A comparison of liver fat fraction measurement on MRI at 3T and 1.5T

Purpose Volumetric liver fat fraction (VLFF) measurements were made using the HepaFat-Scan® technique at 1.5T and 3T to determine the agreement between the measurements obtained at the two fields. Methods Sixty patients with type 2 diabetes (67% male, mean age 50.92 ± 6.56yrs) and thirty healthy volunteers (50% male, mean age 48.63 ± 6.32yrs) were scanned on 1.5T Aera and 3T Skyra (Siemens, Erlangen, Germany) MRI scanners on the same day using the HepaFat-Scan® gradient echo protocol with modification of echo times for 3T (TEs 2.38, 4.76, 7.14 ms at 1.5T and 1.2, 2.4, 3.6 ms at 3T). The 3T analyses were performed independently of the 1.5T analyses by a different analyst, blinded from the 1.5T results. Data were analysed for agreement and bias using Bland-Altman methods and intraclass correlation coefficients (ICC). A second cohort of 17 participants underwent interstudy repeatability assessment of VLFF measured by HepaFat-Scan® at 3T. Results A small, but statistically significant mean bias of 0.48% was observed between 3T and 1.5T with 95% limits of agreement -2.2% to 3.2% VLFF. The ICC for agreement between field strengths was 0.983 (95% CI 0.972–0.989). In the repeatability cohort studied at 3T the repeatability coefficient was 4.2%. The ICC for agreement was 0.971 (95% CI 0.921–0.989). Conclusion There is minimal bias and excellent agreement between the measures of VLFF using the HepaFat-Scan® at 1.5 and 3T. The test retest repeatability coefficient at 3T is comparable to the 95% limits of agreement between 1.5T and 3T suggesting that measurements can be made interchangeably between field strengths.

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Autorefraction, Retinoscopy, Javal’s Rule, and Grosvenor’s Modified Javal’s Rule: The Best Predictor of Refractive Astigmatism

Journal of Ophthalmology ◽

10.1155/2016/3584137 ◽

2016 ◽

Vol 2016 ◽

pp. 1-6 ◽

Cited By ~ 1

Author(s):

Kofi Asiedu ◽

Samuel Kyei ◽

Emmanuel Ekow Ampiah

Keyword(s):

Clinical Sample ◽

Intraclass Correlation ◽

Correlation Coefficients ◽

Spherical Equivalent ◽

Limits Of Agreement ◽

Intraclass Correlation Coefficients ◽

Starting Point ◽

Cylinder Power ◽

Level Of Agreement

The aim of the study was to determine the level of agreement between Javal’s rule, autorefraction, retinoscopy, and refractive astigmatism and to determine which technique is the most suitable substitute when subjective refraction is not applicable using a clinical sample. A total of 36 subjects, 14 males and 22 females, were involved in this study. The intraclass correlation coefficients between subjective refraction, autorefraction, and retinoscopy were 0.895 and 0.989, respectively, for the spherical equivalent. The Bland-Altman 95% limits of agreement between subjective refraction and autorefraction; subjective refraction and retinoscopy; and autorefraction and retinoscopy were −2.84 to 3.58, −0.88 to 1.12, and −3.01 to 3.53, respectively, for the spherical equivalent. The intraclass correlation coefficients between spectacle total astigmatism and the following techniques were as follows: retinoscopy (0.85); autorefraction (0.92); Javal’s rule (0.82); and Grosvenor et al. version (0.85). The Bland-Altman 95% limits of agreement between subjective refraction and autorefraction; subjective refraction and retinoscopy; subjective refraction and Javal’s rule; and subjective refraction and Grosvenor et al. version were −0.87 to 1.25, −1.49 to 1.99, −0.73 to 1.93, and −0.89 to 1.7, respectively, for the total astigmatism. The study showed that autorefraction and Javal’s rule may provide a starting point for subjective refraction cylinder power determination but only retinoscopy may satisfactorily replace subjective refraction total astigmatism when subjective refraction is not applicable.

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Test–Retest Reliability of Soccer Dribbling Tests in Children

Journal of Motor Learning and Development ◽

10.1123/jmld.2021-0003 ◽

2021 ◽

pp. 1-7

Author(s):

Michael J. Duncan ◽

Darren Richardson ◽

Rhys Morris ◽

Emma Eyre ◽

Neil D. Clarke

Keyword(s):

Coefficient Of Variation ◽

Pediatric Population ◽

Intraclass Correlation ◽

Correlation Coefficients ◽

Systematic Bias ◽

Limits Of Agreement ◽

Good Reliability ◽

Retest Reliability ◽

Intraclass Correlation Coefficients ◽

Test Retest Reliability

The present study examined the test–retest reliability of the Ghent University dribbling test and short dribble test in a pediatric population. Fifty-four boys aged 9–14 years (mean ± SD = 11 ± 2 years) undertook the Ghent University and dribbling tests on two occasions separated by 2 weeks. Intraclass correlation coefficients, coefficient of variation, and 95% limits of agreement were conducted for each test. Intraclass correlation coefficients and coefficient of variation indicated good to excellent reliability, and relatively small variability for both dribbling tests. The 95% limits of agreement indicated relatively little bias Ghent University dribbling test for both running alone and running with the ball components, and the Bangsbo and Mohr short dribble test. The results of the present study suggest both dribbling tests examined in the present study demonstrate good reliability and low levels of systematic bias.

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Reliability of a Computerized Target-Pursuit System for Measuring Coordinated Exertion of Force

Perceptual and Motor Skills ◽

10.2466/pms.2003.96.3c.1071 ◽

2003 ◽

Vol 96 (3_suppl) ◽

pp. 1071-1085 ◽

Cited By ~ 18

Author(s):

Yoshinori Nagasawa ◽

Shinichi Demura ◽

Masakatsu Nakada

Keyword(s):

Grip Strength ◽

Intraclass Correlation ◽

Correlation Coefficients ◽

Visual Images ◽

Visually Guided ◽

Time Analysis ◽

Limits Of Agreement ◽

Intraclass Correlation Coefficients ◽

Pursuit System ◽

Target Pursuit

The purpose was to examine trial-to-trial and day-to-day reliability and sensitivity for measurements of the ability to coordinate exertion of force based on target-pursuit, 30 college students were required to match their grip strength to a changing demand value appearing on the display of a personal computer, using two visual images in the form of a bar chart and waveform. The variable was the sum of the differences between demanded and produced grip strength over time. Analysis indicated high intraclass correlation coefficients (ICC) for bar chart and waveform displays (ICC = .87, ICC = .95, respectively). The limits of agreement, designating the interval comprising 95% of the differences between three measurements in a stable individual, were −14.8 to 99.3% for the bar chart and −3.5 to 113.6% for the waveform displays. One-tailed, paired t tests of the day-to-day measurements showed significant ( p < .05) improvement in both the bar chart and waveform displays. ICCs for day-to-day measurements were low-to-moderate for bar chart and waveform displays (ICC = .33 to .71, ICC = .48 to .76, respectively). The limits of agreement between measurements of two trials for day-to-day measurements were −112.2 to 218.6% for the bar chart and −139.2 to 352.8% for the waveform displays. The repeatability coefficients of trial-to-trial and day-to-day measurements for bar chart and waveform displays were 141 and 173%, and 152 and 176%, respectively. The limits of agreement between each test were relatively wide. We believe that these tests, on which the force response is visually guided, can be useful in objectively documenting the ability to coordinate exertion of force.

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Evaluating Intratester Reliability of Manual Masking of Plantar Pressure Measurements Associated with Chronic Gout

Journal of the American Podiatric Medical Association ◽

10.7547/1010424 ◽

2011 ◽

Vol 101 (5) ◽

pp. 424-429

Author(s):

Keith Rome ◽

David George Survepalli ◽

Maria Lobo ◽

Nicola Dalbeth ◽

Fiona McQueen ◽

...

Keyword(s):

Plantar Pressure ◽

Intraclass Correlation ◽

Correlation Coefficients ◽

Minimal Detectable Change ◽

Pressure Measurements ◽

Detectable Change ◽

Limits Of Agreement ◽

Intraclass Correlation Coefficients ◽

Chronic Gout ◽

Pressure Time

Background: Plantar pressure measurements are commonly used to evaluate foot function in chronic musculoskeletal conditions. However, manually identifying anatomical landmarks is a source of measurement error and can produce unreliable data. The aim of this study was to evaluate intratester reliability associated with manual masking of plantar pressure measurements in patients with gout. Methods: Twenty-five patients with chronic gout (mean disease duration, 22 years) were recruited from rheumatology outpatient clinics. Patients were excluded if they were experiencing an acute gout flare at the time of assessment, had lower-limb amputation, or had diabetes mellitus. Manual masking of peak plantar pressures and pressure-time integrals under ten regions of the foot were undertaken on two occasions on the same day using an in-shoe pressure measurement system. Test-retest reliability was assessed by using intraclass correlation coefficients, SEM, 95% limits of agreement, and minimal detectable change. Results: Mean peak pressure intraclass correlation coefficients ranged from 0.92 to 0.97, with SEM of 8% to 14%. The 95% limits of agreement ranged from−150.3 to 133.5 kPa, and the minimal detectable change ranged from 30.8 to 80.6 kPa. For pressure-time integrals, intraclass correlation coefficients were 0.86 to 0.94, and SEM were 5% to 29%, with the greater errors observed under the toes. The 95% limits of agreement ranged from −48.5 to 48.8 kPa/sec, and the minimal detectable change ranged from 6.8 to 21.0 kPa/sec. Conclusions: These findings provide clinicians with information confirming the errors associated with manual masking of plantar pressure measurements in patients with gout. (J Am Podiatr Med Assoc 101(5): 424–429, 2011)

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Assessment of Operator Reliability in Ultrasound of the Median and Ulnar Nerve Using Bland-Altman Analysis

Diagnostics ◽

10.3390/diagnostics11112134 ◽

2021 ◽

Vol 11 (11) ◽

pp. 2134

Author(s):

Jörg Philipps ◽

Hannah Mork ◽

Maria Katz ◽

Mark Knaup ◽

Kira Beyer ◽

...

Keyword(s):

Ulnar Nerve ◽

Intraclass Correlation ◽

Sample Size Calculation ◽

Correlation Coefficients ◽

Altman Analysis ◽

Nerve Ultrasound ◽

Limits Of Agreement ◽

Bland Altman Analysis ◽

Intraclass Correlation Coefficients ◽

Coefficients Of Variation

Currently, there is no standardized method to evaluate operator reliability in nerve ultrasound. A short prospective protocol using Bland–Altman analysis was developed to assess the level of agreement between operators with different expertise levels. A control rater without experience in nerve ultrasound, three novices after two months of training, an experienced rater with two years of experience, and a reference rater performed blinded ultrasound examinations of the left median and ulnar nerve in 42 nerve sites in healthy volunteers. The precision of Bland–Altman agreement analysis was tested using the Preiss–Fisher procedure. Intraclass correlation coefficients (ICC), coefficients of variation, and Bland–Altman limits of agreement were calculated. The sample size calculation and Preiss–Fisher procedure showed a sufficient precision of Bland–Altman agreement analysis. Limits of agreement of all trained novices ranged from 2.0 to 2.9 mm2 and were within the test’s maximum tolerated difference. Ninety-five percent confidence intervals of limits of agreement revealed a higher precision in the experienced rater’s measurements. Operator reliability in nerve ultrasound of the median and ulnar nerve arm nerves can be evaluated with a short prospective controlled protocol using Bland–Altman statistics, allowing a clear distinction between an untrained rater, trained novices after two months of training, and an experienced rater.

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Repeatability of OPD-Scan III and its agreement with Pentacam in measuring keratometry, astigmatism and axis in patients with cataract and moderate to high astigmatism

10.21203/rs.3.rs-35643/v1 ◽

2020 ◽

Author(s):

YU Song ◽

Panpan Li ◽

Yuanyuan Tu ◽

Ying Wu ◽

Lili Huang ◽

...

Keyword(s):

Intraclass Correlation ◽

Correlation Coefficients ◽

High Accuracy ◽

Wilcoxon Test ◽

Spearman Correlation ◽

Limits Of Agreement ◽

Intraclass Correlation Coefficients ◽

Bland Altman Method ◽

The Difference ◽

Cataract Patients

Abstract Purpose To assess accuracy of OPD-Scan III in measuring keratometry, astigmatism and axis in patients with cataract and moderate to high astigmatism Materials and Methods Measurements were taken with OPD-Scan III and Pentacam in cataract patients with keratometric astigmatism (KA) more than 0.75 D. Keratometry in the steepest axis (Ks) and flattest axis (Kf), KA and axis, which are power vector components of astigmatism (J0 and J45), were evaluated. Intraclass correlation coefficients (ICCs) were used to assess repeatability. The Wilcoxon test was used to assess differences, the Spearman correlation was used to assess correlations, and the Bland-Altman method was used to assess agreement. Results Seventy eyes of 63 patients were included to analyze the repeatability of the two devices. The ICCs of Ks, Kf, KA, axis, J0 and J45 were 0.991, 0.995, 0.946, 0.883, 0.946 and 0.892, respectively, with OPD-Scan III. Seven hundred and thirty-two eyes of 516 patients were included to analyze the difference, correlation and agreement of the two devices. There were significant differences between the two devices in terms of Ks, Kf, axis, J0 and J45 (all p < 0.01). There were significant correlations between the two devices in each parameter (all p < 0.01). The 95% limits of agreement (LOAs) for Ks, Kf, KA, astigmatic axis, J0 and J45 were (-0.34, 0.44) D, (-0.24, 0.38) D, (-0.46, 0.48) D, (-10.20, 12.92)°, (-0.24, 0.24) D, and (-0.27, 0.35) D respectively.The 95% LOAs for the degree of IOL caculated according to parameter measured by OPD-Scan III and Pentacam was (-0.32, 0.22) D. Conclusions OPD-Scan III has a high accuracy for measuring keratometry, but its accuracy for measuring astigmatism and axis is poor in eyes with moderate to high astigmatism.

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Investigating the Dutch Movement-Specific Reinvestment Scale in people with stroke

Clinical Rehabilitation ◽

10.1177/0269215512448381 ◽

2012 ◽

Vol 27 (2) ◽

pp. 160-165 ◽

Cited By ~ 19

Author(s):

Melanie Kleynen ◽

Susy M Braun ◽

Anna JHM Beurskens ◽

Jeanine A Verbunt ◽

Rob A de Bie ◽

...

Keyword(s):

Confidence Interval ◽

Intraclass Correlation ◽

Correlation Coefficients ◽

Limits Of Agreement ◽

Rehabilitation Centre ◽

Altman Plot ◽

Rehabilitation Process ◽

Bland Altman Plot ◽

Intraclass Correlation Coefficients ◽

Conscious Control

Objective: Reinvestment is a phenomenon in which conscious control of movements that are best controlled automatically disrupts performance. The propensity for reinvestment may therefore play an important role in the movement rehabilitation process. The Movement-Specific Reinvestment Scale measures an individual’s propensity for reinvestment. The aim of this study was to translate the scale for use with Dutch participants with stroke and to assess its reliability. Design: A test–retest design. Setting: In community after discharge from rehabilitation centre. Subjects: Forty-five people with stroke. Measures: Reliability of the translated scale was assessed using intraclass correlation coefficients (ICC) and Bland–Altman plot. Results: The ICC was 0.85 (95% confidence interval (CI) 0.74–0.91). Limits of agreement ranged from −2.38 to 3.10. Conclusion: The Dutch Movement-Specific Reinvestment Scale appears to be a reliable tool with which to assess the propensity for movement-specific reinvestment by people with stroke.

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Equivalency of Sleep Estimates: Comparison of Three Research-Grade Accelerometers

Journal for the Measurement of Physical Behaviour ◽

10.1123/jmpb.2019-0047 ◽

2020 ◽

Vol 3 (4) ◽

pp. 294-303

Author(s):

Tatiana Plekhanova ◽

Alex V. Rowlands ◽

Tom Yates ◽

Andrew Hall ◽

Emer M. Brady ◽

...

Keyword(s):

Intraclass Correlation ◽

Sleep Onset ◽

Correlation Coefficients ◽

Sleep Time ◽

Sleep Efficiency ◽

Limits Of Agreement ◽

Wake Time ◽

Intraclass Correlation Coefficients ◽

Equivalence Tests ◽

Sleep Log

Introduction: This study examined the equivalency of sleep estimates from Axivity, GENEActiv, and ActiGraph accelerometers worn on the nondominant and dominant wrists and with and without using a sleep log to guide the algorithm. Methods: 47 young adults wore an Axivity, GENEActiv, and ActiGraph accelerometer continuously on both wrists for 4–7 days. Sleep time, sleep window, sleep efficiency, sleep onset, and wake time were produced using the open-source software (GGIR). For each outcome, agreement between accelerometer brands, dominant and nondominant wrists, and with and without use of a sleep log, was examined using pairwise 95% equivalence tests (±10% equivalence zone) and intraclass correlation coefficients (ICCs), with 95% confidence intervals and limits of agreement. Results: All sleep outcomes were within a 10% equivalence zone irrespective of brand, wrist, or use of a sleep log. ICCs were poor to good for sleep time (ICCs ≥ .66) and sleep window (ICCs ≥ .56). Most ICCs were good to excellent for sleep efficiency (ICCs ≥ .73), sleep onset (ICCs ≥ .88), and wake time (ICCs ≥ .87). There were low levels of mean bias; however, there were wide 95% limits of agreement for sleep time, sleep window, sleep onset, and wake time outcomes. Sleep time (up to 25 min) and sleep window (up to 29 min) outcomes were higher when use of the sleep log was not used. Conclusion: The present findings suggest that sleep outcomes from the Axivity, GENEActiv, and ActiGraph, when analyzed identically, are comparable across studies with different accelerometer brands and wear protocols at a group level. However, caution is advised when comparing studies that differ on sleep log availability.

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Validation of a Low-Cost Electrocardiography (ECG) System for Psychophysiological Research

Sensors ◽

10.3390/s21134485 ◽

2021 ◽

Vol 21 (13) ◽

pp. 4485

Author(s):

Ruth Erna Wagner ◽

Hugo Plácido da Silva ◽

Klaus Gramann

Keyword(s):

Low Cost ◽

Intraclass Correlation ◽

Correlation Coefficients ◽

Mobile Systems ◽

Recording Device ◽

Limits Of Agreement ◽

Intraclass Correlation Coefficients ◽

Psychophysiological Research ◽

Recorded Data

Background and Objective: The reliability of low-cost mobile systems for recording Electrocardiographic (ECG) data is mostly unknown, posing questions regarding the quality of the recorded data and the validity of the extracted physiological parameters. The present study compared the BITalino toolkit with an established medical-grade ECG system (BrainAmp-ExG). Methods: Participants underwent simultaneous ECG recordings with the two instruments while watching pleasant and unpleasant pictures of the “International Affective Picture System” (IAPS). Common ECG parameters were extracted and compared between the two systems. The Intraclass Correlation Coefficients (ICCs) and the Bland–Altman Limits of Agreement (LoA) method served as criteria for measurement agreement. Results: All but one parameter showed an excellent agreement (>80%) between both devices in the ICC analysis. No criteria for Bland–Altman LoA and bias were found in the literature regarding ECG parameters. Conclusion: The results of the ICC and Bland–Altman methods demonstrate that the BITalino system can be considered as an equivalent recording device for stationary ECG recordings in psychophysiological experiments.

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Interobserver Reliability Using the Phonetic Level Evaluation With Severely and Profoundly Hearing-Impaired Children

Journal of Speech Language and Hearing Research ◽

10.1044/jshr.3405.989 ◽

1991 ◽

Vol 34 (5) ◽

pp. 989-999 ◽

Cited By ~ 6

Author(s):

Stephanie Shaw ◽

Truman E. Coggins

Keyword(s):

Interrater Reliability ◽

Interobserver Reliability ◽

Intraclass Correlation ◽

Correlation Coefficients ◽

Hearing Impaired ◽

Intraclass Correlation Coefficients ◽

Assessment Measure ◽

Impaired Children ◽

Speech Assessment ◽

Hearing Impaired Children

This study examines whether observers reliably categorize selected speech production behaviors in hearing-impaired children. A group of experienced speech-language pathologists was trained to score the elicited imitations of 5 profoundly and 5 severely hearing-impaired subjects using the Phonetic Level Evaluation (Ling, 1976). Interrater reliability was calculated using intraclass correlation coefficients. Overall, the magnitude of the coefficients was found to be considerably below what would be accepted in published behavioral research. Failure to obtain acceptably high levels of reliability suggests that the Phonetic Level Evaluation may not yet be an accurate and objective speech assessment measure for hearing-impaired children.

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