical suspicion and request. Since then, efforts have been made to improve the diagnostic tests used by laboratories and to increase the awareness of this disease among both clinicians and microbiologists. Our objective was to evaluate the impact of these efforts by assessing the current magnitude of underdiagnosis of CDI in Spain using two point-prevalence studies performed on one day each in January and July of 2013. A total of 111 Spanish laboratories selected all unformed stool specimens received for microbiological diagnosis on these days, and toxigenic culture was performed at a central reference laboratory. Toxigenic isolates were characterized both pheno- and genotypically. The reference laboratory detected 103 episodes of CDI in patients aged 2 years or more. Half (50.5 %) of the episodes were not diagnosed in the participating laboratories, owing to insensitive diagnostic tests (15.5 %) or the lack of clinical suspicion and request (35.0 %). The main ribotypes were 014, 078/126, 001/072, and 106. Ribotype 027 caused 2.9 % of all cases. Despite all the interventions undertaken, CDI remains a highly neglected disease because of the lack of sensitive diagnostic tests in some institutions and, especially, the absence of clinical suspicion, mainly in patients with community-associated CDI. Toxigenic C. difficile should be routinely sought in unformed stools sent for microbiological diagnosis, regardless of their origin.

Dual-Objective Item Selection Criteria in Cognitive Diagnostic Computerized Adaptive Testing

ERIC Educational Resources Information Center

Kang, Hyeon-Ah; Zhang, Susu; Chang, Hua-Hua

2017-01-01

The development of cognitive diagnostic-computerized adaptive testing (CD-CAT) has provided a new perspective for gaining information about examinees' mastery on a set of cognitive attributes. This study proposes a new item selection method within the framework of dual-objective CD-CAT that simultaneously addresses examinees' attribute mastery…

Reporting standards for studies of diagnostic test accuracy in dementia

PubMed Central

Noel-Storr, Anna H.; McCleery, Jenny M.; Richard, Edo; Ritchie, Craig W.; Flicker, Leon; Cullum, Sarah J.; Davis, Daniel; Quinn, Terence J.; Hyde, Chris; Rutjes, Anne W.S.; Smailagic, Nadja; Marcus, Sue; Black, Sandra; Blennow, Kaj; Brayne, Carol; Fiorivanti, Mario; Johnson, Julene K.; Köpke, Sascha; Schneider, Lon S.; Simmons, Andrew; Mattsson, Niklas; Zetterberg, Henrik; Bossuyt, Patrick M.M.; Wilcock, Gordon

2014-01-01

Objective: To provide guidance on standards for reporting studies of diagnostic test accuracy for dementia disorders. Methods: An international consensus process on reporting standards in dementia and cognitive impairment (STARDdem) was established, focusing on studies presenting data from which sensitivity and specificity were reported or could be derived. A working group led the initiative through 4 rounds of consensus work, using a modified Delphi process and culminating in a face-to-face consensus meeting in October 2012. The aim of this process was to agree on how best to supplement the generic standards of the STARD statement to enhance their utility and encourage their use in dementia research. Results: More than 200 comments were received during the wider consultation rounds. The areas at most risk of inadequate reporting were identified and a set of dementia-specific recommendations to supplement the STARD guidance were developed, including better reporting of patient selection, the reference standard used, avoidance of circularity, and reporting of test-retest reliability. Conclusion: STARDdem is an implementation of the STARD statement in which the original checklist is elaborated and supplemented with guidance pertinent to studies of cognitive disorders. Its adoption is expected to increase transparency, enable more effective evaluation of diagnostic tests in Alzheimer disease and dementia, contribute to greater adherence to methodologic standards, and advance the development of Alzheimer biomarkers. PMID:24944261

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

Pearls and pitfalls of allergy diagnostic testing: report from the American College of Allergy, Asthma and Immunology/American Academy of Allergy, Asthma and Immunology Specific IgE Test Task Force.

PubMed

Cox, Linda; Williams, Brock; Sicherer, Scott; Oppenheimer, John; Sher, Larry; Hamilton, Robert; Golden, David

2008-12-01

The intended purpose of this monograph is to provide a general overview of allergy diagnostics for health care professionals who care for patients with allergic disease. For a more comprehensive review of allergy diagnostic testing, readers can refer to the Allergy Diagnostic Practice Parameters. A key message is that a positive allergy test result (skin or blood) indicates only the presence of allergen specific IgE (called sensitization). It does not necessarily mean clinical allergy (ie, allergic symptoms with exposure). It is important for this reason that the allergy evaluation be based on the patient's history and directed by a health care professional with sufficient understanding of allergy diagnostic testing to use the information obtained from his/her evaluation of the patient to determine (1) what allergy diagnostic tests to order, (2) how to interpret the allergy diagnostic test results, and (3) how to use the information obtained from the allergy evaluation to develop an appropriate therapeutic treatment plan.

Validating the Astronomy Diagnostics Test for Undergraduate Non-Science Majors

NASA Astrophysics Data System (ADS)

Slater, T. F.; Hufnagel, B.; Adams, J. P.

1999-05-01

The Astronomy Diagnostics Test (ADT) is a standard diagnostic test for undergraduate non-science majors taking introductory astronomy. Serving to compare the effectiveness of various instructional interventions, the ADT has been developed and field-tested over the last year by a multi-institutional team, known as the Collaboration for Astronomy Education Research (CAER). The team includes Jeff Adams, Rebecca Lindell Adrian, Christine Brick, Gina Brissenden, Grace Deming, Beth Hufnagel, Tim Slater, and Michael Zeilik, among others. The need for a nationally normed, valid, and reliable assessment instrument in astronomy has been articulated in a wide variety of forums. This need results from the simultaneous occurrence of several important phenomena over the last decade including: the inclusion of astronomy concepts in national science education standards; documentation of widespread astronomical misconceptions; the influence of the Force Concept Inventory guiding reform in physics; and the call for university faculty to document improvements in instruction. In a triangulated effort to validate the ADT for widespread use, the researchers used on a three-phase strategy. In this context, "validity" means that the ADT measures what it purports to measure. In other words, do students give the correct answer for the scientifically correct reasons or, alternatively, do students give the correct answer even though they have misunderstandings about the phenomena being tested? These three phases were: (1) conduct statistical item-analysis on each test question for a large and diverse student population (n=2000 from 21 institutions); (2) conduct 60 clinical student interviews using the test questions as the script; and (3) conduct an inductive analysis of 30 student supplied written responses to ADT questions posed without the multiple-choices provided. The ADT and its supporting comparative database is available at URL: http://solar.physics.montana.edu/aae/adt/. This research

42 CFR 415.180 - Teaching setting requirements for the interpretation of diagnostic radiology and other diagnostic...

Code of Federal Regulations, 2011 CFR

2011-10-01

... interpretation of diagnostic radiology and other diagnostic tests. 415.180 Section 415.180 Public Health CENTERS... for the interpretation of diagnostic radiology and other diagnostic tests. (a) General rule. Physician fee schedule payment is made for the interpretation of diagnostic radiology and other diagnostic tests...

42 CFR 415.180 - Teaching setting requirements for the interpretation of diagnostic radiology and other diagnostic...

Code of Federal Regulations, 2010 CFR

2010-10-01

... interpretation of diagnostic radiology and other diagnostic tests. 415.180 Section 415.180 Public Health CENTERS... for the interpretation of diagnostic radiology and other diagnostic tests. (a) General rule. Physician fee schedule payment is made for the interpretation of diagnostic radiology and other diagnostic tests...

Defining the next generation of Plasmodium vivax diagnostic tests for control and elimination: Target product profiles

PubMed Central

Ade, Maria Paz; Baird, J. Kevin; Cheng, Qin; Cunningham, Jane; Dhorda, Mehul; Drakeley, Chris; Felger, Ingrid; Gamboa, Dionicia; Harbers, Matthias; Herrera, Socrates; Lucchi, Naomi; Mayor, Alfredo; Mueller, Ivo; Sattabongkot, Jetsumon; Ratsimbason, Arsène; Richards, Jack; Tanner, Marcel; González, Iveth J.

2017-01-01

The global prevalence of malaria has decreased over the past fifteen years, but similar gains have not been realized against Plasmodium vivax because this species is less responsive to conventional malaria control interventions aimed principally at P. falciparum. Approximately half of all malaria cases outside of Africa are caused by P. vivax. This species places dormant forms in human liver that cause repeated clinical attacks without involving another mosquito bite. The diagnosis of acute patent P. vivax malaria relies primarily on light microscopy. Specific rapid diagnostic tests exist but typically perform relatively poorly compared to those for P. falciparum. Better diagnostic tests are needed for P. vivax. To guide their development, FIND, in collaboration with P. vivax experts, identified the specific diagnostic needs associated with this species and defined a series of three distinct target product profiles, each aimed at a particular diagnostic application: (i) point-of-care of acutely ill patients for clinical care purposes; (ii) point-of-care asymptomatic and otherwise sub-patent residents for public health purposes, e.g., mass screen and treat campaigns; and (iii) ultra-sensitive not point-of-care diagnosis for epidemiological research/surveillance purposes. This report presents and discusses the rationale for these P. vivax-specific diagnostic target product profiles. These contribute to the rational development of fit-for-purpose diagnostic tests suitable for the clinical management, control and elimination of P. vivax malaria. PMID:28369085

[Pilot tests using molecular diagnostic assay cervicovaginal infection during pregnancy].

PubMed

Beltrán-Montoya, J; Escudero-Gontes, S; Martínez-Huerta, N E; Ávila-Vergara, M A; Morales-Hernández, V; Canchola-Sotelo, C; Palacios-González, B; Vadillo-Ortega, F

2016-08-01

The prevalence of cervicovaginal infections during pregnancy has been associated with adverse perinatal outcomes however, the actual approach used for diagnosis is not effective. The aim of this study was to compare the diagnosis of vaginal infections in pregnant women using clinical, molecular diagnostic and traditional microbiological culture in a pilot study, to determine the prevalence and association with the development of preterm labor. We performed a nested cross-sectional study composed by 54 women in a cohort of pregnant women in Mexico City. Cervicovaginal infections were evaluated by clinical methods, microbiology culture and a commercially available molecular biology test. Prevalence of cervicovaginal infections during pregnancy was estimated between 28% and 50% according to methodologies. Considering the clinical diagnosis of preterm labor as the gold standard, all diagnostic tests were poor as predictors of preterm labor. Traditional approaches to establish the significance of cervicovaginal infection in pregnancy are exhausted, so be sought new ways to understand this complex relationship. Meanwhile it is recommended to continue to use traditional methods to identify infections during pregnancy in both knowledge of new methods aimed at understanding these relationships are sophisticated.

The methodological quality of diagnostic test accuracy studies for musculoskeletal conditions can be improved.

PubMed

Henschke, Nicholas; Keuerleber, Julia; Ferreira, Manuela; Maher, Christopher G; Verhagen, Arianne P

2014-04-01

To provide an overview of reporting and methodological quality in diagnostic test accuracy (DTA) studies in the musculoskeletal field and evaluate the use of the QUality Assessment of Diagnostic Accuracy Studies (QUADAS) checklist. A literature review identified all systematic reviews that evaluated the accuracy of clinical tests to diagnose musculoskeletal conditions and used the QUADAS checklist. Two authors screened all identified reviews and extracted data on the target condition, index tests, reference standard, included studies, and QUADAS items. A descriptive analysis of the QUADAS checklist was performed, along with Rasch analysis to examine the construct validity and internal reliability. A total of 19 systematic reviews were included, which provided data on individual items of the QUADAS checklist for 392 DTA studies. In the musculoskeletal field, uninterpretable or intermediate test results are commonly not reported, with 175 (45%) studies scoring "no" to this item. The proportion of studies fulfilling certain items varied from 22% (item 11) to 91% (item 3). The interrater reliability of the QUADAS checklist was good and Rasch analysis showed excellent construct validity and internal consistency. This overview identified areas where the reporting and performance of diagnostic studies within the musculoskeletal field can be improved. Copyright © 2014 Elsevier Inc. All rights reserved.

Review: Diagnostic accuracy of PCR-based detection tests for Helicobacter Pylori in stool samples.

PubMed

Khadangi, Fatemeh; Yassi, Maryam; Kerachian, Mohammad Amin

2017-12-01

Although different methods have been established to detect Helicobacter pylori (H. pylori) infection, identifying infected patients is an ongoing challenge. The aim of this meta-analysis was to provide pooled diagnostic accuracy measures for stool PCR test in the diagnosis of H. pylori infection. In this study, a systematic review and meta-analysis were carried out on various sources, including MEDLINE, Web of Sciences, and the Cochrane Library from April 1, 1999, to May 1, 2016. This meta-analysis adheres to the guidelines provided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses report (PRISMA Statement). The clinical value of DNA stool PCR test was based on the pooled false positive, false negative, true positive, and true negative of different genes. Twenty-six of 328 studies identified met the eligibility criteria. Stool PCR test had a performance of 71% (95% CI: 68-73) sensitivity, 96% (95% CI: 94-97) specificity, and 65.6 (95% CI: 30.2-142.5) diagnostic odds ratio (DOR) in diagnosis of H. pylori. The DOR of genes which showed the highest performance of stool PCR tests was as follows: 23S rRNA 152.5 (95% CI: 55.5-418.9), 16S rRNA 67.9 (95%CI: 6.4-714.3), and glmM 68.1 (95%CI: 20.1-231.7). The sensitivity and specificity of stool PCR test are relatively in the same spectrum of other diagnostic methods for the detection of H. pylori infection. In descending order of significance, the most diagnostic candidate genes using PCR detection were 23S rRNA, 16S rRNA, and glmM. PCR for 23S rRNA gene which has the highest performance could be applicable to detect H. pylori infection. © 2017 John Wiley & Sons Ltd.

Update on diagnostic value of breath test in gastrointestinal and liver diseases

PubMed Central

Siddiqui, Imran; Ahmed, Sibtain; Abid, Shahab

2016-01-01

In the field of gastroenterology, breath tests (BTs) are used intermittently as diagnostic tools that allow indirect, non-invasive and relatively less cumbersome evaluation of several disorders by simply quantifying the appearance in exhaled breath of a metabolite of a specific substrate administered. The aim of this review is to have an insight into the principles, methods of analysis and performance parameters of various hydrogen, methane and carbon BTs which are available for diagnosing gastrointestinal disorders such as Helicobacter pylori infection, small intestinal bacterial overgrowth, and carbohydrate malabsorption. Evaluation of gastric emptying is routinely performed by scintigraphy which is however, difficult to perform and not suitable for children and pregnant women, this review has abridged the 13C-octanoic acid test in comparison to scintigraphy and has emphasized on its working protocol and challenges. A new development such as electronic nose test is also highlighted. Moreover we have also explored the limitations and constraints restraining the wide use of these BT. We conclude that breath testing has an enormous potential to be used as a diagnostic modality. In addition it offers distinct advantages over the traditional invasive methods commonly employed. PMID:27574563

Healthcare Fragmentation and the Frequency of Radiology and Other Diagnostic Tests: A Cross-Sectional Study.

PubMed

Kern, Lisa M; Seirup, Joanna K; Casalino, Lawrence P; Safford, Monika M

2017-02-01

Fragmented ambulatory care has been associated with high rates of emergency department visits and hospitalizations, but effects on other types of utilization are unclear. To determine whether more fragmented care is associated with more radiology and other diagnostic tests, compared to less fragmented care. We conducted a cross-sectional study using claims from five commercial payers for 2010. The study took place in the Hudson Valley, a seven-county region in New York State. We included adult patients who were insured through the participating payers and were attributed to a primary care physician in the region. We restricted the cohort to those with ≥4 ambulatory visits, as measures of fragmentation are not reliable if based on ≤3 visits (N = 126,801). For each patient, we calculated fragmentation using a reversed Bice-Boxerman Index, which we divided into seven categories. We used negative binomial regression to determine the association between fragmentation category and rates of radiology and other diagnostic tests, stratified by number of chronic conditions and adjusting for patient age, gender, and number of visits. Patients with the most fragmented care had approximately twice as many radiology and other diagnostic tests as patients with the least fragmented care, across all groups stratified by number of chronic conditions (each adjusted p < 0.0001). For example, among patients with ≥5 chronic conditions, those with the least fragmented care had 258 tests per 100 patients, and those with the most fragmented care had 542 tests per 100 patients (+284 tests per 100 patients, or +110 %, adjusted p < 0.0001). More fragmented care was independently associated with higher rates of radiology and other diagnostic tests than less fragmented care.

Comparison of a New and Rapid Method: Brucella Coombs Gel Test With Other Diagnostic Tests.

PubMed

Kalem, Fatma; Ergün, Ayşe Gül; Durmaz, Süleyman; Doğan, Metin; Ertuğrul, Ömür; Gündem, Seval

2016-09-01

The aim of this study was to detect reliability of Brucella Coombs gel test (BCGT) by comparing with with ELISA (IgG + IgM), Standard agglutination test, and Brucella immunocapture agglutination methods in serological diagnosis of brucellosis. Brucella Coombs gel test (BCGT), Brucella ELISA (IgG + IgM), Standard agglutination test, and Brucella immunocapture agglutination tests of 78 patients with presumptive diagnosis of brucellosis which were sent to Microbiology Laboratory of Konya Numune Hospital from various regions of Konya were studied. Of 78 patients with ELISA IgG and IgM, STA, BICA and BCGT; 26, 21, 10, 12 and 12 were positive. When compared with BICA, the sensitivity and specifity of BCGT were 100% and 100%, respectively. According to results BCGT can be used as a diagnostic test in routine laboratories after more comprehensive studies in control groups and patients. © 2016 Wiley Periodicals, Inc.

[Assessment of a rapid diagnostic test for malaria in rural health care facilities in Senegal].

PubMed

Munier, A; Diallo, A; Sokhna, C; Chippaux, J P

2009-10-01

The aim of the study was to determine the accuracy of a rapid diagnostic test in confirming presumptive malaria diagnosis in a rural zone of Senegal. Thick blood smear was used as the reference technique for comparison. METHOHDOLOGY: Testing was conducted on children between the ages of 1 and 14 years at three health care facilities located in the Niakhar are from August 2006 to June 2007. If malaria was suspected by the nurse based on clinical findings, two thick smears and one rapid diagnostic test (Core Malaria Pf) were performed. Blood slides were stained in Niakhar and read in Dakar. A total of 474 patients were examined. Three-fourths (75%) of these patients were seen during the rainy season. Malaria was suspected in 335 patients (71%). Rapid tests and thick smears were obtained in 330 of these patients with positive results in 194 (59%) and 180 (55%) respectively. The sensitivity, specificity, positive predictive value and negative predictive value of the rapid test were 96%, 87%, 90% and 95% respectively. Our data show that the rapid diagnostic test used in this study exhibits good sensitivity and positive predictive value. Despite its cost this test could be helpful in confirming malaria diagnosis in outlying health care facilities without the necessary resources to perform blood smears. Confirmation is necessary to avoid unwarranted prescription of malaria treatment due to inaccurate clinical diagnosis

The meaning of diagnostic test results: a spreadsheet for swift data analysis.

PubMed

Maceneaney, P M; Malone, D E

2000-03-01

To design a spreadsheet program to: (a) analyse rapidly diagnostic test result data produced in local research or reported in the literature; (b) correct reported predictive values for disease prevalence in any population; (c) estimate the post-test probability of disease in individual patients. Microsoft Excel(TM)was used. Section A: a contingency (2 x 2) table was incorporated into the spreadsheet. Formulae for standard calculations [sample size, disease prevalence, sensitivity and specificity with 95% confidence intervals, predictive values and likelihood ratios (LRs)] were linked to this table. The results change automatically when the data in the true or false negative and positive cells are changed. Section B: this estimates predictive values in any population, compensating for altered disease prevalence. Sections C-F: Bayes' theorem was incorporated to generate individual post-test probabilities. The spreadsheet generates 95% confidence intervals, LRs and a table and graph of conditional probabilities once the sensitivity and specificity of the test are entered. The latter shows the expected post-test probability of disease for any pre-test probability when a test of known sensitivity and specificity is positive or negative. This spreadsheet can be used on desktop and palmtop computers. The MS Excel(TM)version can be downloaded via the Internet from the URL ftp://radiography.com/pub/Rad-data99.xls A spreadsheet is useful for contingency table data analysis and assessment of the clinical meaning of diagnostic test results. Copyright 2000 The Royal College of Radiologists.

Effect of Accreditation on Accuracy of Diagnostic Tests in Medical Laboratories.

PubMed

Jang, Mi Ae; Yoon, Young Ahn; Song, Junghan; Kim, Jeong Ho; Min, Won Ki; Lee, Ji Sung; Lee, Yong Wha; Lee, You Kyoung

2017-05-01

Medical laboratories play a central role in health care. Many laboratories are taking a more focused and stringent approach to quality system management. In Korea, laboratory standardization efforts undertaken by the Korean Laboratory Accreditation Program (KLAP) and the Korean External Quality Assessment Scheme (KEQAS) may have facilitated an improvement in laboratory performance, but there are no fundamental studies demonstrating that laboratory standardization is effective. We analyzed the results of the KEQAS to identify significant differences between laboratories with or without KLAP and to determine the impact of laboratory standardization on the accuracy of diagnostic tests. We analyzed KEQAS participant data on clinical chemistry tests such as albumin, ALT, AST, and glucose from 2010 to 2013. As a statistical parameter to assess performance bias between laboratories, we compared 4-yr variance index score (VIS) between the two groups with or without KLAP. Compared with the group without KLAP, the group with KLAP exhibited significantly lower geometric means of 4-yr VIS for all clinical chemistry tests (P<0.0001); this difference justified a high level of confidence in standardized services provided by accredited laboratories. Confidence intervals for the mean of each test in the two groups (accredited and non-accredited) did not overlap, suggesting that the means of the groups are significantly different. These results confirmed that practice standardization is strongly associated with the accuracy of test results. Our study emphasizes the necessity of establishing a system for standardization of diagnostic testing. © The Korean Society for Laboratory Medicine

"Shotgun" versus sequential testing. Cost-effectiveness of diagnostic strategies for vaginitis.

PubMed

Carr, Phyllis L; Rothberg, Michael B; Friedman, Robert H; Felsenstein, Donna; Pliskin, Joseph S

2005-09-01

Although vaginitis is a common outpatient problem, only 60% of patients can be diagnosed at the initial office visit of a primary care provider using the office procedures of pH testing, whiff tests, normal saline, and potassium hydroxide preps. To determine the most cost-effective diagnostic and treatment approach for the medical management of vaginitis. Decision and cost-effectiveness analyses. Healthy women with symptoms of vaginitis undiagnosed after an initial pelvic exam, wet mount preparations, pH, and the four criteria to diagnose bacterial vaginosis. General office practice. We evaluated 28 diagnostic strategies comprised of combinations of pH testing, vaginal cultures for yeast and Trichomonas vaginalis, Gram's stain for bacterial vaginosis, and DNA probes for Neisseria gonorrhoeae and Chlamydia. Data sources for the study were confined to English language literature. The outcome measures were symptom-days and costs. The least expensive strategy was to perform yeast culture, gonorrhoeae and Chlamydia probes at the initial visit, and Gram's stain and Trichomonas culture only when the vaginal pH exceeded 4.9 (330 dollars, 7.30 symptom days). Other strategies cost 8 dollars to 76 dollars more and increased duration of symptoms by up to 1.3 days. In probabilistic sensitivity analysis, this strategy was always the most effective strategy and was also least expensive 58% of the time. For patients with vaginitis symptoms undiagnosed by pelvic examination, wet mount preparations and related office tests, a comprehensive, pH-guided testing strategy at the initial office visit is less expensive and more effective than ordering tests sequentially.

Diagnostic efficacy of in vitro methods vs. skin testing in patients with inhalant allergies

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

Corey, J.P.; Liudahl, J.J.; Young, S.A.

1991-03-01

The purpose of our study was to investigate the diagnostic efficacy of two selected methods of in vitro allergy testing. Specifically, the PRIST/modified RAST I125 isotope systems and the Quantizyme/modified EAST alkaline phosphatase method were compared. The time, expense, convenience, and diagnostic efficacy of the two procedures are discussed. Special attention is given to the practicality of each method for the practicing physician.

Diagnostic Accuracy of Molecular Amplification Tests for Human African Trypanosomiasis—Systematic Review

PubMed Central

Boer, Kimberly R.; Dyserinck, Heleen C.; Büscher, Philippe; Schallig, Henk D. H. F.; Leeflang, Mariska M. G.

2012-01-01

Background A range of molecular amplification techniques have been developed for the diagnosis of Human African Trypanosomiasis (HAT); however, careful evaluation of these tests must precede implementation to ensure their high clinical accuracy. Here, we investigated the diagnostic accuracy of molecular amplification tests for HAT, the quality of articles and reasons for variation in accuracy. Methodology Data from studies assessing diagnostic molecular amplification tests were extracted and pooled to calculate accuracy. Articles were included if they reported sensitivity and specificity or data whereby values could be calculated. Study quality was assessed using QUADAS and selected studies were analysed using the bivariate random effects model. Results 16 articles evaluating molecular amplification tests fulfilled the inclusion criteria: PCR (n = 12), NASBA (n = 2), LAMP (n = 1) and a study comparing PCR and NASBA (n = 1). Fourteen articles, including 19 different studies were included in the meta-analysis. Summary sensitivity for PCR on blood was 99.0% (95% CI 92.8 to 99.9) and the specificity was 97.7% (95% CI 93.0 to 99.3). Differences in study design and readout method did not significantly change estimates although use of satellite DNA as a target significantly lowers specificity. Sensitivity and specificity of PCR on CSF for staging varied from 87.6% to 100%, and 55.6% to 82.9% respectively. Conclusion Here, PCR seems to have sufficient accuracy to replace microscopy where facilities allow, although this conclusion is based on multiple reference standards and a patient population that was not always representative. Future studies should, therefore, include patients for which PCR may become the test of choice and consider well designed diagnostic accuracy studies to provide extra evidence on the value of PCR in practice. Another use of PCR for control of disease could be to screen samples collected from rural areas and test in reference

Diagnostic accuracy of molecular amplification tests for human African trypanosomiasis--systematic review.

PubMed

Mugasa, Claire M; Adams, Emily R; Boer, Kimberly R; Dyserinck, Heleen C; Büscher, Philippe; Schallig, Henk D H F; Leeflang, Mariska M G

2012-01-01

A range of molecular amplification techniques have been developed for the diagnosis of Human African Trypanosomiasis (HAT); however, careful evaluation of these tests must precede implementation to ensure their high clinical accuracy. Here, we investigated the diagnostic accuracy of molecular amplification tests for HAT, the quality of articles and reasons for variation in accuracy. Data from studies assessing diagnostic molecular amplification tests were extracted and pooled to calculate accuracy. Articles were included if they reported sensitivity and specificity or data whereby values could be calculated. Study quality was assessed using QUADAS and selected studies were analysed using the bivariate random effects model. 16 articles evaluating molecular amplification tests fulfilled the inclusion criteria: PCR (n = 12), NASBA (n = 2), LAMP (n = 1) and a study comparing PCR and NASBA (n = 1). Fourteen articles, including 19 different studies were included in the meta-analysis. Summary sensitivity for PCR on blood was 99.0% (95% CI 92.8 to 99.9) and the specificity was 97.7% (95% CI 93.0 to 99.3). Differences in study design and readout method did not significantly change estimates although use of satellite DNA as a target significantly lowers specificity. Sensitivity and specificity of PCR on CSF for staging varied from 87.6% to 100%, and 55.6% to 82.9% respectively. Here, PCR seems to have sufficient accuracy to replace microscopy where facilities allow, although this conclusion is based on multiple reference standards and a patient population that was not always representative. Future studies should, therefore, include patients for which PCR may become the test of choice and consider well designed diagnostic accuracy studies to provide extra evidence on the value of PCR in practice. Another use of PCR for control of disease could be to screen samples collected from rural areas and test in reference laboratories, to spot epidemics quickly and

Validation of diagnostic tests for depressive disorder in drug-resistant mesial temporal lobe epilepsy.

PubMed

de Lemos Zingano, Bianca; Guarnieri, Ricardo; Diaz, Alexandre Paim; Schwarzbold, Marcelo Liborio; Bicalho, Maria Alice Horta; Claudino, Lucia Sukys; Markowitsch, Hans J; Wolf, Peter; Lin, Katia; Walz, Roger

2015-09-01

This study aimed to evaluate the diagnostic accuracy of the Hamilton Rating Scale for Depression (HRSD), the Beck Depression Inventory (BDI), the Hospital Anxiety and Depression Scale (HADS), and the Hospital Anxiety and Depression Scale-Depression subscale (HADS-D) as diagnostic tests for depressive disorder in drug-resistant mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS). One hundred three patients with drug-resistant MTLE-HS were enrolled. All patients underwent a neurological examination, interictal and ictal video-electroencephalogram (V-EEG) analyses, and magnetic resonance imaging (MRI). Psychiatric interviews were based on DSM-IV-TR criteria and ILAE Commission of Psychobiology classification as a gold standard; HRSD, BDI, HADS, and HADS-D were used as psychometric diagnostic tests, and receiver operating characteristic (ROC) curves were used to determine the optimal threshold scores. For all the scales, the areas under the curve (AUCs) were approximately 0.8, and they were able to identify depression in this sample. A threshold of ≥9 on the HRSD and a threshold of ≥8 on the HADS-D showed a sensitivity of 70% and specificity of 80%. A threshold of ≥19 on the BDI and HADS-D total showed a sensitivity of 55% and a specificity of approximately 90%. The instruments showed a negative predictive value of approximately 87% and a positive predictive value of approximately 65% for the BDI and HADS total and approximately 60% for the HRSD and HADS-D. HRSD≥9 and HADS-D≥8 had the best balance between sensitivity (approximately 70%) and specificity (approximately 80%). However, with these thresholds, these diagnostic tests do not appear useful in identifying depressive disorder in this population with epilepsy, and their specificity (approximately 80%) and PPV (approximately 55%) were lower than those of the other scales. We believe that the BDI and HADS total are valid diagnostic tests for depressive disorder in patients with MTLE-HS, as

Development and Validation of a Diagnostic Grammar Test for Japanese Learners of English

ERIC Educational Resources Information Center

Koizumi, Rie; Sakai, Hideki; Ido, Takahiro; Ota, Hiroshi; Hayama, Megumi; Sato, Masatoshi; Nemoto, Akiko

2011-01-01

This article reports on the development and validation of the English Diagnostic Test of Grammar (EDiT Grammar) for Japanese learners of English. From among the many aspects of grammar, this test focuses on the knowledge of basic English noun phrases (NPs), especially their internal structures, because previous research has indicated the…

Diagnostic validation of three test methods for detection of cyprinid herpesvirus 3 (CyHV-3).

PubMed

Clouthier, Sharon C; McClure, Carol; Schroeder, Tamara; Desai, Megan; Hawley, Laura; Khatkar, Sunita; Lindsay, Melissa; Lowe, Geoff; Richard, Jon; Anderson, Eric D

2017-03-06

Cyprinid herpesvirus 3 (CyHV-3) is the aetiological agent of koi herpesvirus disease in koi and common carp. The disease is notifiable to the World Organisation for Animal Health. Three tests-quantitative polymerase chain reaction (qPCR), conventional PCR (cPCR) and virus isolation by cell culture (VI)-were validated to assess their fitness as diagnostic tools for detection of CyHV-3. Test performance metrics of diagnostic accuracy were sensitivity (DSe) and specificity (DSp). Repeatability and reproducibility were measured to assess diagnostic precision. Estimates of test accuracy, in the absence of a gold standard reference test, were generated using latent class models. Test samples originated from wild common carp naturally exposed to CyHV-3 or domesticated koi either virus free or experimentally infected with the virus. Three laboratories in Canada participated in the precision study. Moderate to high repeatability (81 to 99%) and reproducibility (72 to 97%) were observed for the qPCR and cPCR tests. The lack of agreement observed between some of the PCR test pair results was attributed to cross-contamination of samples with CyHV-3 nucleic acid. Accuracy estimates for the PCR tests were 99% for DSe and 93% for DSp. Poor precision was observed for the VI test (4 to 95%). Accuracy estimates for VI/qPCR were 90% for DSe and 88% for DSp. Collectively, the results show that the CyHV-3 qPCR test is a suitable tool for surveillance, presumptive diagnosis and certification of individuals or populations as CyHV-3 free.

42 CFR 414.509 - Reconsideration of basis for and amount of payment for a new clinical diagnostic laboratory test.

Code of Federal Regulations, 2011 CFR

2011-10-01

...) or § 414.509(a)(3) that the basis for payment for a new test will be gapfilling, CMS posts interim... for a new clinical diagnostic laboratory test. 414.509 Section 414.509 Public Health CENTERS FOR... FOR PART B MEDICAL AND OTHER HEALTH SERVICES Payment for New Clinical Diagnostic Laboratory Tests...

Improving the Efficiency and Quality of the Value Assessment Process for Companion Diagnostic Tests: The Companion test Assessment Tool (CAT).

PubMed

Canestaro, William J; Pritchard, Daryl E; Garrison, Louis P; Dubois, Robert; Veenstra, David L

2015-08-01

Companion diagnostic tests (CDTs) have emerged as a vital technology in the effective use of an increasing number of targeted drug therapies. Although CDTs can offer a multitude of potential benefits, assessing their value within a health technology appraisal process can be challenging because of a complex array of factors that influence clinical and economic outcomes. To develop a user-friendly tool to assist managed care and other health care decision makers in screening companion tests and determining whether an intensive technology review is necessary and, if so, where the review should be focused to improve efficiency. First, we conducted a systematic literature review of CDT cost-effectiveness studies to identify value drivers. Second, we conducted key informant interviews with a diverse group of stakeholders to elicit feedback and solicit any additional value drivers and identify desirable attributes for an evidence review tool. A draft tool was developed based on this information that captured value drivers, usability features, and had a particular focus on practical use by nonexperts. Finally, the tool was pilot tested with test developers and managed care evidence evaluators to assess face-validity and usability. The tool was also evaluated using several diverse examples of existing companion diagnostics and refined accordingly. We identified 65 cost-effectiveness studies of companion diagnostic technologies. The following factors were most commonly identified as value drivers from our literature review: clinical validity of testing; efficacy, safety, and cost of baseline and alternative treatments; cost and mortality of health states; and biomarker prevalence and testing cost. Stakeholders identified the following additional factors that they believed influenced the overall value of a companion test: regulatory status, actionability, utility, and market penetration. These factors were used to maximize the efficiency of the evidence review process

A False Positive Dengue Fever Rapid Diagnostic Test Result in a Case of Acute Parvovirus B19 Infection.

PubMed

Izumida, Toshihide; Sakata, Hidenao; Nakamura, Masahiko; Hayashibara, Yumiko; Inasaki, Noriko; Inahata, Ryo; Hasegawa, Sumiyo; Takizawa, Takenori; Kaya, Hiroyasu

2016-01-01

An outbreak of dengue fever occurred in Japan in August 2014. We herein report the case of a 63-year-old man who presented with a persistent fever in September 2014. Acute parvovirus B19 infection led to a false positive finding of dengue fever on a rapid diagnostic test (Panbio Dengue Duo Cassette(TM)). To the best of our knowledge, there are no previous reports of a false positive result for dengue IgM with the dengue rapid diagnostic test. We believe that epidemiological information on the prevalence of parvovirus B19 is useful for guiding the interpretation of a positive result with the dengue rapid diagnostic test.

Fan Noise Source Diagnostic Test: Rotor Alone Aerodynamic Performance Results

NASA Technical Reports Server (NTRS)

Hughes, Christopher E.; Jeracki, Robert J.; Woodward, Richard P.; Miller, Christopher J.

2005-01-01

The aerodynamic performance of an isolated fan or rotor alone model was measured in the NASA Glenn Research Center 9- by 15- Foot Low Speed Wind Tunnel as part of the Fan Broadband Source Diagnostic Test conducted at NASA Glenn. The Source Diagnostic Test was conducted to identify the noise sources within a wind tunnel scale model of a turbofan engine and quantify their contribution to the overall system noise level. The fan was part of a 1/5th scale model representation of the bypass stage of a current technology turbofan engine. For the rotor alone testing, the fan and nacelle, including the inlet, external cowl, and fixed area fan exit nozzle, were modeled in the test hardware; the internal outlet guide vanes located behind the fan were removed. Without the outlet guide vanes, the velocity at the nozzle exit changes significantly, thereby affecting the fan performance. As part of the investigation, variations in the fan nozzle area were tested in order to match as closely as possible the rotor alone performance with the fan performance obtained with the outlet guide vanes installed. The fan operating performance was determined using fixed pressure/temperature combination rakes and the corrected weight flow. The performance results indicate that a suitable nozzle exit was achieved to be able to closely match the rotor alone and fan/outlet guide vane configuration performance on the sea level operating line. A small shift in the slope of the sea level operating line was measured, which resulted in a slightly higher rotor alone fan pressure ratio at take-off conditions, matched fan performance at cutback conditions, and a slightly lower rotor alone fan pressure ratio at approach conditions. However, the small differences in fan performance at all fan conditions were considered too small to affect the fan acoustic performance.

9 CFR 130.16 - User fees for veterinary diagnostic serology tests performed at NVSL (excluding FADDL) or at...

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false User fees for veterinary diagnostic serology tests performed at NVSL (excluding FADDL) or at authorized sites. 130.16 Section 130.16 Animals... USER FEES § 130.16 User fees for veterinary diagnostic serology tests performed at NVSL (excluding...

9 CFR 130.17 - User fees for other veterinary diagnostic laboratory tests performed at NVSL (excluding FADDL) or...

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false User fees for other veterinary... FEES USER FEES § 130.17 User fees for other veterinary diagnostic laboratory tests performed at NVSL (excluding FADDL) or at authorized sites. (a) User fees for veterinary diagnostics tests performed at the...

9 CFR 130.17 - User fees for other veterinary diagnostic laboratory tests performed at NVSL (excluding FADDL) or...

Code of Federal Regulations, 2010 CFR

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false User fees for other veterinary... FEES USER FEES § 130.17 User fees for other veterinary diagnostic laboratory tests performed at NVSL (excluding FADDL) or at authorized sites. (a) User fees for veterinary diagnostics tests performed at the...

9 CFR 130.16 - User fees for veterinary diagnostic serology tests performed at NVSL (excluding FADDL) or at...

Code of Federal Regulations, 2010 CFR

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false User fees for veterinary diagnostic serology tests performed at NVSL (excluding FADDL) or at authorized sites. 130.16 Section 130.16 Animals... USER FEES § 130.16 User fees for veterinary diagnostic serology tests performed at NVSL (excluding...

Basic haemoglobinopathy diagnostics in Dutch laboratories; providing an informative test result.

PubMed

Kaufmann, J O; Smit, J W; Huisman, W; Idema, R N; Bakker, E; Giordano, P C

2013-08-01

After a first survey in 2001, the Dutch Association of Hematological Laboratory Research (VHL) advised its members to adopt a basic protocol for haemoglobinopathy carrier detection and to provide genetic information with all positive results to allow health-care professionals to inform carriers about potential genetic risks. This article reports on the compliance with these recommendations and their consequences. Clinical chemists of all 106 Dutch laboratories were invited to answer a survey on patient population, diagnostic techniques used, (self-reported) knowledge, use and effect of the additional information. The average increase in diagnostic output was over 60% and the recommended basic protocol was applied by 65% of the laboratories. Over 84% of the laboratories reported to be aware of the additional recommendations and 77% to be using them. Most laboratories with limited diagnostic requests were still sending their cases to other laboratories and included the genetic information received from these laboratories in their diagnostic reports. The effect of information on subsequent 'family analysis' was estimated to be between 26 and 50%. The present study shows an increase in diagnostic potential for haemoglobinopathy over the last decade, especially in the larger cities. Low 'family testing' rates were mostly found in areas with lower carrier prevalence or associated with local reluctance to pass the information to carriers. In spite of a dramatic improvement, too many carriers are still not informed because of lack of awareness among health-care providers and more education is needed. © 2012 John Wiley & Sons Ltd.

Diagnostic properties of the methacholine and mannitol bronchial challenge tests: a comparison study.

PubMed

Kim, Min-Hye; Song, Woo-Jung; Kim, Tae-Wan; Jin, Hyun-Jung; Sin, You-Seob; Ye, Young-Min; Kim, Sang-Heon; Park, Heung-Woo; Lee, Byung-Jae; Park, Hae-Sim; Yoon, Ho-Joo; Choi, Dong-Chull; Min, Kyung-Up; Cho, Sang-Heon

2014-08-01

Airway hyperresponsiveness is a common feature of asthma. Methacholine and mannitol are two representative agonists for bronchial challenge. They have theoretically different mechanisms of action, and may have different diagnostic properties. However, their difference has not been directly evaluated among Korean adults. In this study, we compare the diagnostic properties of methacholine and mannitol bronchial provocation tests. Asthmatic patients and non-asthmatic controls were recruited prospectively from four referral hospitals in Korea. Participants were challenged with each of methacholine and mannitol inhalation on different days. Their diagnostic utility was evaluated by calculating their sensitivity and specificity for asthma diagnosis. Response-dose ratio was also compared. A total of 50 asthmatic adults and 54 controls were enrolled (mean age 43.8 years). The sensitivity and specificity of mannitol challenge (defined by a PD15 of <635 mg) were 48.0% and 92.6%, respectively, whereas those of methacholine (defined by a PC20 of <16 mg/mL) were 42.0% and 98.1%, respectively. Twenty asthmatic participants (24%) showed positive response to a single agonist only. In the receiver operating curve analyses using response-dose ratio values, area under the curve was 0.77 (95% confidence interval (CI): 0.68-0.86) for mannitol, and 0.89 (95% CI: 0.83-0.95) for methacholine. The correlations between log- transformed mannitol and methacholine response-dose ratios were significant but moderate (r = 0.683, P < 0.001). The present study demonstrated overall similar diagnostic properties of two diagnostic tests, but also suggested their intercomplementary roles for asthma. The clinical trial registration number at ClinicalTrial.gov is NCT02104284. © 2014 Asian Pacific Society of Respirology.

Standardizing Plasmodium falciparum infection prevalence measured via microscopy versus rapid diagnostic test.

PubMed

Mappin, Bonnie; Cameron, Ewan; Dalrymple, Ursula; Weiss, Daniel J; Bisanzio, Donal; Bhatt, Samir; Gething, Peter W

2015-11-17

Large-scale mapping of Plasmodium falciparum infection prevalence relies on opportunistic assemblies of infection prevalence data arising from thousands of P. falciparum parasite rate (PfPR) surveys conducted worldwide. Variance in these data is driven by both signal, the true underlying pattern of infection prevalence, and a range of factors contributing to 'noise', including sampling error, differing age ranges of subjects and differing parasite detection methods. Whilst the former two noise components have been addressed in previous studies, the effect of different diagnostic methods used to determine PfPR in different studies has not. In particular, the majority of PfPR data are based on positivity rates determined by either microscopy or rapid diagnostic test (RDT), yet these approaches are not equivalent; therefore a method is needed for standardizing RDT and microscopy-based prevalence estimates prior to use in mapping. Twenty-five recent Demographic and Health surveys (DHS) datasets from sub-Saharan Africa provide child diagnostic test results derived using both RDT and microscopy for each individual. These prevalence estimates were aggregated across level one administrative zones and a Bayesian probit regression model fit to the microscopy- versus RDT-derived prevalence relationship. An errors-in-variables approach was employed to account for sampling error in both the dependent and independent variables. In addition to the diagnostic outcome, RDT type, fever status and recent anti-malarial treatment were extracted from the datasets in order to analyse their effect on observed malaria prevalence. A strong non-linear relationship between the microscopy and RDT-derived prevalence was found. The results of regressions stratified by the additional diagnostic variables (RDT type, fever status and recent anti-malarial treatment) indicate that there is a distinct and consistent difference in the relationship when the data are stratified by febrile status and RDT

A Novel Malaria Pf/Pv Ab Rapid Diagnostic Test Using a Differential Diagnostic Marker Identified by Network Biology.

PubMed

Cho, Sung Jin; Lee, Jihoo; Lee, Hyun Jae; Jo, Hyun-Young; Sinniah, Mangalam; Kim, Hak-Yong; Chong, Chom-Kyu; Song, Hyun-Ok

2016-01-01

Rapid diagnostic tests (RDTs) can detect anti-malaria antibodies in human blood. As they can detect parasite infection at the low parasite density, they are useful in endemic areas where light infection and/or re-infection of parasites are common. Thus, malaria antibody tests can be used for screening bloods in blood banks to prevent transfusion-transmitted malaria (TTM), an emerging problem in malaria endemic areas. However, only a few malaria antibody tests are available in the microwell-based assay format and these are not suitable for field application. A novel malaria antibody (Ab)-based RDT using a differential diagnostic marker for falciparum and vivax malaria was developed as a suitable high-throughput assay that is sensitive and practical for blood screening. The marker, merozoite surface protein 1 (MSP1) was discovered by generation of a Plasmodium-specific network and the hierarchical organization of modularity in the network. Clinical evaluation revealed that the novel Malaria Pf/Pv Ab RDT shows improved sensitivity (98%) and specificity (99.7%) compared with the performance of a commercial kit, SD BioLine Malaria P.f/P.v (95.1% sensitivity and 99.1% specificity). The novel Malaria Pf/Pv Ab RDT has potential for use as a cost-effective blood-screening tool for malaria and in turn, reduces TTM risk in endemic areas.

42 CFR 414.509 - Reconsideration of basis for and amount of payment for a new clinical diagnostic laboratory test.

Code of Federal Regulations, 2013 CFR

2013-10-01

...) or § 414.509(a)(3) that the basis for payment for a new test will be gapfilling, CMS posts interim... for a new clinical diagnostic laboratory test. 414.509 Section 414.509 Public Health CENTERS FOR... Laboratory Tests § 414.509 Reconsideration of basis for and amount of payment for a new clinical diagnostic...

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

42 CFR 414.50 - Physician or other supplier billing for diagnostic tests performed or interpreted by a physician...

Code of Federal Regulations, 2011 CFR

2011-10-01

...) or professional component (PC) of a diagnostic test that was ordered by the physician or other... behalf of the beneficiary) for the TC or PC of the diagnostic test may not exceed the lowest of the... who supervised the TC, and with respect to the PC, the performing supplier is the physician who...

Diagnostic Accuracy, Sensitivity, and Specificity of Executive Function Tests in Moderate Traumatic Brain Injury in Ghana.

PubMed

Adjorlolo, Samuel

2018-06-01

The sociocultural differences between Western and sub-Saharan African countries make it imperative to standardize neuropsychological tests in the latter. However, Western-normed tests are frequently administered in sub-Saharan Africa because of challenges hampering standardization efforts. Yet a salient topical issue in the cross-cultural neuropsychology literature relates to the utility of Western-normed neuropsychological tests in minority groups, non-Caucasians, and by extension Ghanaians. Consequently, this study investigates the diagnostic accuracy, sensitivity, and specificity of executive function (EF) tests (The Stroop Test, Trail Making Test, and Controlled Oral Word Association Test), and a Revised Quick Cognitive Screening Test (RQCST) in a sample of 50 patients diagnosed with moderate traumatic brain injury and 50 healthy controls in Ghana. The EF test scores showed good diagnostic accuracy, with area under the curve (AUC) values of the Trail Making Test scores ranging from .746 to .902. With respect to the Stroop Test scores, the AUC values ranged from .793 to .898, while Controlled Oral Word Association Test had AUC value of .787. The RQCST scores discriminated between the groups, with AUC values ranging from .674 to .912. The AUC values of composite EF score and a neuropsychological score created from EF and RQCST scores were .936 and. 942, respectively. Additionally, the Stroop Test, Trail Making Test, EF composite score, and RQCST scores showed good to excellent sensitivities and specificities. In general, this study has shown that commonly used EF tests in Western countries have diagnostic accuracy, sensitivity, and specificity when administered in Ghanaian samples. The findings and implications of the study are discussed.

Diagnostic performance of rapid diagnostic tests for the diagnosis of malaria at public health facilities in north-west Ethiopia.

PubMed

Getnet, Gebeyaw; Getie, Sisay; Srivastava, Mitaly; Birhan, Wubet; Fola, Abebe A; Noedl, Harald

2015-11-01

To assess the performance of RDTs against nested polymerase chain reaction (nPCR) for the diagnosis of malaria in public health facilities in north-western Ethiopia. Cross-sectional study at public health facilities in North Gondar, Ethiopia, of 359 febrile patients with signs and symptoms consistent with malaria. Finger prick blood samples were collected for testing in a P. falciparum/pan-malaria RDTs and for molecular analysis. Sensitivity, specificity and predictive values were determined for the RDTs using nPCR as reference diagnostic method. Kappa value was determined to demonstrate the consistency of the results between the diagnostic tools. By RDTs, 22.28% (80/359) of patients tested positive for malaria, and by nPCR, 27.02% (97/359) did. In nPCR, 1.67% (6/359) and 0.28% (1/359) samples were positive for P. ovale and P. malariae, which had almost all tested negative in the RDTs. The sensitivity, specificity, positive and negative predictive values of RDTs for the diagnosis of malaria were 62.9%, 92.7%, 76.3% and 87.1%, respectively, with 0.589 measurement agreement between RDTs and nPCR. The sensitivity and specificity of RDTs for P. falciparum identification only were 70.8% and 95.2%, and 65.2% and 93.1% for P. vivax. Although RDTs are commonly used at health posts in resource-limited environments, their sensitivity and specificity for the detection and species identification of Plasmodium parasites were poor compared to nPCR, suggesting caution in interpreting RDTs results. Particularly, in the light of expanded efforts to eliminate malaria in the country, more sensitive diagnostic procedures will be needed. © 2015 John Wiley & Sons Ltd.

Persistent digestive disorders in the tropics: causative infectious pathogens and reference diagnostic tests

PubMed Central

2013-01-01

Background Persistent digestive disorders account for considerable disease burden in the tropics. Despite advances in understanding acute gastrointestinal infections, important issues concerning epidemiology, diagnosis, treatment and control of most persistent digestive symptomatologies remain to be elucidated. Helminths and intestinal protozoa are considered to play major roles, but the full extent of the aetiologic spectrum is still unclear. We provide an overview of pathogens causing digestive disorders in the tropics and evaluate available reference tests. Methods We searched the literature to identify pathogens that might give rise to persistent diarrhoea, chronic abdominal pain and/or blood in the stool. We reviewed existing laboratory diagnostic methods for each pathogen and stratified them by (i) microscopy; (ii) culture techniques; (iii) immunological tests; and (iv) molecular methods. Pathogen-specific reference tests providing highest diagnostic accuracy are described in greater detail. Results Over 30 pathogens may cause persistent digestive disorders. Bacteria, viruses and parasites are important aetiologic agents of acute and long-lasting symptomatologies. An integrated approach, consisting of stool culture, microscopy and/or specific immunological techniques for toxin, antigen and antibody detection, is required for accurate diagnosis of bacteria and parasites. Molecular techniques are essential for sensitive diagnosis of many viruses, bacteria and intestinal protozoa, and are increasingly utilised as adjuncts for helminth identification. Conclusions Diagnosis of the broad spectrum of intestinal pathogens is often cumbersome. There is a need for rapid diagnostic tests that are simple and affordable for resource-constrained settings, so that the management of patients suffering from persistent digestive disorders can be improved. PMID:23347408

Reactor protection system with automatic self-testing and diagnostic

DOEpatents

Gaubatz, Donald C.

1996-01-01

A reactor protection system having four divisions, with quad redundant sensors for each scram parameter providing input to four independent microprocessor-based electronic chassis. Each electronic chassis acquires the scram parameter data from its own sensor, digitizes the information, and then transmits the sensor reading to the other three electronic chassis via optical fibers. To increase system availability and reduce false scrams, the reactor protection system employs two levels of voting on a need for reactor scram. The electronic chassis perform software divisional data processing, vote 2/3 with spare based upon information from all four sensors, and send the divisional scram signals to the hardware logic panel, which performs a 2/4 division vote on whether or not to initiate a reactor scram. Each chassis makes a divisional scram decision based on data from all sensors. Automatic detection and discrimination against failed sensors allows the reactor protection system to automatically enter a known state when sensor failures occur. Cross communication of sensor readings allows comparison of four theoretically "identical" values. This permits identification of sensor errors such as drift or malfunction. A diagnostic request for service is issued for errant sensor data. Automated self test and diagnostic monitoring, sensor input through output relay logic, virtually eliminate the need for manual surveillance testing. This provides an ability for each division to cross-check all divisions and to sense failures of the hardware logic.

Reactor protection system with automatic self-testing and diagnostic

DOEpatents

Gaubatz, D.C.

1996-12-17

A reactor protection system is disclosed having four divisions, with quad redundant sensors for each scram parameter providing input to four independent microprocessor-based electronic chassis. Each electronic chassis acquires the scram parameter data from its own sensor, digitizes the information, and then transmits the sensor reading to the other three electronic chassis via optical fibers. To increase system availability and reduce false scrams, the reactor protection system employs two levels of voting on a need for reactor scram. The electronic chassis perform software divisional data processing, vote 2/3 with spare based upon information from all four sensors, and send the divisional scram signals to the hardware logic panel, which performs a 2/4 division vote on whether or not to initiate a reactor scram. Each chassis makes a divisional scram decision based on data from all sensors. Automatic detection and discrimination against failed sensors allows the reactor protection system to automatically enter a known state when sensor failures occur. Cross communication of sensor readings allows comparison of four theoretically ``identical`` values. This permits identification of sensor errors such as drift or malfunction. A diagnostic request for service is issued for errant sensor data. Automated self test and diagnostic monitoring, sensor input through output relay logic, virtually eliminate the need for manual surveillance testing. This provides an ability for each division to cross-check all divisions and to sense failures of the hardware logic. 16 figs.

High-Content Optical Codes for Protecting Rapid Diagnostic Tests from Counterfeiting.

PubMed

Gökçe, Onur; Mercandetti, Cristina; Delamarche, Emmanuel

2018-06-19

Warnings and reports on counterfeit diagnostic devices are released several times a year by regulators and public health agencies. Unfortunately, mishandling, altering, and counterfeiting point-of-care diagnostics (POCDs) and rapid diagnostic tests (RDTs) is lucrative, relatively simple and can lead to devastating consequences. Here, we demonstrate how to implement optical security codes in silicon- and nitrocellulose-based flow paths for device authentication using a smartphone. The codes are created by inkjet spotting inks directly on nitrocellulose or on micropillars. Codes containing up to 32 elements per mm 2 and 8 colors can encode as many as 10 45 combinations. Codes on silicon micropillars can be erased by setting a continuous flow path across the entire array of code elements or for nitrocellulose by simply wicking a liquid across the code. Static or labile code elements can further be formed on nitrocellulose to create a hidden code using poly(ethylene glycol) (PEG) or glycerol additives to the inks. More advanced codes having a specific deletion sequence can also be created in silicon microfluidic devices using an array of passive routing nodes, which activate in a particular, programmable sequence. Such codes are simple to fabricate, easy to view, and efficient in coding information; they can be ideally used in combination with information on a package to protect diagnostic devices from counterfeiting.

[Assessment of a rapid diagnostic test and portable fluorescent microscopy for malaria diagnosis in Cotonou (Bénin)].

PubMed

Ogouyèmi-Hounto, A; Kinde-Gazard, D; Keke, C; Gonçalves, E; Alapini, N; Adjovi, F; Adisso, L; Bossou, C; Denon, Y V; Massougbodji, A

2013-02-01

The aim of the study was to determine the accuracy of a rapid diagnostic test (SD Bioline Malaria Ag P.f/ Pan®) and fluorescent microscopy (CyScope®) in confirming presumptive malaria diagnosis in Cotonou. Thick blood smear was used as the reference technique for comparison. Testing was conducted on persons between the ages of 6 months and 70 years at two hospitals from June to October 2010. If malaria was suspected in the sample by the nurse based on clinical findings and sent to laboratory for confirmation, one thick smear, one rapid diagnostic test and one slide for the fluorescent microscopy were performed. All tests were read in hospital laboratories involved with the quality control of thick blood smear in the parasitology laboratory of National University Hospital of Cotonou. A total of 354 patients with clinical diagnosis of malaria were included. Malaria prevalence determined by thick smear, rapid diagnostic test and fluorescent microscopy was 22.8%, 25.4%, and 25.1% respectively. The sensitivity, specificity, positive and negative predictive values compared to the thick smears were 96.3, 95.6, 86.7, and 98.9% for rapid diagnostic test; and 97.5, 96.7, 89.8, and 99.27% for fluorescent microscopy. With these performances, these tests meet acceptability standards recommended by WHO for rapid tests (sensitivity > 95%). These two methods have advantages for the confirmation of malaria diagnosis in peripheral health structures that lack the resources to conduct diagnosis confirmation by the thick blood smear.

HIV misdiagnosis in sub-Saharan Africa: performance of diagnostic algorithms at six testing sites

PubMed Central

Kosack, Cara S.; Shanks, Leslie; Beelaert, Greet; Benson, Tumwesigye; Savane, Aboubacar; Ng’ang’a, Anne; Andre, Bita; Zahinda, Jean-Paul BN; Fransen, Katrien; Page, Anne-Laure

2017-01-01

Abstract Introduction: We evaluated the diagnostic accuracy of HIV testing algorithms at six programmes in five sub-Saharan African countries. Methods: In this prospective multisite diagnostic evaluation study (Conakry, Guinea; Kitgum, Uganda; Arua, Uganda; Homa Bay, Kenya; Doula, Cameroun and Baraka, Democratic Republic of Congo), samples from clients (greater than equal to five years of age) testing for HIV were collected and compared to a state-of-the-art algorithm from the AIDS reference laboratory at the Institute of Tropical Medicine, Belgium. The reference algorithm consisted of an enzyme-linked immuno-sorbent assay, a line-immunoassay, a single antigen-enzyme immunoassay and a DNA polymerase chain reaction test. Results: Between August 2011 and January 2015, over 14,000 clients were tested for HIV at 6 HIV counselling and testing sites. Of those, 2786 (median age: 30; 38.1% males) were included in the study. Sensitivity of the testing algorithms ranged from 89.5% in Arua to 100% in Douala and Conakry, while specificity ranged from 98.3% in Doula to 100% in Conakry. Overall, 24 (0.9%) clients, and as many as 8 per site (1.7%), were misdiagnosed, with 16 false-positive and 8 false-negative results. Six false-negative specimens were retested with the on-site algorithm on the same sample and were found to be positive. Conversely, 13 false-positive specimens were retested: 8 remained false-positive with the on-site algorithm. Conclusions: The performance of algorithms at several sites failed to meet expectations and thresholds set by the World Health Organization, with unacceptably high rates of false results. Alongside the careful selection of rapid diagnostic tests and the validation of algorithms, strictly observing correct procedures can reduce the risk of false results. In the meantime, to identify false-positive diagnoses at initial testing, patients should be retested upon initiating antiretroviral therapy. PMID:28691437

HIV misdiagnosis in sub-Saharan Africa: performance of diagnostic algorithms at six testing sites.

PubMed

Kosack, Cara S; Shanks, Leslie; Beelaert, Greet; Benson, Tumwesigye; Savane, Aboubacar; Ng'ang'a, Anne; Andre, Bita; Zahinda, Jean-Paul Bn; Fransen, Katrien; Page, Anne-Laure

2017-07-03

We evaluated the diagnostic accuracy of HIV testing algorithms at six programmes in five sub-Saharan African countries. In this prospective multisite diagnostic evaluation study (Conakry, Guinea; Kitgum, Uganda; Arua, Uganda; Homa Bay, Kenya; Doula, Cameroun and Baraka, Democratic Republic of Congo), samples from clients (greater than equal to five years of age) testing for HIV were collected and compared to a state-of-the-art algorithm from the AIDS reference laboratory at the Institute of Tropical Medicine, Belgium. The reference algorithm consisted of an enzyme-linked immuno-sorbent assay, a line-immunoassay, a single antigen-enzyme immunoassay and a DNA polymerase chain reaction test. Between August 2011 and January 2015, over 14,000 clients were tested for HIV at 6 HIV counselling and testing sites. Of those, 2786 (median age: 30; 38.1% males) were included in the study. Sensitivity of the testing algorithms ranged from 89.5% in Arua to 100% in Douala and Conakry, while specificity ranged from 98.3% in Doula to 100% in Conakry. Overall, 24 (0.9%) clients, and as many as 8 per site (1.7%), were misdiagnosed, with 16 false-positive and 8 false-negative results. Six false-negative specimens were retested with the on-site algorithm on the same sample and were found to be positive. Conversely, 13 false-positive specimens were retested: 8 remained false-positive with the on-site algorithm. The performance of algorithms at several sites failed to meet expectations and thresholds set by the World Health Organization, with unacceptably high rates of false results. Alongside the careful selection of rapid diagnostic tests and the validation of algorithms, strictly observing correct procedures can reduce the risk of false results. In the meantime, to identify false-positive diagnoses at initial testing, patients should be retested upon initiating antiretroviral therapy.

Assessment of the diagnostic value of a urinary adipsin rapid strip test for pre-eclampsia: A prospective multicenter study.

PubMed

Peng, Bing; Zhang, Li; Yan, Jianying; Qi, Hongbo; Zhang, Weiyuan; Fan, Ling; Hu, Yayi; Lin, Li; Li, Xiaotian; Hu, Rong; Xie, Lan; Zhang, Jianping; Wu, Yanqiao; Li, Li; Zhou, Rong

2017-01-01

The purpose of the present study was to evaluate the clinical value of the rapid strip test of urinary adipsin for the quick diagnosis of pre-eclampsia. In a multicenter diagnostic test study, we studied the diagnostic accuracy of the rapid strip test of urinary adipsin in women presenting with pre-eclampsia. A total of 204 pre-eclampsia patients and 254 healthy pregnant women were recruited for this study, respectively. The rapid strip test of urinary adipsin was used to detect the adipsin in the urine of each patient. The diagnostic value of the rapid strip test of urinary adipsin for pre-eclampsia was demonstrated by its high sensitivity and specificity (95.10% and 97.64%, respectively). The diagnostic accuracy was 96.51%. The consistency analysis showed that the kappa value was 0.93 compared with the gold standard diagnosis of pre-eclampsia. The rapid strip test of urinary adipsin is a non-invasive test for the diagnosis of pre-eclampsia with high sensitivity and specificity. It could help the quick diagnosis of pre-eclampsia in clinical practice greatly. © 2016 Japan Society of Obstetrics and Gynecology.

Bias in logistic regression due to imperfect diagnostic test results and practical correction approaches.

PubMed

Valle, Denis; Lima, Joanna M Tucker; Millar, Justin; Amratia, Punam; Haque, Ubydul

2015-11-04

Logistic regression is a statistical model widely used in cross-sectional and cohort studies to identify and quantify the effects of potential disease risk factors. However, the impact of imperfect tests on adjusted odds ratios (and thus on the identification of risk factors) is under-appreciated. The purpose of this article is to draw attention to the problem associated with modelling imperfect diagnostic tests, and propose simple Bayesian models to adequately address this issue. A systematic literature review was conducted to determine the proportion of malaria studies that appropriately accounted for false-negatives/false-positives in a logistic regression setting. Inference from the standard logistic regression was also compared with that from three proposed Bayesian models using simulations and malaria data from the western Brazilian Amazon. A systematic literature review suggests that malaria epidemiologists are largely unaware of the problem of using logistic regression to model imperfect diagnostic test results. Simulation results reveal that statistical inference can be substantially improved when using the proposed Bayesian models versus the standard logistic regression. Finally, analysis of original malaria data with one of the proposed Bayesian models reveals that microscopy sensitivity is strongly influenced by how long people have lived in the study region, and an important risk factor (i.e., participation in forest extractivism) is identified that would have been missed by standard logistic regression. Given the numerous diagnostic methods employed by malaria researchers and the ubiquitous use of logistic regression to model the results of these diagnostic tests, this paper provides critical guidelines to improve data analysis practice in the presence of misclassification error. Easy-to-use code that can be readily adapted to WinBUGS is provided, enabling straightforward implementation of the proposed Bayesian models.

Comparison of visual and automated Deki Reader interpretation of malaria rapid diagnostic tests in rural Tanzanian military health facilities.

PubMed

Kalinga, Akili K; Mwanziva, Charles; Chiduo, Sarah; Mswanya, Christopher; Ishengoma, Deus I; Francis, Filbert; Temu, Lucky; Mahikwano, Lucas; Mgata, Saidi; Amoo, George; Anova, Lalaine; Wurrapa, Eyako; Zwingerman, Nora; Ferro, Santiago; Bhat, Geeta; Fine, Ian; Vesely, Brian; Waters, Norman; Kreishman-Deitrick, Mara; Hickman, Mark; Paris, Robert; Kamau, Edwin; Ohrt, Colin; Kavishe, Reginald A

2018-05-29

Although microscopy is a standard diagnostic tool for malaria and the gold standard, it is infrequently used because of unavailability of laboratory facilities and the absence of skilled readers in poor resource settings. Malaria rapid diagnostic tests (RDT) are currently used instead of or as an adjunct to microscopy. However, at very low parasitaemia (usually < 100 asexual parasites/µl), the test line on malaria rapid diagnostic tests can be faint and consequently hard to visualize and this may potentially affect the interpretation of the test results. Fio Corporation (Canada), developed an automated RDT reader named Deki Reader™ for automatic analysis and interpretation of rapid diagnostic tests. This study aimed to compare visual assessment and automated Deki Reader evaluations to interpret malaria rapid diagnostic tests against microscopy. Unlike in the previous studies where expert laboratory technicians interpreted the test results visually and operated the device, in this study low cadre health care workers who have not attended any formal professional training in laboratory sciences were employed. Finger prick blood from 1293 outpatients with fever was tested for malaria using RDT and Giemsa-stained microscopy for thick and thin blood smears. Blood samples for RDTs were processed according to manufacturers' instructions automated in the Deki Reader. Results of malaria diagnoses were compared between visual and the automated devise reading of RDT and microscopy. The sensitivity of malaria rapid diagnostic test results interpreted by the Deki Reader was 94.1% and that of visual interpretation was 93.9%. The specificity of malaria rapid diagnostic test results was 71.8% and that of human interpretation was 72.0%. The positive predictive value of malaria RDT results by the Deki Reader and visual interpretation was 75.8 and 75.4%, respectively, while the negative predictive values were 92.8 and 92.4%, respectively. The accuracy of RDT as interpreted by DR

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.

Combining functional and structural tests improves the diagnostic accuracy of relevance vector machine classifiers

PubMed Central

Racette, Lyne; Chiou, Christine Y.; Hao, Jiucang; Bowd, Christopher; Goldbaum, Michael H.; Zangwill, Linda M.; Lee, Te-Won; Weinreb, Robert N.; Sample, Pamela A.

2009-01-01

Purpose To investigate whether combining optic disc topography and short-wavelength automated perimetry (SWAP) data improves the diagnostic accuracy of relevance vector machine (RVM) classifiers for detecting glaucomatous eyes compared to using each test alone. Methods One eye of 144 glaucoma patients and 68 healthy controls from the Diagnostic Innovations in Glaucoma Study were included. RVM were trained and tested with cross-validation on optimized (backward elimination) SWAP features (thresholds plus age; pattern deviation (PD); total deviation (TD)) and on Heidelberg Retina Tomograph II (HRT) optic disc topography features, independently and in combination. RVM performance was also compared to two HRT linear discriminant functions (LDF) and to SWAP mean deviation (MD) and pattern standard deviation (PSD). Classifier performance was measured by the area under the receiver operating characteristic curves (AUROCs) generated for each feature set and by the sensitivities at set specificities of 75%, 90% and 96%. Results RVM trained on combined HRT and SWAP thresholds plus age had significantly higher AUROC (0.93) than RVM trained on HRT (0.88) and SWAP (0.76) alone. AUROCs for the SWAP global indices (MD: 0.68; PSD: 0.72) offered no advantage over SWAP thresholds plus age, while the LDF AUROCs were significantly lower than RVM trained on the combined SWAP and HRT feature set and on HRT alone feature set. Conclusions Training RVM on combined optimized HRT and SWAP data improved diagnostic accuracy compared to training on SWAP and HRT parameters alone. Future research may identify other combinations of tests and classifiers that can also improve diagnostic accuracy. PMID:19528827

Diagnostic evaluation of rapid tests for scrub typhus in the Indian population is needed.

PubMed

Shivalli, Siddharudha

2016-05-12

Owing to frequent outbreaks witnessed in different parts of the country in the recent past, scrub typhus is being described as a re-emerging infectious disease in India. Differentiating scrub typhus from other endemic diseases like malaria, leptospirosis, dengue fever, typhoid, etc. is difficult due to overlapping clinical features and a lower positivity for eschars in Asian populations. Hence, the diagnosis heavily relies on laboratory tests. Costs and the need of technical expertise limit the wide use of indirect immunoperoxidase or immunofluorescence assays, ELISA and PCR. The Weil-Felix test is the most commonly used and least expensive serological test, but lacks both sensitivity and specificity. Hence, the diagnosis of scrub typhus is often delayed or overlooked. With due consideration of the cost, rapidity, single test result and simplicity of interpretation, rapid diagnostic tests have come into vogue. However, evaluation of rapid diagnostic tests for scrub typhus in the Indian population is needed to justify or discourage their use. Research studies are needed to find the most suitable test in terms of the rapidity of the result, simplicity of the procedure, ease of interpretation and cost to be used in the Indian populace.

9 CFR 130.15 - User fees for veterinary diagnostic isolation and identification tests performed at NVSL...

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false User fees for veterinary diagnostic isolation and identification tests performed at NVSL (excluding FADDL) or other authorized site. 130.15... AGRICULTURE USER FEES USER FEES § 130.15 User fees for veterinary diagnostic isolation and identification...

9 CFR 130.15 - User fees for veterinary diagnostic isolation and identification tests performed at NVSL...

Code of Federal Regulations, 2010 CFR

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false User fees for veterinary diagnostic isolation and identification tests performed at NVSL (excluding FADDL) or other authorized site. 130.15... AGRICULTURE USER FEES USER FEES § 130.15 User fees for veterinary diagnostic isolation and identification...

Mathematics Diagnostic Testing in Engineering: An International Comparison between Ireland and Portugal

ERIC Educational Resources Information Center

Carr, M.; Fidalgo, C.; Bigotte de Almeida, M. E.; Branco, J. R.; Santos, V.; Murphy, E.; Ní Fhloinn, E.

2015-01-01

Concern has been expressed throughout Europe about the significant deficiencies in the basic mathematical skills of many engineering undergraduates. Mathematics diagnostic tests in the UK, Ireland and Portugal have shown these shortcomings, which provide a challenge to those striving to introduce more innovative educational practices into…

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

Diagnostic validity of physical examination tests for common knee disorders: An overview of systematic reviews and meta-analysis.

PubMed

Décary, Simon; Ouellet, Philippe; Vendittoli, Pascal-André; Roy, Jean-Sébastien; Desmeules, François

2017-01-01

More evidence on diagnostic validity of physical examination tests for knee disorders is needed to lower frequently used and costly imaging tests. To conduct a systematic review of systematic reviews (SR) and meta-analyses (MA) evaluating the diagnostic validity of physical examination tests for knee disorders. A structured literature search was conducted in five databases until January 2016. Methodological quality was assessed using the AMSTAR. Seventeen reviews were included with mean AMSTAR score of 5.5 ± 2.3. Based on six SR, only the Lachman test for ACL injuries is diagnostically valid when individually performed (Likelihood ratio (LR+):10.2, LR-:0.2). Based on two SR, the Ottawa Knee Rule is a valid screening tool for knee fractures (LR-:0.05). Based on one SR, the EULAR criteria had a post-test probability of 99% for the diagnosis of knee osteoarthritis. Based on two SR, a complete physical examination performed by a trained health provider was found to be diagnostically valid for ACL, PCL and meniscal injuries as well as for cartilage lesions. When individually performed, common physical tests are rarely able to rule in or rule out a specific knee disorder, except the Lachman for ACL injuries. There is low-quality evidence concerning the validity of combining history elements and physical tests. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Implication of inverse-probability weighting method in the evaluation of diagnostic test with verification bias].

PubMed

Kang, Leni; Zhang, Shaokai; Zhao, Fanghui; Qiao, Youlin

2014-03-01

To evaluate and adjust the verification bias existed in the screening or diagnostic tests. Inverse-probability weighting method was used to adjust the sensitivity and specificity of the diagnostic tests, with an example of cervical cancer screening used to introduce the Compare Tests package in R software which could be implemented. Sensitivity and specificity calculated from the traditional method and maximum likelihood estimation method were compared to the results from Inverse-probability weighting method in the random-sampled example. The true sensitivity and specificity of the HPV self-sampling test were 83.53% (95%CI:74.23-89.93)and 85.86% (95%CI: 84.23-87.36). In the analysis of data with randomly missing verification by gold standard, the sensitivity and specificity calculated by traditional method were 90.48% (95%CI:80.74-95.56)and 71.96% (95%CI:68.71-75.00), respectively. The adjusted sensitivity and specificity under the use of Inverse-probability weighting method were 82.25% (95% CI:63.11-92.62) and 85.80% (95% CI: 85.09-86.47), respectively, whereas they were 80.13% (95%CI:66.81-93.46)and 85.80% (95%CI: 84.20-87.41) under the maximum likelihood estimation method. The inverse-probability weighting method could effectively adjust the sensitivity and specificity of a diagnostic test when verification bias existed, especially when complex sampling appeared.

DECIDE: a software for computer-assisted evaluation of diagnostic test performance.

PubMed

Chiecchio, A; Bo, A; Manzone, P; Giglioli, F

1993-05-01

The evaluation of the performance of clinical tests is a complex problem involving different steps and many statistical tools, not always structured in an organic and rational system. This paper presents a software which provides an organic system of statistical tools helping evaluation of clinical test performance. The program allows (a) the building and the organization of a working database, (b) the selection of the minimal set of tests with the maximum information content, (c) the search of the model best fitting the distribution of the test values, (d) the selection of optimal diagnostic cut-off value of the test for every positive/negative situation, (e) the evaluation of performance of the combinations of correlated and uncorrelated tests. The uncertainty associated with all the variables involved is evaluated. The program works in a MS-DOS environment with EGA or higher performing graphic card.

Self Diagnostic Accelerometer Testing on the C-17 Aircraft

NASA Technical Reports Server (NTRS)

Tokars, Roger P.; Lekki, John D.

2013-01-01

The self diagnostic accelerometer (SDA) developed by the NASA Glenn Research Center was tested for the first time in an aircraft engine environment as part of the Vehicle Integrated Propulsion Research (VIPR) program. The VIPR program includes testing multiple critical flight sensor technologies. One such sensor, the accelerometer, measures vibrations to detect faults in the engine. In order to rely upon the accelerometer, the health of the accelerometer must be ensured. The SDA is a sensor system designed to actively determine the accelerometer structural health and attachment condition, in addition to vibration measurements. The SDA uses a signal conditioning unit that sends an electrical chirp to the accelerometer and recognizes changes in the response due to changes in the accelerometer health and attachment condition. To demonstrate the SDAs flight worthiness and robustness, multiple SDAs were mounted and tested on a C-17 aircraft engine. The engine test conditions varied from engine off, to idle, to maximum power. The SDA attachment conditions were varied from fully tight to loose. The newly developed SDA health algorithm described herein uses cross correlation pattern recognition to discriminate a healthy from a faulty SDA. The VIPR test results demonstrate for the first.

Evaluation of the methodological quality of studies of the performance of diagnostic tests for bovine tuberculosis using QUADAS.

PubMed

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

2018-05-01

There has been little assessment of the methodological quality of studies measuring the performance (sensitivity and/or specificity) of diagnostic tests for animal diseases. In a systematic review, 190 studies of tests for bovine tuberculosis (bTB) in cattle (published 1934-2009) were assessed by at least one of 18 reviewers using the QUADAS (Quality Assessment of Diagnostic Accuracy Studies) checklist adapted for animal disease tests. VETQUADAS (VQ) included items measuring clarity in reporting (n = 3), internal validity (n = 9) and external validity (n = 2). A similar pattern for compliance was observed in studies of different diagnostic test types. Compliance significantly improved with year of publication for all items measuring clarity in reporting and external validity but only improved in four of the nine items measuring internal validity (p < 0.05). 107 references, of which 83 had performance data eligible for inclusion in a meta-analysis were reviewed by two reviewers. In these references, agreement between reviewers' responses was 71% for compliance, 32% for unsure and 29% for non-compliance. Mean compliance with reporting items was 2, 5.2 for internal validity and 1.5 for external validity. The index test result was described in sufficient detail in 80.1% of studies and was interpreted without knowledge of the reference standard test result in only 33.1%. Loss to follow-up was adequately explained in only 31.1% of studies. The prevalence of deficiencies observed may be due to inadequate reporting but may also reflect lack of attention to methodological issues that could bias the results of diagnostic test performance estimates. QUADAS was a useful tool for assessing and comparing the quality of studies measuring the performance of diagnostic tests but might be improved further by including explicit assessment of population sampling strategy. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

Development and Preparation of Lead-Containing Paint Films and Diagnostic Test Materials

EPA Science Inventory

Lead in paint continues to be a threat to children’s health in cities across the United States, which means there is an ongoing need for testing and analysis of paint. This ongoing analytical effort and especially development of new methods continue to drive the need for diagnost...

Evaluation of Altona Diagnostics RealStar Zika Virus Reverse Transcription-PCR Test Kit for Zika Virus PCR Testing

PubMed Central

Lombos, Ernesto; Tang, Elaine; Perusini, Stephen; Eshaghi, Alireza; Nagra, Sandeep; Frantz, Christine; Olsha, Romy; Kristjanson, Erik; Dimitrova, Kristina; Safronetz, David; Drebot, Mike

2017-01-01

ABSTRACT With the emerging Zika virus (ZIKV) epidemic, accessible real-time reverse transcription-PCR (rRT-PCR) assays are needed to streamline testing. The commercial Altona Diagnostics RealStar ZIKV rRT-PCR test kit (Altona PCR) has been approved for emergency use authorization by the U.S. FDA. Our aim was to verify the Altona PCR by comparing it to the CDC-designed dual-target ZIKV rRT-PCR reference assay (reference PCR) and describe the demographics of patients tested for ZIKV by rRT-PCR in Ontario, Canada. A large set of clinical specimens was tested for ZIKV by the Altona PCR and the reference PCR. Positive or equivocal specimens underwent PCR and Sanger sequencing targeting the ZIKV NS5 gene. A total of 671 serum specimens were tested by the reference PCR: 58 (8.6%) were positive, 193 (28.8%) were equivocal, and 420 (62.6%) were negative. Ninety percent of the reference PCR-positive patients were tested in the first 5 days after symptom onset. The Altona PCR was performed on 284/671 specimens tested by the reference PCR. The Altona PCR was positive for 53/58 (91%) reference PCR-positive specimens and 16/193 (8%) reference PCR-equivocal specimens; the ZIKV NS5 PCR was positive for all 68 Altona PCR-positive specimens and negative for all 181 Altona PCR-negative specimens that underwent the NS5 PCR. The Altona PCR has very good sensitivity (91%) and specificity (97%) compared to the reference PCR. The Altona PCR can be used for ZIKV diagnostic testing and has less extensive verification requirements than a laboratory-developed test. PMID:28298448

Cholera Rapid Test with Enrichment Step Has Diagnostic Performance Equivalent to Culture

PubMed Central

Ontweka, Lameck N.; Deng, Lul O.; Rauzier, Jean; Debes, Amanda K.; Tadesse, Fisseha; Parker, Lucy A.; Wamala, Joseph F.; Bior, Bior K.; Lasuba, Michael; But, Abiem Bona; Grandesso, Francesco; Jamet, Christine; Cohuet, Sandra; Ciglenecki, Iza; Serafini, Micaela; Sack, David A.; Quilici, Marie-Laure; Azman, Andrew S.; Luquero, Francisco J.

2016-01-01

Cholera rapid diagnostic tests (RDT) could play a central role in outbreak detection and surveillance in low-resource settings, but their modest performance has hindered their broad adoption. The addition of an enrichment step may improve test specificity. We describe the results of a prospective diagnostic evaluation of the Crystal VC RDT (Span Diagnostics, India) with enrichment step and of culture, each compared to polymerase chain reaction (PCR), during a cholera outbreak in South Sudan. RDTs were performed on alkaline peptone water inoculated with stool and incubated for 4–6 hours at ambient temperature. Cholera culture was performed from wet filter paper inoculated with stool. Molecular detection of Vibrio cholerae O1 by PCR was done from dry Whatman 903 filter papers inoculated with stool, and from wet filter paper supernatant. In August and September 2015, 101 consecutive suspected cholera cases were enrolled, of which 36 were confirmed by PCR. The enriched RDT had 86.1% (95% CI: 70.5–95.3) sensitivity and 100% (95% CI: 94.4–100) specificity compared to PCR as the reference standard. The sensitivity of culture versus PCR was 83.3% (95% CI: 67.2–93.6) for culture performed on site and 72.2% (95% CI: 54.8–85.8) at the international reference laboratory, where samples were tested after an average delay of two months after sample collection, and specificity was 98.5% (95% CI: 91.7–100) and 100% (95% CI: 94.5–100), respectively. The RDT with enrichment showed performance comparable to that of culture and could be a sustainable alternative to culture confirmation where laboratory capacity is limited. PMID:27992488

Clinical Evaluation of Rapid Diagnostic Test Kit for Scrub Typhus with Improved Performance.

PubMed

Kim, Young-Jin; Park, Sungman; Premaratna, Ranjan; Selvaraj, Stephen; Park, Sang-Jin; Kim, Sora; Kim, Donghwan; Kim, Min Soo; Shin, Dong Hoon; Choi, Kyung-Chan; Kwon, Soon-Hwan; Seo, Wonjun; Lee, Nam Taek; Kim, Seung-Han; Kang, Heui Keun; Kim, Yoon-Won

2016-08-01

Diagnosis of scrub typhus is challenging due to its more than twenty serotypes and the similar clinical symptoms with other acute febrile illnesses including leptospirosis, murine typhus and hemorrhagic fever with renal syndrome. Accuracy and rapidity of a diagnostic test to Orientia tsutsugamushi is an important step to diagnose this disease. To discriminate scrub typhus from other diseases, the improved ImmuneMed Scrub Typhus Rapid Diagnostic Test (RDT) was evaluated in Korea and Sri Lanka. The sensitivity at the base of each IgM and IgG indirect immunofluorescent assay (IFA) in Korean patients was 98.6% and 97.1%, and the specificity was 98.2% and 97.7% respectively. The sensitivity and specificity for retrospective diagnosis at the base of IFA in Sri Lanka was 92.1% and 96.1%. ImmuneMed RDT was not reactive to any serum from seventeen diseases including hemorrhagic fever with renal syndrome (n = 48), leptospirosis (n = 23), and murine typhus (n = 48). ImmuneMed RDT shows superior sensitivity (98.6% and 97.1%) compared with SD Bioline RDT (84.4% at IgM and 83.3% at IgG) in Korea. The retrospective diagnosis of ImmuneMed RDT exhibits 94.0% identity with enzyme-linked Immunosorbent assay (ELISA) using South India patient serum samples. These results suggest that this RDT can replace other diagnostic tests and is applicable for global diagnosis of scrub typhus. This rapid and accurate diagnosis will be beneficial for diagnosing and managing scrub typhus.

Addressing Barriers to the Development and Adoption of Rapid Diagnostic Tests in Global Health.

PubMed

Miller, Eric; Sikes, Hadley D

Immunochromatographic rapid diagnostic tests (RDTs) have demonstrated significant potential for use as point-of-care diagnostic tests in resource-limited settings. Most notably, RDTs for malaria have reached an unparalleled level of technological maturity and market penetration, and are now considered an important complement to standard microscopic methods of malaria diagnosis. However, the technical development of RDTs for other infectious diseases, and their uptake within the global health community as a core diagnostic modality, has been hindered by a number of extant challenges. These range from technical and biological issues, such as the need for better affinity agents and biomarkers of disease, to social, infrastructural, regulatory and economic barriers, which have all served to slow their adoption and diminish their impact. In order for the immunochromatographic RDT format to be successfully adapted to other disease targets, to see widespread distribution, and to improve clinical outcomes for patients on a global scale, these challenges must be identified and addressed, and the global health community must be engaged in championing the broader use of RDTs.

Addressing Barriers to the Development and Adoption of Rapid Diagnostic Tests in Global Health

PubMed Central

Miller, Eric; Sikes, Hadley D.

2015-01-01

Immunochromatographic rapid diagnostic tests (RDTs) have demonstrated significant potential for use as point-of-care diagnostic tests in resource-limited settings. Most notably, RDTs for malaria have reached an unparalleled level of technological maturity and market penetration, and are now considered an important complement to standard microscopic methods of malaria diagnosis. However, the technical development of RDTs for other infectious diseases, and their uptake within the global health community as a core diagnostic modality, has been hindered by a number of extant challenges. These range from technical and biological issues, such as the need for better affinity agents and biomarkers of disease, to social, infrastructural, regulatory and economic barriers, which have all served to slow their adoption and diminish their impact. In order for the immunochromatographic RDT format to be successfully adapted to other disease targets, to see widespread distribution, and to improve clinical outcomes for patients on a global scale, these challenges must be identified and addressed, and the global health community must be engaged in championing the broader use of RDTs. PMID:26594252

A weighted generalized score statistic for comparison of predictive values of diagnostic tests.

PubMed

Kosinski, Andrzej S

2013-03-15

Positive and negative predictive values are important measures of a medical diagnostic test performance. We consider testing equality of two positive or two negative predictive values within a paired design in which all patients receive two diagnostic tests. The existing statistical tests for testing equality of predictive values are either Wald tests based on the multinomial distribution or the empirical Wald and generalized score tests within the generalized estimating equations (GEE) framework. As presented in the literature, these test statistics have considerably complex formulas without clear intuitive insight. We propose their re-formulations that are mathematically equivalent but algebraically simple and intuitive. As is clearly seen with a new re-formulation we presented, the generalized score statistic does not always reduce to the commonly used score statistic in the independent samples case. To alleviate this, we introduce a weighted generalized score (WGS) test statistic that incorporates empirical covariance matrix with newly proposed weights. This statistic is simple to compute, always reduces to the score statistic in the independent samples situation, and preserves type I error better than the other statistics as demonstrated by simulations. Thus, we believe that the proposed WGS statistic is the preferred statistic for testing equality of two predictive values and for corresponding sample size computations. The new formulas of the Wald statistics may be useful for easy computation of confidence intervals for difference of predictive values. The introduced concepts have potential to lead to development of the WGS test statistic in a general GEE setting. Copyright © 2012 John Wiley & Sons, Ltd.

A weighted generalized score statistic for comparison of predictive values of diagnostic tests

PubMed Central

Kosinski, Andrzej S.

2013-01-01

Positive and negative predictive values are important measures of a medical diagnostic test performance. We consider testing equality of two positive or two negative predictive values within a paired design in which all patients receive two diagnostic tests. The existing statistical tests for testing equality of predictive values are either Wald tests based on the multinomial distribution or the empirical Wald and generalized score tests within the generalized estimating equations (GEE) framework. As presented in the literature, these test statistics have considerably complex formulas without clear intuitive insight. We propose their re-formulations which are mathematically equivalent but algebraically simple and intuitive. As is clearly seen with a new re-formulation we present, the generalized score statistic does not always reduce to the commonly used score statistic in the independent samples case. To alleviate this, we introduce a weighted generalized score (WGS) test statistic which incorporates empirical covariance matrix with newly proposed weights. This statistic is simple to compute, it always reduces to the score statistic in the independent samples situation, and it preserves type I error better than the other statistics as demonstrated by simulations. Thus, we believe the proposed WGS statistic is the preferred statistic for testing equality of two predictive values and for corresponding sample size computations. The new formulas of the Wald statistics may be useful for easy computation of confidence intervals for difference of predictive values. The introduced concepts have potential to lead to development of the weighted generalized score test statistic in a general GEE setting. PMID:22912343

30 CFR 250.520 - When do I have to perform a casing diagnostic test?

Code of Federal Regulations, 2010 CFR

2010-07-01

... test? 250.520 Section 250.520 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Well-Completion Operations Casing Pressure Management § 250.520 When do I have to perform a casing diagnostic test? (a) You...

Publishing nutrition research: validity, reliability, and diagnostic test assessment in nutrition-related research.

PubMed

Gleason, Philip M; Harris, Jeffrey; Sheean, Patricia M; Boushey, Carol J; Bruemmer, Barbara

2010-03-01

This is the sixth in a series of monographs on research design and analysis. The purpose of this article is to describe and discuss several concepts related to the measurement of nutrition-related characteristics and outcomes, including validity, reliability, and diagnostic tests. The article reviews the methodologic issues related to capturing the various aspects of a given nutrition measure's reliability, including test-retest, inter-item, and interobserver or inter-rater reliability. Similarly, it covers content validity, indicators of absolute vs relative validity, and internal vs external validity. With respect to diagnostic assessment, the article summarizes the concepts of sensitivity and specificity. The hope is that dietetics practitioners will be able to both use high-quality measures of nutrition concepts in their research and recognize these measures in research completed by others. Copyright 2010 American Dietetic Association. Published by Elsevier Inc. All rights reserved.

CT-guided transthoracic core needle biopsy for small pulmonary lesions: diagnostic performance and adequacy for molecular testing.

PubMed

Tian, Panwen; Wang, Ye; Li, Lei; Zhou, Yongzhao; Luo, Wenxin; Li, Weimin

2017-02-01

Computed tomography (CT)-guided transthoracic needle biopsy is a well-established, minimally invasive diagnostic tool for pulmonary lesions. Few large studies have been conducted on the diagnostic performance and adequacy for molecular testing of transthoracic core needle biopsy (TCNB) for small pulmonary lesions. This study included CT-guided TCNB with 18-gauge cutting needles in 560 consecutive patients with small (≤3 cm) pulmonary lesions from January 2012 to January 2015. There were 323 males and 237 females, aged 51.8±12.7 years. The size of the pulmonary lesions was 1.8±0.6 cm. The sensitivity, specificity, accuracy and complications of the biopsies were investigated. The risk factors of diagnostic failure were assessed using univariate and multivariate analyses. The sample's adequacy for molecular testing of non-small cell lung cancer (NSCLC) was analyzed. The overall sensitivity, specificity, and accuracy for diagnosis of malignancy were 92.0% (311/338), 98.6% (219/222), and 94.6% (530/560), respectively. The incidence of bleeding complications was 22.9% (128/560), and the incidence of pneumothorax was 10.4% (58/560). Logistic multivariate regression analysis showed that the independent risk factors for diagnostic failure were a lesion size ≤1 cm [odds ratio (OR), 3.95; P=0.007], lower lobe lesions (OR, 2.83; P=0.001), and pneumothorax (OR, 1.98; P=0.004). Genetic analysis was successfully performed on 95.45% (168/176) of specimens diagnosed as NSCLC. At least 96.8% of samples with two or more passes from a lesion were sufficient for molecular testing. The diagnostic yield of small pulmonary lesions by CT-guided TCNB is high, and the procedure is relatively safe. A lesion size ≤1 cm, lower lobe lesions, and pneumothorax are independent risk factors for biopsy diagnostic failure. TCNB specimens could provide adequate tissues for molecular testing.

Recall Tests Are Effective to Detect Mild Cognitive Impairment: A Systematic Review and Meta-analysis of 108 Diagnostic Studies.

PubMed

Tsoi, Kelvin K F; Chan, Joyce Y C; Hirai, Hoyee W; Wong, Adrian; Mok, Vincent C T; Lam, Linda C W; Kwok, Timothy C Y; Wong, Samuel Y S

2017-09-01

Mild cognitive impairment (MCI) is a prevalent symptom associated with the increased risk of dementia. There are many cognitive tests available for detection of MCI, and investigation of the diagnostic performance of the tests is deemed necessary. This study aims to evaluate the diagnostic performance of different cognitive tests used for MCI detection. A list of cognitive tests was identified in previous reviews and from online search engines. Literature searches were performed on each of the cognitive tests in MEDLINE, Embase, and PsycINFO from the earliest available dates of individual databases to December 31, 2016. Google Scholar was used as a supplementary search tool. Studies that were used to assess the diagnostic performance of the cognitive tests were extracted with inclusion and exclusion criteria. Each test's performance was compared with the standard diagnostic criteria. Bivariate random effects models were used to summarize the test performance as a point estimate for sensitivity and specificity, and presented in a summary receiver operating characteristic curve. Reporting quality and risk of bias were evaluated. A total of 108 studies with 23,546 participants were selected to evaluate 9 cognitive tests for MCI detection. Most of the studies used the Mini-Mental State Examination (MMSE) (n = 58) and the Montreal Cognitive Assessment (MoCA) (n = 35). The combined diagnostic performance of the MMSE in MCI detection was 0.71 sensitivity [95% confidence interval (CI): 0.66-0.75] and 0.74 specificity (95% CI: 0.70-0.78), and of the MoCA in MCI detection was 0.83 sensitivity (95% CI: 0.80-0.86) and 0.75 specificity (95% CI: 0.69-0.80). Among the 9 cognitive tests, recall tests showed the best diagnostic performance with 0.89 sensitivity (95% CI: 0.86-0.92) and 0.84 specificity (95% CI, 0.79-0.89). In subgroup analyses, long- or short-delay recall tests have shown better performance than immediate recall tests. Recall tests were shown to be the most

Biological variability of the sweat chloride in diagnostic sweat tests: A retrospective analysis.

PubMed

Vermeulen, F; Lebecque, P; De Boeck, K; Leal, T

2017-01-01

The sweat test is the current gold standard for the diagnosis of cystic fibrosis (CF). CF is unlikely when sweat chloride (Cl sw ) is lower than 30mmol/L, Cl sw >60 is suggestive of CF, with intermediate values between 30 and 60mmol/L. To correctly interpret a sweat chloride value, the biological variability of the sweat chloride has to be known. Sweat tests performed in two centers using the classic Gibson and Cooke method were retrospectively reviewed (n=5904). Within test variability of Cl sw was measured by comparing results from right and left arm collected on the same day. Between test variability was calculated from subjects with sweat tests performed on more than one occasion. Within test variability of Cl sw calculated in 1022 subjects was low with differences between -3.2 (p5) and +3.6mmol/L (p95). Results from left and right arm were classified differently in only 3 subjects. Between test variability of Cl sw in 197 subjects was larger, with differences between -18.2mmol/L (p5) and +14.1mmol/L (p95) between repeat tests. Changes in diagnostic conclusion were seen in 55/197 subjects, the most frequent being changing from indeterminate to 'CF unlikely' range (48/102). Variability of sweat chloride is substantial, with frequent changes in diagnostic conclusion, especially in the intermediate range. Copyright © 2016 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Evaluation of the Ortho-Clinical Diagnostics Vitros ECi Anti-HCV test: comparison with three other methods.

PubMed

Watterson, Jeannette M; Stallcup, Paulina; Escamilla, David; Chernay, Patrick; Reyes, Alfred; Trevino, Sylvia C

2007-01-01

After observing a high incidence of low positive hepatitis C virus (HCV) antibody screens by the Ortho-Clinical Vitros ECi test (Orthoclinical Diagnostics, Raritan, NJ), we compared results against those obtained using another chemiluminescent analyzer, as well as two U.S. Food and Drug Administration (FDA)-approved confirmatory methodologies. To ascertain the true anti-HCV status of samples deemed low-positive by the Ortho-Clinical Vitros ECi test, we tested samples using the ADVIA Centaur HCV screen test (Siemens Medical Solutions Diagnostics), the Chiron recombinant immunoblot assay (RIBA) test (Chiron Corp., Emeryville, CA), and the Roche COBAS Amplicor HCV qualitative test (Roche Diagnostics, Indianapolis, IN) in a series of studies. Of 94 specimens positive by Vitros ECi, 19% were observed to be negative by Centaur. A separate study of 91 samples with signal-to-cutoff (s/co) values less than 8.0 showed that all but one was negative for HCV ribonucleic acid (RNA). In comparison with RIBA, 100% (77) samples positive by the Vitros ECi test with s/co values less than 12.0 were negative or indeterminate by RIBA. A final study comparing all four methods side-by-side showed 63% disagreement by Centaur for Vitros ECi low-positive samples, 75% disagreement by RIBA, and 97% disagreement by polymerase chain reaction (PCR). In conclusion, the Ortho-Clinical Vitros ECi Anti-HCV test yields a high rate of false-positive results in the low s/co range in our patient population. (c) 2007 Wiley-Liss, Inc.

Implementation of Rapid Molecular Infectious Disease Diagnostics: the Role of Diagnostic and Antimicrobial Stewardship.

PubMed

Messacar, Kevin; Parker, Sarah K; Todd, James K; Dominguez, Samuel R

2017-03-01

New rapid molecular diagnostic technologies for infectious diseases enable expedited accurate microbiological diagnoses. However, diagnostic stewardship and antimicrobial stewardship are necessary to ensure that these technologies conserve, rather than consume, additional health care resources and optimally affect patient care. Diagnostic stewardship is needed to implement appropriate tests for the clinical setting and to direct testing toward appropriate patients. Antimicrobial stewardship is needed to ensure prompt appropriate clinical action to translate faster diagnostic test results in the laboratory into improved outcomes at the bedside. This minireview outlines the roles of diagnostic stewardship and antimicrobial stewardship in the implementation of rapid molecular infectious disease diagnostics. Copyright © 2017 American Society for Microbiology.

Analysis of the Astronomy Diagnostic Test

NASA Astrophysics Data System (ADS)

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

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 with both lab and discussion. Statistical analysis shows that there are no significant differences in normalized gain among the self- reported classroom formats. Prerequisites related to mathematics courses did show differences in normalized gain. Of all reported course activities, only the lecture and the readings for the course correlate significantly with the normalized gain. This analysis suggests that the ADT may not have enough sensitivity to measure differences in the effectiveness of different course formats because of the wide range of topics that the ADT addresses with few questions. Different measures of gain and their biases are discussed. We argue that the use of the normalized gain is not always warranted because of its strong bias toward high pretest scores.

Real-world utilization of molecular diagnostic testing and matched drug therapies in the treatment of metastatic cancers.

PubMed

Chawla, Anita; Peeples, Miranda; Li, Nanxin; Anhorn, Rachel; Ryan, Jason; Signorovitch, James

2018-06-01

To assess the frequency of biopsies and molecular diagnostic testing (human DNA/RNA analysis), anti-cancer drug use (genomically-matched targeted therapy [GMTT], unmatched targeted therapy [UTT], endocrine therapy [ET], and chemotherapy [CT]), and medical service costs among adults with metastatic cancer. Adults diagnosed with metastatic breast, non-small cell lung (NSCLC), colorectal, head and neck, ovarian, and uterine cancer (2010Q1-2015Q1) were identified in the OptumHealth Care Solutions claims database and followed from first metastatic diagnosis for ≥1 month and until the end of data availability. Utilization was assessed for each cancer cohort (all and patients aged ≥65 years); per-patient-per-month (PPPM) medical service costs were assessed for all patients. Testing frequency estimates were applied to Surveillance, Epidemiology, and End Results Program data to estimate the number of untested patients (2010-2014). Patients with metastatic cancer (n = 8,193; breast [n = 3,414], NSCLC [n = 2,231], colorectal [n = 1,611], head and neck [n = 511], ovarian [n = 275], and uterine [n = 151]) were 63 years old (mean), with 11.1-22.2 months of observation. Biopsy and molecular diagnostic testing frequencies ranged from 7% (uterine) to 73% (ovarian), and from 34% (head and neck) to 52% (breast), respectively. Few were treated with GMTT (breast, 11%; NSCLC, 9%; colorectal, 6%). Treatment with UTT ranged from 0.7% (uterine) to 21% (colorectal). Biopsy, diagnostic testing, and anti-cancer drug therapy were less frequent for those ≥65 years. Medical service costs (PPPM, mean) ranged from $6,618 (head and neck) to $9,940 (ovarian). The estimated number of untested new patients with metastatic cancer was 636,369 (all) and 341,397 (≥65). In addition to the limitations of claims analyses, diagnostic testing frequency may be under-estimated if patients underwent testing prior to study inclusion. The low frequency of molecular diagnostic

Repeated significance tests of linear combinations of sensitivity and specificity of a diagnostic biomarker

PubMed Central

Wu, Mixia; Shu, Yu; Li, Zhaohai; Liu, Aiyi

2016-01-01

A sequential design is proposed to test whether the accuracy of a binary diagnostic biomarker meets the minimal level of acceptance. The accuracy of a binary diagnostic biomarker is a linear combination of the marker’s sensitivity and specificity. The objective of the sequential method is to minimize the maximum expected sample size under the null hypothesis that the marker’s accuracy is below the minimal level of acceptance. The exact results of two-stage designs based on Youden’s index and efficiency indicate that the maximum expected sample sizes are smaller than the sample sizes of the fixed designs. Exact methods are also developed for estimation, confidence interval and p-value concerning the proposed accuracy index upon termination of the sequential testing. PMID:26947768

Auditory brainstem response (ABR) profiling tests as diagnostic support for schizophrenia and adult attention-deficit hyperactivity disorder (ADHD).

PubMed

Juselius Baghdassarian, Eva; Nilsson Markhed, Maria; Lindström, Eva; Nilsson, Björn M; Lewander, Tommy

2018-06-01

To evaluate the performances of two auditory brainstem response (ABR) profiling tests as potential biomarkers and diagnostic support for schizophrenia and adult attention-deficit hyperactivity disorder (ADHD), respectively, in an investigator-initiated blinded study design. Male and female patients with schizophrenia (n=26) and adult ADHD (n=24) meeting Diagnostic and Statistical Manual of Mental Disorders Fourth Edition (DSM IV) diagnostic criteria and healthy controls (n=58) comprised the analysis set (n=108) of the total number of study participants (n=119). Coded sets of randomized ABR recordings were analysed by an independent party blinded to clinical diagnoses before a joint code-breaking session. The ABR profiling test for schizophrenia identified schizophrenia patients versus controls with a sensitivity of 84.6% and a specificity of 93.1%. The ADHD test identified patients with adult ADHD versus controls with a sensitivity of 87.5% and a specificity of 91.4%. The ABR profiling tests discriminated schizophrenia and ADHD versus healthy controls with high sensitivity and specificity. The methods deserve to be further explored in larger clinical studies including a broad range of psychiatric disorders to determine their utility as potential diagnostic biomarkers.

The impact of a computerised test of attention and activity (QbTest) on diagnostic decision-making in children and young people with suspected attention deficit hyperactivity disorder: single-blind randomised controlled trial.

PubMed

Hollis, Chris; Hall, Charlotte L; Guo, Boliang; James, Marilyn; Boadu, Janet; Groom, Madeleine J; Brown, Nikki; Kaylor-Hughes, Catherine; Moldavsky, Maria; Valentine, Althea Z; Walker, Gemma M; Daley, David; Sayal, Kapil; Morriss, Richard

2018-04-26

Diagnosis of attention deficit hyperactivity disorder (ADHD) relies on subjective methods which can lead to diagnostic uncertainty and delay. This trial evaluated the impact of providing a computerised test of attention and activity (QbTest) report on the speed and accuracy of diagnostic decision-making in children with suspected ADHD. Randomised, parallel, single-blind controlled trial in mental health and community paediatric clinics in England. Participants were 6-17 years-old and referred for ADHD diagnostic assessment; all underwent assessment-as-usual, plus QbTest. Participants and their clinician were randomised to either receive the QbTest report immediately (QbOpen group) or the report was withheld (QbBlind group). The primary outcome was number of consultations until a diagnostic decision confirming/excluding ADHD within 6-months from baseline. Health economic cost-effectiveness and cost utility analysis was conducted. Assessing QbTest Utility in ADHD: A Randomised Controlled Trial was registered at ClinicalTrials.gov (https://clinicaltrials.gov/ct2/show/NCT02209116). One hundred and thirty-two participants were randomised to QbOpen group (123 analysed) and 135 to QbBlind group (127 analysed). Clinicians with access to the QbTest report (QbOpen) were more likely to reach a diagnostic decision about ADHD (hazard ratio 1.44, 95% CI 1.04-2.01). At 6-months, 76% of those with a QbTest report had received a diagnostic decision, compared with 50% without. QbTest reduced appointment length by 15% (time ratio 0.85, 95% CI 0.77-0.93), increased clinicians' confidence in their diagnostic decisions (odds ratio 1.77, 95% CI 1.09-2.89) and doubled the likelihood of excluding ADHD. There was no difference in diagnostic accuracy. Health economic analysis showed a position of strict dominance; however, cost savings were small suggesting that the impact of providing the QbTest report within this trial can best be viewed as 'cost neutral'. QbTest may increase the

The diagnostic value of troponin T testing in the community setting.

PubMed

Planer, David; Leibowitz, David; Paltiel, Ora; Boukhobza, Rina; Lotan, Chaim; Weiss, Teddy A

2006-03-08

Many patients presenting with chest pain to their family physician are referred to the emergency room, in part, due to lack of accurate objective diagnostic tools. This study aimed to assess the diagnostic value of bedside troponin T kit testing in patients presenting with chest pain to their family physician. Prospective, multi-center study. Consecutive subjects with chest pain were recruited from 44 community clinics in Jerusalem. Following clinical assessment by the family physician, qualitative troponin kit testing was performed. Patients with a negative clinical assessment and negative troponin kit were sent home and all others were referred to the emergency room. The final diagnosis at the time of hospital discharge was recorded and telephone follow up was performed after 60 days. Positive predictive value, negative predictive value, sensitivity and specificity of troponin kit for myocardial infarction diagnosis and of family physician for hospitalization, were assessed. Of 392 patients enrolled, 349 (89%) were included in the final analysis. The prevalence of myocardial infarction was 1.7%. The positive and negative predictive values of the troponin kit for myocardial infarction diagnosis were 100% and 99.7%, respectively. The positive and negative predictive values of the family physician's assessment to predict hospitalization were 41.4% and 94.1%, respectively. Troponin kit testing is an important tool to assist the family physician in the assessment of patients with chest pain in the community setting. Troponin kit testing may identify otherwise undiagnosed cases of myocardial infarctions, and reduce unnecessary referrals to the emergency room.

Size-based molecular diagnostics using plasma DNA for noninvasive prenatal testing.

PubMed

Yu, Stephanie C Y; Chan, K C Allen; Zheng, Yama W L; Jiang, Peiyong; Liao, Gary J W; Sun, Hao; Akolekar, Ranjit; Leung, Tak Y; Go, Attie T J I; van Vugt, John M G; Minekawa, Ryoko; Oudejans, Cees B M; Nicolaides, Kypros H; Chiu, Rossa W K; Lo, Y M Dennis

2014-06-10

Noninvasive prenatal testing using fetal DNA in maternal plasma is an actively researched area. The current generation of tests using massively parallel sequencing is based on counting plasma DNA sequences originating from different genomic regions. In this study, we explored a different approach that is based on the use of DNA fragment size as a diagnostic parameter. This approach is dependent on the fact that circulating fetal DNA molecules are generally shorter than the corresponding maternal DNA molecules. First, we performed plasma DNA size analysis using paired-end massively parallel sequencing and microchip-based capillary electrophoresis. We demonstrated that the fetal DNA fraction in maternal plasma could be deduced from the overall size distribution of maternal plasma DNA. The fetal DNA fraction is a critical parameter affecting the accuracy of noninvasive prenatal testing using maternal plasma DNA. Second, we showed that fetal chromosomal aneuploidy could be detected by observing an aberrant proportion of short fragments from an aneuploid chromosome in the paired-end sequencing data. Using this approach, we detected fetal trisomy 21 and trisomy 18 with 100% sensitivity (T21: 36/36; T18: 27/27) and 100% specificity (non-T21: 88/88; non-T18: 97/97). For trisomy 13, the sensitivity and specificity were 95.2% (20/21) and 99% (102/103), respectively. For monosomy X, the sensitivity and specificity were both 100% (10/10 and 8/8). Thus, this study establishes the principle of size-based molecular diagnostics using plasma DNA. This approach has potential applications beyond noninvasive prenatal testing to areas such as oncology and transplantation monitoring.

[Potentialities of the vegetative resonance test for diagnostics of hyperplastic processes in vocal folds].

PubMed

Ukhankova, N I; Sotskaia, T Iu

2010-01-01

The objective of the present study was to evaluate potentialities of the vegetative resonance test (VRT) for the elucidation of metabolic aspects of the inflammatory process in different forms of chronic vocal fold hyperplasty. The proposed diagnostic criteria characterize the inflammatory process in the larynx, specific features of metabolism in patients presenting with catarrhal and oedematopolypous laryngitis, characteristic changes in oedematofibrous and fibrous polyps. The use of VRT allowed diagnostic criteria for precarcinogenic conditions in the larynx to be developed.

Diagnostic grand rounds: a new teaching concept to train diagnostic reasoning.

PubMed

Stieger, Stefan; Praschinger, Andrea; Kletter, Kurt; Kainberger, Franz

2011-06-01

Diagnostic reasoning is a core skill in teaching and learning in undergraduate curricula. Diagnostic grand rounds (DGRs) as a subform of grand rounds are intended to train the students' skills in the selection of appropriate tests and in the interpretation of test results. The aim of this study was to test DGRs for their ability to improve diagnostic reasoning by using a pre-post-test design. During one winter term, all 398 fifth-year students (36.1% male, 63.9% female) solved 23 clinical cases presented in 8 DGRs. In an online questionnaire, a Diagnostic Thinking Inventory (DTI) with 41 items was evaluated for flexibility in thinking and structure of knowledge in memory. Results were correlated with those from a summative multiple-choice knowledge test and of the learning objectives in a logbook. The students' DTI scores in the post-test were significantly higher than those reported in the pre-test. DTI scores at either testing time did not correlate with medical knowledge as assessed by a multiple-choice knowledge test. Abilities acquired during clinical clerkships as documented in a logbook could only account for a small proportion of the increase in the flexibility subscale score. This effect still remained significant after accounting for potential confounders. Establishing DGRs proofed to be an effective way of successfully improving both students' diagnostic reasoning and the ability to select the appropriate test method in routine clinical practice. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

SSME Post Test Diagnostic System: Systems Section

NASA Technical Reports Server (NTRS)

Bickmore, Timothy

1995-01-01

An assessment of engine and component health is routinely made after each test firing or flight firing of a Space Shuttle Main Engine (SSME). Currently, this health assessment is done by teams of engineers who manually review sensor data, performance data, and engine and component operating histories. Based on review of information from these various sources, an evaluation is made as to the health of each component of the SSME and the preparedness of the engine for another test or flight. The objective of this project - the SSME Post Test Diagnostic System (PTDS) - is to develop a computer program which automates the analysis of test data from the SSME in order to detect and diagnose anomalies. This report primarily covers work on the Systems Section of the PTDS, which automates the analyses performed by the systems/performance group at the Propulsion Branch of NASA Marshall Space Flight Center (MSFC). This group is responsible for assessing the overall health and performance of the engine, and detecting and diagnosing anomalies which involve multiple components (other groups are responsible for analyzing the behavior of specific components). The PTDS utilizes several advanced software technologies to perform its analyses. Raw test data is analyzed using signal processing routines which detect features in the data, such as spikes, shifts, peaks, and drifts. Component analyses are performed by expert systems, which use 'rules-of-thumb' obtained from interviews with the MSFC data analysts to detect and diagnose anomalies. The systems analysis is performed using case-based reasoning. Results of all analyses are stored in a relational database and displayed via an X-window-based graphical user interface which provides ranked lists of anomalies and observations by engine component, along with supporting data plots for each.

The bone diagnostic instrument III: Testing mouse femora

NASA Astrophysics Data System (ADS)

Randall, Connor; Mathews, Phillip; Yurtsev, Eugene; Sahar, Nadder; Kohn, David; Hansma, Paul

2009-06-01

Here we describe modifications that allow the bone diagnostic instrument (BDI) [P. Hansma et al., Rev. Sci. Instrum. 79, 064303 (2008); Rev. Sci. Instrum. 77, 075105 (2006)], developed to test human bone, to test the femora of mice. These modifications include reducing the effective weight of the instrument on the bone, designing and fabricating new probe assemblies to minimize damage to the small bone, developing new testing protocols that involve smaller testing forces, and fabricating a jig for securing the smaller bones for testing. With these modifications, the BDI was used to test the hypothesis that short-term running has greater benefit on the mechanical properties of the femur for young growing mice compared to older, skeletally mature mice. We measured elastic modulus, hardness, and indentation distance increase (IDI), which had previously been shown to be the best discriminators in model systems known to exhibit differences in mechanical properties at the whole bone level. In the young exercised murine femora, the IDI was significantly lower than in young control femora. Since IDI has a relation to postyield properties, these results suggest that exercise during bone development increases post yield mechanical competence. We were also able to measure effects of aging on bone properties with the BDI. There was a significant increase in the IDI, and a significant decrease in the elastic modulus and hardness between the young and old groups. Thus, with the modifications described here, the BDI can take measurements on mouse bones and obtain statistically significant results.

Constructing and Validating a Q-Matrix for Cognitive Diagnostic Analyses of a Reading Test

ERIC Educational Resources Information Center

Li, Hongli; Suen, Hoi K.

2013-01-01

Cognitive diagnostic analyses have been advocated as methods that allow an assessment to function as a formative assessment to inform instruction. To use this approach, it is necessary to first identify the skills required for each item in the test, known as a Q-matrix. However, because the construct being tested and the underlying cognitive…

Test-treatment RCTs are susceptible to bias: a review of the methodological quality of randomized trials that evaluate diagnostic tests.

PubMed

Ferrante di Ruffano, Lavinia; Dinnes, Jacqueline; Sitch, Alice J; Hyde, Chris; Deeks, Jonathan J

2017-02-24

There is a growing recognition for the need to expand our evidence base for the clinical effectiveness of diagnostic tests. Many international bodies are calling for diagnostic randomized controlled trials to provide the most rigorous evidence of impact to patient health. Although these so-called test-treatment RCTs are very challenging to undertake due to their methodological complexity, they have not been subjected to a systematic appraisal of their methodological quality. The extent to which these trials may be producing biased results therefore remains unknown. We set out to address this issue by conducting a methodological review of published test-treatment trials to determine how often they implement adequate methods to limit bias and safeguard the validity of results. We ascertained all test-treatment RCTs published 2004-2007, indexed in CENTRAL, including RCTs which randomized patients to diagnostic tests and measured patient outcomes after treatment. Tests used for screening, monitoring or prognosis were excluded. We assessed adequacy of sequence generation, allocation concealment and intention-to-treat, appropriateness of primary analyses, blinding and reporting of power calculations, and extracted study characteristics including the primary outcome. One hundred three trials compared 105 control with 119 experimental interventions, and reported 150 primary outcomes. Randomization and allocation concealment were adequate in 57 and 37% of trials. Blinding was uncommon (patients 5%, clinicians 4%, outcome assessors 21%), as was an adequate intention-to-treat analysis (29%). Overall 101 of 103 trials (98%) were at risk of bias, as judged using standard Cochrane criteria. Test-treatment trials are particularly susceptible to attrition and inadequate primary analyses, lack of blinding and under-powering. These weaknesses pose much greater methodological and practical challenges to conducting reliable RCT evaluations of test-treatment strategies than standard