Estimating positive predictive value from a regression model: Screening with a non-invasive test

1989 ◽  
Vol 10 (3) ◽  
pp. 325-326
2016 ◽  
Vol 34 (2_suppl) ◽  
pp. 471-471
Author(s):  
Charles Joel Rosser ◽  
Yoshiko Shimizu ◽  
Hideki Furuya ◽  
Peter Bryant-Greenwood ◽  
Owen Chan ◽  
...  

471 Background: Urine based assays that can non-invasively detect bladder cancer (BCa) have the potential to reduce unnecessary and invasive procedures. The purpose of this study was to develop a multiplex immunoassay that can accurately and simultaneously monitor 10 diagnostic urinary protein biomarkers for application as a non-invasive test for BCa detection Methods: A custom electrochemiluminescent (ECL) multiplex assay was constructed (Meso Scale Diagnostics, LLC, Rockville, MD) to detect the following urinary proteins; IL8, MMP9, MMP10, ANG, APOE, SDC1, A1AT, PAI1, CA9 and VEGFA. Voided urine samples from two cohorts (cohort #1 n = 62 and cohort #2 n = 200) were collected prior to cystoscopy and samples were analyzed blinded to the clinical status of the participants. Means (±SD) and receiver operating characteristic (ROC) curve analysis were used to compare assay performance and to assess the diagnostic accuracy of the diagnostic signature. Results: Comparative diagnostic performance analyses revealed an AUROC value of 0.9258 for the multiplex assay and 0.9467 for the combination of the single-target ELISA assays (p = 0.625), so there was no loss of diagnostic utility for the MSD multiplex assay. Analysis of the independent 200-sample cohort using the multiplex assay achieved an overall diagnostic sensitivity of 0.85, specificity of 0.81, positive predictive value 0.82 and negative predictive value 0.84. Conclusions: It is technically feasible to simultaneously monitor complex urinary diagnostic signatures in a single assay without loss of performance. The described protein-based assay has the potential to be developed for the non-invasive detection of BCa.


2010 ◽  
Vol 59 (12) ◽  
pp. 1490-1496 ◽  
Author(s):  
Teresa J. Stradomska ◽  
Dorota Sobielarska ◽  
Zbigniew Mielniczuk ◽  
Dorota Jagiełłowicz ◽  
Małgorzata Syczewska ◽  
...  

A non-invasive, non-culture-based method of determining urinary d-/l-arabinitol (d-/l-ARA) ratios was investigated as a tool for the diagnosis of invasive candidiasis in nosocomial paediatric infection cases. The study encompassed 138 children aged 4 days to 16 years (mean±sd=1.6±4.2 years) with congenital heart defects (91.4 %) or with rhythm disorders or circulatory failure (8.6 %). ARA enantiomers were detected by GC using an electron capture detector. Positive d-/l-ARA ratios were found for 11/11 patients with proven candidiasis and 17/19 patients with clinically suspected invasive candidiasis. Thirty children were undergoing antifungal chemotherapy. d-/l-ARA ratios (mean±sd) were 2.601±0.544 in hospitalized cardiac patients without fungal infection and 5.120±1.253 in those receiving antifungal therapy (P<0.001). The sensitivity of the method was 100 %, the specificity 97.2 %, the positive predictive value was 78.6 % and the negative predictive value was 100 %.


PLoS ONE ◽  
2017 ◽  
Vol 12 (3) ◽  
pp. e0167130 ◽  
Author(s):  
Charles M. Strom ◽  
Ben Anderson ◽  
David Tsao ◽  
Ke Zhang ◽  
Yan Liu ◽  
...  

2016 ◽  
Vol 27 (2) ◽  
pp. 20-22
Author(s):  
Md Naushad Ali ◽  
Rehana Parvin ◽  
Md Abul Kalam Azad ◽  
AKM Mazharul Islam

This cross sectional study was carried out in the department of gastroenterology, Rangpur Medical College Hospital, Rangpur from January 2014 to July 2014 to compare between Invasive & Non-Invasive Diagnostic Evaluation of Tuberculosis Peritonitis In our prospective in clinically suspected patients. Total 30 patients (age 39.69±21.26, 18M/12F) with clinical suspicion of peritoneal tuberculosis were included in this study after analyzing selection criteria. Laparoscopic peritoneal biopsy with 'histopathological' diagnosis was considered as gold standard against which accuracies non-invasive test of two biomarkers (ADA & CA-125) were compared. Cut off value of ADA and CA-125 is 24 U/l, 35 U/ml respectively. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of ADA as a diagnostic modality in peritoneal tuberculosis were 87.5%, 83.33%, 95.45%, 62.5% and 86.67% respectively whereas CA-125 was found to have 83.33% sensitivity, 50% specificity, 86.9% positive predictive value, 42.85% negative predictive value and 76.6% accuracy. Both biomarkers were simple, non-invasive, rapid and relatively cheap diagnostic test whereas laparoscopy was an invasive procedure, costly & requires trained staff and not without risk and also not feasible in the entire centre in our country. So ascitic fluid ADA and serum CA-125 was important non-invasive diagnostic test for peritoneal tuberculosis.Medicine Today 2015 Vol.27(2): 20-22


2021 ◽  
Vol 71 (1) ◽  
pp. 12-17
Author(s):  
Laima Alam ◽  
Farrukh Saeed

Objective: To assess the non-invasive biomarkers of fibrosis for predicting varices-needing-treatment in patients with cirrhosis secondary to chronic-hepatitis-C. Study Design: Cross sectional comparative study. Place and Duration of Study: Department of Gastroenterology, Pak Emirates Military Hospital Rawalpindi, from Jan 2017 to Dec 2017. Methodology: A total of 153 patients aged 18-79 with cirrhosis, whether compensated or decompensated, secondary to chronic-hepatitis-C were enrolled. Relevant serum tests were used to calculate non-invasive fibrosis indices and their diagnostic performance to predict the presence of varices and varices-needing-treatment was calculated. Results: King’s score showed the best performance in detecting varices due to high positive predictive value of 96.4% and positive likelihood ratio of 2.4. Overall, all the non-invasive fibrosis indices exhibited good performance with positive predictive value >85% but none could rule out the presence of varices with adequate reliability due to low negative-predictive-value (<65%). King’s score exhibited relatively higher positive-predictivevalue (70%) and negative predictive value (51.1%) and the lowest negative-likelihood-ratio (0.6) for predicting varices needing treatment. Taken together, none of the non-invasive biomarkers of fibrosis could predict the presence of varices-needing-treatment with adequate accuracy due to low positive-predictive-value (<85%) andlow negative-predictive-value (<65%). Conclusion: The calculated non-invasive biomarkers of fibrosis and their optimum cutoff values showed modest accuracy for predicting varices and varices-needing-treatment. These indices may be used as first-line screening method for segregation of clinically significant portal hypertension and high risk esophageal varices-needingtreatment but may not be able to replace the gold standards like Fibroscan liver and Hepatic Venous Pressure Gradient measurements.


Author(s):  
Sunil Mathew ◽  
Sachin Chacko ◽  
Tomy Philip ◽  
R. N. Sharma ◽  
Kanniyan Binub

Background: Esophageal variceal bleeding is one among the common complication of cirrhosis which is fatal. Latest studies are focusing more on using non-invasive techniques to classify cirrhotic patients according to their risk of having varices. The platelet count-splenic diameter ratio is considered as one such parameter and is used in predicting esophageal varices in patients with cirrhosis. Objectives of the study was to assess the utility of platelet count-splenic diameter ratio as a useful non- invasive parameter in predicting the presence/ absence /size of esophageal varices in patients with cirrhosis.Methods: Diagnostic evaluation study was done in a tertiary hospital of Kerala state India. 93 adults above the age of 18 yrs with diagnosis of cirrhosis was selected and detailed history, physical, systemic examination and imaging was done. The degree of correlation between platelet count-splenic size ratio and the presence/absence/size of esophageal varices was studied along with its utility as an independent non- invasive marker. Frequency was expressed in percentages.Results: Best cut-off for prediction of esophageal varices Grade 1 was platelet count/spleen diameter ratio of 954, which had Specificity of 85.7% and Positive predictive value of 94.1% Cut-off for prediction of Grade 2 esophageal varices was platelet count/spleen diameter ratio of 916 which had a Sensitivity of 78.9%, Specificity of 88.9%. Whereas cut-off for prediction of Grade 3 esophageal varices was a ratio of 899 which had a high Sensitivity of 88% and Negative predictive value of 93.6 % but Specificity was only 64.7% and Positive predictive value of 47.8% only.Conclusions: The platelet count splenic diameter ratio is accurate to be used as screening tool to predict the presence of Grade 2 Esophageal varices in Patients with Cirrhosis. More studies need to be done around the globe for more evidence.


2020 ◽  
Vol 5 (3) ◽  
pp. 1196-1200
Author(s):  
Manish Raj Pathak ◽  
Mahesh Gautam ◽  
Rashmita Bhandari

Introduction: Breast carcinoma is the second leading cause of cancer related mortality in females around the world. Ultrasound plays a key role in differentiating cystic and solid lesions and is a convenient and non-invasive diagnostic tool to differentiate between benign and malignant lesions. Objectives: The aim of this study is to evaluate the diagnostic accuracy of ultrasound in palpable breast lesions. Methodology: A prospective cross-sectional study was carried out in patients with palpable breast lesions who presented in Department of radio diagnosis and imaging of Nobel Medical collegefor a period of one-year from February 2019- January 2020 using ultrasound. A total of 60 patientswereevaluated in the study. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy were calculated. Results: Out of 60 patients evaluated, ultrasound showed 46 (76.7%) cases to be benign and 14 (23.3%) cases to be malignant. FNAC revealed benign disease in 47 (78.3%) patients and malignant disease in 13 (21.7%) patients. The most common benign lesion was fibroadenoma. We found nearly 91.7% of the malignant lesions had spiculated margins and microcalcification. The sensitivity of ultrasound was 95.74% and specificity 92.3% with diagnostic accuracy 95%. Conclusion: Ultrasound is a convenient and non-invasive diagnostic tool with good sensitivity, specificity, positive predictive value, negative predictive value and accuracy in palpable breast lesions.


2014 ◽  
Vol 25 (2) ◽  
pp. 44-49
Author(s):  
P Das ◽  
R Pramanik ◽  
M Kataruka ◽  
RN Haldar ◽  
S Samanta ◽  
...  

Abstract Introduction Over the years NCS has been used to diagnose and monitor the patients with CTS though USG has several advantages as diagnostic tool. This study has been done to find out the diagnostic accuracy of USG in CTS and to compare the efficacy of USG with standard NCS in CTS. Prospective cross-sectional analytical study was conducted at Dept. of PM&R, IPGME&R, Kolkata from 1st March, 2012 to 31st August 2012 (6 months). Patient with clinical diagnosis of CTS of age >18 year of both sexes were included in this study and on the other hand patient with previous wrist surgery /injury, wrist deformity, diabetes mellitus, anatomical variants of median nerve on ultrasound were excluded from the study. Methodology After getting institutional ethical committee clearance, all patients who fulfil the above criteria were included in the study and further diagnostic conformation done by the standard diagnostic criteria of NCS. The same group of patients have been also screened by ultrasonography (USG). Results At the end of the study, data analysis showed that sensitivity and specificity were 92.3 and 70.0% respectively. Predictive value of +test, predictive value of -test were 88.9 and 77.8% respectively. Kappa value was 0.64 (between 0.5 and 0.7). It signifies that there is good correlation between NCS and USG as diagnostic tool of CTS. The comparison of the numerical values of median latency, amplitude and CSA USG within the groups with the help of ANOVA followed by Tukey's test showed that there was good correlation between latency and amplitude in mild, moderate, severe and profound CTS but unfortunately it was not correlated with the CSA measured by USG. Conclusion USG can be used for screening large population of patients as it is simple, easily available, non-invasive test and has relatively low cost and useful in evaluating and excluding local causes of nerve compression.


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