scholarly journals Diagnostic performances of manual and automated reticulocyte parameters in anaemic cats

2017 ◽  
Vol 20 (2) ◽  
pp. 122-127 ◽  
Author(s):  
Saverio Paltrinieri ◽  
Marco Fossati ◽  
Valentina Menaballi
Keyword(s):  
Receiver Operating Characteristic ◽  
Sensitivity And Specificity ◽  
Operating Characteristic ◽  
Positive Likelihood Ratio ◽  
Roc Curves ◽  
Blood Samples ◽  
Production Index ◽  
Instrumental Measurement ◽  
Sensitivity Specificity ◽  
Reticulocyte Production

Objectives The objective of this study was to evaluate the diagnostic performances of manual and instrumental measurement of reticulocyte percentage (Ret%), reticulocyte number (Ret#) and reticulocyte production index (RPI) to differentiate regenerative anaemia (RA) from non-regenerative anaemia (NRA) in cats. Methods Data from 106 blood samples from anaemic cats with manual counts (n = 74; 68 NRA, six RA) or instrumental counts of reticulocytes (n = 32; 25 NRA, seven RA) collected between 1995 and 2013 were retrospectively analysed. Sensitivity, specificity and positive likelihood ratio (LR+) were calculated using either cut-offs reported in the literature or cut-offs determined from receiver operating characteristic (ROC) curves. Results All the reticulocyte parameters were significantly higher in cats with RA than in cats with NRA. All the ROC curves were significantly different ( P <0.001) from the line of no discrimination, without significant differences between the three parameters. Using the cut-offs published in literature, the Ret% (cut-off: 0.5%) was sensitive (100%) but not specific (<75%), the RPI (cut-off: 1.0) was specific (>92%) but not sensitive (<15%), and the Ret# (cut-off: 50 × 10³/µl) had a sensitivity and specificity >80% and the highest LR+ (manual count: 14; instrumental count: 6). For all the parameters, sensitivity and specificity approached 100% using the cut-offs determined by the ROC curves. These cut-offs were higher than those reported in the literature for Ret% (manual: 1.70%; instrumental: 3.06%), lower for RPI (manual: 0.39; instrumental: 0.59) and variably different, depending on the method (manual: 41 × 10³/µl; instrumental: 57 × 10³/µl), for Ret#. Using these cut-offs, the RPI had the highest LR+ (manual: 22.7; instrumental: 12.5). Conclusions and relevance This study indicated that all the reticulocyte parameters may confirm regeneration when the pretest probability is high, while when this probability is moderate, RA should be identified using the RPI providing that cut-offs <1.0 are used.

Diagnostic studies

2010 ◽  
pp. 339-351
Author(s):  
Janet L. Peacock ◽  
Philip J. Peacock
Keyword(s):  
Receiver Operating Characteristic ◽  
Likelihood Ratio ◽  
Sensitivity And Specificity ◽  
Operating Characteristic ◽  
Characteristic Curve ◽  
Diagnostic Testing ◽  
Roc Curves ◽  
Clinical Situation ◽  
Post Test ◽  
Receiver Operating

Sensitivity and specificity 340 Calculations for sensitivity and specificity 342 Effect of prevalence 344 Likelihood ratio, pre-test odds, post-test odds 346 Receiver operating characteristic (ROC) curves 348 Links to other statistics 350 In this chapter we describe how statistical methods are used in diagnostic testing to obtain different measures of a test’s performance. We describe how to calculate sensitivity, specificity, and positive and negative predictive values, and show the relevance of pre- and post-test odds and likelihood ratio in evaluating a test in a clinical situation. We also describe the receiver operating characteristic curve and show how this links with logistic regression analysis. All methods are illustrated with examples....

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.

A Brief Measure of High Nicotine Dependence for Busy Clinicians and Large Epidemiological Surveys

2005 ◽  
Vol 39 (3) ◽  
pp. 161-168 ◽  
Author(s):  
Francisco J. Diaz ◽  
Mireia Jané ◽  
Esteve Saltó ◽  
Hélios Pardell ◽  
Lluís Salleras ◽  
...  
Keyword(s):  
Receiver Operating Characteristic ◽  
Nicotine Dependence ◽  
Sensitivity And Specificity ◽  
Operating Characteristic ◽  
Psychiatric Patients ◽  
Standard Test ◽  
Heavy Smoking ◽  
Epidemiological Surveys ◽  
Sensitivity Specificity ◽  
Receiver Operating

Objective: It is important to perform a routine screening of nicotine dependence in psychiatric patients. The Fagerström Test for Nicotine Dependence (FTND) is a widely used six-item questionnaire. The Heavy Smoking Index (HSI) is a briefer measure including only two FTND items (time to first cigarette of day and number of daily cigarettes). In a prior study comparing HSI with FTND, a high HSI (score ≥ 4) was a good and briefer alternative for detecting high nicotine dependence. The goals of this study were: (i) to compare the effectiveness of the HSI with the effectiveness of Items 1 and 4 alone for the screening of high nicotine dependence; (ii) to investigate the optimality of 4 as a cut-off score for the HSI so that the HSI can be used as a binary indicator of high nicotine dependence; and (iii) to compare the sensitivity and specificity of four indexes of high nicotine dependence, namely ‘High HSI’, ‘Very Early Smoking’, ‘Heavy Smoking’ and ‘High in Either Item’. Method: The FTND was administered to 819 current daily smokers from a general population survey. As in a prior study, an FTND score ≥ 6 was considered the reference or ‘gold standard’ test for detecting high nicotine dependence. Receiver-operating characteristic analyses were performed. Results: This new study using more sophisticated statistical methodology verified that a cut-off of 4 for the HSI is appropriate and that the ‘high’ HSI has good sensitivity and specificity even across different population subclassifications. Conclusions: With four questions (smoking, daily smoking, time to first cigarette of day and number of daily cigarettes) and minimal calculations, it may be possible to screen whether a smoker has high nicotine dependence. If other studies in other populations and settings verify this finding, this brief measure might be an ideal screening instrument for busy clinicians, epidemiologists developing questionnaires for health surveys and psychiatric researchers. Key words: nicotine dependence, receiver-operating characteristic analyses, sensitivity, specificity, tobacco smoking.

Single group studies

2017 ◽  
Author(s):  
Janet L. Peacock ◽  
Sally M. Kerry ◽  
Raymond R. Balise
Keyword(s):  
Receiver Operating Characteristic ◽  
Sensitivity And Specificity ◽  
Operating Characteristic ◽  
Rare Condition ◽  
Roc Curves ◽  
Single Group ◽  
Receiver Operating

Chapter 6 discusses single group studies, and covers prevalence, how to present results, screening studies, calculating, and presenting sensitivity and specificity. It discusses how to deal with calculations with a rare condition where the numbers are small. Finally, it discusses the use of receiver operating characteristic (ROC) curves. The chapter includes analyses using Stata, SAS, SPSS, and R.

Why Almost Always Animals? Ranking Fluency Tasks for the Detection of Dementia Based on Receiver Operating Characteristic (ROC) and Quality ROC Analyses

2016 ◽  
Vol 43 (1-2) ◽  
pp. 59-70 ◽  
Author(s):  
F. Javier Moreno-Martínez ◽  
Marcos Ruiz ◽  
Pedro R. Montoro
Keyword(s):  
Receiver Operating Characteristic ◽  
Sensitivity And Specificity ◽  
Operating Characteristic ◽  
Empirical Evaluation ◽  
Empirical Support ◽  
Roc Curves ◽  
Semantic Categories ◽  
Healthy Elderly ◽  
Category Fluency ◽  
Receiver Operating

Background/Aims: Category fluency tasks have been widely used to assess cognitive functioning in both clinical and experimental environments as an index of cognitive and psycholinguistic dysfunctions in dementia. Typically, a reduced group of semantic categories has been selected for neuropsychological assessment (e.g., animals, fruits or vegetables), although empirical support for the prevalence of one category among others is absent in the literature. Methods: We provide an empirical evaluation of the ability of 14 category fluency tasks to discriminate between subjects with dementia of the Alzheimer type and healthy elderly participants. As a novelty, we used both receiver operating characteristic (ROC) curves and quality ROC calibrated analyses to characterize the interplay of sensitivity and specificity of every category fluency task performance as a screening tool. The use of calibrated measures provided us with a useful tool for comparing the diagnostic ability of the different categories, as well as making rankings of categories based on the quality indices of efficiency, sensitivity, and specificity. Results: The habitually used category of animals is far from being the most efficient one in terms of its diagnostic power to evaluate dementia. Conclusion: Our study might guide the selection of suitable category fluency tasks according to the diagnostic purposes in dementia.

Use of Receiver Operating Characteristic (ROC) Curves to Evaluate Computer Confidence Threshold and Clinical Performance in the Diagnosis of Appendicitis

1978 ◽  
Vol 17 (03) ◽  
pp. 157-161 ◽  
Author(s):  
F. T. De Dombal ◽  
Jane C. Horrocks
Keyword(s):  
Receiver Operating Characteristic ◽  
Operating Characteristic ◽  
Clinical Performance ◽  
Roc Curves ◽  
Final Diagnosis ◽  
Confidence Threshold ◽  
Computer Aided ◽  
Computer Confidence ◽  
Overall Performance ◽  
Receiver Operating

This paper uses simple receiver operating characteristic (ROC) curves (i) to study the effect of varying computer confidence of threshold levels and (ii) to evaluate clinical performance in the diagnosis of acute appendicitis. Over 1300 patients presenting to five centres with abdominal pain of short duration were studied in varying detail. Clinical and computer-aided diagnostic predictions were compared with the »final« diagnosis. From these studies it is concluded the simplistic setting of a 50/50 confidence threshold for the computer program is as »good« as any other. The proximity of a computer-aided system changed clinical behaviour patterns; a higher overall performance level was achieved and clinicians performance levels became associated with the »mildly conservative« end of the computers ROC curve. Prior forecasts of over-confidence or ultra-caution amongst clinicians using the computer-aided system have not been fulfilled.

scholarly journals MicroRNAs-1299, -126-3p and -30e-3p as Potential Diagnostic Biomarkers for Prediabetes

Diagnostics ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 949
Author(s):  
Cecil J. Weale ◽  
Don M. Matshazi ◽  
Saarah F. G. Davids ◽  
Shanel Raghubeer ◽  
Rajiv T. Erasmus ◽  
...  
Keyword(s):  
Receiver Operating Characteristic ◽  
Operating Characteristic ◽  
Characteristic Curve ◽  
Predictive Ability ◽  
Roc Curves ◽  
Tolerance Test ◽  
Cross Sectional Study ◽  
Oral Glucose ◽  
Cross Sectional ◽  
Receiver Operating

This cross-sectional study investigated the association of miR-1299, -126-3p and -30e-3p with and their diagnostic capability for dysglycaemia in 1273 (men, n = 345) South Africans, aged >20 years. Glycaemic status was assessed by oral glucose tolerance test (OGTT). Whole blood microRNA (miRNA) expressions were assessed using TaqMan-based reverse transcription quantitative-PCR (RT-qPCR). Receiver operating characteristic (ROC) curves assessed the ability of each miRNA to discriminate dysglycaemia, while multivariable logistic regression analyses linked expression with dysglycaemia. In all, 207 (16.2%) and 94 (7.4%) participants had prediabetes and type 2 diabetes mellitus (T2DM), respectively. All three miRNAs were significantly highly expressed in individuals with prediabetes compared to normotolerant patients, p < 0.001. miR-30e-3p and miR-126-3p were also significantly more expressed in T2DM versus normotolerant patients, p < 0.001. In multivariable logistic regressions, the three miRNAs were consistently and continuously associated with prediabetes, while only miR-126-3p was associated with T2DM. The ROC analysis indicated all three miRNAs had a significant overall predictive ability to diagnose prediabetes, diabetes and the combination of both (dysglycaemia), with the area under the receiver operating characteristic curve (AUC) being significantly higher for miR-126-3p in prediabetes. For prediabetes diagnosis, miR-126-3p (AUC = 0.760) outperformed HbA1c (AUC = 0.695), p = 0.042. These results suggest that miR-1299, -126-3p and -30e-3p are associated with prediabetes, and measuring miR-126-3p could potentially contribute to diabetes risk screening strategies.

scholarly journals A New Evaluation Method for Lumbar Spinal Instability: Passive Lumbar Extension Test

2006 ◽  
Vol 86 (12) ◽  
pp. 1661-1667 ◽  
Author(s):  
Yuichi Kasai ◽  
Koichiro Morishita ◽  
Eiji Kawakita ◽  
Tetsushi Kondo ◽  
Atsumasa Uchida
Keyword(s):  
Likelihood Ratio ◽  
Sensitivity And Specificity ◽  
Evaluation Method ◽  
Positive Likelihood Ratio ◽  
Spinal Instability ◽  
Predictive Values ◽  
Flexion Extension ◽  
Lumbar Extension ◽  
Lumbar Spinal ◽  
Sensitivity Specificity

Abstract Background and PurposeAlthough many studies have described clinical examination measures for the diagnosis of lumbar spinal instability, few of them have investigated the sensitivity and specificity of the measures that were used. The authors devised a passive lumbar extension (PLE) test for assessing lumbar spinal instability. The purpose of this study was to investigate the sensitivity, specificity, and positive likelihood ratio of this test. Subjects and Methods. The PLE test as well as the instability catch sign, painful catch sign, and apprehension sign tests were done for 122 subjects with lumbar degenerative diseases. The subjects were divided into 2 groups—instability positive and instability negative—on the basis of findings on flexion-extension films of the lumbar spine. The sensitivity, specificity, predictive values, and positive likelihood ratio of each test were investigated. Results. The sensitivity and specificity of the PLE test were 84.2% and 90.4%, respectively. These values were higher than those of other signs. The positive likelihood ratio of the PLE test was 8.84 (95% confidence interval=4.51–17.33). Discussion and Conclusion. The PLE test is an effective method for examining patients for lumbar spinal instability and can be performed easily in an outpatient clinic.

scholarly journals Clinical utility of microRNA-451 as diagnostic biomarker for human cancers

2019 ◽  
Vol 39 (1) ◽  
Author(s):  
Zhanzhan Li ◽  
Yanyan Li ◽  
Jun Fu ◽  
Na Li ◽  
Liangfang Shen
Keyword(s):  
Likelihood Ratio ◽  
Sensitivity And Specificity ◽  
Odds Ratio ◽  
Random Effect ◽  
Random Effect Model ◽  
Positive Likelihood Ratio ◽  
Negative Likelihood Ratio ◽  
Diagnostic Odds Ratio ◽  
Diagnostic Ability ◽  
Sensitivity Specificity

AbstractWe conducted comprehensive analyses to assess the diagnostic ability of miRNA-451 in cancers. A systematic online search was conducted in PubMed, Web of Science, China’s national knowledge infrastructure, and VIP databases from inception to July 31, 2017. The bivariate random effect model was used for calculating sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and area under cure (AUC). The whole pooled sensitivity and specificity were 0.85 (0.77–0.90) and 0.85 (0.78–0.90) with their 95% confidence interval (95%CI), respectively. The pooled AUC was 0.91 (95%CI: 0.89–0.94). Positive likelihood ratio was 5.57 (95%CI: 3.74–8.31), negative likelihood ratio was 0.18 (95%CI: 0.11–0.28), and diagnostic odds ratio was 31.33 (95%CI: 15.19–64.61). Among Asian population, the sensitivity and specificity were 0.85 (95%CI: 0.77–0.91) and 0.86 (95%CI: 0.78–0.91), respectively. The positive likelihood ratio and negative likelihood ratio were 5.87 (95%CI: 3.78–9.12) and 0.17 (95%CI: 0.11–0.28). The diagnostic odds ratio and AUC were 34.31 (15.51–75.91) and 0.92 (0.89–0.94). The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and AUC for digestive system cancer were 0.83, 0.88, 6.87, 0.20, 35.13, and 0.92, respectively. The other cancers were 0.87, 0.81, 4.55, 0.16, 28.51, and 0.90, respectively. For sample source, the results still remain consistent. Our results indicated miRNA-451 has a moderate diagnostic ability for cancers, and could be a potential early screening biomarker, and considered as an adjuvant diagnostic index when being combined with other clinical examinations.

Sign in / Sign up

Export Citation Format

Share Document