Understanding Diagnostic Test Results: Development of the Knowledge of Diagnostic Test Scale

As there are an increasing number of medical tests, it is even more important that patients understand the results from diagnostic tests in order to increase their probability of making accurate, informed decisions about their healthcare. The current paper outlines the development of the Knowledge of Diagnostic Test scale (KDT), a new instrument designed to measure the ability to understand the methodology of diagnostic testing and to apply diagnostic test results to accurate informed decision-making. Using Item Response Theory (IRT) in two studies, we investigated items to create an efficient measure of knowledge of diagnostic tests. Results suggested three items had desirable psychometric properties (i.e., of discriminability and difficulty) for measuring an average person’s diagnostic test knowledge. Implications for use in healthcare settings are briefly discussed.

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Overuse of diagnostic testing in healthcare: a systematic review

BMJ Quality & Safety ◽

10.1136/bmjqs-2020-012576 ◽

2021 ◽

pp. bmjqs-2020-012576

Author(s):

Joris L J M Müskens ◽

Rudolf Bertijn Kool ◽

Simone A van Dulmen ◽

Gert P Westert

Keyword(s):

Low Back Pain ◽

Back Pain ◽

Diagnostic Tests ◽

Patient Population ◽

English Language ◽

Diagnostic Testing ◽

Low Back ◽

Preoperative Testing ◽

Healthcare Settings ◽

Major Variation

BackgroundOveruse of diagnostic testing substantially contributes to healthcare expenses and potentially exposes patients to unnecessary harm. Our objective was to systematically identify and examine studies that assessed the prevalence of diagnostic testing overuse across healthcare settings to estimate the overall prevalence of low-value diagnostic overtesting.MethodsPubMed, Web of Science and Embase were searched from inception until 18 February 2020 to identify articles published in the English language that examined the prevalence of diagnostic testing overuse using database data. Each of the assessments was categorised as using a patient-indication lens, a patient-population lens or a service lens.Results118 assessments of diagnostic testing overuse, extracted from 35 studies, were included in this study. Most included assessments used a patient-indication lens (n=67, 57%), followed by the service lens (n=27, 23%) and patient-population lens (n=24, 20%). Prevalence estimates of diagnostic testing overuse ranged from 0.09% to 97.5% (median prevalence of assessments using a patient-indication lens: 11.0%, patient-population lens: 2.0% and service lens: 30.7%). The majority of assessments (n=85) reported overuse of diagnostic testing to be below 25%. Overuse of diagnostic imaging tests was most often assessed (n=96). Among the 33 assessments reporting high levels of overuse (≥25%), preoperative testing (n=7) and imaging for uncomplicated low back pain (n=6) were most frequently examined. For assessments of similar diagnostic tests, major variation in the prevalence of overuse was observed. Differences in the definitions of low-value tests used, their operationalisation and assessment methods likely contributed to this observed variation.ConclusionOur findings suggest that substantial overuse of diagnostic testing is present with wide variation in overuse. Preoperative testing and imaging for non-specific low back pain are the most frequently identified low-value diagnostic tests. Uniform definitions and assessments are required in order to obtain a more comprehensive understanding of the magnitude of diagnostic testing overuse.

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Is One Diagnostic Test for COVID-19 Enough?

Journal of Risk and Financial Management ◽

10.3390/jrfm13040077 ◽

2020 ◽

Vol 13 (4) ◽

pp. 77 ◽

Cited By ~ 4

Author(s):

Michael McAleer

Keyword(s):

Diagnostic Test ◽

Diagnostic Tests ◽

Diagnostic Testing ◽

Experimental Tests ◽

Positive Outcome ◽

Correct Decision ◽

Social Distancing ◽

Disease Testing

There is no doubt about the importance of diagnostic testing in an emergency; specifically, which range of tests is available, where and when they are dispensed, and who might be tested using laboratory-developed tests, or other diagnostic tests including experimental tests. This includes testing for the SARS-CoV-2 virus that causes the COVID-19 disease. Testing is essential to “flatten the curve” of the number of confirmed positive cases of the disease, in addition to handwashing, isolation, and social distancing, among other essential measures. Is one diagnostic test enough to obtain the correct decision about a confirmed positive outcome?

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Opportunities of Evaluation Diagnostic Test Results of Roller Bearings from Signals Correlation of Bearing and its Environment / Możliwości Oceny Wyników Badań Diagnostycznych Łożysk Tocznych Z Korelacji Sygnałów Łożyska I Jego Otoczenia

Journal of Konbin ◽

10.2478/jok-2013-0026 ◽

2012 ◽

Vol 22 (1) ◽

pp. 109-118

Author(s):

Marek Zboiński ◽

Paweł Lindstedt ◽

Maciej Deliś

Keyword(s):

Diagnostic Test ◽

Diagnostic Tests ◽

Ball Bearings ◽

Test Results ◽

Autocorrelation Functions ◽

Roller Bearings ◽

Functional Methods ◽

Diagnostic Thresholds

Abstract The article discusses the opportunities of evaluation results of ball bearings diagnostic tests including signals from bearing and its environment. Diagnostic signals are obtained tribological methods, signals from environment functional methods. Relations between the two signals are described autocorrelation functions and cross. It has been shown that for a small number of measurements (3, 4) diagnostic thresholds μ+σ, μ+2σ, μ+3σ are reliable if covariance γxy2 will be close to 1, and the strengthening of amplitude |A|2 is close to 0.

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Intensivists’ beliefs about rapid multiplex molecular diagnostic testing and its potential role in improving prescribing decisions and antimicrobial stewardship: a qualitative study

Antimicrobial Resistance and Infection Control ◽

10.1186/s13756-021-00961-4 ◽

2021 ◽

Vol 10 (1) ◽

Author(s):

Alyssa M. Pandolfo ◽

Robert Horne ◽

Yogini Jani ◽

Tom W. Reader ◽

Natalie Bidad ◽

...

Keyword(s):

Molecular Diagnostics ◽

Antimicrobial Stewardship ◽

Diagnostic Tests ◽

Pathogenic Bacteria ◽

Point Of Care ◽

Diagnostic Testing ◽

Molecular Diagnostic ◽

Antibiotic Prescribing ◽

Test Results ◽

Structured Interviews

Abstract Background Rapid molecular diagnostic tests to investigate the microbial aetiology of pneumonias may improve treatment and antimicrobial stewardship in intensive care units (ICUs). Clinicians’ endorsement and uptake of these tests is crucial to maximise engagement; however, adoption may be impeded if users harbour unaddressed concerns or if device usage is incompatible with local practice. Accordingly, we strove to identify ICU clinicians’ beliefs about molecular diagnostic tests for pneumonias before implementation at the point-of-care. Methods We conducted semi-structured interviews with 35 critical care doctors working in four ICUs in the United Kingdom. A clinical vignette depicting a fictitious patient with signs of pneumonia was used to explore clinicians’ beliefs about the importance of molecular diagnostics and their concerns. Data were analysed thematically. Results Clinicians’ beliefs about molecular tests could be grouped into two categories: perceived potential of molecular diagnostics to improve antibiotic prescribing (Molecular Diagnostic Necessity) and concerns about how the test results could be implemented into practice (Molecular Diagnostic Concerns). Molecular Diagnostic Necessity stemmed from beliefs that positive results would facilitate targeted antimicrobial therapy; that negative results would signal the absence of a pathogen, and consequently that having the molecular diagnostic results would bolster clinicians’ prescribing confidence. Molecular Diagnostic Concerns included unfamiliarity with the device’s capabilities, worry that it would detect non-pathogenic bacteria, uncertainty whether it would fail to detect pathogens, and discomfort with withholding antibiotics until receiving molecular test results. Conclusions Clinicians believed rapid molecular diagnostics for pneumonias were potentially important and were open to using them; however, they harboured concerns about the tests’ capabilities and integration into clinical practice. Implementation strategies should bolster users’ necessity beliefs while reducing their concerns; this can be accomplished by publicising the tests’ purpose and benefits, identifying and addressing clinicians’ misconceptions, establishing a trial period for first-hand familiarisation, and emphasising that, with a swift (e.g., 60–90 min) test, antibiotics can be started and refined after molecular diagnostic results become available.

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Clinical Epidemiology

Mayo Clinic Internal Medicine Board Review ◽

10.1093/med/9780190464868.003.0024 ◽

2016 ◽

pp. 285-290

Author(s):

Scott C. Litin ◽

John B. Bundrick

Keyword(s):

Diagnostic Test ◽

Diagnostic Tests ◽

Clinical Decision Making ◽

Clinical Epidemiology ◽

Clinical Decision ◽

Test Results ◽

Specific Patient ◽

Predictive Values ◽

Test Sensitivity ◽

Sensitivity Specificity

Diagnostic tests are tools that either increase or decrease the likelihood of disease. The sensitivity, specificity, and predictive values of normal and abnormal test results can be calculated with even a limited amount of information. Some physicians prefer interpreting diagnostic test results by using the likelihood ratio. This ratio takes properties of a diagnostic test (sensitivity and specificity) and makes them more helpful in clinical decision making. It helps the clinician determine the probability of disease in a specific patient after a diagnostic test has been performed.

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Implications of covariate induced test dependence on the diagnostic accuracy of latent class analysis in pulmonary tuberculosis

10.21203/rs.3.rs-900353/v1 ◽

2021 ◽

Author(s):

Alfred Kipyegon Keter ◽

Lutgarde Lynen ◽

Alastair van Heerden ◽

Els Goetghebeur ◽

Bart K.M. Jacobs

Keyword(s):

Pulmonary Tuberculosis ◽

Diagnostic Accuracy ◽

Diagnostic Test ◽

Sensitivity And Specificity ◽

Diagnostic Tests ◽

Latent Class ◽

Test Accuracy ◽

Test Results ◽

Test Sensitivity ◽

Correct Estimation

Abstract Background Lack of a perfect reference standard for pulmonary tuberculosis (PTB) diagnosis complicates assessment of accuracy of new diagnostic tests. Alternative strategies such as discrepant resolution and use of composite reference standards may lead to incorrect inferences on disease prevalence and diagnostic test sensitivity and specificity. Latent class analysis (LCA), a statistical method for analyzing diagnostic test results in the absence of a gold standard, allows correct estimation under strict assumptions. The model assumes that the diagnostic tests are independent conditional on the true disease status and that the diagnostic test sensitivity and specificity remain constant across subpopulations. These assumptions are violated when a factor such as severe comorbidity affects the prevalence and/or alters the diagnostic test performance. We aim to provide guidance on correct estimation of the prevalence and diagnostic test accuracy based on LCA when a known factor induces dependence among the diagnostic tests. If unaccounted for, this dependence may lead to misleading inferences. Methods Through likelihood evaluation and simulation we examined implications of likely model violations on estimation of prevalence, sensitivity and specificity among passive case-finding presumptive PTB patients with or without HIV. We generated independent results for five diagnostic tests conditional on PTB and HIV. We performed Bayesian LCA, separately for five and three diagnostic tests using four working models with or without constant PTB prevalence and diagnostic test accuracy across HIV subpopulations. Results In evaluating three diagnostic tests, the models accounting for heterogeneity in diagnostic accuracy produced consistent estimates while the models ignoring it produced biased estimates. The model ignoring heterogeneity in PTB prevalence is less problematic. When evaluating five diagnostic tests, the models were robust to violation of the assumptions. Conclusions Well-chosen covariate-specific adaptations of the model can avoid bias implied by recognized heterogeneity in PTB patient populations generating otherwise dependent test results in LCA.

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Early detection and persistent positivity of anti-Leishmania antibodies using a recombinant protein-based ELISA in naturally infected dogs in Brazil

Parasites & Vectors ◽

10.1186/s13071-021-04895-z ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Matheus Silva de Jesus ◽

João Victor Andrade Cruz ◽

Lívia Brito Coelho ◽

Lairton Souza Borja ◽

Edmilson Domingos da Silva ◽

...

Keyword(s):

Cohort Study ◽

Visceral Leishmaniasis ◽

Recombinant Protein ◽

Diagnostic Test ◽

Diagnostic Tests ◽

Clinical Signs ◽

Diagnostic Methods ◽

Test Results ◽

Time Points ◽

Positive Results

Abstract Background Visceral leishmaniasis (VL) is a zoonotic disease caused by Leishmania infantum, for which dogs constitute the main urban parasite reservoir. Control measures and the treatment of canine visceral leishmaniasis (CVL) are essential to reduce VL cases. Early and accurate detection of L. infantum-infected dogs is crucial to the success of VL control. To improve the serological detection of L. infantum-exposed dogs, we evaluated the early diagnosis capacity of a recombinant protein (rLci5) in an immunosorbent assay (ELISA) to detect naturally infected dogs. Additionally, we evaluated the persistence of the positive results obtained by rLci5 ELISA in comparison to other conventional diagnostic test methods. Methods Serum samples obtained from 48 L. infantum-infected dogs involved in a cohort study were evaluated using different diagnostic methods (qPCR, EIE-LVC, DPP-LVC and splenic culture). The results were compared to rLci5 ELISA to determine its capacity to diagnose L. infantum infection at earlier infection time points. The persistence of positive diagnostic test results was also compared for each dog evaluated. Results rLci5 ELISA presented higher rates of positive results at early time points compared to the other diagnostic tests employed in the cohort study, as early as 24 months prior to detection by other tests. rLci5 ELISA positivity was 52.1% (25/48) at baseline, while qPCR was 35.4% (17/48), DPP-LVC 27.1% (13/48), EIE-LVC 22.9% (11/48) and culture only 4.2% (2/48). In at least one of the time points of the 24-month cohort study, rLci5 ELISA was positive in 100% (48/48) of the dogs, versus 83% (40/48) for qPCR, 75% (36/48) for DPP-LVC, 65% (31/48) for EIE-LVC and 31% (15/48) for culture. Investigating clinical signs in association with diagnostic test positivity, rLci5 ELISA successfully detected CVL in 62.9% (95/151) of the clinical evaluations with a score of 0–3, 64.3% (45/70) with scores between 4 and 7, and 73.7% (14/19) with scores > 7, providing higher rates of positivity than all other methods evaluated. Moreover, rLci5 ELISA presented the greatest persistence with respect to test positivity: 45.8% of the dogs evaluated. Conclusion Four diagnostic tests were compared to rLci5 ELISA, which presented earlier infection diagnosis and a greater persistence of positive test results. Accordingly, the use of the rLci5 ELISA can improve CVL diagnostic performance by detecting infected dogs sooner than other testing methods, with enhanced persistence of positive results over the course of the infection. Graphic abstract

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Abstract 18053: Prognostic Value of Anatomic versus Functional Diagnostic Testing in Symptomatic Patients With Suspected CAD: The PROMISE Trial (PROspective Multicenter Imaging Study for Evaluation of Chest Pain)

Circulation ◽

10.1161/circ.132.suppl_3.18053 ◽

2015 ◽

Vol 132 (suppl_3) ◽

Author(s):

Udo Hoffmann ◽

Maros Ferencik ◽

James E Udelson ◽

Michael H Picard ◽

John Heitner ◽

...

Keyword(s):

Diagnostic Test ◽

Prognostic Value ◽

Proportional Hazards ◽

Diagnostic Testing ◽

Imaging Study ◽

Computed Tomographic Angiography ◽

Cox Proportional Hazards ◽

Functional Testing ◽

Test Results ◽

Normal Test

Introduction: Symptoms suggestive of coronary artery disease (CAD) are common, but no randomized comparison of the prognostic value of coronary computed tomographic angiography (CTA) vs. functional testing has been performed. Methods: Patients (10,003) with suspected CAD were randomized to functional testing (exercise ECG, nuclear stress, or stress echo) or CTA. Site-based diagnostic test reports were classified as normal or mildly, moderately, or severely abnormal. Cox proportional hazards models assessed the relationship of test results to a composite of time to death, myocardial infarction, or unstable angina, and the discriminatory ability of the two tests was compared using the C-index. Adjusted HRs for events in patients with abnormal vs. normal test results were determined for CTA and functional testing. Results: Overall, 4516 patients received CTA and 4572 functional testing as the randomized diagnostic test. The proportions of normal, mild, moderate, and severe abnormalities on CTA were 33.3%, 42.7%, 10.0%, and 14.0%, respectively, and for functional testing 78.9%, 8.5%, 4.2%, and 8.4% (P=0.001). Event rates over 26.0 months’ (IQR 18.0, 34.4) follow-up were similar: CTA 137/4516 (3.0%) vs. functional 132/4572 (2.9%). Compared to patients with normal CTAs, those with abnormal CTAs had increasing HRs for events with increasingly severe abnormalities, while only patients with moderate and severely abnormal functional testing had an increased HR for events (Figure). The probability of having an event given a normal test result was lower for CTA compared to functional testing (0.9% vs. 2.2%; HR 0.47 [95% CI 0.26, 0.83]; P=0.009), but not significantly different for other test strata. The overall prognostic performance (C-index) of CTA vs. functional testing was 0.72 (0.68, 0.76) vs. 0.64 (0.60, 0.69); P=0.022 (see KM curves in Figure). Conclusions: In symptomatic patients with suspected CAD, CTA has better prognostic value than functional testing.

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Challenges in Interpretation of Diagnostic Test Results in a Mumps Outbreak in a Highly Vaccinated Population

Clinical and Vaccine Immunology ◽

10.1128/cvi.00542-16 ◽

2016 ◽

Vol 24 (2) ◽

Cited By ~ 9

Author(s):

L. A. Trotz-Williams ◽

N. J. Mercer ◽

K. Paphitis ◽

J. M. Walters ◽

D. Wallace ◽

...

Keyword(s):

Diagnostic Tests ◽

Diagnostic Testing ◽

Local Area ◽

Case Definition ◽

Test Results ◽

Rt Pcr ◽

Mmr Vaccine ◽

Published Report ◽

The World ◽

Outbreak Case

ABSTRACT In spite of a greatly reduced incidence rate due to vaccination, mumps outbreaks continue to occur in several areas of the world, sometimes in vaccinated populations. This article describes an outbreak in a highly vaccinated population in southwestern Ontario, Canada, and the challenges encountered in interpreting the results of diagnostic tests used in the outbreak. During the outbreak, patients were interviewed and classified according to the outbreak case definition, and specimens were collected for diagnostic testing according to Ontario guidelines. Twenty-seven individuals were classified as confirmed cases (n = 19) or suspect cases (n = 8) according to the case definition, only 9 of which were laboratory-confirmed cases: 7 confirmed by reverse transcriptase PCR (RT-PCR) and 2 by IgM serology. All 19 confirmed cases represented patients who were associated with secondary schools in the local area and had been vaccinated against mumps with one (n = 2) or two (n = 17) doses of the measles-mumps-rubella (MMR) vaccine. This is the first published report of an outbreak of mumps in Ontario in which all confirmed cases had been vaccinated against the disease. It highlights the limitations of and difficulties in interpreting current mumps diagnostic tests when used in vaccinated individuals.

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Diagnostic testing: an emergency medicine perspective

CJEM ◽

10.1017/s1481803500007764 ◽

2002 ◽

Vol 4 (05) ◽

pp. 348-354 ◽

Cited By ~ 8

Author(s):

Andrew Worster ◽

Grant Innes ◽

Riyad B. Abu-Laban

Keyword(s):

Diagnostic Tests ◽

Diagnostic Testing ◽

Test Results ◽

Emergency Physicians ◽

Likelihood Ratios ◽

Predictive Values ◽

The Core ◽

Core Concepts ◽

Sensitivity Specificity ◽

Test Probability

ABSTRACT: Emergency physicians use diagnostic tests extensively, and the ability to order and interpret test results appropriately is a critical skill. An understanding of sensitivity, specificity, predictive values and likelihood ratios, as well as an awareness of the importance of pre-test probability, is essential. The purpose of this article is to explain, in a straightforward and clinically applicable manner, the core concepts related to diagnostic testing.

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