scholarly journals Improving Linkage to Care of Hepatitis C: Clinical Validation of GeneXpert® HCV Viral Load Point-of-Care Assay in Indonesia

2021 ◽  
Author(s):  
Meta Dewi Thedja ◽  
Dhita Prabasari Wibowo ◽  
Korri Elvanita El-Khobar ◽  
Susan Irawati Ie ◽  
Turyadi ◽  
...  
Keyword(s):  
Viral Load ◽  
Hepatitis C ◽  
Point Of Care ◽  
Pearson Correlation ◽  
Diagnosis And Treatment ◽  
Altman Plot ◽  
Modular Systems ◽  
Bland Altman Plot ◽  
Plot Analysis ◽  
Deming Regression

Hepatitis C virus (HCV) infection large-scale diagnosis and treatment are hampered by lack of a simple, rapid, and reliable point-of-care (POC) test, which poses a challenge for the elimination of hepatitis C as a public health problem. This study aimed to evaluate Cepheid Xpert® HCV Viral Load performance in comparison with the Roche Cobas® TaqMan® HCV Test using serum samples of HCV-infected patients in Indonesia. Viral load quantification was performed on 243 anti-HCV positive patients’ samples using both Xpert HCV VL and Roche HCV tests, followed by HCV genotyping by reverse hybridization. Strength of the relationship between the assays was measured by Pearson correlation coefficient, while level of agreement was analyzed by Deming regression and Bland–Altman plot analysis using log10-transformed viral load values. Quantifiable viral load was detected in 180/243 (74.1%), with Xpert HCV VL sensitivity of 100% (95% CI 0.98, 1.00) and specificity of 98.4% (95% CI 0.91, 0.99) based on Roche HCV tests, while HCV genotypes were determined in 172/180 (95.6%) samples. There was a good correlation between both assays (r = 0.97, P < 0.001), overall and per genotype, with good concordance by Deming regression and a mean difference of −0.25 log10 IU/mL (95% CI −0.33, −0.18) by Bland–Altman plot analysis. Xpert HCV VL test was demonstrated as a POC platform with good performance for HCV diagnosis and treatment decision that would be beneficial for decentralized service in resource-limited areas. HCV testing sites, alongside additional GeneXpert modular systems distributed toward the fight against COVID-19, could ensure some continuity, once this pandemic is controlled.

scholarly journals Improving linkage to care of hepatitis C: Evaluation of GeneXpert® HCV Viral Load Point-of-Care Assay in Indonesia

2020 ◽  
Author(s):  
Meta Dewi Thedja ◽  
Dhita Prabasari Wibowo ◽  
Korri Elvanita El-Khobar ◽  
Susan Irawati Ie ◽  
Turyadi Turyadi ◽  
...  
Keyword(s):  
Viral Load ◽  
Hepatitis C ◽  
Point Of Care ◽  
Pearson Correlation ◽  
Load Test ◽  
Diagnosis And Treatment ◽  
Altman Plot ◽  
Bland Altman Plot ◽  
Plot Analysis ◽  
Deming Regression

Abstract Background: Lack of simple, rapid, and reliable point-of-care (POC) test hampers large-scale diagnosis and treatment of hepatitis C virus (HCV) infection and pose a challenge for its elimination as a public health threat. This study aimed to evaluate Cepheid Xpert® HCV Viral Load performance in comparison to Roche Cobas® TaqMan® HCV Test using HCV-samples with various genotypes in Indonesia.Methods: Viral load (VL) quantification was performed on 243 anti-HCV positive patients’ samples using both Xpert and Roche HCV tests, followed by HCV genotyping by reverse hybridization. Strength of relationship between the assays was measured by Pearson correlation coefficient, while level of agreement was analyzed by Deming regression and Bland-Altman plot analysis using log10-transformed VL values.Results: Quantifiable VL was detected in 180/243 (74.1%), with Xpert sensitivity of 100% (95% CI 0.98, 1.00) and specificity of 98.41% (95% CI 0.91, 0.99), while HCV genotypes were determined in 172/180 (95.6%) samples. There was a very good correlation between both assays (r = 0.97, P < 0.001), overall and per genotype, with good concordance by Deming regression and mean difference of −0.25 log10 IU/mL (95% CI −0.33, −0.18) by Bland-Altman plot analysis.Conclusion: Good performance of Xpert HCV Viral Load test was demonstrated as a POC platform for HCV diagnosis and treatment decision, which would be beneficial for decentralized service in resource-limited areas.

scholarly journals Amyloid PET Quantification Using Low-dose CT-guided Anatomic Standardization

2021 ◽  
Author(s):  
Hiroshi Matsuda ◽  
Tensho Yamao ◽  
Mitsuru Shakado ◽  
Yoko Shigemoto ◽  
Kyoji Okita ◽  
...  
Keyword(s):  
Correlation Analysis ◽  
Low Dose ◽  
Pearson Correlation ◽  
Quantitative Measure ◽  
Amyloid Pet ◽  
Altman Plot ◽  
Ct Guided ◽  
Bland Altman Plot ◽  
Low Dose Ct ◽  
Pet Ct

Abstract BackgroundCentiloid (CL) scaling has become a standardized quantitative measure in amyloid PET because it facilitates the direct comparison of results across institutions, even when different analytical methods or tracers are used. Standard volumes of interest must be used to calculate the CL scale after the anatomic standardization of amyloid PET images using coregistered MRI; if the MRI is unavailable, the CL scale cannot be accurately calculated. This study sought to determine the substitutability of low-dose CT, which is used to correct PET attenuation in PET/CT equipment, by evaluating the measurement accuracy when low-dose CT is used as an alternative to MRI in the calculation of the CL scale. Amyloid PET images obtained using 18F-flutemetamol from 24 patients with possible or probable Alzheimer’s disease were processed to calculate the CL scale using 3D T1-weighted MRI and low-dose CT of PET/CT. CLMRI and CLCT were respectively defined as the use of MRI and CT for anatomic standardization and compared. Trial registration: Japan Registry of Clinical Trials, jRCTs031180321. Registered 18 March 2019, https://jrct.niph.go.jp/latest-detail/jRCTs031180321.ResultsA Bland–Altman plot showed that CLCT was slightly but significantly underestimated (mean ± standard deviation, −1.7 ± 2.4; p < 0.002) compared with CLMRI. The 95% limits of agreement ranged from −2.8 to −0.7. Pearson correlation analysis showed a highly significant correlation of r = 0.998 between CLCT and CLMRI (p < 0.001). The linear regression equation was CLMRI = 1.027 × CLCT + 0.762. In a Bland-Altman plot, Spearman correlation analysis did not identify a significant association between the CLMRI versus CLCT difference and the CL load (ρ = −0.389, p = 0.060). This slight underestimation of CLCT may derive from slightly higher uptake when the cerebellum is used as a reference area in CT-based anatomically standardized PET images versus MRI-based images.ConclusionsLow-dose CT of PET/CT can substitute for MRI in the anatomic standardization used to calculate the CL scale from amyloid PET, although a slight underestimation occurs.

scholarly journals Correlation of Corneal Thickness Measurements Between Tono-pachymeter and Scheimpflug- Placido Topography

2021 ◽  
Vol 16 (2) ◽  
pp. 161-167
Author(s):  
Zeynep Eylül Ercan ◽  
Keyword(s):  
Corneal Thickness ◽  
Age Groups ◽  
Limits Of Agreement ◽  
Altman Plot ◽  
Bland Altman Plot ◽  
Significant Relationships ◽  
Plot Analysis ◽  
Group 2 ◽  
Thickness Measurements ◽  
Group 1

Central corneal thickness (CCT) measurements are important for diagnosis, treatment, and surgery planning in ophthalmology. The purpose of this study was to see whether CCT measurements taken with Tono-pachymeter and Scheimpflug- Placido Topography had any significant differences. Tono-pachymeter and topography CCT measurements were taken (n=400). Inter-measurement agreement between them was determined using Bland-Altman Plot analysis. Age groups were also formed as group 1 (aged 18-50 years, 94 males, 106 females) and group 2 (age >51 years, 100 males, 100 females). Mean CCTs measured by Tonopachymeter and topography were 563.77 +±26.43 and 560.88 + 26.341 microns. Bland-Altman Plot analysis showed in total, 13 were above the upper limit and 5 were under the minimum limit of agreement with regression analysis showing no significant relationships (p=0.213). Group 1 had 7 above and 2 below from the limits of agreement. Group two had 9 above and 2 below from the limits of agreement. Both groups showed insignificant differences between devices (p=0.07 and p=0.86). Tono-pachymeter and Scheimpflug-Placido Topography give reliable CCT results within each other. However, since the limit of agreement ranges can still affect one-to-one patient evaluations, we recommend clinics that use these devices to not interchange measurements in practice.

scholarly journals Comparison of VIDAS and Radioimmunoassay Methods for Measurement of Cortisol Concentration in Bovine Serum

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Daniela Proverbio ◽  
Roberta Perego ◽  
Eva Spada ◽  
Giada Bagnagatti de Giorgi ◽  
Angelo Belloli ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Bovine Serum ◽  
Serum Cortisol ◽  
Cortisol Concentration ◽  
Altman Plot ◽  
Gold Standard Method ◽  
Bland Altman Plot ◽  
Deming Regression ◽  
Significant Difference ◽  
Serum Cortisol Concentration

Radioimmunoassay (RIA) is the “gold standard” method for evaluation of serum cortisol concentration. The VIDAS cortisol test is an enzyme-linked fluorescent assay designed for the MiniVidas system. The aim of this study was to compare the VIDAS method with RIA for measurement of bovine serum cortisol concentration. Cortisol concentrations were evaluated in 40 cows using both VIDAS and RIA methods, the latter as the reference method. A paired Student’s -test, Pearson’s correlation analysis, Bland-Altman plot, and Deming regression analysis were used to compare the two methods. There was no statistically significant difference between mean serum cortisol concentrations measured by VIDAS or RIA methods (). Both methods were able to detect significant differences in mean low and high cortisol concentrations ( RIA and VIDAS). The correlation coefficient was low, but a Bland-Altman plot and Deming regression analysis show neither constant nor proportional error. The VIDAS method produced slightly higher values than RIA, but the difference was small and in no case did the mean value move the normal range. Results suggest that VIDAS method is suitable for the determination of bovine serum cortisol concentration in studies of large numbers of animals.

scholarly journals Original article. Repeatability assessment of the New Numbers Contrast Sensitivity Chart

2014 ◽  
Vol 8 (3) ◽  
pp. 361-369
Author(s):  
Bharkbhum Khambhiphant ◽  
Sunee Chansangpetch ◽  
Wasee Tulvatana ◽  
Mathu Busayarat
Keyword(s):  
Contrast Sensitivity ◽  
Narrow Range ◽  
Primary Language ◽  
Altman Plot ◽  
Bland Altman Plot ◽  
Plot Analysis ◽  
Good Repeatability ◽  
The Mean ◽  
Mean Differences ◽  
The Right

Abstract Background: The validity and agreement of the New Numbers Contrast Sensitivity Chart with the original Mars chart have been found to be good. The two charts can be used interchangeably; however, evidence of the repeatability of the new chart remains to be sought. This study was to assess the repeatability of the New Numbers Contrast Sensitivity Chart. Objectives: We assessed the repeatability of the Numbers Contrast Sensitivity Chart. Methods: Two hundred subjects from the ophthalmic clinic of the King Chulalongkorn Memorial Hospital, who were able to communicate and read Arabic numerals were recruited. The contrast sensitivity (CS) scores were collected by reading the same Numbers Contrast Sensitivity Chart in the same environment with each eye and both eyes ten minutes apart. The repeatability of the CS score was assessed by Bland-Altman plot analysis. Results: The visual acuity of subjects with variety in diagnoses ranged from 20/480 to 20/20. The mean differences were -0.006, -0.008, -0.002 log CS and the coefficients of repeatability were 0.155, 0.141, and 0.093 for the right eye, left eye, and both eyes, respectively. The plots showed a narrow range of 95% limit of agreement, which were (+0.146, -0.159) in the right eye, (+0.130, -0.147) in the left eye, and (+0.089, -0.093) in both eyes. Conclusions: The New Numbers Contrast Sensitivity Chart has good repeatability. With proven good validity and repeatability, this easy and convenient numbers chart is beneficial for practical use in a clinical setting where English is not used as the primary language.

Cervical length at 31–34 weeks of gestation: transvaginal vs. transperineal ultrasonographic approach

2019 ◽  
Vol 47 (8) ◽  
pp. 817-821 ◽  
Author(s):  
Ioannis Tsakiridis ◽  
Themistoklis Dagklis ◽  
Apostolos Mamopoulos ◽  
Angeliki Gerede ◽  
Apostolos Athanasiadis
Keyword(s):  
Correlation Coefficient ◽  
Pearson Correlation ◽  
Close Correlation ◽  
Cervical Length ◽  
Tolerance Interval ◽  
Pearson Correlation Coefficient ◽  
Altman Plot ◽  
Bland Altman Plot ◽  
Paired Samples ◽  
The Mean

Abstract Objectives To investigate the correlation between transperineal (TP) and transvaginal (TV) ultrasonography in the measurement of cervical length (CL) in the third trimester of pregnancy. Methods In this prospective study, CL measurements were conducted in women between 31 and 34 weeks of gestation by both the TP and TV approaches. A comparison of the measurements was made between the two techniques. The Pearson correlation coefficient, the paired samples t-test and Bland-Altman plot were used. Results In total, 240 women participated in the study. The CL was successfully measured transvaginally in all cases and transperineally in 229 (95.4%) of the cases. The mean TV CL was 32.8 ± 8.2 mm and the mean TP CL was 32.5 ± 8.1 mm. In the 229 cases with paired measurements, the Pearson correlation coefficient was 0.964. No significant differences in mean CL were identified between the two methods (t = 1.805; P = 0.072). In the Bland-Altman plot, the difference between the paired means was 0.26 mm and the 95% tolerance interval for any given paired observation (TV CL–TP CL) was −4.05 to 4.57 mm. Conclusion The findings of this study suggest that at 31–34 weeks of gestation the cervix can be visualized adequately by both the TV and TP sonography in about 95% of cases. The TP CL measurements demonstrate a close correlation with the TV measurements. TP ultrasound is a feasible alternative, especially in cases where the use of the vaginal transducer should be minimized or is not acceptable by women.

P1522Validating a new device for precise assessment of pulse wave velocity in arteries of various structures in patients in different age groups

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
R Olszewski ◽  
T Sondej ◽  
K Sieczkowski ◽  
K Obiala ◽  
I Jannasz ◽  
...  
Keyword(s):  
Arterial Stiffness ◽  
Pulse Wave Velocity ◽  
Wave Velocity ◽  
Pulse Wave ◽  
Pearson Correlation ◽  
Age Groups ◽  
Altman Plot ◽  
Bland Altman Plot ◽  
New Device ◽  
The Difference

Abstract Background Arterial stiffness (AS) is a process that develops with age and obesity, but is also an independent predictive factor for the development of hypertension, and cardiovascular complications. Measuring the pulse wave velocity (PWV) is the most common method of assessing arterial stiffness. Two methods of PWV evaluation dominate in the world (carotid-femoral and brachial-ankle). However, recent studies have indicated that the age-related increase in PWV was not even uniform in different arteries and the AS gradient is a better predictor of mortality than the classic PWV one. So we need the devices for a more accurate assessment of AS in different areas. Our group constructed a precise, multi-site system (M3S) for the simultaneous, real-time, synchronous measurement of PWV. M3S has a maximum of eight photopletysmographic (PPG) detectors – Fig. 1A. Aim The purpose of the study is to validate the PWV measurement by M3S device against a gold standard (SphygmoCor XCEL) for patients in different age groups. Methods Measurements collected from 62 subjects (36 young [19–24], 26 older [62–89]) using the M3S were compared with simultaneously recorded SphygmoCor XCEL measurements. With the 59 paired PWV values, we investigated the agreement between the M3S prototype and the SphygmoCor XCEL device using Pearson correlation analysis and Bland-Altman plot. We also performed analysis on the determinants and reproducibility of PWV measured with both devices. Results The correlation coefficient for PWV measured with the two devices was 0.87 (p<0.001) – Fig. 1B. Compared with the SphygmoCor XCEL device, the M3S prototype slightly underestimated PWV by r=−0.47 m/s (±1.96 standard deviations SD: +2.2 m/s, r=−3.2 m/s). The coefficient of variation (CV) between the difference and the average of the M3S and SphygmoCor XCEL measurements was 19% (p=0.10) – Fig. 1C. Figure 1. A. Block diagram of M3S measurement system with configuration for PWV validation. B. Relationship between PWV for SphygmoCor XCEL (carotid-femoral) and M3S (forehead-toes (right, left mean). C. Bland-Altman plot for the analysis of the difference between the SphygmoCor XCEL and M3S devices. Conclusion This technique used by the M3S could provided a multi-site measurement of PWV. It can be potentially extended for measurement and non-invasive characterization of global arterial stiffness with the possibility of calculating the different AS gradients.

scholarly journals Validation of a pre-coded food diary with energy expenditure, comparison of under-reporters v. acceptable reporters

2005 ◽  
Vol 94 (6) ◽  
pp. 998-1003 ◽  
Author(s):  
I. T. L. Lillegaard ◽  
L. F. Andersen
Keyword(s):  
Food Intake ◽  
Energy Expenditure ◽  
Pearson Correlation ◽  
Pearson Correlation Coefficient ◽  
Confidence Limits ◽  
Food Diary ◽  
Limits Of Agreement ◽  
Altman Plot ◽  
Bland Altman Plot ◽  
Males And Females

The objective of the present study was to compare energy intake (EI) assessed from a pre-coded food diary (PFD) with energy expenditure (EE) measured by a validated position-and-movement monitor (ActiReg®; PreMed AS, Oslo, Norway) in a group of Norwegian 9-year-olds. Moreover, we examined whether and how under-reporters (UR), identified with ActiReg®, differed from acceptable reporters (AR) according to food intake and BMI. A total of fifty-one 9-year-olds completed PFD and ActiReg®. The present study showed that on average EI was underestimated by 18 % compared with EE measured by ActiReg®. The 95 % confidence limits of agreement in a Bland–Altman plot for EI and EE varied from 1·97 MJ to −4·23 MJ (sd 2) among the girls and from 0·74 MJ to −5·26 MJ (sd 2) among the boys. The Pearson correlation coefficient between EI and EE was 0·28 (P=0·05) for males and females combined. Fifty-seven per cent of the participants were classified as AR, 39 % as UR and 4 % as over-reporters with the PFD. Under-reporting of energy remains a problem with the PFD method used in a group of 9-year-olds, especially among boys. However, UR and AR did not show a systematic misreporting related to macronutrients, unhealthy foods or BMI.

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