Glucosuria: accuracy and precision of laboratory diagnosis by dip stick analysis.

1979 ◽  
Vol 25 (6) ◽  
pp. 996-1001 ◽  
Author(s):  
G P James ◽  
D E Bee

Abstract Two urine dip-stick assays for glucose were studied and compared to a quantitative hexokinase procedure. We determined sensitivity, specificity, predictive value of "normal" and "abnormal" dip stick results, assay efficiency, technologist precision, and method association. Precision was poor. Attempts to estimate urine glucose concentration with the dip sticks frequently produced gross inaccuracies. We believe the dip stick glucose assay should be considered qualitative only; as a qualitative test, the dip sticks are fairly efficient at distinguishing glucose concentrations of less than 0.3 g/L from concentrations greater than 0.3 g/L.

1978 ◽  
Vol 24 (11) ◽  
pp. 1934-1939 ◽  
Author(s):  
G P James ◽  
D E Bee ◽  
J B Fuller

Abstract We studied and compared results of two urine dip-stick procedures for protein with those of quantitative measurements of total protein and albumin in urine. Sensitivity, specificity, and predictive value of "normal" and "abnormal" dip-stick results, assay efficiency, technologist precision, and method association were determined. Precision was poor, attributable largely to variation within each technologist. Relative to a defined measure of precision, technologist performance appears to be uniform within each product. Patients' urinary protein concentrations of less than 200 mg/liter can be distinguished from concentrations greater than 3000 mg/liter with confidence by dip-stick procedures. Urin samples with low albumin/total protein ratios were frequently falsely negative by dip-stick assays.


2021 ◽  
Vol 104 (4) ◽  
pp. 1513-1515 ◽  
Author(s):  
Ángel Guevara ◽  
Sandra Vivero ◽  
Victoria Nipaz ◽  
Victor Guaraca ◽  
Josefina Coloma

ABSTRACTLaboratory diagnosis of the COVID-19 relies on RT-PCR to amplify specific fragments of SARS-CoV-2 genome. However, serological tests are required to determine the immune response elicited after infection. Here, we analyzed convalescent sera collected from positive individuals by RT-PCR to SARS-CoV-2 (n = 78), Zika (n = 20), dengue (n = 20), chikungunya (n = 54), intestinal parasites (n = 11), and HIV (n = 1), from different areas of Ecuador, with an in-house ELISA using a SARS-CoV-2 receptor binding domain recombinant (rRBD) antigen to detect IgG antibodies elicited by SARS-CoV-2 infection. Of the 78 samples positive for SARS-CoV-2 by RT-PCR, 73 showed high absorbance value compared with the cutoff and five were negative. All tested sera from other infections showed no reactivity. Sensitivity, specificity, positive predictive value, and negative predictive value were 93.6%, 100%, 100%, and 95.4%, respectively. This in-house anti-IgG rRBD ELISA offers an economic and simple alternative to determine IgG immune responses after SARS-CoV-2 infection.


2014 ◽  
Vol 40 (2) ◽  
pp. 148-154 ◽  
Author(s):  
Leonardo Bruno Paz Ferreira Barreto ◽  
Maria Cristina da Silva Lourenço ◽  
Valéria Cavalcanti Rolla ◽  
Valdiléia Gonçalves Veloso ◽  
Gisele Huf

OBJECTIVE: To compare the accuracy of the amplified Mycobacterium tuberculosis direct (AMTD) test with reference methods for the laboratory diagnosis of tuberculosis in HIV-infected patients. METHODS: This was a study of diagnostic accuracy comparing AMTD test results with those obtained by culture on Löwenstein-Jensen (LJ) medium and by the BACTEC Mycobacteria Growth Indicator Tube 960 (BACTEC MGIT 960) system in respiratory samples analyzed at the Bioassay and Bacteriology Laboratory of the Oswaldo Cruz Foundation Evandro Chagas Clinical Research Institute in the city of Rio de Janeiro, Brazil. RESULTS: We analyzed respiratory samples collected from 118 patients, of whom 88 (74.4%) were male. The mean age was 36.6 ± 10.6 years. Using the AMTD test, the BACTEC MGIT 960 system, and LJ culture, we identified M. tuberculosis complex in 31.0%, 29.7%, and 27.1% of the samples, respectively. In comparison with LJ culture, the AMTD test had a sensitivity, specificity, positive predictive value, and negative predictive value of 87.5%, 89.4%, 75.7%, and 95.0%, respectively, for LJ culture, whereas, in comparison with the BACTEC MGIT 960 system, it showed values of 88.6%, 92.4%, 83.8%, and 94.8%, respectively. CONCLUSIONS: The AMTD test showed good sensitivity and specificity in the population studied, enabling the laboratory detection of M. tuberculosis complex in paucibacillary respiratory specimens.


2009 ◽  
Vol 29 (S 01) ◽  
pp. S87-S89 ◽  
Author(s):  
I. Music ◽  
M. Novak ◽  
B. Acham-Roschitz ◽  
W. Muntean

SummaryAim: In children, screening for haemorrhagic disorders is further complicated by the fact that infants and young children with mild disease in many cases most likely will not have a significant history of easy bruising or bleeding making the efficacy of a questionnaire even more questionable. Patients, methods: We compared the questionnaires of a group of 88 children in whom a haemorrhagic disorder was ruled out by rigorous laboratory investigation to a group of 38 children with mild von Willebrand disease (VWD). Questionnaires about child, mother and father were obtained prior to the laboratory diagnosis on the occasion of routine preoperative screening. Results: 23/38 children with mild VWD showed at least one positive question in the questionnaire, while 21/88 without laboratory signs showed at least one positive question. There was a trend to more specific symptoms in older children. Three or more positive questions were found only in VWD patients, but only in a few of the control group. The question about menstrual bleeding in mothers did not differ significantly. Sensitivity of the questionnaire for a hemostatic disorder was 0.60, while specifity was 0.76. The negative predictive value was 0.82, but the positive predictive value was only 0.52. Conclusions: Our small study shows, that a questionnaire yields good results to exclude a haemostatic disorder, but is not a sensitive tool to identify such a disorder.


2012 ◽  
Vol 15 (1) ◽  
pp. 12 ◽  
Author(s):  
Levent Sahiner ◽  
Ali Oto ◽  
Kudret Aytemir ◽  
Tuncay Hazirolan ◽  
Musturay Karcaaltincaba ◽  
...  

<p><b>Background:</b> The aim of this study was to investigate the diagnostic accuracy of 16-slice multislice, multidetector computed tomography (MDCT) angiography for the evaluation of grafts in patients with coronary artery bypass grafting (CABG).</p><p><b>Methods:</b> Fifty-eight consecutive patients with CABG who underwent both MDCT and conventional invasive coronary angiography were included. The median time interval between the 2 procedures was 10 days (range, 1-32 days). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of MDCT for the detection of occluded grafts were calculated. The accuracy of MDCT angiography for detecting significant stenoses in patent grafts and the evaluability of proximal and distal anastomoses were also investigated.</p><p><b>Results:</b> Optimal diagnostic images could not be obtained for only 3 (2%) of 153 grafts. Evaluation of the remaining 150 grafts revealed values for sensitivity, specificity, PPV, NPV, and diagnostic accuracy of the MDCT angiography procedure for the diagnosis of occluded grafts of 87%, 97%, 94%, 93%, and 92%, respectively. All of the proximal anastomoses were optimally visualized. In 4 (8%) of 50 patent arterial grafts, however, the distal anastomotic region could not be evaluated because of motion and surgical-clip artifacts. The accuracy of MDCT angiography for the detection of significant stenotic lesions was relatively low (the sensitivity, specificity, PPV, and NPV were 67%, 98%, 50%, and 99%, respectively). The number of significant lesions was insufficient to reach a reliable conclusion, however.</p><p><b>Conclusion:</b> Our study showed that MDCT angiography with 16-slice systems has acceptable diagnostic performance for the evaluation of coronary artery bypass graft patency.</p>


2018 ◽  
Vol 1 ◽  
pp. 9
Author(s):  
Harshad Arvind Vanjare ◽  
Jyoti Panwar

Objective The objective of the study was to assess the accuracy of ultrasound examination for the diagnosis of rotator cuff tear and tendinosis performed by a short experienced operator, compared to magnetic resonance imaging (MRI) results. Method A total of 70 subjects suspected to have rotator cuff tear or tendinosis and planned for shoulder MRI were included in the study. Shoulder ultrasound was performed either before or after the MRI scan on the same day. Ultrasound operator had a short experience in performing an ultrasound of the shoulder. Ultrasound findings were correlated to MRI findings. Results Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for the diagnosis of tendinosis were 58%, 84%, 63%, 80%, and 75%, respectively, and it was 68%, 91%, 73%, 88%, and 85%, respectively, for the diagnosis of rotator cuff tear. Conclusions Sensitivity for diagnosing rotator cuff tear or tendinosis was moderate but had a higher negative predictive value. Thus, the ultrasound operator with a short experience in performing shoulder ultrasound had moderate sensitivity in diagnosing tendinosis or tears; however, could exclude them with confidence.


2017 ◽  
pp. 59-63
Author(s):  
Thanh Hung Dieu ◽  
Anh Vu Nguyen

Objects: We assessed the ability of ST-segment elevation in lead aVR to predict left main and/or 3-vessel disease (LM/3VD) in patients with acute coronary syndromes (ACS). Meterial and Method: 410 patients with ACS, who underwent coronary angiography, were evaluated. Results: 131 (31.9%) patients have been LM/3VD. ST segment elevation > 0.05 mV in leads aVR have been an independent predictor LM/3VD with sensitivity, specificity, positive predictive value PPV) and negative predictive value (NPV) 74.0%, 78.1%, 61.4% and 86.5%, respectively (p<0.001). ST segment elevation > 0.05 mV in leads aVR with ST segment depression in leads V4-V6 have related LM/3VD with sensitivity, specificity, PPV and NPV 44.3%, 92.8%, 74.4% and 75.2%, respectively (p<0.001). ST segment elevation > 0.1 mV in leads aVR have related LM/3VD with sensitivity, specificity, PPV and NPV 51.9%, 87.1%, 65.1% and 79.4%, respectively (p<0.001). Conclusions: ST segment elevation > 0.05 mV in leads aVR have been an independent predictor LM/3VD in patients with ACS. Key words: Acute coronary syndromes, ST-segment elevation, aVR


2008 ◽  
Vol 47 (04) ◽  
pp. 163-166 ◽  
Author(s):  
D. Steiner ◽  
S. Laurich ◽  
R. Bauer ◽  
J. Kordelle ◽  
R. Klett

SummaryIn not infected knee prostheses bone scintigraphy is a possible method to diagnose mechanical loosening, and therefore, to affect treatment regimes in symptomatic patients. However, hitherto studies showed controversial results for the reliability of bone scintigraphy in diagnosing loosened knee prostheses by using asymptomatic control groups. Therefore, the aim of our study was to optimize the interpretation procedure and to evaluate the accuracy using results from revision surgery as standard. Methods: Retrospectively, we were able to examine the tibial component in 31 cemented prostheses. In this prostheses infection was excluded by histological or bacteriological examination during revision surgery. To quantify bone scintigraphy, we used medial and lateral tibial regions with a reference region from the contralateral femur. Results: To differentiate between loosened and intact prostheses we found a threshold of 5.0 for the maximum tibia to femur ratio of the both tibial regions and a threshold of 18% for the difference of the ratio of both tibial regions. Using these thresholds, values of 0.9, 1, 0.85, 1, and 0.94 were calculated for sensitivity, specificity, negative predictive value, positive predictive value, and accuracy, respectively. To get a sensitivity of 1, we found a lower threshold of 3.3 for the maximum tibia to femur ratio. Conclusion: Quantitative bone scintigraphy appears to be a reliable diagnostic tool for aseptic loosening of knee prostheses with thresholds evaluated by revision surgery results being the golden standard.


2020 ◽  
Vol 103 (6) ◽  
pp. 585-593

Objective: To evaluate the accuracy of transvaginal ultrasonography (TVS) and saline infusion sonography (SIS) in use for the diagnosis of endometrial polyps and submucous myoma compared to hysteroscopy. Histopathology was considered as the gold standard for final diagnosis. Materials and Methods: The present retrospective study was conducted at Bhumibol Adulyadej Hospital, Bangkok, Thailand between January 2014 and December 2017. Medical records of 150 patients who attended for hysteroscopy and histopathological diagnosis were reviewed. The accuracy of TVS and SIS for the diagnosis of endometrial polyps and submucous myoma were determined. Results: Out of 150 enrolled cases, endometrial polyp was the most frequent hysteroscopic finding in participants of the present study (92/150). Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of TVS, SIS, and hysteroscopy compared to pathologic reports for detection endometrial polyps were 71.7% versus 93.5% versus 97.8%, 38.5% versus 52.2% versus 68.2%, 80.5% versus 88.7% versus 92.8%, 27.8% versus 66.7% versus 88.2%, and 64.4% versus 85.2% versus 92.1%, respectively. The sensitivity, specificity, PPV, NPV, and accuracy of TVS, SIS, and hysteroscopy for detection of submucous myoma were 81.6% versus 92.1% versus 94.7%, 66.7% versus 86.9% versus 100%, 77.5% versus 92.1% versus 100%, 72.0% versus 86.9% versus 90.9%, and 75.4% versus 90.2% versus 96.6%, respectively. The kappa value from TVS, SIS, and hysteroscopy when the histopathologic reports were overall intrauterine abnormalities, endometrial polyps and submucous myoma were 0.45/0.43/0.72, 0.77/0.76/0.89, and 0.92/0.92/1.00, respectively. Conclusion: Sensitivity, specificity, PPV, NPV, accuracy, and kappa value of SIS for detecting endometrial polyps and submucous myoma were better than TVS. Keywords: Ultrasonography, Saline infusion sonography, Hysteroscopy, Accuracy


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