scholarly journals Calculating Sensitivity, Specificity and Predictive Values for Medical Diagnostic Tests

2018 ◽  
Vol 5 (2) ◽  
Author(s):  
Kareem Hatam Nahavandi
Keyword(s):  
Diagnostic Tests ◽  
Predictive Values ◽  
Medical Diagnostic ◽  
Sensitivity Specificity

scholarly journals Performance of Diagnostic Tests for Plasma Cell Myeloma

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 5570-5570
Author(s):  
Gilda Zagoya ◽  
Alejandro Ruiz-Argüelles ◽  
Guillermo J. Ruiz-Arguelles
Keyword(s):  
Plasma Cell ◽  
Diagnostic Tests ◽  
Laboratory Tests ◽  
Light Chains ◽  
Plasma Cell Myeloma ◽  
Immunoglobulin Light Chains ◽  
Predictive Values ◽  
Sensitivity Specificity ◽  
Total Immunoglobulin

Abstract Introduction. In vitro laboratory tests to diagnose of plasma cell myeloma vary considerably in sensitivity, specificity and positive and negative predictive values. We compared the performance of quantification of free immunoglobulin light chains with other methods used to detect a monoclonal protein in serum and/or urine. Objective. Compare sensitivity, specificity and positive and negative predictive values of several in vitro laboratory tests to detect monoclonal proteins in serum and urine in persons with plasma cell myeloma. Methods. 70 subjects with plasma cell myeloma and 50 controls were studied. Diagnostic tests included: (1) quantification of free and total immunoglobulin light-chains by immune assays; (2) immune fixation of heavy-and light-chains in serum and urine after gel electrophoresis; and (3) serum protein capillary electrophoresis. Diagnosis of plasma cell myeloma was based on clinical and radiological criteria, bone marrow examination and flow cytometric immune phenotyping with monoclonal antibodies to CD56, CD19, CD138 (CD38) and CD45. Sensitivity, specificity and positive and negative predictive values for each tests were estimated from contingency tables. Results. Quantification of free immmunoglobulin light-chains had the highest sensitivity and specificity and best positive and negative predictive values. Immune fixation of serum immunoglobulins was next best. Quantification of total immunoglobulin light-chains was the least sensitive and specific with the worst positive and negative predictive values. Quantitation of free light-chains had the additional advantage of objectivity (independence from observer bias). The immune fixation test was the most subject to observer bias. Conclusion. Quantification of free immunoglobulin light-chains had the best sensitivity, specificity and positive and negative predictive values for diagnosing plasma cell myeloma. (Table 1) Disclosures No relevant conflicts of interest to declare.

Clinical Epidemiology

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.

scholarly journals Clinicians' guide to evaluating diagnostic and screening tests in psychiatry

2004 ◽  
Vol 10 (6) ◽  
pp. 446-454 ◽  
Author(s):  
James Warner
Keyword(s):  
Diagnostic Tests ◽  
Critical Appraisal ◽  
Evidence Base ◽  
Psychiatric Practice ◽  
Screening Tests ◽  
Clinical Settings ◽  
Likelihood Ratios ◽  
Predictive Values ◽  
Incorrect Diagnosis ◽  
Sensitivity Specificity

The emphasis on the evidence base of treatments may diminish awareness that critical appraisal of research into other aspects of psychiatric practice is equally important. There is a risk that diagnostic tests may be inappropriate in some clinical settings or the results of a particular test may be over-interpreted, leading to incorrect diagnosis. This article outlines the method of critically evaluating the validity of articles about diagnostic and screening tests in psychiatry and discusses concepts of sensitivity, specificity and predictive values. The use of likelihood ratios in improving clinical certainty that a disease is present or absent is examined.

scholarly journals Diagnosis of asthma in children: the contribution of a detailed history and test results

2019 ◽  
Vol 54 (6) ◽  
pp. 1901326 ◽  
Author(s):  
Carmen C.M. de Jong ◽  
Eva S.L. Pedersen ◽  
Rebeca Mozun ◽  
Myrofora Goutaki ◽  
Daniel Trachsel ◽  
...  
Keyword(s):  
Diagnostic Tests ◽  
Area Under The Curve ◽  
Forced Expiratory Volume ◽  
Predictive Values ◽  
Detailed History ◽  
Provocation Tests ◽  
Skin Prick Tests ◽  
Asthma In Children ◽  
Few Data ◽  
Sensitivity Specificity

IntroductionThere are few data on the usefulness of different tests to diagnose asthma in children.AimWe assessed the contribution of a detailed history and a variety of diagnostic tests for diagnosing asthma in children.MethodsWe studied children aged 6–16 years referred consecutively for evaluation of suspected asthma to two pulmonary outpatient clinics. Symptoms were assessed by parental questionnaire. The clinical evaluation included skin-prick tests, measurement of exhaled nitric oxide fraction (FeNO), spirometry, bronchodilator reversibility and bronchial provocation tests (BPT) by exercise, methacholine and mannitol. Asthma was diagnosed by the physicians at the end of the visit. We assessed diagnostic accuracy of symptoms and tests by calculating sensitivity, specificity, positive and negative predictive values and area under the curve (AUC).ResultsOf the 111 participants, 80 (72%) were diagnosed with asthma. The combined sensitivity and specificity was highest for reported frequent wheeze (more than three attacks per year) (sensitivity 0.44, specificity 0.90), awakening due to wheeze (0.41, 0.90) and wheeze triggered by pollen (0.46, 0.83) or by pets (0.29, 0.99). Of the diagnostic tests, the AUC was highest for FeNO measurement (0.80) and BPT by methacholine (0.81) or exercise (0.74), and lowest for forced expiratory volume in 1 s (FEV1) (0.62) and FEV1/forced vital capacity ratio (0.66), assessed by spirometry.ConclusionThis study suggests that specific questions about triggers and severity of wheeze, measurement of FeNO and BPT by methacholine or exercise contribute more to the diagnosis of asthma in school-aged children than spirometry, bronchodilator reversibility and skin-prick tests.

scholarly journals Evaluating the use of microscopic examination and rapid diagnostic tests to diagnose malaria in North Central Nigeria

2014 ◽  
Vol 3 (1) ◽  
Author(s):  
Innocent C. Omalu ◽  
George Uzoaga ◽  
Israel Kayode Olayemi ◽  
Charles Mgbemena ◽  
Suleiman Hassan ◽  
...  
Keyword(s):  
Diagnostic Tests ◽  
Test Line ◽  
Rapid Diagnostic Tests ◽  
Effective Management ◽  
Infection Rates ◽  
Predictive Values ◽  
North Central ◽  
Diagnostic Strategies ◽  
Global Impact ◽  
Sensitivity Specificity

The global impact of malaria has spurred interest in developing prompt and accurate diagnostic strategies to provide an effective management of the disease. The aim of this study was to compare rapid diagnostic tests (RDTs) for malaria with routine microscopy. Samples were collected randomly from 364 febrile out-patients with clinical suspicion of malaria from four hospitals in North Central Nigeria. Results from the rapid diagnostic kits were analysed and compared to those obtained by general microscopy. Of the 364 out-patients involved in the study, 218 (59.89%) tested positive for <em>Plasmodium falciparum</em> by RDTs, whereas 263 (72.256%) tested positive by microscopy. There are significant differences (P&lt;0.05) in infection rates between RDT and microscopy. The sensitivity, specificity and negative predictive values of RDTs compared to microscopy are low, while the positive predictive value is high. Evaluation of RDTs against the parasite-positive panel with parasite densities of &lt;1000 parasites/μL, between 1000-5000 parasites/μL and above 5000 parasites/ μL was 11.73, 30.61, 57.65% for RDTs compared to 6.11, 27.95 and 65.94% for microscopy, respectively. Test line intensity increases with increase in parasite densities for both methods.

The Interpretation of Test Results

2000 ◽  
Vol 4 (1) ◽  
pp. 19-25 ◽  
Author(s):  
Michael Binder ◽  
Stephan Dreiseitl
Keyword(s):  
Decision Making ◽  
Receiver Operating Characteristic ◽  
Diagnostic Tests ◽  
Operating Characteristic ◽  
Roc Curves ◽  
Test Results ◽  
Likelihood Ratios ◽  
Clinical Routine ◽  
Predictive Values ◽  
Sensitivity Specificity

Background: Dermatologists need to interpret an increasing number of research studies and diagnostic tests. Understanding the techniques for interpreting test results and making decisions based upon those tests represent important tools for decision making for both clinicians and researchers. Objective: This article focuses briefly on the key parameters of diagnostic tests: sensitivity, specificity, prevalence, predictive values, likelihood ratios, and the concept of receiver-operating-characteristic (ROC) curves. A simple example is presented in a step-by-step manner. Conclusion: The principles of interpreting test results are easy to learn and applicable in daily clinical routine. Therefore, dermatologists should be familiar with the concepts outlined in this paper.

scholarly journals Sensitivity, Specificity, Predictive Values, and Accuracy of Three Diagnostic Tests to Predict Inferior Alveolar Nerve Blockade Failure in Symptomatic Irreversible Pulpitis

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Daniel Chavarría-Bolaños ◽  
Laura Rodríguez-Wong ◽  
Danny Noguera-González ◽  
Vicente Esparza-Villalpando ◽  
Mauricio Montero-Aguilar ◽  
...  
Keyword(s):  
Diagnostic Tests ◽  
Inferior Alveolar Nerve ◽  
Roc Curves ◽  
Cross Sectional Study ◽  
Anesthetic Technique ◽  
Cross Sectional ◽  
Predictive Values ◽  
Anesthetic Failure ◽  
Sensitivity Specificity ◽  
Irreversible Pulpitis

Introduction.The inferior alveolar nerve block (IANB) is the most common anesthetic technique used on mandibular teeth during root canal treatment. Its success in the presence of preoperative inflammation is still controversial. The aim of this study was to evaluate the sensitivity, specificity, predictive values, and accuracy of three diagnostic tests used to predict IANB failure in symptomatic irreversible pulpitis (SIP).Methodology.A cross-sectional study was carried out on the mandibular molars of 53 patients with SIP. All patients received a single cartridge of mepivacaine 2% with 1 : 100000 epinephrine using the IANB technique. Three diagnostic clinical tests were performed to detect anesthetic failure. Anesthetic failure was defined as a positive painful response to any of the three tests. Sensitivity, specificity, predictive values, accuracy, and ROC curves were calculated and compared and significant differences were analyzed.Results.IANB failure was determined in 71.7% of the patients. The sensitivity scores for the three tests (lip numbness, the cold stimuli test, and responsiveness during endodontic access) were 0.03, 0.35, and 0.55, respectively, and the specificity score was determined as 1 for all of the tests. Clinically, none of the evaluated tests demonstrated a high enough accuracy (0.30, 0.53, and 0.68 for lip numbness, the cold stimuli test, and responsiveness during endodontic access, resp.). A comparison of the areas under the curve in the ROC analyses showed statistically significant differences between the three tests (p<0.05).Conclusion.None of the analyzed tests demonstrated a high enough accuracy to be considered a reliable diagnostic tool for the prediction of anesthetic failure.

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