P1088BRAND NEW METHOD TO CALCULATE THE VOLUME OF EXTRA CELLULAR FLUID IN HEMODIALYSIS PATIENT ONLY FROM REGULAR BLOOD TEST

Abstract Background and Aims Uric acid is a small molecule with molecular weight 168, but has an electrical pole which enables pass through the phospholipid bilayers of cell membranes by simple diffusion. Urate transport proteins of cell membranes (URAT1, GLUT9, OAT, MRP4, MCT9, NPT4, ABCG2) are expressed only in uric acid-excreting tissues. These findings suggest that uric acid does not pass through the cell membrane, either by diffusion or active transport. Since uric acid does not pass through cell membranes, the uric acid distribution volume (UDiV) would reflect the extracellular volume (ECV). At ASN 2018, we reported that UDiV significantly correlated with ECV predicted by the bio-impedance method measured by InBody, S 20 (Biospace Co., Ltd, Korea). However, both data were correlated, there was a large fixed error. This time, we examined the correlation with the UDiV again using the Fresenius BCM (Fresenius Medical Care, Bad Homberg, Germany), which is trusted worldwide. Method We calculated UDiV from regular blood test results by uric acid kinetic modeling. This study was performed in Yokohama Minami Clinic. One hundred nine patient under hemodialysis was consented and enrolled in this study. The HD patients were 59males and 50females. 68.0±10.9years old. We performed UDiV calculation from blood samples obtained before and after hemodialysis. Then, after the hemodialysis session, 30minutes interval was made to measure the BIA-ECV using BCM. Then, we compared UDiV with BIA-ECV . We used least squares regression analysis and Bland–Altman analysis to compare the UDiV method and the BIA-ECV method, and the Steel test for multiple comparisons of UDiV and symptoms. All analyses were performed using JMP 9.0.2 (SAS Institute, Inc., Cary, NC, USA). Results There was a significant correlation between UDiV(x) and BIA-ECFV (y): (y = 0.70x +3.02, r-square = 0.61, p < 0.0001, Figure 1a). The regression line closely coincided with the line of identity. Bland–Altman analysis showed a systematic error for UDiVvs. BIA-ECV (Figure 1b). There was a significant difference between UDiVand BIA-ECV (mean difference 1.32 L, 95% CI -2.6 to 5.2 L). Conclusion UdiV could be a viable alternative marker of BIA-ECV for the assessment of hydration status of patients with HD.

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Uric acid distribution volume calculated by kinetic modeling and extracellular volume predicted by bioimpedance method

The International Journal of Artificial Organs ◽

10.1177/0391398820909835 ◽

2020 ◽

Vol 43 (11) ◽

pp. 701-709

Author(s):

Toru Shinzato ◽

Shigeru Nakai ◽

Takahito Ito ◽

Kazuhiko Shibata ◽

Teppei Matsuoka ◽

...

Keyword(s):

Uric Acid ◽

Mass Balance ◽

Blood Test ◽

Cell Membranes ◽

Extracellular Volume ◽

Distribution Volume ◽

Facilitated Diffusion ◽

Bioimpedance Analysis ◽

Test Results ◽

Simple Diffusion

Background: Several reports indicate that extracellular volume predicted by bioimpedance analysis method is associated with hydration status of hemodialysis patients. Theory: Fundamentally, uric acid does not cross cell membranes by simple diffusion, either by facilitated diffusion or by active transport. In addition, uric acid cannot move through cell membranes in most tissues other than those involved in uric acid excretion. These facts support the interpretation that uric acid distribution volume would therefore correlate with extracellular volume. Methods: We examined correlation between uric acid distribution volume calculated by uric acid mass-balance modeling from regular blood test results and extracellular volume predicted by bioimpedance analysis predicted by BCM (Fresenius Medical Care) in 53 patients. Results: There was a significant correlation between uric acid distribution volume ( x) and extracellular volume predicted by bioimpedance analysis ( y): y = 0.69 x + 3.39, r2 = 0.61, p < 0.0001. Bland–Altman analysis showed systematic error for uric acid distribution volume versus extracellular volume predicted by bioimpedance analysis (mean difference between uric acid distribution volume and extracellular volume predicted by bioimpedance analysis was 0.94 L, 95% confidence interval of difference was −3.29 to 5.17 L). Conclusion: Uric acid distribution volume calculated by uric acid mass-balance modeling from regular blood test results may be an alternative marker of extracellular volume predicted by bioimpedance analysis.

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Comparison of IOP Measurement by Goldmann Applanation Tonometer, ICare Rebound Tonometer, and Tono-Pen in Keratoconus Patients after MyoRing Implantation

Journal of Ophthalmology ◽

10.1155/2019/1964107 ◽

2019 ◽

Vol 2019 ◽

pp. 1-7

Author(s):

Mahmoud Rateb ◽

Mahmoud Abdel-Radi ◽

Zeiad Eldaly ◽

Mohamed Nagy Elmohamady ◽

Asaad Noor El Din

Keyword(s):

Central Corneal Thickness ◽

Pearson Correlation ◽

Corneal Thickness ◽

Altman Analysis ◽

Bland Altman Analysis ◽

Rebound Tonometer ◽

Goldmann Applanation Tonometer ◽

Significant Difference ◽

Applanation Tonometer ◽

Icare Rebound Tonometer

Purpose. To evaluate the different IOP readings by Goldmann applanation tonometer (GAT), ICare rebound tonometer, and Tono-Pen in keratoconus patients after MyoRing implantation. To assess the influence of central corneal thickness (CCT) and thinnest corneal location (TCL) on IOP measurements by different tonometers. Setting. Prospective observational study was conducted in two private centers in Egypt from February 2015 to November 2016. Methods. Seventeen eyes of 10 patients suffering from keratoconus and who underwent MyoRing implantation were recruited. All subjects underwent GAT, ICare, and Tono-Pen IOP measurements in random order. Central corneal thickness and thinnest corneal location were assessed by Pentacam. Difference in mean in IOP readings was assessed by T-test. Correlation between each pair of devices was evaluated by Pearson correlation coefficient. The Bland–Altman analysis was used to assess intertonometer agreement. Results. Seventeen eyes (10 patients) were evaluated. The mean IOP reading was 13.9 ± 3.68, 12.41 ± 2.87, and 14.29 ± 1.31 mmHg in GAT, ICare, and Tono-Pen group, respectively. There was a significant difference between IOP readings by GAT/ICare and Tono-Pen/ICare (p value: 0.032 and 0.002, respectively) with no significant difference between GAT/Tono-Pen (p value: 0.554). Mean difference in IOP measurements between GAT/ICare was 1.49 ± 2.61 mmHg, Tono-Pen/ICare was 1.89 ± 2.15 mmHg, and GAT/Tono-Pen was −0.39 ± 2.59 mmHg. There was no significant correlation between the difference in IOP readings among any pair of devices and CCC or TCL. The Bland–Altman analysis showed a reasonable agreement between any pair of tonometers.

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Validation of the visual acuity iPad app Eye Chart Pro compared to the standard Early Treatment Diabetic Retinopathy Study chart in a low-vision population

Journal of Telemedicine and Telecare ◽

10.1177/1357633x20960640 ◽

2020 ◽

pp. 1357633X2096064

Author(s):

Hassan Hazari ◽

Rachel Curtis ◽

Karen Eden ◽

Wilma M Hopman ◽

Isabella Irrcher ◽

...

Keyword(s):

Visual Acuity ◽

Diabetic Retinopathy ◽

Early Treatment ◽

Low Vision ◽

Test Methods ◽

Absolute Difference ◽

Altman Analysis ◽

Bland Altman Analysis ◽

Significant Difference ◽

Ipad App

Introduction A low-vision assessment (LVA) is central to developing a vision rehabilitation plan. However, access to LVAs is often limited by the quantity and geographic distribution of low-vision providers, as well as patient-centred transportation challenges. A tablet-based LVA tool kit, delivered virtually, has the potential to overcome many of these barriers. The purpose of this research was to validate a key component of the tablet-based tool kit – a commercially available iPad visual acuity (VA) test (Eye Chart Pro) iPad app – in a low-vision population. Methods Participants with low vision ( n = 26) and those who were normally sighted ( n = 25) underwent VA testing with both the iPad VA test application and the Early Treatment Diabetic Retinopathy Study (ETDRS) chart. The VA data were compared using a t-test, linear regression and Bland–Altman analysis. Results There was no significant difference in the mean absolute difference in VA (log of minimum angle of resolution (logMAR)=0.11; p = 0.82). Eye Chart Pro and Standard ETDRS Chart measures were also not significantly different ( p = 0.98). However, there were significant differences between test methods in the low-vision group and the normally sighted group ( p > 0.0001 and p = 0.007, respectively). The Bland–Altman analysis showed a mean bias (difference) of –0.0005 logMAR between methods, and 95% limits of agreement of 0.298 and –0.299 logMAR. Discussion The ETDRS chart function on the Eye Chart Pro application can reliably measure VA across a range, from normally sighted patients to those with low vision.

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Clinical validation of time reduction strategy in continuous step-and-shoot mode during SPECT acquisition

EJNMMI Physics ◽

10.1186/s40658-021-00354-x ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Valentin Picone ◽

Nikolaos Makris ◽

Fanny Boutevin ◽

Sarah Roy ◽

Margot Playe ◽

...

Keyword(s):

Image Quality ◽

Head Rotation ◽

Visual Assessment ◽

Motion Artifacts ◽

Altman Analysis ◽

Bland Altman Analysis ◽

Focal Uptake ◽

Significant Difference ◽

Lung Scan ◽

Step And Shoot

Abstract Background The SwiftScan solution (General Electric Healthcare) combines a new low-energy high-resolution sensitivity collimator and a tomographic step-and-shoot continuous (SSC) mode acquisition. The purpose of this study is to determine whether SSC mode can be used in clinical practice with shorter examination times, while preserving image quality and ensuring accurate semi-quantification. Twenty bone scan and 10 lung scan studies were randomly selected over a period of 2 months. Three sets of image datasets were produced: step-and-shoot (SS) acquisition, simulated 25% count reduction using the Poisson resampling method (SimSS), and SimSS continuous acquisition (SimSSC), where SimSS was summed with counts acquired during detector head rotation. Visual assessment (5-point Likert scale, 2 readers) and semi-quantitative evaluation (50 focal uptake from 10 bone studies), assessed by SUVmean, coefficient of variation (COV), and contrast-to-noise ratio (CNR), were performed using t test and Bland-Altman analysis. Results Intra-reader agreement was substantial for reader 1 (k = 0.71) and for reader 2 (k = 0.61). Inter-reader agreement was substantial for SS set (k = 0.93) and moderate for SimSSC (k = 0.52). Bland-Altman analysis showed a good interchangeability of SS and SimSSC SUV values. The mean CNR between SS and SimSSC was not significantly different: 42.9 ± 43.7 [23.7–62.1] vs. 43.1 ± 46 [22.9–63.3] (p = 0.46), respectively. COV values, assessing noise level, did not deviate significantly between SS and SimSSC: 0.20 ± 0.08 [0.18–0.23] vs. 0.21 ± 0.08, [0.18–0.23] (p = 0.15), respectively, whereas a significant difference was demonstrated between SS and SimSS: 0.20 ± 0.08 [0.18–0.23] vs. 0.23 ± 0.09 [0.20–0.25] (p < 0.0001), respectively. Conclusions SSC mode acquisition decreases examination time by approximately 25% in bone and lung SPECT/CT studies compared to SS mode (~ 2 min per single-bed SPECT), without compromising image quality and signal quantification. This SPECT sensitivity improvement also offers the prospect of more comfortable exams, with less motion artifacts, especially in painful or dyspneic patients.

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Comparison between optical and digital blur using near visual acuity

Scientific Reports ◽

10.1038/s41598-021-82965-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

David Kordek ◽

Laura K. Young ◽

Jan Kremláček

Keyword(s):

Visual Acuity ◽

Refractive Error ◽

Low Cost ◽

Pairwise Comparison ◽

Clinical Population ◽

Altman Analysis ◽

Bland Altman Analysis ◽

Laboratory Setup ◽

Significant Difference ◽

Near Visual Acuity

AbstractIn a low-cost laboratory setup, we compared visual acuity (VA) for stimuli rendered with Zernike aberrations to an equivalent optical dioptric defocus in emmetropic individuals using a relatively short observing distance of 60 cm. The equivalent spherical refractive error of + 1, + 2 or + 4 D, was applied in the rendering of Landolt Rings. Separately, the refractive error was introduced dioptrically in: (1) unchanged Landolt Rings with an added external lens (+ 1, + 2 or + 4 D) at the subject's eye; (2) same as (1) but with an added accommodation and a vertex distance adjustment. To compare all three approaches, we examined VA in 10 healthy men. Stimuli were observed on a PC CRT screen. For all three levels of refractive error, the pairwise comparison did not show a statistically significant difference between digital blur and accommodation-plus-vertex-distance-adjusted dioptric blur (p < 0.204). The best agreement, determined by Bland–Altman analysis, was measured for + 4 D and was in line with test–retest limits for examination in the clinical population. Our results show that even for a near observing distance, it is possible to use digitally rendered defocus to replicate dioptric blur without a significant change in VA in emmetropic subjects.

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Heart Transplant Patients in a wide population observed for Mycophenolic Acid Area Under The Curve executed with a limited sampling strategy technique

10.22541/au.161818635.55661375/v1 ◽

2021 ◽

Author(s):

Francesco Lo Re ◽

Sandro Sponga ◽

Chiara Nalli ◽

Antonella Zucchetto ◽

Ugolino Livi ◽

...

Keyword(s):

Linear Regression ◽

Heart Transplant ◽

Mycophenolic Acid ◽

Sampling Strategy ◽

Limited Sampling Strategy ◽

Altman Analysis ◽

Bland Altman Analysis ◽

Limited Sampling ◽

Standard Clinical Practice ◽

Significant Difference

Aim The study aim is the validation of two algorithms of Limited Sampling Strategy (LSS) for the quantification of Mycophenolic Acid (MPA) Area under the plasma concentration-time curve from 0 to 12h (AUC0-12h) in a cohort of non-selected Heart Transplant (HTx) recipients treated, as standard clinical practice, with Mycophenolate Mofetil (MMF) combined with Cyclosporine (CsA), or Tacrolimus (TAC). These two LSSs were previously tested and validated by Baraldo et al. in a cohort of selected HTx recipients 1,2. The value of MPA AUC0-12h (real and estimated with LSSs) among non-rejected (NR) and rejected (R) patients were evaluated. Methods Linear regression and Bland Altman Analysis validated two LSSs methods (named LSS3 and LSS4 by number of blood samples used). The value of MPA AUC0-12h between NR and R patients were compared by Mann-Whitney test. Results The validation reports positive results for LSS3 and LSS4 according to linear regression (r=0.91 and 0.94 and R2=0.84 and 0.88, respectively) and Bland Altman Analysis (p=0.04 and 0.04). There was a difference of borderline statistically significance (p=0.06) for the median value of MPA AUC0-12h (mg×h/L) between NR and R patients (46.60; Interquartile Range (IQR): 34.80-64.10 vs 33.70; IQR: 23.60-48.25); whereas the difference was statistically significant for both LSS3 and LSS4 (p=0.03 and 0.04). Conclusion The capability of these two LSSs to estimate MPA AUC0-12h in cohort of non-selected HTx recipients and the suggestion of a significant difference on MPA AUC0-12h between NR and R patients, confirm the importance of MPA quantification in the clinical field.

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Validity and Reliability of the GymAware Linear Position Transducer for Squat Jump and Counter-Movement Jump Height

Sports ◽

10.3390/sports6040177 ◽

2018 ◽

Vol 6 (4) ◽

pp. 177 ◽

Cited By ~ 2

Author(s):

Tanuj Wadhi ◽

Jacob Rauch ◽

Nauris Tamulevicius ◽

Jody Andersen ◽

Eduardo De Souza

Keyword(s):

Test Validity ◽

Jump Height ◽

Altman Analysis ◽

Squat Jump ◽

Retest Reliability ◽

Bland Altman Analysis ◽

Position Transducer ◽

Counter Movement Jump ◽

Significant Difference ◽

Test Retest Reliability

The purpose of this study was to assess the concurrent validity and test-retest reliability of a linear position transducer (LPT) for the squat jump (SJ) and counter-movement jump (CMJ) height. Twenty-eight subjects (25.18 ± 7.1 years) performed three SJs followed by three CMJs using a force plate concurrently with the LPT to test validity. Subjects returned on a separate day, at least 48 h apart, to measure test-retest reliability. A t-test showed a significant difference between the two devices for both SJ (p < 0.001) and CMJ (p < 0.001) while Bland–Altman analysis for validity revealed that the LPT overestimated jump height for both SJ (mean difference (MD) = 8.01 ± 2.93 cm) and CMJ (MD = 8.68 ± 2.99 cm). With regards to reliability of the LPT, mean intraclass correlation (ICC) for both SJ (ICC = 0.84) and CMJ (ICC = 0.95) were high, and Bland–Altman analysis showed mean differences lower than minimal detectable change (MDC) between the days for both SJ (MD = 1.89 ± 4.16 cm vs. MDC = 2.72 cm) and CMJ (MD = 0.47 ± 3.23 cm vs. MDC = 2.11 cm). Additionally, there was a low coefficient of variation (CV) between days for both SJ (CV = 3.25%) and CMJ (CV = 0.74%). Therefore, while the LPT overestimates jump height, it is a reliable tool for tracking changes in jump height to measure performance improvement and monitor fatigue.

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Anomalous Aortic Origin of a Coronary Artery: Symptoms Do Not Correlate With Intramural Length or Ostial Diameter

World Journal for Pediatric and Congenital Heart Surgery ◽

10.1177/2150135117710926 ◽

2017 ◽

Vol 8 (4) ◽

pp. 445-452 ◽

Cited By ~ 2

Author(s):

Shyamasundar Balasubramanya ◽

Michael C. Mongé ◽

Osama M. Eltayeb ◽

Anne E. Sarwark ◽

John M. Costello ◽

...

Keyword(s):

Coronary Artery ◽

Surgical Repair ◽

Preoperative Imaging ◽

Altman Analysis ◽

Resonance Imaging ◽

Surgical Indications ◽

Bland Altman Analysis ◽

Significant Difference ◽

Magnetic Resonance Imaging Mri ◽

Strong Agreement

Background: Anomalous aortic origin of a coronary artery (AAOCA) is a known cause of sudden death. Our hypothesis was that longer intramural length and smaller ostial diameter correlate with preoperative symptoms. If true, this would assist in the decision for surgical indications. We also assessed the accuracy of preoperative imaging to predict intramural length. Methods: Retrospective analysis of patients who underwent AAOCA unroofing from 2006 to 2014. Patients had preoperative computed tomography angiography (CTA) or magnetic resonance imaging (MRI). Intramural length was measured. Intramural lengths and ostial diameters were also measured intraoperatively (operating room [OR]). Symptoms were noted. Intramural lengths and ostial diameters were compared between patients with and without preoperative symptoms. The accuracy of intramural length measured by CTA/MRI versus the length measured in the OR was assessed using a Bland-Altman analysis. Results: Sixty-six patients underwent surgical repair of AAOCA. Fifty-two (79%) patients were symptomatic and 14 (21%) were asymptomatic. Mean age was 12.4 ± 4.0 years. There was no mortality. There was strong agreement between intramural length measured by CTA/MRI and measured in the OR. There was no significant difference in AAOCA intramural length in the symptomatic (8.6 ± 3.5 mm) and asymptomatic (8.9 ± 2.8 mm, P = .77) patients, which were measured both by CTA/MRI and intraoperatively (symptomatic 7.3 ± 2.5 mm, asymptomatic 6.9 ± 2.8 mm; P = .62). There was also no significant difference in AAOCA ostial diameters between groups (symptomatic = 1.9 ± 0.5 mm, asymptomatic = 1.6 ± 0.5 mm; P = .09). Conclusion: Preoperative CTA/MRI was very accurate in predicting the length of surgical unroofing. There was no demonstrable correlation between preoperative symptoms and intramural AAOCA length or AAOCA ostial diameter.

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Faster HbA1c Turnaround Times Using a Dedicated Analyzer Based on Turbidimetric Inhibition Immunoassay Technology

The Journal of Applied Laboratory Medicine ◽

10.1093/jalm/jfaa154 ◽

2020 ◽

Author(s):

Chin Shern Lau ◽

Melva Lim ◽

See Ping Hoo ◽

Cherlyn Gan ◽

Tar Choon Aw

Keyword(s):

Complete Blood Count ◽

Point Of Care ◽

Altman Analysis ◽

Bland Altman Analysis ◽

Deming Regression ◽

Significant Difference ◽

The Difference ◽

Interassay Precision ◽

Hba1c Levels ◽

Comparable Time

Abstract Introduction The Roche Cobas c513 (c513) is a dedicated stand-alone high throughput HbA1c analyzer. We evaluated the performance and the difference in turnaround times (TAT) of the c513 against our Cobas 8000 c502 (c502). Methods We assessed the linearity and precision of the c513, and its agreement (Deming regression and Bland–Altman analysis) with the c502 assay. We compared TAT for these analyzers for a single run of 50 samples and for all samples run over 2 comparable time periods. Results The c513 assay was linear from 4.4–18.3% HbA1c. Interassay precision (CV%) was 1.2 and 0.8 at HbA1c levels of 5.7 and 10.5%, respectively. The c513 assay showed excellent concordance with the c502 assay (r = 0.997) with no significant difference between methods by Bland–Altman analysis (mean difference = 0.021% HbA1c, P = 0.1422). The c513 took 17 min to analyze 50 samples, compared to 40 min on the c502. Over comparable 2-month periods, 90% of samples requiring HbA1c tests only were completed under 25 min (c513) vs 30–35 min (c502). For tubes sharing complete blood count (CBC) testing with HbA1c, the 90th percentile TAT was 35–40 min (c513) compared to 45–50 min (c502). Conclusion The c513 assay performs well with excellent correlation to the c502 assay. The improved TAT of the c513 is suitable when there are demands for rapid HbA1c results and it may forestall requests for point-of-care testing. It is also attractive to sites with heavy workloads with a claimed throughput of 400 tests / h.

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Comparison of the SITA Faster–a new visual field strategy with SITA Fast strategy

International Journal of Ophthalmology ◽

10.18240/ijo.2021.08.08 ◽

2021 ◽

Vol 14 (8) ◽

pp. 1185-1191

Author(s):

Chao-Xu Qian ◽

◽

Qing Cun ◽

Yi-Jin Tao ◽

Wen-Yan Yang ◽

...

Keyword(s):

Visual Field ◽

Visual Field Defects ◽

Test Time ◽

Mean Deviation ◽

Test Duration ◽

Altman Analysis ◽

Bland Altman Analysis ◽

Significant Difference ◽

Probability Plots ◽

Field Defects

AIM: To compare visual field defects using the Swedish Interactive Thresholding Algorithm (SITA) Fast strategy with SITA Faster strategy, a newly developed time-saving threshold visual field strategy. METHODS: Ninety-three participants (60 glaucoma patients and 33 normal controls) were enrolled. One eye from each participant was selected randomly for the study. SITA Fast and SITA Faster were performed using the 24-2 default mode for each test. The differences of visual field defects between the two strategies were compared using the test duration, false-positive response errors, mean deviation (MD), visual field index (VFI) and the numbers of depressed test points at the significant levels of P<5%, <2%, <1%, and <0.5% in probability plots. The correlation between strategies was analyzed. The agreement between strategies was acquired by Bland-Altman analysis. RESULTS: Mean test durations were 246.0±60.9s for SITA Fast, and 156.3±46.3s for SITA Faster (P<0.001). The test duration of SITA Faster was 36.5% shorter than SITA Fast. The MD, VFI and numbers of depressed points at P<5%, <2%, <1%, and <0.5% in probability plots showed no statistically significant difference between two strategies (P>0.05). Correlation analysis showed a high correlation for MD (r=0.986, P<0.001) and VFI (r=0.986, P<0.001) between the two strategies. Bland-Altman analysis showed great agreement between the two strategies. CONCLUSION: SITA Faster, which saves considerable test time, has a great test quality comparing to SITA Fast, but may be not directly interchangeable.

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