scholarly journals On the importance of early testing even when imperfect in a pandemic such as COVID-19

2020 ◽  
Author(s):  
Neal D. Goldstein ◽  
Igor Burstyn
Keyword(s):  
False Negative ◽  
Clinical Findings ◽  
Laboratory Findings ◽  
Predictive Values ◽  
Clinical Observations ◽  
The Face ◽  
The Usa ◽  
Early Testing ◽  
The Difference ◽  
Sensitivity Specificity

Diagnosis of COVID-19 may be based on clinical observations, laboratory findings, and epidemiological linkage.1 Underscoring this diagnosis is accurate data from laboratory tests: this can make the difference between a false positive based on the clinical findings that are attributable to another cause, or a false negative based on lack of clinical findings that are attributable to SARS-CoV-2 viral infection, the causal agent for COVID-19. We conducted a simulation depicting how predictive values vary in the face of unknown data surrounding test sensitivity, specificity, and reported cases. in the USA. There are two main implications of our findings. First, the prevalence of COVID-19 in the tested population is likely inflated: clinical disease attributable to other sources of infection such as influenza, or other respiratory viruses, is a plausible explanation. Second, we should be less alarmed by not being able to trace chain of transmission for many who test positive early in this pandemic when population prevalence is low.

Histological Findings in Infected and Noninfected Second Stage Revision Knee Arthroplasties

2018 ◽  
Vol 32 (10) ◽  
pp. 1015-1019
Author(s):  
Yoshinobu Uchihara ◽  
Yusuke Inagaki ◽  
Mitsuru Munemoto ◽  
Yasuhito Tanaka ◽  
Nicholas Athanasou
Keyword(s):  
Joint Infection ◽  
Clinical Findings ◽  
Laboratory Findings ◽  
Predictive Values ◽  
Musculoskeletal Infection ◽  
Second Stage ◽  
Histological Criteria ◽  
Microbiological Criteria ◽  
Sensitivity Specificity ◽  
Hematoxylin Eosin

AbstractTissues from a periprosthetic joint infection (PJI) of the knee contain a heavy neutrophil polymorph (NP) infiltrate (> 5 NPs per high-powered field [HPF] by Musculoskeletal Infection Society [MSIS] criteria). PJI of the knee can be treated by a two-stage procedure and our aim was to determine whether the MSIS histological criteria for PJI diagnosis are valid in a second-stage revision knee arthroplasty. Periprosthetic tissues from 45 second-stage revision knee cases were analyzed histologically by hematoxylin–eosin and chloroacetate esterase (CAE) staining for the identification of NPs. The number of NPs was determined semiquantitatively and results correlated with the microbiological and clinical findings. In 9 of the 45 cases, an organism was cultured in two or more samples, meeting MSIS microbiological criteria for a definite diagnosis of PJI; histologically, seven of these cases contained > 5 per NPs per HPF on average, with the remaining two cases containing 1 NP and 2 NPs per HPF. In noninfected second-stage revisions, NPs were not seen in 30 cases with 6 cases showing less than 1 NP per HPF on average. The sensitivity, specificity, accuracy, and positive and negative predictive values of MSIS histological criteria (> 5 NPs per HPF) to diagnose PJI were 78%, 100%, 96%, 100%, and 95%, respectively. MSIS histological criteria for the diagnosis of PJI are valid for most but not all infected second-stage revision knee arthroplasties. Correlation of histology with clinical, microbiology and other laboratory findings is required to establish a diagnosis of PJI in second-stage revision knee arthroplasties.

scholarly journals THE ROLE OF ULTRASONOGRAPHY IN THE DETECTION OF UROLITHIASIS IN PATIENTS WITH ACUTE RENAL COLIC

2020 ◽  
Vol 4 (6) ◽  
Author(s):  
Sanjay Narayangiri Gosavi ◽  
Virendra K Meena ◽  
Ayush Tambi
Keyword(s):  
Ct Scan ◽  
Renal Colic ◽  
False Negative ◽  
Helical Ct ◽  
Urinary Stones ◽  
Predictive Values ◽  
Acute Renal Colic ◽  
Mean Size ◽  
Acute Flank Pain ◽  
Sensitivity Specificity

This study was conducted to assess the diagnostic Ultrasonography compared to unenhanced helical CT scan in detecting urinary stones in patients with acute renal colic. This retrospective study comprised of 156 patients who undergo unenhanced urinary tract CT scan and ultrasonography for thought of urolithiasis. Both techniques were used to resolve the presence or absence, site, size, and number of urinary stones, as well as company of any other intra-abdominal pathology. For statistical analysis, the sensitivity, specificity, predictive values, and diagnostic accuracy of ultrasonography were deliberate considering unenhanced CT scan as a gold normal. Unpaired two-tailed student’s t-test was used for judgment between mean size of true positive, false positive, and false negative stones. There were 68 patients having 115 urinary stones. Ultrasound identified 54 stones, missed 43, and falsely diagnosed 18 stones. The mean size of true positive, false positive, and false negative stones were 4.8 ± 3.3 mm, 6 ± 1.8 mm and 4.18 ± 3 mm, respectively. There were 23 patients with other intra-abdominal pathologies, equally detected by both techniques. Ultrasound helped in identifying the cause of acute flank pain in 62% of cases. The overall sensitivity, specificity, positive and negative predictive values, and correctness of ultrasonography in the diagnosis of renal stone disease were 58%, 91%, 79%, 78%, and 78%, respectively. Our study suggests that, despite its limited value in detecting urinary stones, ultrasonography should be performed as an initial assessment in patients with acute flank pain. Unenhanced helical CT should be reserved for patients in whom ultrasonography is uncertain. Keywords: Ultrasonography, CT scan

scholarly journals An assessment of chromosomal alterations detected by fluorescence in situ hybridisation in pancreatobiliary tract malignancy

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Xiaohong Pu ◽  
Hongwei Zheng ◽  
Xin Yang ◽  
Qing Ye ◽  
Zhiwen Fan ◽  
...  
Keyword(s):  
Predictive Value ◽  
In Situ Hybridisation ◽  
False Negative ◽  
Chinese Patients ◽  
Fluorescence In Situ Hybridisation ◽  
Predictive Values ◽  
Formalin Fixed Paraffin Embedded ◽  
9P21 Locus ◽  
Sensitivity Specificity

Abstract Background Using fluorescence in situ hybridisation (FISH) to detect any gain of chromosomes 3, 7, or 17 and loss of the 9p21 locus has been proven to be sensitive in the diagnosis of pancreatobiliary tumors. However, both genetic and environmental factors contribute to the pathogenesis of pancreatobiliary tumors. Therefore, it is unknown whether this method is suitable for Chinese patients with pancreatobiliary tumors. This study aims to compare the sensitivity, specificity, predictive values and accuracy of cytology, ERCP/MRCP and FISH based on Chinese patients with pancreatobiliary tumors,and to analyze differences between brushing-based and formalin-fixed paraffin-embedded (FFPE)-based FISH. Methods A total of 66 brush cytology specimens obtained during ERCP were detected by FISH and cytology test respectively to compare the sensitivity, specificity, predictive values and accuracy. Besides, FFPE-based FISH was performed on 46 corresponding paraffin sections of pancreatobiliary tumors obtained by surgical resection. Results Our findings demonstrate that FISH greatly improves diagnostic sensitivity and negative predictive value compared to ERCP/MRCP and cytology without much reduction in specificity and positive predictive value. However, our results also indicate that FFPE-based FISH could not effectively identify the false-negative of brushing-based FISH. Conclusions We believe that FISH can effectively distinguish true positive and false positive results of cytological or radiological suspicions of malignancy. However, FFPE-based FISH still does not precisely recognize the false-negative of brushing-based FISH. Both cytology-based and PPFE-based FISH had limitation in some specimens.

scholarly journals SAT-422 Evaluation of the Siemens Thyroid Stimulating Immunoglobulin (TSI) Assay for Diagnosis and Prognosis of Graves’ Disease

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Heather Paul ◽  
Nadia Moledina ◽  
Jason Robinson ◽  
Alex Chin ◽  
Gregory A Kline ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Predictive Value ◽  
False Negative ◽  
Thyroid Stimulating Hormone ◽  
Clinical Findings ◽  
Graves Disease ◽  
Sample Collection ◽  
Primary Analysis ◽  
Sensitivity Specificity ◽  
Stimulating Hormone

Abstract Background: Hyperthyroidism due to Graves’ disease (GD) is an autoimmune condition caused by thyroid stimulating hormone receptor (TSHR) autoantibodies. Autoantibodies to the TSHR can stimulate or block thyroid hormone production, therefore testing specifically for stimulating antibodies would be beneficial for diagnosis of GD. Objectives: The primary objective of the first phase of this trial is to assess the diagnostic capability of the Siemens Thyroid Stimulating Immunoglobulin (TSI) immunoassay in diagnosing GD and to compare it with the Roche TSH Receptor Antibody (TRAb) assay. Design and Methods: Two hundred patients with suspected GD are being enrolled in this single-center multiphase prospective cohort study. Consenting patients undergo biochemical testing including thyroid stimulating hormone (TSH), free T3 (FT3) and T4 (FT4), TRAb and TSI measurements. GD diagnosis was confirmed by endocrinologists that were blinded to TSI results. Results: To date, 85 patients were included in the analysis, of which 66 were diagnosed with GD. For the primary analysis, all patients taking anti-thyroid drugs (ATD) at time of sample collection (n=14) were removed. The respective sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) for TSI was 98, 84, 94 and 94%, which were comparable to those generated by TRAb (98, 95, 95, and 98%). In patients with clinical findings of GD (ie. orbitopathy or goiter, n=33), both the TSI and TRAb assays had identical sensitivity and specificity at 96% and 80% respectively. In patients without orbitopathy or goiter (n=38), the TSI assay had perfect sensitivity and excellent specificity of 100% and 86% respectively (TRAb had 100% sensitivity and specificity). Sensitivity, specificity, NPV, and PPV were slightly lower for both TSI and TRAb in patients treated with ATDs compared to patients without treatment (TSI: 85, 84, 62, 95%; TRAb: 91, 95, 75, 98%). Of ten patients with GD and false negative TSI results, nine were on ATDs. Of this subset, four patients had discordant results between TSI (negative) and TRAb (positive). Notably, one of these patients had normalization of their FT3 and FT4 on the day of sample collection. Discussion and Conclusion: Based on our preliminary results, TSI is an excellent marker for diagnosing GD, particularly in untreated GD patients. The performance of the TSI assay has been comparable to the TRAb assay and correlates well with clinical findings. Discordant false negative results were only seen in patients on ATD. One potential explanation is that the TSI assay is detecting a decrease in stimulating autoantibodies when there is normalization of FT3 and FT4. Importantly, all discordant samples will be tested by a TSI bioassay to confirm diagnosis. Further patient enrollment is occurring, and prognostic assessment of these assays will soon be possible.

The role of ultrasonography in the diagnosis of talocalcaneal coalitions

2020 ◽  
pp. 028418512094491
Author(s):  
Tiezheng Wang ◽  
Hengtao Qi ◽  
Kai Rong ◽  
Shuqian Zhang ◽  
Shougang Bao ◽  
...  
Keyword(s):  
False Negative ◽  
Fibrous Tissue ◽  
Joint Space ◽  
Clinical Suspicion ◽  
Youden Index ◽  
Imaging Method ◽  
Predictive Values ◽  
Negative Results ◽  
Reduced Space ◽  
Sensitivity Specificity

Background Patients with talocalcaneal coalitions (TCC) often undergo computed tomography (CT). However, ultrasonography diagnosis of TCC has been seldom done according to the literature. Purpose To investigate the accuracy of ultrasonography in diagnosing TCC compared to CT. Material and Methods Ninety-seven consecutive patients with a clinical suspicion of TCC were included. Ultrasonography was used to assess the classification and complication of TCC. The main sonographic criteria for a positive diagnosis in cases of osseous coalition were the joint space between the medial surface of talar head and the underlying sustentaculum tali of calcaneus disappearing and being replaced by a continuous hyperechoic bony structure. In cases of fibrous coalition, ultrasonography revealed a reduced space of the joint associated with an irregular, angular appearance of its outline and hypoechoic fibrous tissue inside. These data were compared with CT findings. κ statistic was applied to determine the level of agreement. The sensitivity, specificity, positive and negative predictive values, accuracy, and Youden index of ultrasonography as a diagnostic method were assessed. Results Ultrasonography findings were positive in 20 of 97 patients with a clinical suspicion of TCC. The diagnosis was confirmed by CT in 21 patients. There were one false-positive result and two false-negative results by ultrasonography. The κ value was 0.907. The sensitivity, specificity, positive and negative predictive values, accuracy, and Youden index of ultrasonography were 90.5%, 98.7%, 95.0%, 97.4%, 96.9%, and 0.892, respectively. Conclusion Ultrasonography could be a reliable, accurate, and non-radioactive diagnostic imaging method in diagnosis of patients with suspected TCC.

Reliability of history of acetaminophen ingestion in intentional drug overdose patients

2010 ◽  
Vol 30 (1) ◽  
pp. 44-50 ◽  
Author(s):  
Yedidia Bentur ◽  
Yael Lurie ◽  
Ada Tamir ◽  
Daniel C Keyes ◽  
Fuad Basis
Keyword(s):  
Drug Overdose ◽  
The Other ◽  
Limited Resources ◽  
Suicidal Patient ◽  
History Taking ◽  
Predictive Values ◽  
Detailed History ◽  
History Of ◽  
The Difference ◽  
Sensitivity Specificity

The objective of this study was to determine the reliability of denial of acetaminophen ingestion in intentional drug overdose patients. All intentional drug overdose patients admitted to an emergency department who were able to provide a history were included. A detailed history was obtained on names, timing and number of medications ingested, and serum acetaminophen was assayed. Multidrug ingestion was defined as the reporting of ≥2 medications. Patients were considered ‘reliable’ if they reported acetaminophen ingestion and had detectable acetaminophen levels or the other way around. Validity parameters of acetaminophen history were assessed by sensitivity, specificity and positive and negative predictive values. A total of 154 patients were included. History was significantly more reliable in patients who denied ingestion of acetaminophen (n = 107) compared with patients who reported it (n = 47; 95.3% vs 65.9%, respectively; p < 0.0001, 95% CI of the difference 17.5%—41.2%). No suicidal patient who denied both acetaminophen and multidrug ingestions had a detectable acetaminophen level (negative predictive value 1, 95% CI 0.93—1.0). It is suggested that denial of both acetaminophen and multidrug ingestions by intentional drug overdose patients after a thorough history taking can be considered reliable for acetaminophen history. In facilities with limited resources, these patients may not require routine acetaminophen screening.

scholarly journals Evaluation of WHO criteria to determine degree of dehydration in children with acute diarrhea

2016 ◽  
Vol 45 (2) ◽  
pp. 76
Author(s):  
Suprawita Sari ◽  
Supriatmo Supriatmo ◽  
S L Margaretha ◽  
S Nafianti ◽  
B Hasibuan ◽  
...  
Keyword(s):  
Acute Diarrhea ◽  
Clinical Signs ◽  
Severe Dehydration ◽  
Chi Square ◽  
Predictive Values ◽  
Who Criteria ◽  
Significant Difference ◽  
Kappa Value ◽  
The Difference ◽  
Sensitivity Specificity

Objective To evaluate the diagnostic accuracy and agreementbetween the 1980 and 1990 WHO criteria for determining the de-gree of dehydration in children with acute diarrhea.Methods This prospective study was conducted in two hospitalsfrom October 2002 to February 2003. Clinical signs of dehydrationall patients were recorded. The degree of dehydration based onthe 1980 and 1990 WHO criteria was determined and comparedwith fluid deficit measured by the difference of body weight on ad-mission and on discharge. Chi-square test and kappa value analy-ses were performed. Sensitivity, specificity, predictive values, andaccuracy of each WHO criteria were assessed. The prevalence ofdehydration was also determined.Results Sixty-five patients, comprising 40 boys and 25 girls, werestudied. There was a significant difference between the two WHOcriteria in differentiating between dehydration and non-dehydra-tion (P<0.05). Based on the 1980 WHO criteria the prevalence ofdehydration was 62.2%. Its sensitivity, specificity, and accuracy indiagnosing dehydration were 100.0%, 55.5%, and 86.2%, respec-tively. Based on the 1990 WHO criteria, the prevalence of dehy-dration was 60.0%. Its sensitivity, specificity, and accuracy in diag-nosing dehydration were 94.9%, 46.1%, and 75.4%, respectively.There was also a significant difference between both criteria indetermining severe dehydration (P<0.05). Based on the 1980 cri-teria, the prevalence of severe dehydration was 15.4%. Its sensi-tivity, specificity, and accuracy in diagnosing severe dehydrationwere 30.0%, 94.5%, and 84.6%, respectively. Based on the 1990criteria, these results were 40.0%, 94.5%, and 86.2%, respectively.The prevalence was 15.4%. Kappa value comparing the two WHOcriteria was 0.852 in diagnosing dehydration and 0.915 in diag-nosing severe dehydration. There was no significant differencebetween the two criteria in their sensitivity and specificity (P>0.05).Conclusion Both WHO criteria can be applied to determine de-hydration in patients with acute diarrhea, although we feel that the1990 criteria is simpler

Introduction: From Sustainability to Surveillance

2014 ◽  
Author(s):  
Robert M. Chiles
Keyword(s):  
Undergraduate Students ◽  
Scientific Knowledge ◽  
False Negative ◽  
Public Officials ◽  
Error Type ◽  
Environmental Consequences ◽  
Term Papers ◽  
The Face ◽  
The Difference ◽  
Political Economic

At Stanford University, a long-standing tradition is for undergraduate students to identify themselves as “techies” or “fuzzies.” Techie students study math, engineering, physics, biology, and related fields in the natural sciences, and most of their coursework revolves around solving problem sets. Fuzzy students study art, history, communications, and other disciplines in the humanities and social sciences, and most of their coursework involves writing term papers. When asked to explain the difference between the two, one student offered a very simple, quotidian explanation: Techies study questions that have right or wrong answers, while fuzzies study questions where acceptable answers can be multiple and ambiguous. While the techie/fuzzy distinction is largely intended to be humorous, there is nonetheless something to it; it reflects multiple historical cleavages: fact versus opinion, natural versus social world, and science versus non-science. The existence of scientific and technological controversies illustrates the woeful inadequacy of these dualistic categories for two reasons. First, the acquisition of scientific knowledge is not a simple matter of factfinding, whereby scientists go out and discover The Truth, straight-forwardly reading off of nature. Scientific knowledge reflects the historical, political, economic, cultural, and institutional environments in which it is embedded (Latour and Woolgar 1979; Pinch and Bijker 1984). Favored methods of investigation, what levels of uncertainty are acceptable, and error type preferences (false positive versus false negative), among other factors that shape how science is done, reflect human history and values. In this context, science and technology are neither above nor immune from controversy. Second, social problems that are intrinsically related to certain technologies (for instance, the environmental consequences of fossil-based energy production) are arguably becoming increasingly acute. In the face of these kinds of challenges, it is no longer sufficient for scientific and technological controversies to be left solely in the hands of scientists and other experts. Scientific claims are becoming increasingly politicized by citizen groups, public officials, and others, many of whom are actively challenging traditional notions of what constitutes valid and acceptable knowledge. The “black box” of scientific expertise has been cracked open, and it is only likely to open wider.

scholarly journals Comparison of Five Methods for the Determination of Rubella Immunity

1994 ◽  
Vol 1 (4) ◽  
pp. 188-192
Author(s):  
Robert L. Sautter ◽  
Arthur E. Crist ◽  
Lynn M. Johnson ◽  
William D. LeBar
Keyword(s):  
Medical Center ◽  
False Negative ◽  
Latex Agglutination ◽  
Walk Away ◽  
Becton Dickinson ◽  
Predictive Values ◽  
Research Triangle ◽  
System A ◽  
Sensitivity Specificity

Objective:The purpose of this study was to compare the accuracy of commonly used methods for the detection of rubella immunity, especially the fully automated IMx assay.Methods:A total of 190 sera (101 immune and 89 non-immune) submitted to Harrisburg Hospital or Polyclinic Medical Center for the determination of rubella immunity were tested by enzyme immunoassay (IMx and Rubazyme, Abbott Diagnostic Laboratories, North Chicago, IL), indirect immunofluorescence (FIAX, Whittaker Bioproducts, Walkersville, MD), and latex agglutination (Rubascan, Becton Dickinson Microbiology Systems, Cockeysville, MD, and Rubalex, Wellcome Diagnostics, Research Triangle Park, NC). Specimens were frozen at –30℃ until the study was initiated. Each of the assays was performed according to the manufacturers' specifications. Sensitivity, specificity, accuracy, and positive and negative predictive values for each assay were calculated using a consensus result of the 5 methods tested.Results:The sensitivity, specificity, and accuracy, respectively, of the test systems were as follows: IMx, 96%, 97%, and 96%; Rubazyme, 100%, 99%, and 99%; Rubascan, 100%, 98%, and 99%; Rubalex, 99%, 97%, and 98%; and FIAX 90%, 100%, and 95%. False negative reactions were seen with the FIAX system.Conclusions:The IMx system, a new “walk away” system from Abbott Diagnostic Laboratories and the Rubazyme systems performed well; however the latex agglutination tests proved to be the most rapid and convenient methods for screening sera for the presence of rubella immunity.

scholarly journals Correlating Pap Smear Results and Colposcopy-Directed Large Loop Excision of the Transformation Zone Histopathology in HIV-Infected and HIV-Uninfected Women: A Case-Control Study in South Africa

2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
Louis-J. van Bogaert
Keyword(s):  
Pap Smear ◽  
False Negative ◽  
Screening Methods ◽  
Cytological Diagnosis ◽  
Predictive Values ◽  
Transformation Zone ◽  
Large Loop ◽  
Cytological Abnormality ◽  
Sensitivity Specificity ◽  
Minimal Abnormality

Background. In low-resource settings (LRS) with high HIV/AIDS and cervical cancer rates, new screening strategies face many logistic hurdles. Since cytology is there to stay, at least in the median-term future, it is important to assess to what extent HIV-HPV coinfection impacts the accuracy of screening methods and strategies. Methods. We audited the correlation between cytological diagnosis of minimal abnormality (CIN1), CIN2+, or cancer and the histological diagnosis of colposcopy-directed large loop excision of the transformation zone of 399 HIV-uninfected controls and 389 HIV-infected cases. Results. The average age at diagnosis of CIN2+ of the cases was 4.2 years younger than controls (). The endpoint used to assess the accuracy of cytology was minimal cytological abnormality (≤CIN1/LGSIL). The sensitivity, specificity, and negative and positive predictive values were 92.7, 18.5, 45.1, and 77.9%, respectively. The overall ratio of discordance/concordance between cytology and histology was similar in both groups. Conclusion. In LRS, where rapid-HPV testing is not yet part of screening algorithms, a cytological diagnosis of minimal abnormality requires visual inspection and treatment of visualized lesions especially in HIV-infected women aged 30 years. The cytological endpoint of accuracy should be set low to avoid false negative smears.

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