Multivariate variance-covariance components (MVCC) and generalized intraclass correlation coefficient (GICC)

1976 ◽  
Vol 18 (7) ◽  
pp. 527-533 ◽  
Author(s):  
H. Ahrens
Keyword(s):  
Correlation Coefficient ◽  
Intraclass Correlation Coefficient ◽  
Intraclass Correlation ◽  
Covariance Components

scholarly journals Biomechanical Measurement of Rabbit Cornea by a Modified Scheimpflug Device

2016 ◽  
Vol 2016 ◽  
pp. 1-6
Author(s):  
Bo Zhang ◽  
Jianjun Gu ◽  
Xiaoxiao Zhang ◽  
Bin Yang ◽  
Zheng Wang ◽  
...  
Keyword(s):  
Bulk Modulus ◽  
Correlation Coefficient ◽  
Intraclass Correlation Coefficient ◽  
Intraclass Correlation ◽  
Anterior Segment ◽  
Intraobserver Reliability ◽  
Rabbit Cornea ◽  
Deformation Response ◽  
Biomechanical Measurements ◽  
Biomechanical Measurement

Purpose. To explore the probability and variation in biomechanical measurements of rabbit cornea by a modified Scheimpflug device.Methods. A modified Scheimpflug device was developed by imaging anterior segment of the model imitating the intact eye at various posterior pressures. The eight isolated rabbit corneas were mounted on the Barron artificial chamber and images of the anterior segment were taken at posterior pressures of 15, 30, 45, 60, and 75 mmHg by the device. The repeatability and reliability of the parameters including CCT, ACD, ACV, and CV were evaluated at each posterior pressure. All the variations of the parameters at the different posterior pressures were calculated.Results. All parameters showed good intraobserver reliability (Cronbach’s alpha; intraclass correlation coefficient,α, ICC > 0.96) and repeatability in the modified Scheimpflug device. With the increase of posterior pressures, the ratio of CCT decreased linearly and the bulk modulus gradually reduced to a platform. The increase of ACD was almost linear with the posterior pressures elevated.Conclusions. The modified Scheimpflug device was a valuable tool to investigate the biomechanics of the cornea. The posterior pressure 15–75 mmHg range produced small viscoelastic deformations and nearly linear pressure-deformation response in the rabbit cornea.

scholarly journals A preliminary study of intensivist-performed DVT ultrasound screening in trauma ICU patients (APSIT Study)

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Lloyd Roberts ◽  
Tom Rozen ◽  
Deirdre Murphy ◽  
Adam Lawler ◽  
Mark Fitzgerald ◽  
...  
Keyword(s):  
Intensive Care ◽  
Deep Vein Thrombosis ◽  
High Risk ◽  
Correlation Coefficient ◽  
Intraclass Correlation Coefficient ◽  
Major Trauma ◽  
Intraclass Correlation ◽  
Trauma Patients ◽  
Vein Thrombosis ◽  
Deep Vein

Abstract Background Multiple screening Duplex ultrasound scans (DUS) are performed in trauma patients at high risk of deep vein thrombosis (DVT) in the intensive care unit (ICU). Intensive care physician performed compression ultrasound (IP-CUS) has shown promise as a diagnostic test for DVT in a non-trauma setting. Whether IP-CUS can be used as a screening test in trauma patients is unknown. Our study aimed to assess the agreement between IP-CUS and vascular sonographer performed DUS for proximal lower extremity deep vein thrombosis (PLEDVT) screening in high-risk trauma patients in ICU. Methods A prospective observational study was conducted at the ICU of Alfred Hospital, a major trauma center in Melbourne, Australia, between Feb and Nov 2015. All adult major trauma patients admitted with high risk for DVT were eligible for inclusion. IP-CUS was performed immediately before or after DUS for PLEDVT screening. The paired studies were repeated twice weekly until the DVT diagnosis, death or ICU discharge. Written informed consent from the patient, or person responsible, or procedural authorisation, was obtained. The individuals performing the scans were blinded to the others’ results. The agreement analysis was performed using Cohen’s Kappa statistics and intraclass correlation coefficient for repeated binary measurements. Results During the study period, 117 patients had 193 pairs of scans, and 45 (39%) patients had more than one pair of scans. The median age (IQR) was 47 (28–68) years with 77% males, mean (SD) injury severity score 27.5 (9.53), and a median (IQR) ICU length of stay 7 (3.2–11.6) days. There were 16 cases (13.6%) of PLEDVT with an incidence rate of 2.6 (1.6–4.2) cases per 100 patient-days in ICU. The overall agreement was 96.7% (95% CI 94.15–99.33). The Cohen’s Kappa between the IP-CUS and DUS was 0.77 (95% CI 0.59–0.95), and the intraclass correlation coefficient for repeated binary measures was 0.75 (95% CI 0.67–0.81). Conclusions There is a substantial agreement between IP-CUS and DUS for PLEDVT screening in trauma patients in ICU with high risk for DVT. Large multicentre studies are needed to confirm this finding.

Test-Retest-Reliability of Computer-Based Metamorphopsia Measurement in Macular Diseases

2020 ◽  
Author(s):  
Daniela Claessens ◽  
Alexander K. Schuster ◽  
Ronald V. Krüger ◽  
Marian Liegl ◽  
Laila Singh ◽  
...  
Keyword(s):  
Macular Edema ◽  
Correlation Coefficient ◽  
Intraclass Correlation Coefficient ◽  
Intraclass Correlation ◽  
Measuring Method ◽  
Repeated Measurements ◽  
Retest Reliability ◽  
Macular Diseases ◽  
Computer Based ◽  
Test Retest Reliability

AbstractIn this study, the test-retest-reliability as one aspect of reliability of metamorphopsia measurements using a computer-based measuring method was determined in patients with macular diseases. Metamorphopsia amplitude, position, and area were quantified using AMD – A Metamorphopsia Detector software (app4eyes GmbH & Co. KG, Germany) in patients with diabetic, myopic, or uveitic macular edema, intermediate or neovascular age-associated macular degeneration, epiretinal membrane, vitelliform maculopathy, Irvine-Gass syndrome, or macular edema due to venous retinal occlusion. The intraclass correlation coefficient (ICC) was calculated in order to determine the repeatability of two repeated measurements and was used as an indicator of the reliability of the measurements. In this study, metamorphopsia measurements were conducted on 36 eyes with macular diseases. Metamorphopsia measurements made using AMD – A Metamorphopsia Detector software were highly reliable and repeatable in patients with maculopathies. The intraclass correlation coefficient of all indices was excellent (0.95 – 0.97). For diseases of the vitreoretinal interface or macular diseases with intra- or subretinal edema, this metamorphopsia measurement represents a supplement for visual function testing in the clinic, as well as in clinical studies.

scholarly journals AB0798 IS THERE A REPRODUCIBILITY OF THE HISTOGRAM AND GRAY SCALE IN ECOEXTRUCTURAL DAMAGES IN RHEUMATOTOLOGICAL DISEASES?

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 1423.2-1424
Author(s):  
J. A. Mendonça ◽  
I. Siste de Almeida Aoki ◽  
C. C. Cavuto ◽  
V. A. Leandro-Merhi ◽  
J. L. B. D. Aquino
Keyword(s):  
Correlation Coefficient ◽  
Intraclass Correlation Coefficient ◽  
Rheumatic Diseases ◽  
Femoral Condyle ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Concordance Correlation Coefficient ◽  
Image Method ◽  
Concordance Correlation ◽  
Gray Scale

Background:The gray scale (GS) in high resolution ultrasound is already well validated for use in rheumatological diseases, but the color map or the histogram, can be considered a new proposal, to better define and complement the echotextural damages detection1.Objectives:To calculate the lesions area measures reproducibility index in arthropathies, between 3 blind evaluators and correlate these measures using the GS and the histogram.Methods:Observational and retrospective study approved by the ethics committee of the Pontifical Catholic University of Campinas, with the opinion number: 1.526.307. A total of 29 patients have been assessed (31% males and 69% females) on period 2014 to 2019 in Rheumatology service. A MyLab 50 -Esaote equipment was used with frequency transducer that ranged between 6.0 and 18.0 MHz, 10 different area measures were performed from each recorded images previously, by the GS and the histogram. Statistical analysis: Spearman’s correlation coefficients, Lin’s concordance coefficient (CCC) and the intraclass correlation coefficient (ICC) and their respective 95% confidence intervals, with the SPSS software package for Windows v. 17.0 (SPSS Inc., Chicago, IL, USA).Results:Average age 43.5 ± 21.5 years of age; with disease duration that varied between ≤ 1 month (48.3%) and ≥36 months (24.1%); with the following diseases: juvenile idiopathic arthritis (17.24%); osteoarthritis (13.79%); psoriatic arthritis (13.79%); undifferentiated spondyloarthritis (3.44%); gout (20.68%); rheumatoid arthritis (27.58%) and reactive arthritis (3.44%). A total of 840 measures of exudative (27.58%), proliferative (27.58%) and snowstorm appearance (6.89%) synovitis were performed; femoral-condyle cartilage (3.44%); synovial cyst (3.44%); paratendinitis (6.89%); calcification (3.44%); nail enthesitis (3.44%); tenosynovitis (6.89%) and tophi (10.34%) (Figure 1). The concordance correlation coefficient showed values closer to 1; p <0.001, the intraclass correlation coefficients with excellent reproducibility (ICC ≥ 0.75); p <0.001, always in relation to the three evaluators (Table 1) and the Spearman correlation between the GS and the histogram ranged from rs = 0.665 to rs = 1,000; p <0.001.Conclusion:The histogram can be considered an image method to better identify echotextural damages.References:[1]Mendonça J, Provenza J, Guissa V, et al AB1059 2D Histogram Ultrasound and 3D Ultrasound Correlation in Rheumatic Diseases Annals of the Rheumatic Diseases 2015; 74:1253-1254.Table 1.Concordance Correlation Coefficient (CCC) and Intraclass Correlation Coefficient (ICC):EvaluatorsGS - CCC(IC 95%)p-valorHistogram (IC 95%)p-valor1 e 20,998(0,994-0,999)<0,0010,999(0,995-1,000)<0,0011 e 30,998(0,995-0,999)<0,0010,999(0,995-1,000)<0,0012 e 30,992(0,980-0,997)<0,010,996(0,979-0,999)<0,01Standard by US 2DICCp-valorGS0,997(0,992-0,999)<0,001Histogram0,998(0,992-0,999)<0,001Legends: Gray Scale (GS).Figure 1.Patient with gout: A and B: Tophi area measures (star) in right metatarsos and efusion (arrow) by GS (45 mm2) and histogram (39 mm2), respectively.Disclosure of Interests:José Alexandre Mendonça Speakers bureau: Novartis, Janssen, Bristol, UCB, Isabella Siste de Almeida Aoki: None declared, Caique Chagas Cavuto: None declared, Vânia Aparecida Leandro-Merhi: None declared, José Luis Braga de Aquino: None declared

Validation and adaptation of the Spanish version of the systemic lupus activity questionnaire (S-SLAQ) in an Argentinean population

Lupus ◽  
2021 ◽  
pp. 096120332110610
Author(s):  
Cecilia Catoggio ◽  
Alejandro Martínez Muñoz ◽  
Rafael Chaparro del Moral ◽  
Diana S Klajn ◽  
Silvia B Papasidero ◽  
...  
Keyword(s):  
Disease Activity ◽  
Correlation Coefficient ◽  
Intraclass Correlation Coefficient ◽  
Internal Consistency ◽  
Intraclass Correlation ◽  
Systemic Lupus ◽  
Cronbach's Alpha ◽  
Clinically Significant ◽  
Significant Disease ◽  
Activity Questionnaire

Objectives To validate the systemic lupus activity questionnaire (SLAQ) in Spanish language. Methods The SLAQ questionnaire was translated and adapted in Spanish. Consecutive SLE patients from 8 centers in Argentina were included. A rheumatologist completed a Systemic Lupus Activity Measure (SLAM), Systemic Lupus Erythematosus Disease Activity Index (SLEDAI)-2K, and a physician’s assessment. Reliability was assessed by internal consistency (Cronbach’s alpha), stability by test–retest reliability (intraclass correlation coefficient), and construct validity by evaluating the correlation with clinically relevant scores. Sensitivity and specificity for clinically significant disease activity (SLEDAI ≥6) of different S-SLAQ cut-off points were evaluated. Results We included 97 patients ((93% female, mean age: 40 years (SD14.7)). Internal consistency was excellent (Cronbach’s alpha = 0.84, p < 0.001), and the intraclass correlation coefficient was 0.95 ( p < 0.001). Mean score of S-SLAQ was 8.2 (SD 7.31). Correlation of S-SLAQ was moderate with Patient NRS (r= 0.63 p< 0.001), weak with SLAM-no lab ( r = 0.42, p <0.001) and SLAM ( r = 0.38, p < 0.0001), and very weak with SLEDAI-2K ( r = 0.15, p =0.1394). Using the S-SLAQ cutoff of five points, the sensitivity was 72.2% and specificity was 37.9%, for clinically significant disease activity. Conclusions The S-SLAQ showed good validity and reliability. A good correlation, similar to the original instrument, was observed with patient´s global disease activity. No correlation was found between S-SLAQ and gold standard disease activity measures like SLEDAI-2K and SLAM. The S-SLAQ cutoff point of 5 showed a good sensitivity to identify the active SLE population and therefore could be an appropriate screening instrument for disease activity in clinical and epidemiological studies.

Reliability, Validity, and Performance Characteristics of Elite Adolescent Athletes at Different Stages of Maturityin the 10 to 5 Repeated Jump Test

2021 ◽  
pp. 1-8
Author(s):  
James Baker ◽  
Barry Shillabeer ◽  
Christopher Brandner ◽  
Philip Graham-Smith ◽  
Patrick Mills ◽  
...  
Keyword(s):  
Correlation Coefficient ◽  
Intraclass Correlation Coefficient ◽  
Intraclass Correlation ◽  
Performance Characteristics ◽  
Height Velocity ◽  
Adolescent Male ◽  
Male Athletes ◽  
Reliable Test ◽  
Jump Test ◽  
And Performance

Purpose: To examine the reliability, validity, and performance characteristics of the 10 to 5 repeated jump test (10–5 RJT) in adolescent male athletes. The 10–5 RJT has been shown to be a valid and reliable test of reactive strength index (RSI) in older adolescents (age 17–19 y), but less is known in younger adolescent athletes at different stages of maturity. Methods: Athletes (age 11–17 y) completed the 10–5 RJT on 2 days, 1 week apart, to examine the reliability (n = 41), validity (n = 18) of the test. Athletes were classified as pre, circa, or post peak height velocity (PHV) height velocity using maturity offset to examine the effect of maturation status on RSI, flight time (FT), ground contact time (GCT), and jump height (JH) (n = 68) using a cross-sectional design. Results: Paired samples t tests showed no significant differences (P ≥ .05), and Bland–Altman analysis showed no bias and close limits of agreement for RSI, JH, FT, and GCT between the contact mat and force plate. Interday reliability was rated excellent for RSI (intraclass correlation coefficient = .91) and good for GCT, FT, and JH (intraclass correlation coefficient = .81–.85). All variables had a coefficient of variation ≤ 10%. RSI increased across maturation groups, with significant differences between pre-PHV and post-PHV groups (P = .014, d = 1.00). Conclusion: The 10–5 RJT is a valid and reliable test for adolescent male athletes. Greater RSI with advancing maturity was primarily due to increased FT and JH, with GCT remaining similar.

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