scholarly journals Validation of quantitative pupillometry, for neuroprognostication in patients resuscitated from cardiac arrest

2021 ◽  
Vol 10 (Supplement_1) ◽  
Author(s):  
B Nyholm ◽  
L Obling ◽  
C Hassager ◽  
J Grand ◽  
JE Moeller ◽  
...  
Keyword(s):  
Cardiac Arrest ◽  
Repeated Measures ◽  
Intraclass Correlation ◽  
Observer Variation ◽  
Altman Analysis ◽  
Prognostic Information ◽  
Private Company ◽  
Bland Altman Analysis ◽  
Funding Sources ◽  
Pupillary Size

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): NovoNordisk Foundation grant Background/Introduction Quantitative pupillometry is being recommended as part of a multimodal approach to the bedside armamentarium, for obtaining prognostic information in post-cardiac arrest management. However, recent guidelines are still based on limited evidence, and lack of knowledge about the variability of pupillary measurements may impair clinical usefulness. Purpose To assess precision and accuracy of quantitative pupillometry to validate its clinical use in neuroprognostication. Methods We conducted a prospective blinded validation study, based on repeated patient assessments in a cardiac intensive care unit. Each assessment was made by two trained staff nurses and consisted of one manual and one quantitative pupillometry each, performed on the same patient within 2 minutes. Data from each measurement was stored in the pupillometers head guard, blinded to the other observer. To investigate inter-observer variation (precision), the repeated measures of pupillary size (both quantitative and manual individually) were compared, and for accuracy by comparing quantitative with manual assessment. Further we assessed the variation in neurological pupil index (NPi), a scalar value (between 0 and 5) calculated from an algorithm comprising several measured pupillary variables. Bland–Altman analysis was performed with mean difference between the two methods of measurement and 95% limits of agreement (LoA), and intraclass correlation coefficient (ICC) assessed for absolute agreement between the methods. Results A total of 56 measurements (left and right eye) were included in this study. Fifty-seven percent were male, with a mean age of 65 years (SD 14). Out of hospital cardiac arrest constituted 57 %, and 65 % of the measurements were made, while patients were sedated. The 30-day mortality of this population was 50 %. Bland-Altman analysis showed mean inter-observer differences equal to -0.14 mm (LoA: 0.71, -1.00) for pupillary size measured by manual pupillometry, and 0.03 mm (LoA: 0.36, -0.31) for pupillary size measured by quantitative pupillometry. Mean pupillary size by automated pupillometry and manual assessment, was 2.28 mm (SD 0.84) and 2.22 mm (SD 0.84) respectively, with significant correlation between manual and quantitative pupillometry (R = 0.84, p < 0.001; ICC 0.83).  Mean inter-observer differences for NPi measured by quantitative pupillometry was -0.02 (LoA: 0.40, -0.43). Conclusion(s) Quantitative pupillometry has twice the precision in assessment of pupillary size compared with manual assessment. Both pupillary size and NPI may, however, still have a challenging reproducibility. Abstract Figure.

scholarly journals Validity and reliability of assessing diaphragmatic mobility by area on X-rays of healthy subjects

2018 ◽  
Vol 44 (3) ◽  
pp. 220-226 ◽  
Author(s):  
Aline Pedrini ◽  
Márcia Aparecida Gonçalves ◽  
Bruna Estima Leal ◽  
Michelle Gonçalves de Souza Tavares ◽  
Wellington Pereira Yamaguti ◽  
...  
Keyword(s):  
Correlation Coefficient ◽  
Intraclass Correlation ◽  
X Rays ◽  
Altman Analysis ◽  
Validity And Reliability ◽  
Anthropometric Parameters ◽  
Rater Reliability ◽  
Bland Altman Analysis ◽  
Left Hemidiaphragm ◽  
The Right

ABSTRACT Objective: To investigate the concurrent validity, as well as the intra- and inter-rater reliability, of assessing diaphragmatic mobility by area (DMarea) on chest X-rays of healthy adults. Methods: We evaluated anthropometric parameters, pulmonary function, and diaphragmatic mobility in 43 participants. Two observers (rater A and rater B) determined diaphragmatic mobility at two time points. We used Pearson’s correlation coefficient to evaluate the correlation between DMarea and the assessment of diaphragmatic mobility by distance (DMdist). To evaluate intra- and inter-rater reliability, we used the intraclass correlation coefficient (ICC [2,1]), 95% CI, and Bland-Altman analysis. Results: A significant correlation was found between the DMarea and DMdist methods (r = 0.743; p < 0.0001). For DMarea, the intra-rater reliability was found to be quite high for the right hemidiaphragm (RHD)-ICC (2,1) = 0.92 (95% CI: 0.86-0.95) for rater A and ICC (2,1) = 0.90 (95% CI: 0.84-0.94) for rater B-and the left hemidiaphragm (LHD)-ICC (2,1) = 0.96 (95% CI: 0.93-0.97) for rater A and ICC (2,1) = 0.91 (95% CI: 0.81-0.95) for rater B-(p < 0.0001 for all). Also for DMarea, the inter-rater reliability was found to be quite high for the first and second evaluations of the RHD-ICC (2,1) = 0.99 (95% CI: 0.98-0.99) and ICC (2,1) = 0.95 (95% CI: 0.86-0.97), respectively-and the LHD-ICC (2,1) = 0.99 (95% CI: 0.98-0.99) and ICC (2,1) = 0.94 (95% CI: 0.87-0.97)-(p < 0.0001 for both). The Bland-Altman analysis showed good agreement between the mobility of the RHD and that of the LHD. Conclusions: The DMarea method proved to be a valid, reliable measure of diaphragmatic mobility.

The Accuracy and Reproducibility of Linear Measurements Made on CBCT-derived Digital Models

2016 ◽  
Vol 17 (4) ◽  
pp. 294-299 ◽  
Author(s):  
Mohammad Y Hajeer ◽  
Ahmad L Maroua ◽  
Mowaffak Ajaj
Keyword(s):  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Intraobserver Reliability ◽  
Altman Analysis ◽  
Digital Models ◽  
Linear Measurements ◽  
Bland Altman Analysis ◽  
Accuracy Of Measurements ◽  
The Mean ◽  
Plaster Models

ABSTRACT Objective To evaluate the accuracy and reproducibility of linear measurements made on cone-beam computed tomography (CBCT)-derived digital models. Materials and methods A total of 25 patients (44% female, 18.7 ± 4 years) who had CBCT images for diagnostic purposes were included. Plaster models were obtained and digital models were extracted from CBCT scans. Seven linear measurements from predetermined landmarks were measured and analyzed on plaster models and the corresponding digital models. The measurements included arch length and width at different sites. Paired t test and Bland–Altman analysis were used to evaluate the accuracy of measurements on digital models compared to the plaster models. Also, intraclass correlation coefficients (ICCs) were used to evaluate the reproducibility of the measurements in order to assess the intraobserver reliability. Results The statistical analysis showed significant differences on 5 out of 14 variables, and the mean differences ranged from −0.48 to 0.51 mm. The Bland–Altman analysis revealed that the mean difference between variables was (0.14 ± 0.56) and (0.05 ± 0.96) mm and limits of agreement between the two methods ranged from −1.2 to 0.96 and from −1.8 to 1.9 mm in the maxilla and the mandible, respectively. The intraobserver reliability values were determined for all 14 variables of two types of models separately. The mean ICC value for the plaster models was 0.984 (0.924–0.999), while it was 0.946 for the CBCT models (range from 0.850 to 0.985). Conclusion Linear measurements obtained from the CBCTderived models appeared to have a high level of accuracy and reproducibility. How to cite this article Maroua AL, Ajaj M, Hajeer MY. The Accuracy and Reproducibility of Linear Measurements Made on CBCT-derived Digital Models. J Contemp Dent Pract 2016;17(4):294-299.

scholarly journals Comparing School-Aged Refraction Measurements Using the 2WIN-S Portable Refractor in Relation to Cycloplegic Retinoscopy: A Cross-Sectional Study

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Ziming Liu ◽  
Emmanuel Eric Pazo ◽  
Hong Ye ◽  
Cui Yu ◽  
Ling Xu ◽  
...  
Keyword(s):  
Gold Standard ◽  
Intraclass Correlation ◽  
Cross Sectional Study ◽  
Mean Value ◽  
Spherical Equivalent ◽  
Sectional Study ◽  
Altman Analysis ◽  
Cross Sectional ◽  
Bland Altman Analysis ◽  
The Mean

Purpose. To assess the repeatability and agreement of refractive measurements using 2WIN-S photoscreening with the gold-standard cycloplegic retinoscope refraction. Design. Single centre, cross-sectional study. Methods. Spherical, cylindrical, axis, and spherical equivalent of 194 bilateral eyes of 97 children were assessed using a retinoscope and 2WIN-S. One week later, another operator repeated the 2WIN-S measurements. The primary outcome measures were to assess the repeatability and agreement between spherical equivalent, J0, and J45 readings of 2WIN-S. The repeatability of measurements was assessed by the within-subject standard deviation (2.77 Sw) and intraclass correlation coefficient (ICC). The agreement between devices was assessed using 95% limits of agreement. The extent of the agreement between cycloplegic retinoscopy and noncycloplegic 2WIN-S measurements was assessed using Bland–Altman analysis. Results. The mean age ± SD was 10.3 ± 2.46 year (range, 4–14 years). The sphere, cylinder, and spherical equivalent measurements were found to be consistent with both apparatus (r value >0.86). ICC for SE, J0, and J45 was 0.900, 0.666, and 0.639, respectively; Sw for SE, J0, and J45 was 0.61D, 0.30D, and 0.31D, respectively; Bland–Altman analysis of retinoscopy with cycloplegia and 2WIN-S for SE was 184/194 (95%) in 95% confidence interval, and the mean value was 0.46. J0 was 184/194 (95%), and the mean value is −0.04. J45 was 181/194 (93%), and the mean value is −0.15. Conclusion. The objective refractive measurement of 2WIN-S had good reliability and high agreement with the gold-standard retinoscopy refraction in children and adolescents. While consistency was observed, it is essential to take into consideration that it is a screening tool.

scholarly journals Test–Retest Reliability of a Conventional Gait Model for Registering Joint Angles during Initial Contact and Toe-Off in Healthy Subjects

2021 ◽  
Vol 18 (3) ◽  
pp. 1343
Author(s):  
Francisco Molina-Rueda ◽  
Pilar Fernández-González ◽  
Alicia Cuesta-Gómez ◽  
Aikaterini Koutsou ◽  
María Carratalá-Tejada ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Intraclass Correlation ◽  
Minimal Detectable Change ◽  
Initial Contact ◽  
Altman Analysis ◽  
Joint Angles ◽  
Retest Reliability ◽  
Bland Altman Analysis ◽  
Motion System ◽  
Test Retest Reliability

The aim of this study was to evaluate the test–retest reliability of a conventional gait model (CGM), the Plug-in Gait model, to calculate the angles of the hip, knee, and ankle during initial contact (IC) and toe-off (TO). Gait analysis was performed using the Vicon Motion System® (Oxford Metrics, Oxford, UK). The study group consisted of 50 healthy subjects. To evaluate the test–retest reliability, the intraclass correlation coefficient (ICC), the standard error of measurement (SEM), the minimal detectable change (MDC), and the Bland–Altman analysis with 95% limits of agreement were calculated. The ICC for the joint angles of the hip, knee, and ankle was higher than 0.80. However, the ankle angle at IC had an ICC lower than 0.80. The SEM was <5° for all parameters. The MDC was large (>5°) for the hip angle at IC. The Bland–Altman analysis indicated that the magnitude of divergence was between ±5° and ±9° at IC and around ±7° at TO. In conclusion, the ICC for the plug-in gait model was good for the hip, knee, and ankle angles during IC and TO. The plots revealed a disagreement between measurements that should be considered in patients’ clinical assessments.

scholarly journals Comparison of reliability of measurements among fetal facial profile parameters by operators with different levels of experience at 15-23 weeks of gestation

2020 ◽  
Author(s):  
Chitkasaem Suwanrath ◽  
Rapphon Sawaddisan ◽  
Pitchaya Booncharoen
Keyword(s):  
Observational Study ◽  
Gestational Age ◽  
Intraclass Correlation ◽  
The Other ◽  
Altman Analysis ◽  
Facial Profile ◽  
Bland Altman Analysis ◽  
Mandible Length ◽  
Different Levels ◽  
Good Agreement

Abstract Background Mandible anomalies are associated with many syndromes. Various methods have been proposed to assess fetal mandibles with different reliability. This study aimed to compare the reliability of measurements among five fetal facial profile parameters by operators with different levels of experience, at 15–23 weeks of gestation in Thai fetuses. Methods An observational study was prospectively conducted. The inferior facial angle (IFA), anteroposterior mandibular diameter (APD), mandible width (MD), maxilla width (MX) and mandible length (ML) were measured in 123 normal fetuses, using 2D ultrasonography, by 3 operators with different levels of experience. Each participant was examined by 2 operators. Each operator performed three independent measurements for each parameter and was blinded to the results of the other. Reliability of measurement was evaluated using intraclass correlation coefficient for both intraobserver and interobserver variabilities. Bland-Altman analysis was used to evaluate the agreement between operators’ measurements. Results The success rate of ML measurement was highest (100%) among the five parameters for all operators. Failure of MX measurement was high in fetuses at a gestational age of less than 18 weeks. Intraobserver variabilities of APD, MD, MX and ML measurements were excellent for all operators (ICC 0.958–0.986), while those of IFA measurement was moderate to excellent (0.560–0.923), depending on the operators’ experience. Interobserver variabilities varied between pairs of operators; only 2 parameters, APD and ML, showed excellent interobserver variabilities for both pairs of operators (ICC > 0.9) with good agreement. Interobserver variabilities of MX measurements for both pairs of operators were good (ICC 0.606–0.709), while MD was excellent for operator 1 and 2 (ICC 0.867), but moderate for operator 1 and 3 (ICC 0.576) and IFA was good for operator 1 and 2 (ICC 0.602), but poor for operator 1 and 3 (ICC 0.128). Conclusions The reliability of ML measurement was the highest, followed by APD, while IFA was the lowest, among the 5 parameters. ML and APD measurements were feasible and reproducible, whereas MX measurement was limited in fetuses with a gestational age of less than 18 weeks. Additionally, reliability of IFA measurement depended on the operator’s experience.

scholarly journals Reliability and Validity of Trunk Assessment for People With Multiple Sclerosis

2006 ◽  
Vol 86 (1) ◽  
pp. 66-76 ◽  
Author(s):  
Geert Verheyden ◽  
Godelieve Nuyens ◽  
Alice Nieuwboer ◽  
Pol Van Asch ◽  
Piet Ketelaer ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Construct Validity ◽  
Intraclass Correlation ◽  
Reliability And Validity ◽  
Correlation Coefficients ◽  
Weighted Kappa ◽  
Altman Analysis ◽  
Bland Altman Analysis ◽  
Intraclass Correlation Coefficients ◽  
Test Retest Reliability

Abstract Background and Purpose. Standardized scales are a prerequisite for rehabilitation and research. This study was designed to determine the reliability and validity of scores on items of the trunk assessment of the Melsbroek Disability Scoring Test (MDST) and Trunk Impairment Scale (TIS) in people with multiple sclerosis (MS). Subjects. Thirty people with MS participated in the study. Methods. Interrater and test-retest reliability and construct validity were assessed. Results. Kappa and weighted kappa values for the items of the trunk assessment of the MDST ranged from .74 to .95, and the kappa and weighted kappa values for the TIS items ranged from .46 to 1.00. Intraclass correlation coefficients for interrater and test-retest agreement were .93 and .92, respectively, for the trunk assessment of the MDST and .97 and .95, respectively, for the TIS. Bland-Altman analysis showed consistency of scores without observer bias. Construct validity was established. Discussion and Conclusion. The MDST and TIS provide reliable assessments of the trunk and are valid scales for measuring trunk performance in people with MS. [Verheyden G, Nuyens G, Nieuwboer A, et al. Reliability and validity of trunk assessment for people with multiple sclerosis.

scholarly journals Comparison of pulmonary vein sizing by transesophageal echocardiogram and by direct angiogram

2021 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
N Bachani ◽  
R Vadivelu ◽  
A Bagchi ◽  
JP Jadwani ◽  
GK Panicker ◽  
...  
Keyword(s):  
Left Atrium ◽  
Pulmonary Vein ◽  
Interatrial Septum ◽  
T Test ◽  
Altman Analysis ◽  
Bland Altman Analysis ◽  
Funding Sources ◽  
Chamber View ◽  
The Right ◽  
Paired T Test

Abstract Funding Acknowledgements Type of funding sources: None. Background Pulmonary vein (PV) anatomy and sizing is important to know before performing PV isolation. This information is conventionally obtained by angiography or by CT scan. Aim We undertook this study to identify and measure the PVs during TEE studies and validate these against angiography. Method 17 consecutive patients due to undergo PV isolation for paroxysmal atrial fibrillation were analysed. Using TEE, the PVs were visualised (Upper panel) as follows:  i) From the mid-esophageal four chamber view, the chamber probe was turned to the right at 110-130º for the bicaval view, where the RSPV was seen entering the left atrium adjacent to the SVC. ii) At 0º the SVC was imaged in its short axis, and the probe advanced till the interatrial septum was seen. The angle was changed to 30º to visualise the right inferior PV (RIPV). iii) From the two chamber view (70-90º), the probe was turned to the left and withdrawn to display the left superior PV (LSPV) entering the left atrium parallel to the appendage.iv) Keeping the LSPV in focus, the angle was changed to 135º and the probe advanced till the AV groove, where the left inferior PV (LIPV) was visualised. After transseptal puncture, each PV was cannulated. The PV angiograms were performed in several projections to obtain the best PV profile (lower panel). Using electronic callipers, each PV was measured within 1 cm of its entry into the left atrium, after having received all tributaries. Those PVs were considered for analysis which were measured by both TEE and angiography. The paired ‘T’ test was used to compare the PV diameters by TEE and angiography and the Bland Altman analysis was done to see the level of agreement. Results Of a total of 68 PVs, 62 could be adequately visualised by TEE and 50 by angiography. These 50 PVs were measured using both methods. The diameters of the PVs measured by TEE and angiography were not statistically different by the paired t test; LSPV14 ± 1.8 mm v/s 14.4 ± 2.1 mm; RSPV 13 ± 1.8 mm v/s 14.6 ± 3.5 mm; LIPV 11.9 ± 2.1 vs 13.2 ± 2.8 mm and RIPV 10.5 ± 2.7 vs 12.1 ± 2.9 mm. Bland Altman analysis showed most PV sizes estimated by TEE and angiography lay within limits of agreement. Conclusions A majority of PVs can be visualised by TEE using a defined protocol. TEE is a good technique to visualise and assess the size of PVs, avoiding the need for contrast medium and radiation. Abstract Figure. TEE and angiographic images of PVs

scholarly journals Reliability and Validity of an Ultrasonic Device for Measuring Height in Adults

2021 ◽  
Vol 42 (5) ◽  
pp. 376-381
Author(s):  
Seon Hwa Cho ◽  
Young Gyu Cho ◽  
Hyun Ah Park ◽  
A Ra Bong
Keyword(s):  
Correlation Coefficient ◽  
Health Surveys ◽  
Intraclass Correlation ◽  
Reliability And Validity ◽  
Altman Analysis ◽  
Bland Altman Analysis ◽  
Community Health Survey ◽  
Measurement Devices ◽  
The Difference ◽  
Very High

Background: The ultrasonic stadiometer was originally developed as a device to measure and monitor children’s height. However, an ultrasonic stadiometer (InLab S50; InBody Co., Seoul, Korea) was used to measure adults’ height in the 2018 Korea Community Health Survey (KCHS). This study was conducted to assess the reliability and validity of the InLab S50 in adults. Methods: The study subjects were 120 adults (reliability test, n=20; validity test, n=100) who had visited a health screening center. The intra- and inter-rater reliabilities of InLab S50 were assessed using the intraclass correlation coefficient (ICC). The agreement between InLab S50 and an automatic stadiometer (HM-201; Fanics, Busan, Korea) was assessed using Pearson’s correlation coefficient and Bland-Altman analysis. Results: The intra- and inter-rater reliabilities of the InLab S50 were excellent (ICC=0.9999 and 0.9998, respectively). The correlation coefficient of the height measured by the two measurement devices was very high (r=0.996). The difference (Δheight [HM-201-InLab S50]) was -0.15±0.78 cm (95% limit of agreement [LOA], -1.69 to 1.38). After excluding the values outside 95% LOA, the difference was further reduced to -0.05±0.59 cm (95% LOA, -1.20 to 1.10). Conclusion: This study showed that the InLab S50 is a reliable and valid device for the measurement of adults’ height. Therefore, we think that InLab S50 could be used to measure adults’ height in household health surveys such as the KCHS.

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

Diagnostics ◽  
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.

scholarly journals Evaluation of Automated Microvascular Flow Analysis Software AVA 4.0: A Validation Study

2020 ◽  
Author(s):  
Christian S. Guay ◽  
Mariam Khebir ◽  
Shiva Shahiri ◽  
Ariana Szilagyi ◽  
Erin Elizabeth Cole ◽  
...  
Keyword(s):  
Validation Study ◽  
Validation Studies ◽  
Intraclass Correlation ◽  
Flow Analysis ◽  
Automated Analysis ◽  
Vessel Density ◽  
Altman Analysis ◽  
Analysis Software ◽  
Bland Altman Analysis ◽  
Microvascular Flow

Abstract BACKGROUND: Real-time automated analysis of videos of the microvasculature is an essential step in the development of research protocols and clinical algorithms that incorporate point-of-care microvascular analysis. Validation studies on the software packages developed to perform these analyses have reported low agreement with the current referent standard semi-automated analysis method. In response to the call for validation studies of available automated analysis software by the European Society of Intensive Care Medicine, we report the first human validation study of AVA 4.0. METHODS: Two retrospective perioperative datasets of human microcirculation videos (P1 and P2) and one prospective healthy volunteer dataset (V1) were used. Video quality was assessed using the Microcirculation Image Quality Selection (MIQS) score. Videos were initially analysed with (1) AVA software 3.2 by two experienced users through a semi-manual method, followed by an analysis with (2) AVA automated software 4.0 for perfused vessel density (PVD), total vessel density (TVD), and proportion of perfused vessels (PPV). Bland-Altman analysis and intraclass correlation coefficients (ICC) were used to measure agreement between the two methods. Each method’s ability to discriminate between microcirculatory states before and after induction of general anesthesia was assessed using paired t-tests. RESULTS: Fifty-two videos from P1, 128 videos from P2 and 26 videos from V1 met inclusion criteria for analysis. Correlational analysis and Bland Altman analysis revealed poor agreement and no correlation between AVA 4.0 and AVA 3.2. Increasing video length did not improve agreement. Automated analysis consistently underestimated measures of vessel density. Following the induction of anesthesia, TVD and PVD measured using AVA 3.2 increased significantly for P1 and P2 (p < 0.05). However, these changes could not be replicated with the data generated by AVA 4.0. CONCLUSIONS: AVA 4.0 is not a suitable tool for research or clinical purposes at this time. Future validation studies of automated microvascular flow analysis software should aim to measure the new software’s agreement with the referent standard, its ability to discriminate between clinical states and the quality thresholds at which its performance becomes unacceptable.

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