Assessing a chip based rapid RTPCR test for SARS CoV-2 detection (TrueNat assay): A diagnostic accuracy study

COVID-19 testing is required before admission of a patient in the hospitals, invasive procedures, major and minor surgeries etc. Real Time Polymerase chain reaction is the gold standard test for the diagnosis, but requires well equipped biosafety laboratory along with trained manpower. In this study we have evaluated the diagnostic accuracy of novel TrueNat molecular assay for detecting SARS CoV-2. TrueNat is a chip-based real time PCR test and works on portable, light weight, battery powered equipment and can be used in remote areas with poor infrastructure. In this study 1807 patients samples were collected for both TrueNat and RTPCR COVID-19 testing during study period. Of these 174 (9.7%) and 174 (15%) were positive by RTPCR and TrueNat respectively and taking results of RTPCR as gold standard TrueNat test showed a sensitivity, specificity and diagnostic accuracy of 69.5, 90.9% and 89.2% respectively. It can be concluded that TrueNat is a simple, easy to use, good rapid molecular diagnostic test for diagnosis of COVID-19 especially in resource limited settings and will prove to be a game changer of molecular diagnostics in future.

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Utility of Nucleic Acid Extraction Free COVID-19 Real Time PCR Protocol in Resource Limited Setting: A Pilot Study

JOURNAL FOR CLINICAL AND DIAGNOSTIC RESEARCH ◽

10.7860/jcdr/2021/48363.14842 ◽

2021 ◽

Author(s):

Santosh Karade ◽

Pratik Thosani ◽

Prashant Patil ◽

Kavita Bala Anand ◽

Sourav Sen ◽

...

Keyword(s):

Nucleic Acid ◽

Pilot Study ◽

Real Time ◽

Gold Standard ◽

Rna Extraction ◽

Molecular Diagnostic ◽

Acid Extraction ◽

Rt Pcr ◽

Nucleic Acid Extraction ◽

Resource Limited

Introduction: Coronavirus Disease (COVID-19), a respiratory infection, caused by severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2), was first identified in Wuhan, Hubei province, China in December 2019. Alarming increase in the number of cases has put tremendous pressure on existing health resources. Real Time Reverse Transcriptase Polymerase Chain Reaction (RT-PCR), a molecular diagnostic method, is considered gold standard for diagnosis of SARS-CoV-2 infection. It involves RNA extraction as the preliminary step. Innovations to cut down cost and time involved in SARS-CoV-2 testing are need of hour. Aim: The aim of this study was to assess the feasibility of Nucleic Acid Extraction Free (NEF) protocol for COVID-19 diagnosis in resource limited settings. Materials and Methods: In this pilot study a panel of 148 Nasopharyngeal (NP) samples was subjected to the novel NEF RT-PCR protocol and results were compared to gold standard RT-PCR on RNA extracted from NP specimen. The cycle threshold value for each target was tabulated in MS Excel Spreadsheet and data analysis was performed using Statistical Package for Social Sciences (SPSS) software version 15.0. Results: Out of 148 collected samples, 120 showed amplification of E and RdRp targets by RNA extraction-based RT-PCR. Overall sensitivity and specificity observed for NEF protocol was 43.94% and 96.42%, respectively. Conclusion: Further refinement in the protocol would be required to improve the sensitivity of NEF protocol and widespread use in laboratories.

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Diagnostic Value of Immature-to-Total Neutrophil Ratio in Neonatal Sepsis

Journal of Islamabad Medical & Dental College ◽

10.35787/jimdc.v8i4.475 ◽

2019 ◽

Vol 8 (4) ◽

pp. 166-170

Author(s):

Husnain Ali ◽

Ejaz Hussain ◽

Imran Mahmood Khan ◽

Iqtada Haider Shirazi ◽

Muhammad Imran ◽

...

Keyword(s):

Blood Culture ◽

Diagnostic Accuracy ◽

Neonatal Sepsis ◽

Predictive Value ◽

Gold Standard ◽

Diagnostic Value ◽

Standard Test ◽

Negative Blood Culture ◽

Gold Standard Test ◽

Sensitivity Specificity

Background: Neonatal sepsis is the third most common reason of neonatal mortality in Pakistan. Blood culture, the gold standard test for diagnosis of neonatal sepsis, is time consuming. Therefore, rapid diagnostic tests with good specificity and sensitivity is needed for accurate and early diagnosis of this condition. The objective of this study was to determine the diagnostic value of abnormal (≥ 0.2) immature-to-total-neutrophil ratio in neonatal sepsis.Material and Methods: This cross-sectional study was carried out on 288 neonates, aged 0-28 days, admitted with suspected sepsis. Detailed history of the neonates was recorded including gender, age, birth weight, maternal age, gestational age and clinical features. Blood culture and Peripheral blood films were done in each case. Differential leucocyte counts, total Polymorphoneutrophil count (PMN), immature neutrophil count, mature neutrophil count and calculation of I/T ratio was carried out in the Pathology Department of PIMS, Islamabad. The study outcome was divided into three groups on the basis of positive or negative blood culture and I/T ratio as normal, probable sepsis and proven sepsis group. Data was analyzed by SPSS version 21.0. Diagnostic value of I/T ratio was determined in NS by calculating values of sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) by considering the blood culture as the gold standard test of NS.Results: The mean age and weight of the neonates at the time of admission was 1.1 (± 0.6) days and 2.51 (± 0.40) kg, respectively. About 60% of the neonates were males and 118(41%) neonates had I/T ratio of ≥ 0.2. On the basis of positive or negative blood culture and I/T ratio, 82 (28.5%) neonates were diagnosed as proven sepsis, 43 (14.9%) neonates had probable sepsis and remaining 163 (56.6%) neonates were declared as normal. Out of 82 neonates with positive blood cultures, 75 (91.5%) had I/T ratio ≥ 0.2, while 7 (8.5%) had I/T ratio ≤ 0.2. The sensitivity, specificity, positive and negative predictive value and diagnostic accuracy of abnormal I/T ratio to diagnose neonatal sepsis was 91%, 79%, 64%, 96% and 83%, respectively.Conclusions: Due to substantially high diagnostic accuracy of I/T ratio ≥ 0.2, we recommend it as a useful, rapid and cost-effective tool in accurate diagnosis of neonatal sepsis.

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Diagnostic Accuracy of Multislice Contrast CT scan in Detection of Squamous cell Carcinoma of Oral cavity, in clinically suspected Patients

10.53350/pjmhs211582500 ◽

2021 ◽

Vol 15 (8) ◽

pp. 2500-2501

Author(s):

Aliya Khan ◽

Abid Ali Sahito ◽

Mahreen Shaikh ◽

Humera Jabeen ◽

Humaira Ashraf ◽

...

Keyword(s):

Computed Tomography ◽

Squamous Cell Carcinoma ◽

Oral Cavity ◽

Diagnostic Accuracy ◽

Cell Carcinoma ◽

Squamous Cell ◽

Gold Standard ◽

Multislice Computed Tomography ◽

Multislice Ct ◽

Sensitivity Specificity

Objective: To evaluate the diagnostic accuracy of multislice computed tomography (CT) in detection of squamous cell carcinoma (SCC) of oral cavity in clinically suspected patients taking histopathology as gold standard. Material and Methods: This cross-sectional study has been conducted at Radiology department of Civil Hospital Karachi from 8th September 2018 to March 2019. All the cases having suspected oral squamous cell carcinoma and either of gender were included. Patients underwent computed tomography by using multislice scanner. Then patients undergone biopsy sampling and patients were labeled as positive or negative for squamous cell carcinoma of oral cavity on MDCT and histopathology. Sensitivity, specificity, and diagnostic accuracy of multislice CT for squamous cell carcinoma of oral cavity were measured taking histopathology as gold standard. Results: Total 168 cases were studied and out of them males were 76.8% and females were 23.2%. Mean gutka addiction history was 11.52±5.21 years. Mean lesion size on CT scan was 2.44±1.43 cm. In our study, 35.1% patients were diagnosed positive by multislice computed tomography and 43.5% through histopathology. Sensitivity, Specificity, PPV, NPV and accuracy were 86.4%, 79.8%, 69.9%, 91.6%, and 82.1% respectively. Conclusion: Multislice CT observed to be the effective diagnostic tool for the detection of SCC of oral cavity. Keywords: Multislice Computed Tomography, cancer, Oral Cavity

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Diagnostic Accuracy of Rapid Diagnostic Kits Test for Diagnosis of Malaria

10.53350/pjmhs2115102826 ◽

2021 ◽

Vol 15 (10) ◽

pp. 2826-2828

Author(s):

Muhammad Ahsan Zafar ◽

Sidra Khalid ◽

Talha Munir

Keyword(s):

Diagnostic Accuracy ◽

Gold Standard ◽

Female Ratio ◽

Diagnostic Kits ◽

Negative Results ◽

Malaria Antigen ◽

The Mean ◽

Sensitivity Specificity ◽

Age Range ◽

Male To Female

Objective: To assess the diagnostic accuracy of rapid diagnostic kits test for diagnosis of malaria taking microscopy as gold standard Methodology: A total of 375 cases with age range 18-65 years of either gender as suspected for malaria were included in the study. We excluded all those cases already taking anti-malarial drugs. The study was conducted at Chughtais Lahore Lab, Lahore. Required blood sample were obtained following aseptic measures. Malaria RDT SD Bioline Malaria Antigen Pf/Pan (Catalogue No. 05FK60, Standard Diagnostics Inc, Hagal-Dong, Korea, from now on referred as “SD RDT”) was used. Patients were labeled as positive or negative on the basis of reports from hematology department assessed by microscopy and patients were labeled as positive or negative Results: The mean age of the patients was 41.84±13.44 years, male to female ratio of the patients was 1.01:1. The sensitivity, specificity, and diagnostic accuracy of the RDT for diagnosing malaria was 96.79%, 96.28% and 96.53% respectively taking microscopy as gold standard Conclusion: Rapid diagnostic kits is very useful reliable test with high diagnostic accuracy for diagnosis of malaria taking microscopy as gold standard Keywords: Microscopy, Rapid Diagnostic kits, Malaria,

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Evaluation of diagnostic accuracy of 10 serological assays for detection of SARS-CoV-2 antibodies.

10.21203/rs.3.rs-65054/v1 ◽

2020 ◽

Cited By ~ 1

Author(s):

MD. ◽

Sara Gómez de Frutos ◽

Diego Domingo García PharmD ◽

Eva Navarro Lara ◽

Ayla Yarci Carrión ◽

...

Keyword(s):

Diagnostic Accuracy ◽

Gold Standard ◽

Epidemiological Studies ◽

Antibody Detection ◽

Diagnostic Tools ◽

Sensitivity Range ◽

Sensitivity Specificity ◽

Negative Controls ◽

Ig G ◽

Positive Controls

Abstract BackgroundAntibody detection is essential to establish exposure, infection and immunity to SARS-CoV-2, as well as to perform epidemiological studies. The worlwide urge for new diagnostic tools to control the pandemic has led to a quick in- corporation in clinical practice of the recently developed serological assays.MethodsWe evaluated the diagnostic accuracy to detect Ig G, Ig M+A and/or IgA anti SARS-CoV-2 of 10 different assays: 3 Lateral Flow card inmunoassays, 4 en- zyme-linked inmunoabsorbent assay (ELISA) and 3 chemiluminescent particle immunoassays (CMIA). Using PCR for COVID-19 as gold standard, sensitivity, specificity, PPV, and NPV were determined. Each assay was tested in 2 groups: Positive Controls, formed by 50 sera from 50 patients with SARS-CoV-2 pneu- monia with positive PCR; Negative Controls, formed by 50 sera from 50 pa- tients with respiratory infection non-COVID-19.ResultsSensitivity range of the 10 assays evaluated for patients with positive COVID-19 PCR was 40-77% (65-81% considering IgG plus IgM). Specificity ranged 83-100%. VPP and VPN were respectively 81-100% and 61.6-81%.ConclusionsResults obtained varied widely among the assays evaluated.Highest diagnostic accuracy was obtained with ELISA and CMIAs, but they last much longer.

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Diagnostic Validation of a Whole-Slide Imaging Scanner in Cytological Samples: Diagnostic Accuracy and Comparison With Light Microscopy

Veterinary Pathology ◽

10.1177/0300985818825128 ◽

2019 ◽

Vol 56 (3) ◽

pp. 429-434 ◽

Cited By ~ 3

Author(s):

Federico Bonsembiante ◽

Ugo Bonfanti ◽

Francesco Cian ◽

Laura Cavicchioli ◽

Beatrice Zattoni ◽

...

Keyword(s):

Flow Cytometry ◽

Diagnostic Accuracy ◽

Gold Standard ◽

Cytological Diagnosis ◽

Whole Slide Imaging ◽

Glass Slides ◽

Remote Sites ◽

Diagnostic Validation ◽

Sensitivity Specificity ◽

Different Levels

Digital slides created by whole-slide imaging scanners can be evaluated by pathologists located in remote sites, but the process must be validated before this technology can be applied to routine cytological diagnosis. The aim of this study was to validate a whole-slide imaging scanner for cytological samples. Sixty cytological samples, whose diagnoses were confirmed by gold-standard examinations (histology or flow cytometry), were digitalized using a whole-slide imaging scanner. Digital slides and glass slides were examined by 3 observers with different levels of cytopathological expertise. No significant differences were noted between digital and glass slides in regard to the number of cases correctly diagnosed, or the sensitivity, specificity, or diagnostic accuracy, irrespective of the observers’ expertise. The agreements between the digital slides and the gold-standard examinations were moderate to substantial, while the agreements between the glass slides and the gold-standard examinations were substantial for all 3 observers. The intraobserver agreements between digital and glass slides were substantial to almost perfect. The interobserver agreements when evaluating digital slides were moderate between observers 1 and 2 and between observers 1 and 3 while they were substantial between observers 2 and 3. In conclusion, our study demonstrated that the digital slides produced by the whole-slide imaging scanner are adequate to diagnose cytological samples and are similar among clinical pathologists with differing levels of expertise.

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Verification bias

BMJ evidence-based medicine ◽

10.1136/bmjebm-2018-110919 ◽

2018 ◽

Vol 23 (2) ◽

pp. 54-55 ◽

Cited By ~ 7

Author(s):

Jack W O’Sullivan ◽

Amitava Banerjee ◽

Carl Heneghan ◽

Annette Pluddemann

Keyword(s):

Diagnostic Accuracy ◽

Standard Test ◽

Supplementary File ◽

Diagnostic Accuracy Study ◽

Reference Standard ◽

Verification Bias ◽

Accuracy Study ◽

Potential Impact ◽

Study Participants ◽

Work Up

This article is part of the Catalogue of Bias series. We present a description of verification bias, and outline its potential impact on research studies and the preventive steps to minimise its risk. We also present teaching slides in the online supplementary file. Verification bias (sometimes referred to as ‘work-up bias’) concerns the test(s) used to confirm a diagnosis within a diagnostic accuracy study. Verification bias occurs when only a proportion of the study participants receive confirmation of the diagnosis by the reference standard test, or if some participants receive a different reference standard test.

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Diagnostic accuracy of magnetic resonance imaging in detection of intra-axial gliomas

Pakistan Journal of Medical Sciences ◽

10.12669/pjms.37.1.2489 ◽

2020 ◽

Vol 37 (1) ◽

Author(s):

Sohbia Munir ◽

Sohail Ahmed Khan ◽

Hina Hanif ◽

Maria Khan

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Diagnostic Accuracy ◽

Gold Standard ◽

High Sensitivity ◽

Cross Sectional Study ◽

Resonance Imaging ◽

Cross Sectional ◽

Post Contrast ◽

Sensitivity Specificity

Objective: To evaluate the diagnostic accuracy of magnetic resonance imaging (MRI) in detection of intra-axial gliomas in suspected cases keeping histopathology as gold standard. Methods: This cross-sectional study was conducted at Dow Institute of Radiology, DUHS from October 2017 - April 2018. Patients of either gender aged 30-70 years presenting with headache were included. Patients already diagnosed and referred for follow up were excluded. MRI was performed on 1.5T scanner by a trained MRI technician. T1, T2, FLAIR, diffusion weighted and T1 post contrast images were acquired and reviewed by two radiologists having more than five years post fellowship experience. Sensitivity, specificity, PPV, NPV and diagnostic accuracy of MRI for intraaxial gliomas was calculated taking histopathology findings as gold standard. Results: Mean age of the patient`s was 51.71 ±10.85 years. Positive intraaxial gliomas on MRI were observed in 123 (79.90%) patients while on histopathology, positive intraaxial gliomas were observed in 131 (85.10%) patients. Diagnostic accuracy of MRI in detection of intra-axial gliomas taking histopathology findings as gold standard showed sensitivity, specificity, positive predicted value (PPV), negative predicted value (NPV) and overall diagnostic accuracy as 89.31%, 73.91%, 95.12%, 54.84% and 87.01%. Conclusions: MRI has high sensitivity, moderate specificity and high diagnostic accuracy in detection of intraaxial gliomas. doi: https://doi.org/10.12669/pjms.37.1.2489 How to cite this:Munir S, Khan SA, Hanif H, Khan M. Diagnostic accuracy of magnetic resonance imaging in detection of intra-axial gliomas. Pak J Med Sci. 2021;37(1):125-130. doi: https://doi.org/10.12669/pjms.37.1.2489 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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Accuracy of Brain MRI Interpretation of Emergency Medicine Specialists versus Radiologist and Neurologist in Suspected Acute Ischemic Stroke Patients; a Diagnostic Accuracy Study

Archives of Neuroscience ◽

10.5812/ans.112166 ◽

2021 ◽

Vol 8 (2) ◽

Author(s):

Atefeh Abdollahi ◽

Sepideh Aarabi ◽

Arash Safaie ◽

Abdorreza Naser Moghadasi ◽

Mohammad Sadegh Vahedi ◽

...

Keyword(s):

Emergency Medicine ◽

Ischemic Stroke ◽

Diagnostic Accuracy ◽

Acute Ischemic Stroke ◽

Gold Standard ◽

Medical Center ◽

Brain Mri ◽

Brain Magnetic Resonance Imaging ◽

Diagnostic Accuracy Study ◽

Accuracy Study

Background: Despite numerous brain magnetic resonance imaging (MRI) utilization in the emergency department (ED), certainly, imaging alone is not enough, and it is necessary to have a correct interpretation by a physician who has sufficient skills in this regard. Objectives: Here, we decided to investigate the accuracy of interpreting brain MRI of suspected acute ischemic stroke (AIS) patients conducted by emergency medicine physicians (EMPs) in comparison with a radiologist and a neurologist. Methods: This diagnostic accuracy study was conducted from April to November 2019 in Tehran, Iran. All attending EMPs of one major educational, medical center, a radiologist, and a neurologist also participated. A set of brain MRI stereotypes related to patients suspected of having a AIS was randomly selected. By reviewing the brain MRI interpretation of EMPs, once in comparison with the radiologist and once in comparison with the neurologist, misinterpretations (presence or absence of findings compatible with the diagnosis of AIS) were extracted. Results: Brain MRI stereotypes of 287 suspected AIS patients were interpreted of these patients, 160 cases (55.7%) were male. The mean age of the study patients was 65.0 ± 14.1 (range of 18 to 98) years. The value of the agreement for diagnosis between EMPs and neurologists was 0.684 (95% CI: 0.580 to 0.787). Considering the neurologist as the gold standard, the accuracy of AIS diagnosis by the EMPs was 0.85% (95% CI: 79.3 to 89.6). The agreement value for diagnosis between EMPs and radiologist was 0.673 (95% CI: 0.553 to 0.794). Considering the radiologist as the gold standard, the accuracy of AIS diagnosis by the EMPs was 86.3% (95% CI: 79.8 to 91.3). The agreement value for diagnosis in these two groups was 0.752 (95% CI: 0.627 to 0.877). Conclusions: The findings of the current study revealed that the accuracy of brain MRI interpretation performed by the EMPs, compared with both neurologist and radiologist was proper.

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