scholarly journals Comparison of GenomEra C. difficile and Xpert C. difficile as Confirmatory Tests in a Multistep Algorithm for Diagnosis of Clostridium difficile Infection

2014 ◽  
Vol 53 (1) ◽  
pp. 332-335 ◽  
Author(s):  
Luis Alcalá ◽  
Elena Reigadas ◽  
Mercedes Marín ◽  
Antonia Fernández-Chico ◽  
Pilar Catalán ◽  
...  
Keyword(s):  
Clostridium Difficile ◽  
Positive Predictive Value ◽  
Negative Predictive Value ◽  
Clostridium Difficile Infection ◽  
Predictive Value ◽  
Confirmatory Test ◽  
Content Type ◽  
Diagnostic Algorithms ◽  
Confirmatory Tests ◽  
Sensitivity Specificity

We compared two multistep diagnostic algorithms based on C. Diff Quik Chek Complete and, as confirmatory tests, GenomEraC. difficileand XpertC. difficile. The sensitivity, specificity, positive predictive value, and negative predictive value were 87.2%, 99.7%, 97.1%, and 98.3%, respectively, for the GenomEra-based algorithm and 89.7%, 99.4%, 95.5%, and 98.6%, respectively, for the Xpert-based algorithm. GenomEra represents an alternative to Xpert as a confirmatory test of a multistep algorithm forClostridium difficileinfection (CDI) diagnosis.

scholarly journals Evaluation of the QiagenartusC. difficile QS-RGQ Kit for Detection of Clostridium difficile Toxins A and B in Clinical Stool Specimens

2015 ◽  
Vol 53 (6) ◽  
pp. 1942-1944 ◽  
Author(s):  
Nathalie Jazmati ◽  
Pia Wiegel ◽  
Božica Ličanin ◽  
Georg Plum
Keyword(s):  
Nucleic Acid ◽  
Clostridium Difficile ◽  
Positive Predictive Value ◽  
Negative Predictive Value ◽  
Predictive Value ◽  
Nucleic Acid Amplification Test ◽  
Nucleic Acid Amplification ◽  
Content Type ◽  
Stool Specimens ◽  
Sensitivity Specificity

We compared the QiagenartusC. difficile QS-RGQ kit, a new nucleic acid amplification test for the detection ofClostridium difficiletoxins in stool specimens, with the Cepheid XpertC. difficiletest. The sensitivity, specificity, positive predictive value, and negative predictive value for the QiagenartusC. difficile QS-RGQ test were 100%, 89.5%, 60.9%, and 100%, and those for the Cepheid XpertC. difficiletest were 100%, 90%, 62.2%, and 100%, respectively.

scholarly journals Foundational Statistical Principles in Medical Research: Sensitivity, Specificity, Positive Predictive Value, and Negative Predictive Value

Medicina ◽  
2021 ◽  
Vol 57 (5) ◽  
pp. 503
Author(s):  
Thomas F. Monaghan ◽  
Syed N. Rahman ◽  
Christina W. Agudelo ◽  
Alan J. Wein ◽  
Jason M. Lazar ◽  
...  
Keyword(s):  
Positive Predictive Value ◽  
Negative Predictive Value ◽  
Predictive Value ◽  
Medical Literature ◽  
Disease Prevalence ◽  
Positive Test Result ◽  
Predictive Values ◽  
Sensitivity Specificity ◽  
Test Result ◽  
Test Probability

Sensitivity, which denotes the proportion of subjects correctly given a positive assignment out of all subjects who are actually positive for the outcome, indicates how well a test can classify subjects who truly have the outcome of interest. Specificity, which denotes the proportion of subjects correctly given a negative assignment out of all subjects who are actually negative for the outcome, indicates how well a test can classify subjects who truly do not have the outcome of interest. Positive predictive value reflects the proportion of subjects with a positive test result who truly have the outcome of interest. Negative predictive value reflects the proportion of subjects with a negative test result who truly do not have the outcome of interest. Sensitivity and specificity are inversely related, wherein one increases as the other decreases, but are generally considered stable for a given test, whereas positive and negative predictive values do inherently vary with pre-test probability (e.g., changes in population disease prevalence). This article will further detail the concepts of sensitivity, specificity, and predictive values using a recent real-world example from the medical literature.

scholarly journals Evaluation of the Carba NP Test for Rapid Detection of Carbapenemase-Producing Enterobacteriaceae and Pseudomonas aeruginosa

2013 ◽  
Vol 57 (9) ◽  
pp. 4578-4580 ◽  
Author(s):  
Nathalie Tijet ◽  
David Boyd ◽  
Samir N. Patel ◽  
Michael R. Mulvey ◽  
Roberto G. Melano
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Positive Predictive Value ◽  
Negative Predictive Value ◽  
Predictive Value ◽  
Rapid Detection ◽  
False Negative ◽  
Bacterial Extract ◽  
Content Type ◽  
Negative Results ◽  
False Negative Results

ABSTRACTThe Carba NP test was evaluated against a panel of 244 carbapenemase- and non-carbapenemase-producingEnterobacteriaceaeandPseudomonas aeruginosaisolates. We confirmed the 100% specificity and positive predictive value of the test, but the sensitivity and negative predictive value were 72.5% and 69.2%, respectively, and increased to 80% and 77.3%, respectively, using a more concentrated bacterial extract. False-negative results were associated with mucoid strains or linked to enzymes with low carbapenemase activity, particularly OXA-48-like, which has emerged globally in enterobacteria.

Diagnostic accuracy of monofilament test to detect diabetic neuropathy

2021 ◽  
Vol 10 (1) ◽  
pp. 20-25
Author(s):  
Sujan Shrestha ◽  
Mamen Prasad Gorhaly ◽  
Manil Ratna Bajracharya
Keyword(s):  
Peripheral Neuropathy ◽  
Positive Predictive Value ◽  
Diagnostic Accuracy ◽  
Negative Predictive Value ◽  
Predictive Value ◽  
Diabetic Peripheral Neuropathy ◽  
Perception Threshold ◽  
Sensitivity Specificity ◽  
Vibration Perception ◽  
Monofilament Test

Background Diabetic peripheral neuropathy (DPN) is a significant independent risk factor for diabetic foot, and an effective screening instrument is required to diagnose DPN early to prevent future ulceration and amputation. This study aims to determine the diagnostic accuracy of monofilament test to detect diabetic peripheral neuropathy. Methods This cross-sectional study was conducted in National Academy of Medical Sciences, Bir hospital, Mahabouddha, Kathmandu from February 2016 to January 2017. A total of 96 diabetic patients attending inpatient and outpatient Department were selected. Diabetic peripheral neuropathy was assessed by measurement of loss of protective sensation (LOPS) by monofilament test and compared with vibration perception threshold by standard biothesiometer. The sensitivity, specificity, positive predictive value and negative predictive value of monofilament test were calculated. Results The prevalence of diabetic peripheral neuropathy was 26%. The sensitivity, specificity, positive predictive value and negative predictive value of monofilament test were found to be 92.0%, 95.8%, 88.5% and 97.1% respectively. There was strong association between LOPS by monofilament and vibration perception threshold by biothesiometer. Conclusion This study showed a strong diagnostic accuracy of monofilament test to detect DPN when compared with biothesiometer. As monofilament test is a cheap, easily available, and portable, it can be used in the periphery where biothesiometer is not available.  

DIAGNOSTIC ACCURACY OF GRAY SCALE ULTRASONOGRAPHY VERSUS COLOR DOPPLER IN SUSPECTED CASES OF ACUTE APPENDICITIS

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Tahir Iqbal ◽  
Muhammad Usman Shahid ◽  
Ishfaq Ahmad Shad ◽  
Shahzad Karim Bhatti ◽  
Syed Amir Gilani ◽  
...  
Keyword(s):  
Acute Appendicitis ◽  
Positive Predictive Value ◽  
Diagnostic Accuracy ◽  
Negative Predictive Value ◽  
Predictive Value ◽  
Color Doppler ◽  
Diagnostic Tools ◽  
Gray Scale ◽  
Versus Color ◽  
Sensitivity Specificity

ABSTRACT: BACKGROUND: A common surgical emergency is acute appendicitis. Various diagnostic tools are available to diagnosis acute appendicitis. Radiological investigations play an important role in making accurate and early diagnosis and thus preventing morbidity associated with the disease. OBJECTIVE: To determine the diagnostic accuracy of gray scale ultrasonography versus color Doppler in suspected cases of acute appendicitis. MATERIALS AND METHODS: The study was carried in the department of Radiology of Mayo Hospital, Lahore. A total of 75 patients were enrolled of age 18-40 years, both genders who were suspected cases of acute appendicitis. All patients underwent baseline investigations along with gray scale ultrasonography and color Doppler. All patients were subjected to surgery to confirm the diagnosis and findings were subjected to statistical analysis. RESULTS: The mean age of the patients was 23.25 ±10.55 and mean transverse diameter of appendix was 8.37 ±3.39. There were 62.7% males and 37.3%females. Findings of gray scale ultrasonography and color Doppler were then correlated with surgical findings to calculate the diagnostic accuracy of these modalities. The results revealed that gray scale ultrasonography sensitivity, specificity, positive predictive value, negative predictive value and accuracy was 92.7%, 94.32%, 95%, 91.4% and 93.3% respectively, whereas color Doppler had sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 97.7%, 93.9%, 95.3%, 97% and 96% respectively. Diagnostic accuracy of both modalities together was 98.6%. CONCLUSION: Color Doppler has better diagnostic accuracy than gray scale ultrasonography for diagnosis of acute appendicitis and the combination of both modalities yields diagnostic accuracy that is similar to gold standard.

scholarly journals Comparison of RMI 3 and RMI 4 in pre-operative evaluation of ovarian masses

2019 ◽  
Vol 8 (9) ◽  
pp. 3602
Author(s):  
Badugu Rao Bahadur ◽  
Gangadhara Rao Koneru ◽  
Prabha Devi Kodey ◽  
Jyothi Melam
Keyword(s):  
Positive Predictive Value ◽  
Negative Predictive Value ◽  
Predictive Value ◽  
Malignant Tumors ◽  
Clinical Approach ◽  
Ovarian Mass ◽  
Medical College ◽  
Operative Evaluation ◽  
Sensitivity Specificity ◽  
Final Confirmation

Background: To differentiate ovarian mass as benign or malignant could change clinical approach. Finding a screening and diagnostic method for ovarian cancer is challenging due to high mortality and insidious symptoms. Risk malignancy index (RMI) has the advantage of rapid and exact triage of patients with ovarian mass.Methods: Prospective study carried for 2 years at NRI Medical College and General Hospital, Chinakakani, Mangalagiri, Andhra Pradesh, India. 79 patients with ovarian mass were investigated and risk malignancy index (RMI-3 and RMI-4) calculated. Final confirmation was done based on histopathological report. Sensitivity, specificity, positive predictive value and negative predictive value were calculated for RMI 3 and RMI 4 taking histopathology as control and comparison was done.Results: (n=79); 50 (63.29%) cases were benign and 29 (36.70%) were malignant based on histopathology. RMI 4 is more sensitive (68.96%) than RMI 3 (62.06%), but RMI 3 is more specific (94%) than RMI 4 (92%).The positive predictive value of RMI-3 and RMI-4 were 85.71%  and 83.33% respectively. The negative predictive value for RMI-4 and RMI-3 were 83.63% and 81.03% respectively.Conclusions: With increasing age, chance of malignancy increases. RMI 4 was more sensitive than RMI-3, however less specific than RMI 3 in differentiating benign and malignant tumors. The positive predictive value is slightly more for RMI 3, than RMI 4. Negative predictive value is slightly more for RMI 4, than RMI 3. 

Συγκριτική μελέτη της μορφομετρίας κατά τον κλασικό ακτινολογικό έλεγχο (MRX) και της μορφομετρίας με χρήση απορροφησιομετρίας (VFA) στον καθορισμό σπονδυλικών παραμορφώσεων σε οστεοπορωτικούς ασθενείς μετά από κυφοπλαστική

2017 ◽  
Author(s):  
Ευστάθιος Δράμπαλος
Keyword(s):  
Positive Predictive Value ◽  
Negative Predictive Value ◽  
Correlation Coefficient ◽  
Intraclass Correlation Coefficient ◽  
Predictive Value ◽  
Intraclass Correlation ◽  
Sensitivity Specificity

Σκοπός: H εφαρμογή για πρώτη φορά διεθνώς της μορφομετρίας της σπονδυλικής στήλης με χρήση απορροφησιομετρίας (VFA) σε ασθενείς με κυφοπλαστική. Αναλύονται τα πλεονεκτήματα και μειονεκτήματα της μεθόδου, ελέγχεται η αξιοπιστία της και συγκρίνεται με την μορφομετρία κατά τον κλασσικό ακτινολογικό έλεγχο (ΜRΧ) στην εκτίμηση των σπονδυλικών παραμορφώσεων στους συγκεκριμένους ασθενείς.Υλικά και Μέθοδος: Πραγματοποιήθηκαν μετρήσεις σε 42 ασθενείς με κυφοπλαστική λόγω οστεοπορωτικών σπονδυλικών καταγμάτων και αναλύθηκαν οι σπόνδυλοι από τον T4 μέχρι τον L4 με την VFA και την MRX. Μετρήθηκαν το πρόσθιο (ha), μέσο (hm) και οπίσθιο (hp) ύψος του σπονδυλικού σώματος και προσδιορίσθηκαν οι λόγοι ha/hp και hm/hp. Αναλύθηκαν για την VFA η συμφωνία αποτελεσμάτων του ίδιου παρατηρητή (IOA) και η συμφωνία αποτελεσμάτων μεταξύ ανεξάρτητων παρατηρητών (INA) για τους λόγους ha/hp και hm/hp καθώς και για την μέθοδο Genant σε επίπεδο σπονδύλου, ‘περιοχής της σπονδυλικής στήλης (θωρακική/ΘΜΣΣ ή οσφυϊκή/ΟΜΣΣ), σε επίπεδο ‘γειτονικών προς την κυφοπλαστική σπονδύλων’, και σε επίπεδο ‘σπονδύλων με κυφοπλαστική’. Σε κάθε επίπεδο χρησιμοποιήθηκε η μέση τιμή ha/hp και hm/hp. Στη συνέχεια, αναλύσαμε την συμφωνία μεταξύ VFA και MRX στον καθορισμό των λόγων ha/hp και hm/hp καθώς και μετά την διχοτόμηση των λόγων ha/hp περί της τιμής όριο που συνήθως χρησιμοποιείται για τον καθορισμό ενός κατάγματος. Αποτελέσματα: Οι IOA και INA για τους λόγους ha/hp και hm/hp στην VFA ήταν ‘σχεδόν τέλεια’ σε όλα τα επίπεδα (ICC 0.94-0.98). Η εφαρμογή της μεθόδου Genant κατά την VFA ανέδειξε επίσης ‘σχεδόν τέλεια’ INA (ICC=0.833). Η ανάλυση σε επίπεδο σπονδύλου έδειξε ‘σχεδόν τέλεια’ συμφωνία μεταξύ VFA και MRX για τον λόγο ha/hp [intraclass correlation coefficient, ICC=0.85], και ‘ισχυρή συμφωνία’ για τον λόγο hm/hp (ICC=0.78). Για τον λόγο ha/hp η συμφωνία ήταν ‘σχεδόν τέλεια’ τόσο στην ΘΜΣΣ (ICC=0.82) όσο και στην ΟΜΣΣ (ICC=0.87), ενώ για τον λόγο hm/hp η συμφωνία ήταν ‘ισχυρή’ στην ΘΜΣΣ (ICC=0.75) και ‘σχεδόν τέλεια’ στην ΟΜΣΣ (ICC=0.80). Η συμφωνία ήταν εξίσου ‘σχεδόν τέλεια’ σε επίπεδο ‘σπονδύλων με κυφοπλαστική’ (ICC=0.83) όσο και σε επίπεδο ‘γειτονικών προς την κυφοπλαστική σπονδύλων’ (ICC=0.80) για τον λόγο ha/hp. Όταν οι λόγοι ha/hp μετατράπηκαν σε κατάγματα (ναι ή όχι κάταγμα) χρησιμοποιώντας διαφορετικές τιμές κατώφλι για την διάγνωση κατάγματος (λόγοι ha/hp 0.75, 0.80 και 0.85) η συμφωνία μεταξύ των μεθόδων ήταν λιγότερο καλή, από μέτρια έως ουσιώδης (κ 0.52-0.63 στην ΟΜΣΣ και 0.53-0.66 στην ΘΜΣΣ). Χρησιμοποιώντας την κατάταξη Genant οι διαφορές στην ταξινόμηση των σπονδύλων ήταν περισσότερο προς την κατεύθυνση της MRX με 32 αναγνωρισμένα κατάγματα μόνο από την MRX και μόνο 5 μόνο από την VFA. Στη μελέτη αυτή, με επιπολασμό σφηνοειδών σπονδυλικών καταγμάτων 9.3%, οι δείκτες ακρίβειας sensitivity, specificity, positive predictive value (PPV) και negative predictive value (NPV) υπολογίστηκαν σε 0.522, 0.97, 0.87 και 0.92 αντίστοιχα. Συμπεράσματα: Η εφαρμογή της VFA σε ασθενείς με κυφοπλαστική έχει υψηλή επαναληψιμότητα και αναπαραγωγιμότητα. Η συμφωνία μεταξύ VFA και MRX στην εκτίμηση των λόγων ha/hp και hm/hm ήταν από ‘ισχυρή’ έως ‘σχεδόν τέλεια’ ανάλογα με το επίπεδο εξέτασης. Η συμφωνία στην αναγνώριση των σπονδυλικών καταγμάτων ήταν μέτρια. Οι διαφορές ήταν περισσότερο προς την κατεύθυνση της MRX. Η υψηλή τιμή του δείκτη NPV της VFA στους ασθενείς με κυφοπλαστική, δείχνει ότι η μέθοδος θα μπορούσε να χρησιμοποιηθεί για τον εντοπισμό αυτών που χρήζουν περαιτέρω ακτινολογικού ελέγχου.

Diagnostic Value of WB-DWI Versus 18 F-FDG PET/CT for the Detection of Multiple Myeloma

2020 ◽  
Author(s):  
Bei Zhang ◽  
Li Zhang ◽  
Bingyang Bian ◽  
Fang Lin ◽  
Zining Zhu ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Positive Predictive Value ◽  
Negative Predictive Value ◽  
Predictive Value ◽  
False Positive ◽  
Fdg Pet ◽  
Pet Ct ◽  
Adc Values ◽  
Sensitivity Specificity ◽  
Fdg Pet Ct

Abstract BACKGROUND Whole body diffusion weighted imaging (WB-DWI) is commonly used for the detection of multiple myeloma (MM). Comparative data on the efficiency of WB-DWI compared with 18 F positron emission tomography computed tomography ( 18 F-FDG PET/CT) to detect MM are lacking. METHODS This was a retrospective, single-center study of twenty-two patients with MM enrolled from January 2019 to December 2019. All patients underwent WB-DWI and 18 F-FDG PET/CT. Pathological and clinical manifestations as well as radiologic follow-up were used for diagnosis. The overall accuracy, sensitivity, specificity, positive predictive value and negative predictive value of both methods were compared. The appearance diffusion coefficient (ADC) values of MM lesions and false-positive lesions were estimated. RESULTS A total of 214 MM bone lesions were evaluated. WB-DWI showed a higher overall accuracy than PET/CT (75.7% and 55.6%, respectively; < 0.05). However, for sensitivity, specificity, positive predictive value and negative predictive value, there were no significant differences for WB-DWI vs PET/CT (99.3% and 83.9%, 64.9% and 94.8%, 63.6% and 54.2%, 98.1% and 65.3%, respectively). The ADC value for MM lesions was significantly lower than that for false-positive lesions (p < 0.001). Receiver operating curve (ROC) curve analysis showed that the AUC was 0.846, and when the cut-off value was 0.745×10 -3 mm 2 /s, the sensitivity and specificity were 86.0% and 82.4%, respectively, which distinguished MM lesions from non-MM lesions. CONCLUSION WB-DWI may be a useful tool for the diagnosis of MM bone disease due to to higher overall accuracy and measurements of ADC values compared with PET/CT.

scholarly journals Clinical Performance of the Spot Vision Photo Screener before and after Induction of Cycloplegia in Children

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Konuralp Yakar
Keyword(s):  
Positive Predictive Value ◽  
Negative Predictive Value ◽  
Predictive Value ◽  
Clinical Performance ◽  
High Specificity ◽  
Screening Criteria ◽  
Predictive Values ◽  
Before And After ◽  
Sensitivity Specificity ◽  
Vision Screener

Aim. To compare the clinical performance of the Spot Vision Screener used to detect amblyopia risk factors (ARFs) in children before and after induction of cycloplegia; the children were referred because they met the screening criteria of the American Association for Pediatric Ophthalmology and Strabismus (AAPOS). Methods. The Spot Vision Screener and a standard autorefractometer were used to examine 200 eyes of 100 children aged 3–10 years, before and after cycloplegia induction, in terms of ARFs. Sensitivity, specificity, and positive and negative predictive values for the detection of significant refractive errors were measured using the AAPOS referral criteria. It was explored that Spot Screener data were affected by cycloplegia. The extent of agreement between cycloplegic/noncycloplegic photoscreening data and cycloplegic autorefraction measurements was assessed using Wilcoxon and Spearman correlation analyses. Results. The Spot’s sensitivity was improved from 60.9% to 85.3% and specificity from 94.9% to 87.4% with cycloplegia compared to cycloplegic standard autorefractometer results. The positive predictive value of Spot was 75.7%, and the negative predictive value was 90.4% without cycloplegia. With cycloplegia, the positive predictive value of Spot was 63.6% and the negative predictive value was 95.8%. Conclusions. The Spot Screener afforded moderate sensitivity and high specificity prior to cycloplegia. The sensitivity and negative predictive value improved after induction of cycloplegia. Examiners should be aware of the effects of cycloplegia on their findings.

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