scholarly journals A20 DIAGNOSTIC ACCURACY OF A LOW COST, WIDELY AVAILABLE TEST STRIP FOR PREDICTING A POSITIVE FECAL CALPROTECTIN TEST

2021 ◽  
Vol 4 (Supplement_1) ◽  
pp. 210-212
Author(s):  
R Trasolini ◽  
S Wong ◽  
B Salh

Abstract Background Fecal calprotectin is a non-invasive test of colonic inflammation used for monitoring inflammatory bowel disease activity and for risk stratifying non-specific colonic symptoms. Calprotectin is a leukocyte specific enzyme. A similar test, leukocyte esterase is used to detect leukocytes in urine and is widely available as a low-cost point-of-care test strip. We hypothesize that an unmodified version of the urine test strip would be highly accurate in predicting a positive fecal calprotectin test in a real world sample of patients. Aims To explore a low cost, rapid alternative to the fecal calprotectin test Methods All inpatient and outpatient stool samples tested for calprotectin by the Vancouver General Hospital laboratory from February 2020 to November 2020 were included prospectively. Samples were simultaneously tested for fecal leukocyte esterase using an unmodified Roche Cobas Chemstrip urinalysis test strip by central lab personnel. An identical aliquot was sent to LifeLabs for calprotectin as per standard protocol. All samples were suspended in buffer using established laboratory protocols prior to testing. Fecal leukocyte esterase results were reported as 0–4+ based on visual interpretation, calprotectin results were reported as mcg/g of stool. REB review and approval was obtained prior to data collection. Sensitivity, Specificity and AUROC were calculated using Microsoft Excel and JROCFIT. Results 26 samples were collected. Using a fecal calprotectin greater than 120 mcg/g as a gold standard an AUROC of 0.89 (SE= .06) was calculated. A leukocyte esterase reading of 2+ or greater had the best test characteristics based on ROC curve analysis. Using this cutoff, 21/26 samples were concordant, giving an accuracy of 80.8%, sensitivity of 90.9% and specificity of 73.3%. Positive likelihood ratio was 8.07 and negative likelihood ratio was 0.29. Assuming an AUROC of 0.8, the sample size N=26 is 90% powered (β=0.9) to predict the true AUROC within 0.1 with a type I error rate of .05 (α<.05). Conclusions This study suggests application of a prepared stool sample to a urinalysis test strip gives a result highly predictive of a positive fecal calprotectin test. Further results are being collected prospectively to improve the robustness of these preliminary data. Secondary outcomes including comparison to endoscopy and biopsy results where available are planned if an adequate sample size can be accrued. Future studies justifying independent clinical use of leukocyte esterase would require a common gold standard comparator such as endoscopy. Fecal calprotectin testing is not universally insured and is not available as a rapid test strip. Use of fecal leukocyte esterase may reduce costs and shorten time to results if proven to be independently reliable. Funding Agencies None

2020 ◽  
Author(s):  
Kris Yuet-Wan Lok ◽  
Charlotte Chow ◽  
Shirley W Tan ◽  
Robert Smith ◽  
Jessie Lin ◽  
...  

Abstract Introduction: Rising prevalence and undetected perinatal depression has been described in many countries and report that treating those who are already symptomatic, more effort should be targeted towards screening strategies to identify perinatal depression at the early stage. The Whooley questions is the recommended case finding strategy to aid the identification of perinatal depression. An official Chinese version has not been validated. The aim of this study was to evaluate the diagnostic accuracy and stability of the translated Whooley questionnaire against the gold standard measurement during pregnancy (antenatal) and early after pregnancy (postnatal).Materials and method: This observational study recruited 131 pregnant women from antenatal clinics in a hospital setting from September 2019 till May 2020 in Hong Kong. We translated the Whooley questionnaire in Chinese and evaluated self-reported responses against an interviewer assessed diagnostic standard (DSM-IV criteria) among 107 women receiving antenatal care at 26-28 weeks gestation. We calculated sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio, negative likelihood ratio and diagnostic odds ratio, with DSM-IV diagnosis taken as the gold standard.Results: Antenatally, the Chinese Whooley questions had a sensitivity of 79% (95% CI 54.4-93.9), a specificity of 97% (95% CI 90.4-99.3), a positive likelihood ratio of 23.2 (95% CI 7.4-72.1) and a negative likelihood ratio of 0.2 (95% CI 0.1-0.5) in identifying perinatal depression. Conclusion: Prevalence of depression in pregnancy have increased and screening early remains a significant tool in Western countries. The translated Chinese Whooley questionnaire appears to have acceptable diagnostic accuracy and can be implemented into health services among Chinese population as only requiring two yes/no questions.


2021 ◽  
Author(s):  
IRERI THIRION-ROMERO ◽  
SELENE GUERRERO-ZUNIGA ◽  
ALEXANDRA ARIAS-MENDOZA ◽  
DORA PATRICIA CORNEJO-JUAREZ ◽  
PATRICIA MEZA-MENESES ◽  
...  

BACKGROUND Point-of-care rapid tests to identify SARS-CoV-2 can be of great help because, in principle, they allow decisions to be made at the site of care for treatment, or for the separation of cohorts avoiding cross-infection, especially in emergency situations. METHODS A cross sectional study in adults requesting care in Emergency Rooms (ER), or the outpatient clinics of referral hospitals for COVID-19, to define the diagnostic characteristics of a rapid antigen test for SARS-CoV-2 (the Abbott PanbioTM) having as a gold standard the RT-PCR for SARS-CoV-2. Health personnel in a routine situation within an active pandemic in several cities of Mexico performed the tests. RESULTS A total of 1,069 participants with a mean age of 47 years (SD 16 years), 47% with a self-reported comorbidity, and an overall prevalence of a positive RT-PCR test of 45%, were recruited from eight hospitals in Mexico. Overall sensitivity of the Panbio test was 54.4% (95%CI 51-57) with a positive likelihood ratio of 35.7, a negative likelihood ratio of 0.46 and a Receiver-Operating Characteristics curve area of 0.77. Positivity for the rapid test depended strongly on an estimate of the viral load (Cycle threshold of RT-PCR, Ct), and the days of symptoms. With a Ct 25, sensitivity of the rapid test was 0.82 (95%CI, 0.76-0.87). For patients during the first week of symptoms sensitivity was 69.6% (95%CI 66-73). On the other hand, specificity of the rapid test was above 97.8% in all groups. CONCLUSIONS The PanbioTM rapid antigen test for SARS-CoV-2 has a good specificity, but due to low and heterogeneous sensitivity in real life, a negative test in a person with suggestive symptoms at a time of community transmission of SARS-CoV-2 requires confirmation with RT-PCR, and after the first week of symptoms, sensitivity decreases considerably.


2008 ◽  
Vol 48 (2) ◽  
pp. 104
Author(s):  
Ity Sulawati ◽  
Amalia Setyati ◽  
A. Samik Wahab ◽  
M. Juffrie

Background The diagnosis of influenza remains difficult toestablish because of its similar symptoms to those of respiratoryinfection caused by other viruses. The “gold standard” for thediagnosis of influenza is viral culture, which takes time to gainthe result and is expensive as well. A simple, rapid, and easilyused tool for detection of influenza virus type A and B is needed.Objective To assess the accuracy of lateral-flow immunoassay withQuick Vue Influenza A+B ® in detecting influenza virus of typeA and B.Methods This was an observational study designed for diagnostictest. The subjects were children aged 0-14 years old presentingwith acute respiratory infection in primary Health Care Jetis ,Godean I, Godean II and Prof. Dr. Sardjito Hospital Yogyakarta,from October 2005 to May 2007. Specimens were collected fromboth the anterior nares and the throat by physicians for lateral-flow immunoassay with Quick Vue Influenza A+B ® and viralculture as gold standard. Lateral-flow immunoassay was done ineach study centre, nasal specimen was placed in an extractionreagent tube and sent to NAMRU II laboratory.Results There were 255 children enrolled in this study. Lateral-flow immunoassay by Quick Vue Influenza A+B ® has sensitivity70% (CI95% 6;83%), specificity 93% (CI95% 90;97%), positivepredictive value 68% (CI95% 54;82%), negative predictive value94% (CI95% 91;97%), positive likelihood ratio 10,56 (CI95%6,14;18,19) and negative likelihood ratio 0,32 (CI95% 0,21; 0,51).Conclusion Lateral-flow immunoassay (Quick Vue InfluenzaA+B ® ), nasal swab specimen is not accurate to detect influenzavirus A and B in children.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Xuan Xiong ◽  
Hongtao Xiao ◽  
Yuan Zhang ◽  
Dongke Yu ◽  
Junlan Chuan ◽  
...  

Objective. To evaluate the diagnostic value of apolipoprotein E (APOE) gene in Alzheimer’s disease (AD). Methods. Databases including PubMed, EMBASE, Google Scholar, Wanfang Med online, China National Knowledge Infrastructure (CNKI), and China Biomedical Literature Database (CBM) were searched for literatures in English or Chinese. No limitations on the date. The sensitivity, specificity, likelihood ratio, and diagnostic odds ratio were pooled for meta-analysis. The symmetric receiver operator characteristic curve (SROC) and Fagan’s Nomogram were drawn, and metaregression and subgroup analysis were used to explore the source of heterogeneity. Results. A total of 13 studies, including 2662 cases and 8843 controls, were analyzed. The combined sensitivity (SEN) was 0.62 (95% CI (0.58-0.66)), specificity (SPE) was 0.84 (95% CI (0.81-0.86)), the positive likelihood ratio was 3.8 (95% CI (3.3-4.3)), and the negative likelihood ratio was 0.45 (95% CI (0.41-0.49)). The area under the ROC curve was 0.80, and the diagnostic ratio (DOR) was 8. Neither publication bias was detected in Deeks’ funnel plot, nor threshold effect was shown in the SROC. Metaregression analysis showed that the diagnostic methods, experimental design, and sample size contributed to the heterogeneity in SEN, while the diagnostic methods, experimental design, blind evaluation on test results, and sample size contributed to the heterogeneity in SPE. When the pretest probability was set as 50%, the posterior probability in Fagan’s Nomogram was 79%, the positive likelihood ratio (LRP) was 5, and the negative likelihood ratio (LRN) was 0.42. Conclusions. AD could neither be confirmed nor excluded by the APOE genotype test. The sensitivity and specificity of the APOE gene test were relatively low in the diagnosis of AD. The diagnostic value of APOE ε4 gene in AD was moderate; it might play an important role in the prevention of AD.


2016 ◽  
Vol 48 (5) ◽  
pp. 299
Author(s):  
Thermiany AS ◽  
W Retayasa ◽  
M Kardana ◽  
IN Lila

Background Neonatal sepsis is a major cause of morbidity andmortality. A positive blood culture is the gold standard fordiagnosis of neonatal sepsis. The signs and symptoms suggestingneonatal sepsis are non-specific. There is no rapid and reliablelaboratory test findings for confirmation of etiologic diagnosis.Clinical signs, symptoms, and laboratory examinations are notperceived as sensitive or specific for diagnosis of sepsis.Objective The purpose of this study was to evaluate the accuracyof the septic markers for diagnosis of neonatal sepsis.Methods Blood culture was used as gold standard to compareseptic markers to diagnose neonatal sepsis. Sensitivity, specificity,positive predictive value (PPV), negative predictive value (NPV),positive and negative likelihood ratio (LR), and accuracy werecalculated.Results We identified 130 cases suspected of neonatal sepsis duringSeptember 2005 until March 2006. Four patients were excludedbecause of major congenital anomalies. The mean age was 2.2 daysand 51.6% were boys. We found fifty six (44.4%) neonates havepositive blood culture. All of septic markers had sensitivity morethan 80%. Immature to Total Neutrophil ratio (Iff) ratio had thehighest sensitivity (96.4%) and C-Reactive Protein (CRP) had thelowest sensitivity (80.4o/o). Combination among leukocyte count,thrombocyte, and Iff ratio had the highest sensitivity (sensitivitywas 85. 7%, specificity was 97.1 o/o, positive predictive value was95.9%, negative predictive value was 89.5%, accuracy was 94.4%,and positive likelihood ratio was 30.0).Conclusion Septic markers can be used in the diagnosticevaluation of neonates with suspected sepsis.


Author(s):  
Tom D Thacher ◽  
Christopher T Sempos ◽  
Ramon A Durazo-Arvizu ◽  
Philip R Fischer ◽  
Craig F Munns ◽  
...  

Abstract Context Nutritional rickets results from the interaction of low vitamin D status and limited calcium intake. Serum alkaline phosphatase (AP) activity is a biomarker of impaired mineralization in rickets. Objective To assess the performance of serum AP activity in identifying nutritional rickets in calcium-deprived Nigerian children. Design, setting, and participants We reanalyzed data from a case-control study of children with active rickets and matched control subjects without rickets, using a multivariate logistic regression to assess the odds of rickets associated with AP activity, adjusting for age, sex, and weight for age z-score. Results A total of 122 children with rickets and 119 controls were included. Rachitic children had a mean (±SD) age of 54±29 months, and 55 (45.1%) were male. Cases and controls had low dietary calcium intakes (216±87 and 214±96 mg/day, respectively). Serum AP activity levels in cases and controls were 812±415 and 245±78 U/L, respectively (P<0.001). AP was negatively associated with 25-hydroxyvitamin D values (r=-0.34; P<0.001). In the adjusted model, the odds ratio (95% confidence interval) for rickets was 6.7 (4.1-12.2) for each 100 U/L increase in AP. The area under the receiver operating characteristic curve was 0.978. AP >350 U/L identified nutritional rickets in Nigerian children with sensitivity 0.93, specificity 0.92, positive likelihood ratio 11.3, and negative likelihood ratio 0.07. Conclusions An AP >350 U/L effectively discriminated between Nigerian children with and without nutritional rickets. AP is a low-cost biochemical test that could be used to screen for nutritional rickets, but cut-off values require validation in other populations, and laboratory values need to be standardized for widespread population studies.


2021 ◽  
Vol 20 ◽  
pp. 153303382110119
Author(s):  
Wen-Ting Zhang ◽  
Guo-Xun Zhang ◽  
Shuai-Shuai Gao

Background: Leukemia is a common malignant disease in the human blood system. Many researchers have proposed circulating microRNAs as biomarkers for the diagnosis of leukemia. We conducted a meta-analysis to evaluate the diagnostic accuracy of circulating miRNAs in the diagnosis of leukemia. Methods: A comprehensive literature search (updated to October 13, 2020) in PubMed, EMBASE, Web of Science, Cochrane Library, Wanfang database and China National Knowledge Infrastructure (CNKI) was performed to identify eligible studies. The sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and area under the curve (AUC) for diagnosing leukemia were pooled for both overall and subgroup analysis. The meta-regression and subgroup analysis were performed to explore heterogeneity and Deeks’ funnel plot was used to assess publication bias. Results: 49 studies from 22 publications with a total of 3,489 leukemia patients and 2,756 healthy controls were included in this meta-analysis. The overall sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio and area under the curve were 0.83, 0.92, 10.8, 0.18, 59 and 0.94, respectively. Subgroup analysis shows that the microRNA clusters of plasma type could carry out a better diagnostic accuracy of leukemia patients. In addition, publication bias was not found. Conclusions: Circulating microRNAs can be used as a promising noninvasive biomarker in the early diagnosis of leukemia.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Bo Zhang ◽  
Bingjie Zhang ◽  
Zhulin Zhou ◽  
Yutong Guo ◽  
Dan Wang

AbstractObjectiveGlycosylated hemoglobin (HbA1c) has obvious clinical value in the diagnosis of diabetes, but the conclusions on the diagnostic value of diabetic retinopathy (DR) are not consistent. This study aims to comprehensively evaluate the accuracy of glycosylated hemoglobin in the diagnosis of diabetic retinopathy through the meta-analysis of diagnostic tests.MethodsCochrane Library, Embase, PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), China Wanfang Database, Chinese Biomedical Literature Database (CBM) were searched until November, 2020. The Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool was used to assess the quality of the included studies. The pooled sensitivity, specificity, positive likelihood ratio (+LR), negative likelihood ratio (-LR), diagnostic odds ratio (DOR) and areas under the receiver operating characteristic (ROC) curve were calculated by Stata 15.0 software.ResultsAfter screening, 18 high-quality papers were included. The results of meta-analysis showed that the combined DOR = 18.19 (95% CI: 10.99–30.11), the sensitivity= 0.81 (95% CI): 0.75 ~ 0.87), specificity = 0.81 (95%CI: 0.72 ~ 0.87), +LR = 4.2 (95%CI: 2.95 ~ 6.00), −LR = 0.23 (95%CI: 0.17 ~ 0.31), and the area under the Summary ROC curve was 0.88 (95%CI:  0.85 ~ 0.90).ConclusionThe overall accuracy of HbA1cC forin diagnosing diabetic retinopathy is good. As it is more stable than blood sugar and is not affected by meals, it may be a suitable indicator for diabetic retinopathy.


2021 ◽  
pp. 1-11
Author(s):  
Bing-Jie Xiang ◽  
Min Jiang ◽  
Ming-Jun Sun ◽  
Cong Dai

<b><i>Objective:</i></b> Fecal calprotectin (FC) is a promising marker for assessment of inflammatory bowel disease (IBD) activity. However, the utility of FC for predicting mucosal healing (MH) of IBD patients has yet to be clearly demonstrated. The objective of our study was to perform a meta-analysis evaluating the diagnostic accuracy of FC in predicting MH of IBD patients. <b><i>Methods:</i></b> We systematically searched the databases for studies from inception to April 2020 that evaluated MH in IBD. The methodological quality of each study was assessed according to the Quality Assessment of Diagnostic Accuracy Studies checklist. The extracted data were pooled using a summary receiver operating characteristic curve model. Random-effects model was used to summarize the diagnostic odds ratio, sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio. <b><i>Results:</i></b> Sixteen studies comprising 1,682 ulcerative colitis (UC) patients and 4 studies comprising 221 Crohn’s disease (CD) patients were included. The best performance of FC for predicting MH in UC was at cut-off range of 60–75 μg/g with area under the curve (AUC) of 0.88 and pooled sensitivity and specificity of 0.87 and 0.79, respectively. The pooled sensitivity and specificity values of cutoff range 180–250 μg/g for predicting MH in CD were 0.67 and 0.76, respectively. The AUC of 0.79 also revealed improved discrimination for identifying MH in CD with FC concentration. <b><i>Conclusion:</i></b> Our meta-analysis has found that FC is a simple, reliable noninvasive marker for predicting MH in IBD patients. FC cutoff range 60–75 μg/g appears to have the best overall accuracy in UC patients.


2021 ◽  
Vol 49 (3) ◽  
pp. 030006052199296
Author(s):  
Juan Wang ◽  
Liu Yang ◽  
Yanjun Diao ◽  
Jiayun Liu ◽  
Jinjie Li ◽  
...  

Objective To evaluate the performance of a DNA methylation-based digital droplet polymerase chain reaction (ddPCR) assay to detect aberrant DNA methylation in cell-free DNA (cfDNA) and to determine its application in the detection of hepatocellular carcinoma (HCC). Methods The present study recruited patients with liver-related diseases and healthy control subjects. Blood samples were used for the extraction of cfDNA, which was then bisulfite converted and the extent of DNA methylation quantified using a ddPCR platform. Results A total of 97 patients with HCC, 80 healthy control subjects and 46 patients with chronic hepatitis B/C virus infection were enrolled in the study. The level of cfDNA in the HCC group was significantly higher than that in the healthy control group. For the detection of HCC, based on a cut-off value of 15.7% for the cfDNA methylation ratio, the sensitivity and specificity were 78.57% and 89.38%, respectively. The diagnostic accuracy was 85.27%, the positive predictive value was 81.91% and the negative predictive value was 87.20%. The positive likelihood ratio of 15.7% in HCC diagnosis was 7.40, while the negative likelihood ratio was 0.24. Conclusions A sensitive methylation-based assay might serve as a liquid biopsy test for diagnosing HCC.


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