Helicobacter PyloriBreath Testing in an Open Access System has a High Rate of Potentially False Negative Results due to Protocol Violations

Helicobacter ◽  
2012 ◽  
Vol 17 (5) ◽  
pp. 391-395 ◽  
Author(s):  
Snorri Olafsson ◽  
Bhaveshkumar Patel ◽  
Christian Jackson ◽  
Jin Cai
Keyword(s):  
Open Access ◽  
False Negative ◽  
High Rate ◽  
Access System ◽  
Negative Results ◽  
False Negative Results

High Incidence of Significant Urinary Ascorbic Acid Concentrations in a West Coast Population—Implications for Routine Urinalysis

1992 ◽  
Vol 38 (3) ◽  
pp. 426-431 ◽  
Author(s):  
M L Brigden ◽  
D Edgell ◽  
M McPherson ◽  
A Leadbeater ◽  
G Hoag
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
False Negative ◽  
High Rate ◽  
High Power Field ◽  
Glucose Testing ◽  
Negative Results ◽  
False Negative Results ◽  
High Incidence ◽  
The Mean

Abstract Examination of 4379 routine urinalysis specimens with dipsticks sensitive to ascorbic acid showed that 22.8% were positive specimens. The mean urinary vitamin C concentration in this population was 2120 mumol/L. There was a high rate of false-negative dipstick results for hemoglobin in patients with vitamin C in the urine. The highest false-negative rates were observed in urine samples containing less than 50 erythrocytes per high-power field. In further experiments when volunteers consumed supplemental oral USP vitamin C at doses of 100, 250, 500, and 1000 mg or vitamin C-containing fruit juices, even the lowest doses of oral vitamin C or juice resulted in sufficient urinary vitamin C to produce false-negative dipstick results in hemoglobin and glucose testing. To prevent potentially dangerous false-negative results, screening urinalysis protocols relying only on dipstick testing should include a check for urinary vitamin C or use a dipstick that is not subject to vitamin C interference.

Trans-perineal Prostate Biopsy under Trans-rectal Ultrasound Guidance

2019 ◽  
Vol 3 (1) ◽  
pp. 1-4
Author(s):  
Hui Xu ◽  
Nirmal Lamichhane
Keyword(s):  
Prostate Biopsy ◽  
Ultrasound Guidance ◽  
False Negative ◽  
Rectal Biopsy ◽  
Accurate Diagnosis ◽  
High Rate ◽  
Western World ◽  
Negative Results ◽  
Common Cancer ◽  
False Negative Results

Prostate cancer is the most common cancer in males in the western world and is an emerging malignancy in eastern world as well. It is less invasive and easily curable in early stages. It requires efficient and accurate diagnosis strategy to detect it early. To date, the standard diagnosis procedure involves a blind biopsy with a high rate of false negative results. Trans-perineal prostate biopsy is re-emerging after decades of being an underused alternative to trans-rectal biopsy guided by trans-rectal ultrasonography. In order to overcome these limitations, the paper proposes the method and advantages of trans-perineal prostate biopsy.  

Critical Evaluation of Impedance Phlebography for the Diagnosis of Deep Vein Thrombosis

1974 ◽  
Vol 31 (02) ◽  
pp. 273-278
Author(s):  
Kenneth K Wu ◽  
John C Hoak ◽  
Robert W Barnes ◽  
Stuart L Frankel
Keyword(s):  
Deep Vein Thrombosis ◽  
False Positive ◽  
False Negative ◽  
Critical Evaluation ◽  
Original Method ◽  
Vein Thrombosis ◽  
Negative Results ◽  
False Negative Results ◽  
Deep Vein ◽  
Positive Results

SummaryIn order to evaluate its daily variability and reliability, impedance phlebography was performed daily or on alternate days on 61 patients with deep vein thrombosis, of whom 47 also had 125I-fibrinogen uptake tests and 22 had radiographic venography. The results showed that impedance phlebography was highly variable and poorly reliable. False positive results were noted in 8 limbs (18%) and false negative results in 3 limbs (7%). Despite its being simple, rapid and noninvasive, its clinical usefulness is doubtful when performed according to the original method.

Scoring System for the Diagnosis of COVID-19

2020 ◽  
Vol 13 (1) ◽  
pp. 413-414 ◽  
Author(s):  
Mohamed Farouk Allam
Keyword(s):  
Scoring System ◽  
Clinical Symptoms ◽  
False Negative ◽  
Nasopharyngeal Swab ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Negative Results ◽  
False Negative Results ◽  
Symptoms And Signs

Due to the international spread of COVID-19, the difficulty of collecting nasopharyngeal swab specimen from all suspected patients, the costs of RT-PCR and CT, and the false negative results of RT-PCR assay in 41% of COVID-19 patients, a scoring system is needed to classify the suspected patients in order to determine the need for follow-up, home isolation, quarantine or the conduction of further investigations. A scoring system is proposed as a diagnostic tool for suspected patients. It includes Epidemiological Evidence of Exposure, Clinical Symptoms and Signs, and Investigations (if available). This scoring system is simple, could be calculated in a few minutes, and incorporates the main possible data/findings of any patient.

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