Lin's Concordance Correlation Research Articles

A deep learning approach for fast muscle water T2 mapping with subject specific fat T2 calibration from multi-spin-echo acquisitions.

This work presents a deep learning approach for rapid and accurate muscle water T2 with subject-specific fat T2 calibration using multi-spin-echo acquisitions. This method addresses the computational limitations of conventional bi-component Extended Phase Graph fitting methods (nonlinear-least-squares and dictionary-based) by leveraging fully connected neural networks for fast processing with minimal computational resources. We validated the approach through in vivo experiments using two different MRI vendors. The results showed strong agreement of our deep learning approach with reference methods, summarized by Lin's concordance correlation coefficients ranging from 0.89 to 0.97. Further, the deep learning method achieved a significant computational time improvement, processing data 116 and 33 times faster than the nonlinear least squares and dictionary methods, respectively. In conclusion, the proposed approach demonstrated significant time and resource efficiency improvements over conventional methods while maintaining similar accuracy. This methodology makes the processing of water T2 data faster and easier for the user and will facilitate the utilization of the use of a quantitative water T2 map of muscle in clinical and research studies.

Total valproate versus free valproate in therapeutic drug monitoring for bipolar disorder: A cross-sectional study.

The debate about observing total versus free serum valproate levels for therapeutic drug monitoring (TDM) has been unresolved for decades. This study was planned to assess the agreement between the total versus free valproate levels and the advantage of one method over the other in TDM. The present cross-sectional study was done on 93 patients with bipolar disorder. The intraclass correlation coefficient, Bland Altman analysis, and Lin's concordance analysis were done to assess the agreement between the total and free valproate concentrations. Linear and polynomial models were constructed to evaluate the relation between the two measurements. Receiver operating characteristics analysis was done to compare the accuracy for differentiating remission from non-remission on Young's mania rating scale (YMRS). The intraclass correlation coefficient and Lin's concordance correlation coefficient were 0.491 (p = .002) and 0.055 (95% CI:0.037, 0.073), respectively. Bland Altman's analysis showed proportional bias. A polynomial model of second order was found to be the best fit for the prediction of free valproate from the data for total valproate, and 81.4% of the variability in free valproate could be explained when adjusted for albumin levels. The area under the curve for total valproate was 0.60 when compared to free valproate 0.56 for differentiating between remission and non-remission, but the comparison between the two ROC analyses was not statistically significant. Free valproate does not provide any added advantage over the total valproate levels; hence, total valproate levels may continue to be used as the marker for drug monitoring.

Reduction of ADC bias in diffusion MRI with deep learning-based acceleration: A phantom validation study at 3.0 T

PurposeFurther acceleration of DWI in diagnostic radiology is desired but challenging mainly due to low SNR in high b-value images and associated bias in quantitative ADC values. Deep learning-based reconstruction and denoising may provide a solution to address this challenge. MethodsThe effects of SNR reduction on ADC bias and variability were investigated using a commercial diffusion phantom and numerical simulations. In the phantom, performance of different reconstruction methods, including conventional parallel (SENSE) imaging, compressed sensing (C-SENSE), and compressed SENSE acceleration with an artificial intelligence deep learning-based technique (C-SENSE AI), was compared at different acceleration factors and flip angles using ROI-based analysis. ADC bias was assessed by Lin's Concordance correlation coefficient (CCC) followed by bootstrapping to calculate confidence intervals (CI). ADC random measurement error (RME) was assessed by the mean coefficient of variation (CV¯) and non-parametric statistical tests. ResultsThe simulations predicted increasingly negative bias and loss of precision towards lower SNR. These effects were confirmed in phantom measurements of increasing acceleration, for which CCC decreased from 0.947 to 0.279 and CV¯ increased from 0.043 to 0.439, and of decreasing flip angle, for which CCC decreased from 0.990 to 0.063 and CV¯ increased from 0.037 to 0.508. At high acceleration and low flip angle, C-SENSE AI reconstruction yielded best denoised ADC maps. For the lowest investigated flip angle, CCC = {0.630, 0.771 and 0.987} and CV¯={0.508, 0.426 and 0.254} were obtained for {SENSE, C-SENSE, C-SENSE AI}, the improvement by C-SENSE AI being significant as compared to the other methods (CV: p = 0.033 for C-SENSE AI vs. C-SENSE and p < 0.001 for C-SENSE AI vs. SENSE; CCC: non-overlapping CI between reconstruction methods). For the highest investigated acceleration factor, CCC = {0.479,0.926,0.960} and CV¯={0.519,0.119,0.118} were found, confirming the reduction of bias and RME by C-SENSE AI as compared to C-SENSE (by trend) and to SENSE (CV: p < 0.001; CCC: non-overlapping CI). ConclusionADC bias and random measurement error in DWI at low SNR, typically associated with scan acceleration, can be effectively reduced by deep-learning based C-SENSE AI reconstruction.

Comparisons of an automated oscillometric device with a hybrid manual auscultatory device for the Korea National Health and Nutrition Examination Survey.

This study evaluated an oscillometric device (OD), Microlife WatchBP Office AFIB, and a hybrid manual auscultatory device (AD), Greenlight 300TM, to determine a suitable blood pressure (BP) measurement device for the Korea National Health and Nutrition Examination Survey in a mercury-free context. Adhering to the 2018 Universal Standard's suggested consensus, the study involved 800 subjects (mean age 51.2±17.5 years; 44.3% male), who underwent triplicate BP measurements following 5 min of rest in a randomized order (OD-first: 398 participants; AD-first: 402 participants). BP difference was calculated as OD value minus AD value, with results stratified by measurement sequence. The overall BP difference and tolerable error probability were -1.1±6.5/-2.6±4.9mmHg and 89.2%/92.5% for systolic/diastolic BP (SBP/DBP), respectively. Lin's concordance correlation coefficient was 0.907/0.844 for SBP/DBP (OD-first/AD-first: 0.925/0.892 for SBP, 0.842/0.845 for DBP). The overall agreement for hypertension (BP ≥ 140 and/or 90mmHg) was 0.71 (p<0.0001), and the OD underestimated the overall hypertension prevalence by 5.1%. Analysis of the AD-first data revealed a lower level of agreement compared to the OD-first data; however, the observed blood pressure difference adhered to Criterion 1 of the 2018 Universal Standard. Microlife met the Criterion 1 of 2018 Universal Standard but underestimated the prevalence of hypertension. The BP discrepancy increased with higher BP levels, male sex, and smaller AC. With increasing age, the discrepancy decreased for SBP and increased for DBP.

Comparison of raw accelerometry data from ActiGraph, Apple Watch, Garmin, and Fitbit using a mechanical shaker table.

The purpose of this study was to evaluate the reliability and validity of the raw accelerometry output from research-grade and consumer wearable devices compared to accelerations produced by a mechanical shaker table. Raw accelerometry data from a total of 40 devices (i.e., n = 10 ActiGraph wGT3X-BT, n = 10 Apple Watch Series 7, n = 10 Garmin Vivoactive 4S, and n = 10 Fitbit Sense) were compared to reference accelerations produced by an orbital shaker table at speeds ranging from 0.6 Hz (4.4 milligravity-mg) to 3.2 Hz (124.7mg). Two-way random effects absolute intraclass correlation coefficients (ICC) tested inter-device reliability. Pearson product moment, Lin's concordance correlation coefficient (CCC), absolute error, mean bias, and equivalence testing were calculated to assess the validity between the raw estimates from the devices and the reference metric. Estimates from Apple, ActiGraph, Garmin, and Fitbit were reliable, with ICCs = 0.99, 0.97, 0.88, and 0.88, respectively. Estimates from ActiGraph, Apple, and Fitbit devices exhibited excellent concordance with the reference CCCs = 0.88, 0.83, and 0.85, respectively, while estimates from Garmin exhibited moderate concordance CCC = 0.59 based on the mean aggregation method. ActiGraph, Apple, and Fitbit produced similar absolute errors = 16.9mg, 21.6mg, and 22.0mg, respectively, while Garmin produced higher absolute error = 32.5mg compared to the reference. ActiGraph produced the lowest mean bias 0.0mg (95%CI = -40.0, 41.0). Equivalence testing revealed raw accelerometry data from all devices were not statistically significantly within the equivalence bounds of the shaker speed. Findings from this study provide evidence that raw accelerometry data from Apple, Garmin, and Fitbit devices can be used to reliably estimate movement; however, no estimates were statistically significantly equivalent to the reference. Future studies could explore device-agnostic and harmonization methods for estimating physical activity using the raw accelerometry signals from the consumer wearables studied herein.

Volumetric quantification identifies some left atrial dilations undetected by left atrium:aorta ratio measurements: A prospective echocardiographic study in 155 Cavalier King Charles Spaniels with and without degenerative mitral valve disease.

Degenerative mitral valve disease (DMVD) is the most common canine heart disease with a high predisposition in Cavalier King Charles Spaniels (CKCSs). Mitral regurgitation related to DMVD can lead to left atrial (LA) dilation, which is associated with survival time. Left-atrial-to-aortic (LA:Ao) ratio assessed by two-dimensional echocardiography is commonly used to evaluate LA size. The objectives of this prospective observational study were therefore 1) to compare different echocardiographic methods (i.e., monoplane and biplane Simpson's methods of discs (SMOD) and area-length methods (ALM)) in evaluating LA volume (LAvol) in CKCSs, 2) to assess LA volumes according to DMVD severity and, 3) compare the ability of LAvol and LA:Ao ratio to identify LA enlargement in CKCSs with subclinical DMVD (i.e., American College of Veterinary Internal Medicine (ACVIM) stage B). 155 CKCSs, either healthy or affected by DMVD, were recruited. Variability and concordance between volumetric methods were evaluated. Values were analyzed according to 2019 ACVIM stages. All Lin's concordance correlation coefficients regarding intra- and inter-observer variability were considered as very good to excellent. Monoplane methods and ALM produced higher values of LAvol than biplane methods and SMOD, respectively. The upper limit of normal end-systolic LAvol/body weight (LASvol/BW) was defined as 0.90 mL/kg. Left atrial volumes significantly increased with ACVIM stages. Additionally, 37% of stage B1 CKCSs demonstrated LA enlargement using LASvol/BW assessment, with significantly lower LASvol/BW values in dogs with regurgitation fraction ≤30% than in others (p<0.01). In CKCSs, LAvol methods are not interchangeable. In ACVIM stage B CKCSs, LAvol quantification is more effective to detect LA enlargement than LA linear measurements.

Single-center experience with Knee+™ augmented reality navigation system in primary total knee arthroplasty.

Computer-assisted systems obtained an increased interest in orthopaedic surgery over the last years, as they enhance precision compared to conventional hardware. The expansion of computer assistance is evolving with the employment of augmented reality. Yet, the accuracy of augmented reality navigation systems has not been determined. To examine the accuracy of component alignment and restoration of the affected limb's mechanical axis in primary total knee arthroplasty (TKA), utilizing an augmented reality navigation system and to assess whether such systems are conspicuously fruitful for an accomplished knee surgeon. From May 2021 to December 2021, 30 patients, 25 women and five men, underwent a primary unilateral TKA. Revision cases were excluded. A preoperative radiographic procedure was performed to evaluate the limb's axial alignment. All patients were operated on by the same team, without a tourniquet, utilizing three distinct prostheses with the assistance of the Knee+™ augmented reality navigation system in every operation. Postoperatively, the same radiographic exam protocol was executed to evaluate the implants' position, orientation and coronal plane alignment. We recorded measurements in 3 stages regarding femoral varus and flexion, tibial varus and posterior slope. Firstly, the expected values from the Augmented Reality system were documented. Then we calculated the same values after each cut and finally, the same measurements were recorded radiologically after the operations. Concerning statistical analysis, Lin's concordance correlation coefficient was estimated, while Wilcoxon Signed Rank Test was performed when needed. A statistically significant difference was observed regarding mean expected values and radiographic measurements for femoral flexion measurements only (Z score = 2.67, P value = 0.01). Nonetheless, this difference was statistically significantly lower than 1 degree (Z score = -4.21, P value < 0.01). In terms of discrepancies in the calculations of expected values and controlled measurements, a statistically significant difference between tibial varus values was detected (Z score = -2.33, P value = 0.02), which was also statistically significantly lower than 1 degree (Z score = -4.99, P value < 0.01). The results indicate satisfactory postoperative coronal alignment without outliers across all three different implants utilized. Augmented reality navigation systems can bolster orthopaedic surgeons' accuracy in achieving precise axial alignment. However, further research is required to further evaluate their efficacy and potential.

Assessing left atrial size and pump function in ischemic stroke patients: Is cardiac MRI superior to transthoracic echocardiography?

ObjectivesCurrent guidelines recommend transthoracic echocardiography (TTE) following an ischemic stroke as the primary technique to identify cardiac abnormalities associated with an increased risk of cerebral embolism. It is unclear whether cardiac magnetic resonance imaging (cMRI), a technique shown to provide increased imaging resolution, may also enhance the cardiac assessment of ischemic stroke patients. We compared cMRI with TTE in the evaluation of Left Atrial (LA) size and pump function in a cohort of 44 patients with ischemic stroke. Materials and methodsThe biplane method was utilized to acquire LA diameters as well as area measurements in both TTE and cMRI. We calculated LA volume (LAV), LAV index (LAVI), LA Global Longitudinal Strain (GLS) and LA pump function. Results were compared using paired two sample for means t-test. Lin's concordance correlation coefficient (CCC) and Bland-Altman methods quantified the agreement of measurements obtained by TTE and cMRI. ResultsLAVI measurements by cMRI were significantly larger (34.97 v. 28.81; p = 0.001) than by TTE. The concordance correlation demonstrated only a weak agreement between LA size measured by cMRI and TTE (ρc = 0.397; p= 0.001, 95% CI 0.16 - 0.59), and the Bland-Altman plot demonstrated that LAVI measured by cMRI averaged 6.3 ml/m2 larger magnitude than those obtained by TTE. ConclusionsUsing TTE alone leads to an underestimation of LA abnormalities important in the evaluation of ischemic stroke patients. Nearly one in every five ischemic stroke patients evaluated based on the current guidelines may have a missed potential source of cardiac embolism.

Reduced cross-scanner variability using vendor-agnostic sequences for single-shell diffusion MRI.

To reduce the inter-scanner variability of diffusion MRI (dMRI) measures between scanners from different vendors by developing a vendor-neutral dMRI pulse sequence using the open-source vendor-agnostic Pulseq platform. We implemented a standard EPI based dMRI sequence in Pulseq. We tested it on two clinical scanners from different vendors (Siemens Prisma and GE Premier), systematically evaluating and comparing the within- and inter-scanner variability across the vendors, using both the vendor-provided and Pulseq dMRI sequences. Assessments covered both a diffusion phantom and three human subjects, using standard error (SE) and Lin's concordance correlation to measure the repeatability and reproducibility of standard DTI metrics including fractional anisotropy (FA) and mean diffusivity (MD). Identical dMRI sequences were executed on both scanners using Pulseq. On the phantom, the Pulseq sequence showed more than a 2.5× reduction in SE (variability) across Siemens and GE scanners. Furthermore, Pulseq sequences exhibited markedly reduced SE in-vivo, maintaining scan-rescan repeatability while delivering lower variability in FA and MD (more than 50% reduction in cortical/subcortical regions) compared to vendor-provided sequences. The Pulseq diffusion sequence reduces the cross-scanner variability for both phantom and in-vivo data, which will benefit multi-center neuroimaging studies and improve the reproducibility of neuroimaging studies.

Validation and inter-device reliability of a behavior monitoring collar to measure rumination, feeding activity, and idle time of lactating dairy cows

Inter-device precision and accuracy are not investigated for precision livestock farming (PLF) technologies, but are fundamental for the use of data in populational metrics and to compare cows' data. This study aimed to validate a behavior monitoring collar (BMC; CowMed, Santa Maria, RS, Brazil) and its inter-device reliability. First, comparing observations with the BMC and second the inter-device precision and accuracy for rumination, feeding activity, and idle time of lactating dairy cows. Holstein cows (n = 23) were housed in a voluntary milk system free-stall barn and fitted with 2 devices within the same cow. Observations were made over 2 periods of one day (0700 to 1100h; 1400 to 1700h); the 7h per cow were summarized for each behavior to assess the agreement of observed behavior and BMC data. To assess the inter-device reliability 26d of BMC data was summarized by day per cow for both devices. Pearson correlation (r), coefficient of determination (R2), Lin's concordance correlation coefficient (ρc), linear regression, and Bland-Altman plots (BAP) were calculated for each period of observation. For the validation, we found high correlations for feeding activity, very high for idle time, but low correlations for rumination. The BAP was deemed acceptable and without bias; BAP mean differences ± SD were 0.83 ± 4.01, −0.48 ± 4.15, and 7.17 ± 3.94 min/h for rumination, feeding activity, and idle time, respectively. The slope of the linear regression did not differ from 1 for all behaviors but idle. For inter-device comparison, we found moderate correlations for feeding activity, idle time and a low correlation for rumination. The BAP was deemed acceptable and without bias; BAP mean differences were −0.36 ± 2.84, 0.45 ± 3.51, and −0.06 ± 2.81 min/h for rumination, feeding activity, and idle time, respectively. All slopes of the linear regressions differed from 1 but feeding time. Thus, the inter-device did not meet the accuracy criteria. In summary, this study validated the precision of the BMC for recording feeding activity of lactating dairy cows.

Exchangeable acidity and pedotransfer functions for the soils of Ghana

AbstractSoil exchangeable acidity (EA) is an indicator of aluminium toxicity potential in acidic soils. Predicting the distribution and dynamics of EA is needed for the identification and management of acidic soils. In this study, we used datasets of 355 pedons from across Ghana and the Cubist rule‐based algorithm to generate pedotransfer functions (PTFs) of EA. Eight soil properties (pH, organic carbon, calcium, sodium, magnesium, total exchangeable bases, cation exchange capacity [CEC] to clay ratio and soil depth) were used to predict EA. We first used the whole dataset to construct generic PTFs and then stratified the dataset based on World Reference Base‐Reference Soil Groups (WRB‐RSGs) to generate soil‐specific PTFs. Goodness‐of‐fit statistics comprising the root mean squared error (RMSE), Lin's concordance correlation coefficient () and coefficient of determination (R2) were used to evaluate the prediction accuracy and reliability of the developed PTF models on both calibration and validation datasets. The Fluvisols EA‐PTF exhibited lower performance metrics in the validation (RMSE = 0.17 cmolc kg−1, = 0.19, R2 = 0.24), whereas the EA‐PTFs for all other WRB‐RSGs and whole dataset had above‐average performance metrics in the validation (0.05 ≤ RMSE ≤ 0.97 cmolc kg−1; 0.34 ≤ ≤ 0.94; 0.52 ≤ R2 ≤ 0.96). Soil pH sufficed for predicting EA in soils with pH above 5.0, but in soils with a pH &lt; 5.0, the levels of exchangeable bases (e.g., Na+, K+, Mg2+, Ca2+), CEC to clay ratio (CCR) and soil depth improved the prediction of EA. The developed EA‐PTFs are useful for estimating the missing values of EA in soil databases.

Accuracy of Early Neuroprognostication in Pediatric Severe Traumatic Brain Injury

BackgroundChildren with severe traumatic brain injury (sTBI) are at risk for neurological sequelae impacting function. Clinicians are tasked with neuroprognostication to assist in decision-making. We describe a single-center study assessing clinicians’ neuroprognostication accuracy. MethodsClinicians of various specialties caring for children with sTBI were asked to predict their patients' functioning three to six months postinjury. Clinicians were asked to participate in the study if their patient had survived but not returned to baseline between day 4 and 7 postinjury. The outcome tool utilized was the functional status scale (FSS), ranging from 6 to 30 (best-worst function). Predicted scores were compared with actual scores three to six months postinjury. Lin concordance correlation coefficients were used to estimate agreement between predicted and actual FSS. Outcome was dichotomized as good (FSS 6 to 8) or poor (FSS ≥9). Positive and negative predictive values for poor outcome were calculated. Pessimistic prognostic prediction was defined as predicted worse outcome by ≥3 FSS points. Demographic and clinical variables were collected. ResultsA total of 107 surveys were collected on 24 patients. Two children died. Fifteen children had complete (FSS = 6) or near-complete (FSS = 7) recovery. Mean predicted and actual FSS scores were 10.8 (S.D. 5.6) and 8.6 (S.D. 4.1), respectively. Predicted FSS scores were higher than actual scores (P < 0.001). Eight children had collective pessimistic prognostic prediction. ConclusionsClinicians predicted worse functional outcomes, despite high percentage of patients with near-normal function at follow-up clinic. Certain patient and provider factors were noted to impact accuracy and need to be studied in larger cohorts.

On-Site Melanoma Diagnosis Utilizing a Swellable Microneedle-Assisted Skin Interstitial Fluid Sampling and a Microfluidic Particle Dam for Visual Quantification of S100A1.

Malignant melanoma (MM) is the most aggressive form of skin cancer. The delay in treatment will induce metastasis, resulting in a poor prognosis and even death. Here, a two-step strategy for on-site diagnosis of MM is developed based on the extraction and direct visual quantification of S100A1, a biomarker for melanoma. First, a swellable microneedle is utilized to extract S100A1 in skin interstitial fluid (ISF) with minimal invasion. After elution, antibody-conjugated magnetic microparticles (MMPs) and polystyrene microparticles (PMPs) are introduced. A high expression level of S100A1 gives rise to a robust binding between MMPs and PMPs and reduces the number of free PMPs. By loading the reacted solution into the device with a microfluidic particle dam, the quantity of free PMPs after magnetic separationis displayed with their accumulation length inversely proportional to S100A1 levels. A limit of detection of 18.7ngmL-1 for S100A1 is achieved. The animal experiment indicates that ISF-based S100A1 quantification using the proposed strategy exhibits a significantly higher sensitivity compared with conventional serum-based detection. In addition, the result is highly comparable with the gold standard enzyme-linked immunosorbent assay based on Lin's concordance correlation coefficient, suggesting the high practicality for routine monitoring of melanoma.

Psychometric properties of the Kidney Disease Quality of Life short form 36 (KDQOL-36) scale for the assessment of quality of life in Colombian patients with chronic kidney disease on dialysis.

Considering the importance of incorporating quality of life (QoL) construct during the health care of patients with stage 5 chronic kidney disease (CKD) on dialysis, it is necessary to have evidence on the clinimetric properties of the instruments used for its measurement. This study aimed to establish the clinimetric properties of the Kidney Disease Quality of Life Short Form 36 (KDQOL-36) scale in patients with stage 5 CKD on dialysis in Colombia. A scale validation study was conducted using the classical test theory methodology. The statistical analysis included exploratory factor analysis (EFA) and confirmatory (CFA) techniques performed on two independent subsamples; concurrent criterion validity assessments; internal consistency using four different coefficients; test-retest reliability; and sensitivity to change using mixed model for repeated measures. The KDQOL-36 scale was applied to 506 patients with a diagnosis of stage 5 CKD on dialysis, attended in five renal units in Colombia. The EFA endorsed the three-factor structure of the scale, and the CFA showed an adequate fit of both the original and empirical models. Spearman's correlation coefficient values ≥0.50 were found between the domains of the CKD-specific core of the KDQOL-36 scale and the KDQ. Cronbach's alpha, McDonald's omega, Greatest lower bound (GLB), and Guttman's lambda coefficients were ≥0.89, indicating a high degree of consistency. A high level of concordance correlation was found between the two moments of application of the instrument, with values for Lin's concordance correlation coefficient ≥0.7. The application of the instrument after experiencing an event that could modify the quality of life showed statistically significant differences in the scores obtained. The KDQOL-36 scale is an adequate instrument for measuring QoL in Colombian patients with stage 5 CKD on dialysis.

High-Throughput Bacteriophage Testing with Potency Determination: Validation of an Automated Pipetting and Phage Drop-Off Method.

The development of bacteriophages (phages) as active pharmaceutical ingredients for the treatment of patients is on its way and regulatory agencies are calling for reliable methods to assess phage potency. As the number of phage banks is increasing, so is the number of phages that need to be tested to identify therapeutic candidates. Currently, assessment of phage potency on a semi-solid medium to observe plaque-forming units is unavoidable and proves to be labor intensive when considering dozens of phage candidates. Here, we present a method based on automated pipetting and phage drop-off performed by a liquid-handling robot, allowing high-throughput testing and phage potency determination (based on phage titer and efficiency of plaquing). Ten phages were tested, individually and assembled into one cocktail, against 126 Escherichia coli strains. This automated method was compared to the reference one (manual assay) and validated in terms of reproducibility and concordance (ratio of results according to the Bland and Altman method: 0.99; Lin's concordance correlation coefficient: 0.86). We found that coefficients of variation were lower with automated pipetting (mean CV: 13.3% vs. 24.5%). Beyond speeding up the process of phage screening, this method could be used to standardize phage potency evaluation.

Development and Calibration of a PATCH Device for Monitoring Children's Heart Rate and Acceleration.

Current wearables that collect heart rate and acceleration were not designed for children and/or do not allow access to raw signals, making them fundamentally unverifiable. This study describes the creation and calibration of an open-source multichannel platform (PATCH) designed to measure heart rate and acceleration in children ages 3-8 years. Children (N = 63; Mean age = 6.3) participated in a 45-minute protocol ranging in intensities from sedentary to vigorous activity. Actiheart-5 was used as a comparison measure. We calculated mean bias, mean absolute error (MAE) mean absolute percent error (MA%E), Pearson correlations and Lin's concordance correlation coefficient (CCC). Mean bias between PATCH and Actiheart heart rate was 2.26 BPM, MAE was 6.67 BPM and M%E was 5.99%. The correlation between PATCH and Actiheart HR was .89 and CCC was .88. For acceleration, mean bias was 1.16 mg and MAE was 12.24 mg. The correlation between PATCH and Actiheart was .96 and CCC was .95. The PATCH demonstrated clinically acceptable accuracies to measure heart rate and acceleration compared to a research grade device.

Comparing AGS Beers 2019, STOPP version 2, and EU(7)-PIM list in Portuguese older adults in primary health care

PurposeThis study aims to identify PIM prevalence in older adults according to the 2019 Beers criteria, Screening Tool of Older Person’s Prescriptions version 2 (STOPP v2) criteria, and the Portuguese EU(7)-PIM list and also to analyze the concordance between these criteria.MethodsA retrospective study was conducted among 1200 Portuguese older adults (≥ 65 years old), users of primary health care. Demographic, clinical, and pharmacological data were collected concerning the period between April 2021 and August 2022. A comparative analysis was performed between the three PIM identification criteria, and the concordance was determined according to the Lin concordance correlation coefficient.ResultsThe mean age was 76.3 (SD 7.7) years old and 57.6% of the older adults were females. Our findings indicate varying prevalence rates among these criteria with 63.8% (95% CI 61.0–66.6%), 66.8% (95% CI 64.1–69.5%), and 50.1% (95% CI 47.2–53.0%) of the older adults take at least one PIM according to the EU(7)-PIM list, Beers 2019, and STOPP v2 criteria, respectively. The highest prevalence observed was for proton pump inhibitors according to EU(7)-PIM list (30.1%, 95% CI 27.6–32.9) and Beers criteria (30.1%, 95% CI 27.6–32.9) and alprazolam according to STOPP v2 criteria (10.1%, 95% CI 8.4–11.9%). A poor concordance between criteria was observed (< 0.834). The highest concordance coefficient was found between the EU(7)-PIM list and the Beers criteria (0.833), and the lowest between the EU(7)-PIM list and STOPP criteria (0.735).ConclusionThis study reveals varying prevalence rates of PIM in older adults, as assessed by different criteria, and highlights the need for targeted interventions and improved prescribing practices. In the future, studies should focus on the occurrence of negative outcomes in older adults associated with PIM consumption.

European Carotid Surgical Trial-based diameter measurement using B-mode ultrasound imaging to quantify low-grade carotid artery stenosis: the QUAMUS study

BackgroundIdentification of carotid atherosclerotic lesions with no hemodynamic effect on Doppler ultrasound examination is a common situation. Although the use of B-mode ultrasound examination has been recommended to assess this type of lesion, there is no validated examination procedure to date for quantifying low-grade carotid stenosis. MethodsWe conducted a single-center prospective study (QUAntification Morphologique en UltraSonographie [QUAMUS] study) to assess the reproducibility of B-mode ultrasound quantification of low-grade internal carotid artery stenosis using the European Carotid Surgical Trial (ECST) measurement method. We included consecutive patients with <50% North American Symptomatic Carotid Endarterectomy Trial carotid stenosis identified by the University of Washington duplex criteria (ie, maximum systolic velocity of <125 cm/second at a Doppler angle of 50°-60°). The examination was carried out and interpreted independently, blindly, and successively by two operators according to a precise methodology based on the measurement of cross-sectional diameter in B-mode and calculation of the stenosis percentage according to the ECST method. The primary objective was to assess the measurement concordance of the stenosis percentage for a difference not exceeding 10% between the two operators. The secondary objective was to assess concordance in relation to examination quality. ResultsAmong the 86 patients included, 159 atherosclerotic carotid arteries were eligible and 157 could be explored (feasibility of 98.74%). The conditions were considered as good by the two operators in 69.43% of cases and poor in 2.55%. The concordance of the stenosis percentage measurement for a maximum difference of 10% between the two operators was 89.17% (95% confidence interval, 83.23-93.56) with a Lin concordance correlation coefficient of 0.87 (95% confidence interval, 0.82-0.90). Under examination conditions estimated as good, average, and poor, the concordance was 95.37%, 78.95%, and 60.00%, respectively. ConclusionsOur study shows that ECST-based B-mode ultrasound measurement of low-grade carotid stenosis is reliable and can be performed in routine practice in most patients with a measurement variation of <10% using a simple standardized examination procedure.

Ejection fraction and ventricular volumes on rubidium positron emission tomography: Validation against cardiovascular magnetic resonance

BackgroundCardiovascular magnetic resonance (CMR) is the non-invasive gold standard for non-invasively determining left ventricular volumes (LVVs) and ejection fraction (EF). We aimed to assess the accuracy of LVV and left ventricular ejection fraction measured by positron emission tomography (PET) as compared to CMR. MethodsPatients who underwent both PET and CMR within 1 year were identified from prospective institutional registries. Analysis was performed to evaluate the agreement between the raw and body-surface-area-normalized left ventricular volume (LVV) and EF derived from PET vs. those derived from CMR. ResultsThe study population consisted of 669 patients (mean age 62 ± 13 years, 65% male). The median (interquartile range [IQR]) duration between CMR and PET imaging was 36 (7–118) days. The median (IQR) EF values were 52% (38–63%) on CMR and 53% (37–65%) on PET (mean difference: 0.53% ± 9.1, P = 0.129) with a strong correlation (Spearman rho = 0.84, P < 0.001; Intraclass Correlation Coefficient 0.84, 95% confidence interval [CI]: 0.82–0.86, P < 0.001; Lin's concordance correlation coefficient was 0.844, 95% CI: 0.822 to 0.865). Results were similar with LVV, normalized LVV/EF, and in subgroups of patients with reduced EF, coronary artery disease scar, and LV hypertrophy as well as in patients with defibrillators. However, PET tended to underestimate LVV compared to CMR. ConclusionOur analysis showed a strong correlation of EF and LVV by PET against a reference standard of CMR, whereas PET significantly underestimated LVV, but not EF, compared to CMR.

Standard area diagrams for pecan leaf scab: Effect of rater experience and location, and leaf size on reliability and accuracy of visual estimates.

Assessments of the severity of scab (Venturia effusa), an economically significant disease of pecan, are critical for determining pecan cultivar susceptibility, disease epidemiology, and integrated disease management approaches. We developed a standard area diagram (SAD) set to aid in assessments of pecan leaflet scab. Leaflets with scab lesions were harvested and scanned using a flatbed scanner at 600 dpi, and Fiji (ImageJ) was used to determine the actual percent disease severity. The SADs had 10 leaflets ranging in severity from 0.2 to 48.9%. Forty 'small' (1.34 - 7.43 cm2) and forty 'large' (7.67 - 25.9 cm2) leaflet images were randomized for rater assessments. The images were assessed twice by 36 raters, first without and then with the SADs as a guide. Data were subjected to analysis using Lin's Concordance Correlation Coefficient (LCC, pc) to determine the accuracy of ratings, and by Intra-class Correlation Coefficient analysis to determine inter-rater reliability. The effects of rater experience, rater location, and leaflet size were also determined. The SADs significantly improved the agreement between raters and the actual values (LCC, pc = 0.70 and 0.84 without and with the SADs, respectively). The reliability of estimates was improved (ICC = 0.54 and 0.82 without and with the SADs, respectively). The effect of rater location on overall concordance was significant without and with the SADs based on an analysis of variance (ANOVA) using a general linear model and lsmeans separation (P<0.05). A generalized linear mixed model analysis revealed that there was a significant interaction between rater location, experience, and the use of the SADs, with some raters having greater improvement in generalized bias and concordance. Raters had a significantly better accuracy when rating 'small' leaves (LCC, pc = 0.86) compared to 'large' leaves (LCC, pc = 0.82) when using the SADs, highlighting the impact of psychophysics on field evaluations of plant disease severity. The proposed SADs will serve as an improved tool for performing pecan leaflet scab assessments by the pecan research community.