Bland-Altman Method Research Articles

Validation of a pregnancy-adapted Mediterranean Diet Adherence Screener (preg-MEDAS): a validation study nested in the Improving Mothers for a better PrenAtal Care Trial BarCeloNa (IMPACT BCN) trial

BackgroundNon-time-consuming and easy-to-administer dietary assessment tools specific for pregnancy are needed. ObjectivesThe aim of this validation study nested in the IMPACT BCN (Improving Mothers for a better PrenAtal Care Trial BarCeloNa) trial is to determine the concurrent validity of the 17-item pregnancy-adapted Mediterranean diet score (preg-MEDAS) and to analyze whether changes in the preg-MEDAS score were associated with maternal favorable dietary and cardiometabolic changes after 3 mo of intervention in pregnant women. MethodsDietary data was collected in 812 participants using the preg-MEDAS and a 151-item validated food frequency questionnaire (FFQ) at baseline (19–23 wk gestation) and final visit (31–34 wk gestation). Concurrent preg-MEDAS validity was evaluated by Pearson and intraclass correlation coefficients, κ statistic, and Bland-Altman methods. ResultsThe preg-MEDAS had a good correlation with the FFQ (r = 0.76 and intraclass correlation coefficient 0.75). The agreement of each of the preg-MEDAS items ranged from 40.9% to 93.8% with a substantial agreement mean concordance (κ = 0.61). A 2-point increase in preg-MEDAS was associated with a decrease in maternal mean and systolic blood pressure (β: −0.51 mmHg; 95% confidence interval [CI]: −0.97, −0.04 mmHg and −0.87 mmHg; 95% CI: −1.48, −0.26 mmHg, respectively). ConclusionsThe preg-MEDAS displays good validity for assessing adherence to the Mediterranean diet, allowing detection of dietary changes over time. In addition, changes observed in preg-MEDAS are significantly associated with a decrease in maternal blood pressure. Therefore, we propose preg-MEDAS as a rapid and simple dietary assessment tool during pregnancy.This trial was registered at clinicaltrials.gov as NCT03166332.

Papel de la tomografía computarizada multidetector como herramienta de selección para cirugía de citorreducción y cirugía de citorreducción y quimioterapia intraperitoneal hipertérmica en la carcinomatosis peritoneal: concordancia entre el Índice de Carcinomatosis Peritoneal radiológico y quirúrgico

ObjectiveTo evaluate the accuracy of multidetector computed tomography (MDCT) to select patients with peritoneal carcinomatosis (PC) as candidates for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS+HIPEC), through an analysis of the degree of correlation between the radiological (rPCI) and surgical (sPCI) scores in the PC index. MethodsObservational, retrospective, single-centre study between 1 May 2014 and 31 May 2018. Calculated rPCI assessed by MDCT was compared with the sPCI using the Concordance Correlation Coefficient (CCC). The Bland-Altman method was used to plot the difference between the two observations against their mean with a confidence interval (CI) of 95%. We assessed whether tumour volume affects the CCC by setting a cut-off point of sPCI at 15 and considering a sensitivity and specificity of rPCI> 20 as a predictor of unresectability. Results50 patients underwent surgery. Mean sPCI was 11.8 (9.5) and rPCI was 11.0 (10.2), with a CCC of 0.94 (95% CI: 0.91–0.97). The CCC in the 35 patients with sPCI 20 had a sensitivity of 0.82 (95% CI: 0.68–0.92) and a specificity of 0.40 (95% CI: 0.05–0.85). The positive predictive value was 0.92 (95% CI: 0.80–0.98), while the negative predictive value was 0.20 (95% CI: 0.03–0.56). ConclusionMDCT, interpreted by an expert radiologist, is reliable for the selection of patients as candidates for CRS+HIPEC; however, the rPCI value cannot be considered in isolation as a contraindication to full treatment. Greater tumour volume usually leads to a worse concordance between rPCI and sPCI.

Clinical validation of an artificial intelligence algorithm offering automated corrected QT-interval measurements from a single lead electrocardiogram

Abstract Introduction A novel smartwatch (Withings Scanwatch, SW) offers automated analysis of the QTc based on single-lead ECG recordings. Prior clinical validation studies showed insufficient accuracy when compared to manual measurements based on a 12-lead ECG. Purpose We hypothesized that a novel AI-based algorithm (PulseAI) is capable of measuring QTc-interval based on PDF-exports from a single-lead ECG with improved accuracy compared to the manufacturer’s automated QTc measurements. Methods In this prospective, observational study, consecutive patients underwent a nearly simultaneously 12-lead ECG and a single-lead ECG. Two blinded, independent cardiologists manually interpreted the QT-interval in leads I and II of the 12-lead ECG using the tangent-method, which served as the gold standard. QTc was calculated using Bazett’s formula. QTc measurements were compared using the Bland-Altman method. Results A total of 317 patients (48% female, mean age 63 ± 17 years) were enrolled. QTc-intervals could be automatically calculated by the SW and by the novel AI algorithm in 175 patients (55%). Diagnostic accuracy of SW-ECG for detection of QTc-intervals ≥ 450 ms as quantified by the area under the curve was 0.85 for the manufacturer and 0.9 for novel AI algorithm. In 21 patients (12%) QTc was ≥450ms. The Bland-Altman analysis resulted in a bias of 21 ms [95% limit of agreement (LoA) -48 to 89 ms] for the manufacturer algorithm and 2 ms [95% LoA -35 to 39 ms] for the novel AI algorithm, respectively, when compared with manual QTc-measurement based on the 12-lead ECG. Conclusion A novel AI algorithm outperformed the manufacturer algorithm for automated QTc-measurements based on PDF-exported single-lead ECGs.Central Illustration

Stent sizing by coronary CT angiography compared with optical coherence tomography

BackgroundCoronary CT angiography (CCTA) is well-established for diagnosis and stratification of coronary artery disease (CAD). Its usefulness in guiding percutaneous coronary interventions (PCI) and stent sizing is unknown. MethodsThis is a sub-analysis of the Precise Percutaneous Coronary Intervention Plan (P3) study (NCT03782688). We analyzed 65 vessels with matched CCTA and pre-PCI optical coherence tomography (OCT) assessment. The CCTA-guided stent size was defined by the mean distal reference lumen diameter rounded up to the nearest stent diameter. The OCT lumen-guided stent size was the mean distal reference lumen diameter rounded to the closest stent diameter. The agreement on stent diameters was determined with Kappa statistics, Passing–Bablok regression analysis, and the Bland-Altman method. ResultsThe distal reference lumen diameter by CCTA and OCT were 2.75 ​± ​0.53 ​mm and 2.72 ​± ​0.55 ​mm (mean difference 0.06, limits of agreement −0.7 to 0.82). There were no proportional or systematic differences (coefficient A 1.06, 95% CI 0.84 to 1.3 and coefficient B −0.22, 95% CI -0.83 to 0.36) between methods. The agreement between the CCTA and OCT stent size was substantial (Cohen's weighted Kappa 0.74, 95% CI 0.64 to 0.85). Compared to OCT stent diameter, CCTA stent size was concordant in 52.3% of the cases; CCTA overestimated stent size in 20.0% and underestimated in 27.7%. ConclusionCCTA accurately assessed the reference vessel diameter used for stent sizing. CCTA-based stent sizing showed a substantial agreement with OCT. CCTA allows for PCI planning and may aid in selecting stent diameter.

Real-time monitoring of chromatic and phenolic dynamics of vinification employing UV-Vis spectroscopy, Python and chemometrics

Increasing consumer demand for high-quality wines required the introduction of more comprehensive monitoring indicators for quality management, necessitating winemakers to strive for rapid, real-time, and affordable monitoring tools during winemaking. This study investigated the feasibility of cost-efficient and easy-to-implement ultraviolet-visible (UV-Vis) spectroscopy combined with chemometric methods to predictively monitor the evolution of wine color and phenolics throughout commercial fermentation. Fermentations on a winery scale were carried out with a daily analysis of the UV-Vis spectra, color, and phenolics. Furthermore, characteristic wavelengths were established by a self-compiled Python program to reduce redundancy in spectra. The optimized partial least squares (PLS) model predicted well with a residual prediction deviation (RPD) greater than 2.54, and the robustness was further verified by a robust external Bland-Altman method. UV-Vis spectroscopy can achieve objective monitoring of the practical fermentation profile, which can better help winemakers make decisions to improve wine quality and consistency.

New sagittal abdominal diameter and transverse abdominal diameter based equations to estimate visceral fat area in type 2 diabetes patients

ObjectiveComputed Tomography (CT) or Magnetic Resonance Imaging (MRI) are considered gold standards for measuring visceral fat area (VFA). However, their relatively high prices and potential radiation exposure limit their widespread use in clinical practice and everyday life. Therefore, our study aims to develop a VFA estimated equation based on sagittal abdominal diameter (SAD) and transverse abdominal diameter (TAD) using anthropometric indexes. To the best of our knowledge, there have been limited studies investigating this aspect thus far.MethodsThis study was designed as a cross-sectional, retrospective cohort survey. A total of 288 patients (167 males and 121 females) aged 18–80 with type 2 diabetes (T2D) were consecutively collected from a multicenter hospital, and VFA was measured by CT. Subsequently, variables highly correlated with VFA were screened through general linear correlation analysis. A stepwise regression analysis was then conducted to develop a VFA estimated equation. Discrepancies between the estimated and actual VFA values were assessed using the Bland-Altman method to validate the accuracy of the equation.ResultsIn the female T2D population, triglyceride (TG), SAD, TAD were found to be independently correlated with VFA; in the male T2D population, BMI, TG, SAD and TAD showed independent correlations with VFA. Among these variables, SAD exhibited the strongest correlation with VFA (r = 0.83 for females, r = 0.88 for males), followed by TAD (r = 0.69 for females, r = 0.79 for males). Based on these findings, a VFA estimated equation was developed for the T2D population: VFA (male) =-364.16 + 15.36*SAD + 0.77*TG + 9.41*TAD − 5.00*BMI (R2 = 0.75, adjusted R2 = 0.74); VFA(female)=-170.87 + 9.72*SAD-24.29*(TG^-1) + 3.93*TAD (R2 = 0.69, adjusted R2 = 0.68). Both models demonstrated a good fit. The Bland-Altman plot indicated a strong agreement between the actual VFA values and the estimated values, the mean differences were close to 0, and the majority of differences fell within the 95% confidence interval.ConclusionsIn the T2D population, a VFA estimated equation is developed by incorporating SAD and TAD along with other measurement indices. This equation demonstrates a favorable estimated performance, suggesting to the development of novel and practical VFA estimation models in the future study.

Training and Comparison of nnU-Net and DeepMedic Methods for Autosegmentation of Pediatric Brain Tumors.

Tumor segmentation is essential in surgical and treatment planning and response assessment and monitoring in pediatric brain tumors, the leading cause of cancer-related death among children. However, manual segmentation is time-consuming and has high interoperator variability, underscoring the need for more efficient methods. After training, we compared 2 deep-learning-based 3D segmentation models, DeepMedic and nnU-Net, with pediatric-specific multi-institutional brain tumor data based on multiparametric MR images. Multiparametric preoperative MR imaging scans of 339 pediatric patients (n = 293 internal and n = 46 external cohorts) with a variety of tumor subtypes were preprocessed and manually segmented into 4 tumor subregions, ie, enhancing tumor, nonenhancing tumor, cystic components, and peritumoral edema. After training, performances of the 2 models on internal and external test sets were evaluated with reference to ground truth manual segmentations. Additionally, concordance was assessed by comparing the volume of the subregions as a percentage of the whole tumor between model predictions and ground truth segmentations using the Pearson or Spearman correlation coefficients and the Bland-Altman method. The mean Dice score for nnU-Net internal test set was 0.9 (SD, 0.07) (median, 0.94) for whole tumor; 0.77 (SD, 0.29) for enhancing tumor; 0.66 (SD, 0.32) for nonenhancing tumor; 0.71 (SD, 0.33) for cystic components, and 0.71 (SD, 0.40) for peritumoral edema, respectively. For DeepMedic, the mean Dice scores were 0.82 (SD, 0.16) for whole tumor; 0.66 (SD, 0.32) for enhancing tumor; 0.48 (SD, 0.27) for nonenhancing tumor; 0.48 (SD, 0.36) for cystic components, and 0.19 (SD, 0.33) for peritumoral edema, respectively. Dice scores were significantly higher for nnU-Net (P ≤ .01). Correlation coefficients for tumor subregion percentage volumes were higher (0.98 versus 0.91 for enhancing tumor, 0.97 versus 0.75 for nonenhancing tumor, 0.98 versus 0.80 for cystic components, 0.95 versus 0.33 for peritumoral edema in the internal test set). Bland-Altman plots were better for nnU-Net compared with DeepMedic. External validation of the trained nnU-Net model on the multi-institutional Brain Tumor Segmentation Challenge in Pediatrics (BraTS-PEDs) 2023 data set revealed high generalization capability in the segmentation of whole tumor, tumor core (a combination of enhancing tumor, nonenhancing tumor, and cystic components), and enhancing tumor with mean Dice scores of 0.87 (SD, 0.13) (median, 0.91), 0.83 (SD, 0.18) (median, 0.89), and 0.48 (SD, 0.38) (median, 0.58), respectively. The pediatric-specific data-trained nnU-Net model is superior to DeepMedic for whole tumor and subregion segmentation of pediatric brain tumors.

Criterion (Concurrent) Validity and Clinical Utility of the Tongueometer Device.

Tongue manometry (i.e., tongue pressure measurement) is a commonly used assessment for patients with suspected oral-motor involvement in swallowing disorders. Availability of lingual manometry has changed in recent years, with the introduction of the Tongueometer device being a more affordable tongue manometry system. The purpose of this study was to test concurrent (criterion) validity of the Tongueometer compared to the current standard reference device, the Iowa Oral Performance Instrument (IOPI). Adults without dysphagia were recruited for participation in this study. Standard lingual measurements (swallowing-related pressures, maximum isometric pressure [MIP], and maximum isometric endurance) were recorded, with the bulb anteriorly placed, with both devices, in a randomized order. The Bland-Altman method was used to determine concurrent (criterion) validity of these measurements compared to the clinical standard IOPI device. A recently available suggested corrective value by Curtis et al. (2023) was also applied, with comparisons made between devices both with and without the Curtis correction. The final sample included 70 adult participants aged 20-89 years (Mage = 52.3 years). Measures with the Tongueometer device were significantly lower when compared with the same measures taken using the IOPI (p < .01) for all measures including MIP, endurance, and swallow pressures. The correction suggested by Curtis and colleagues did not ameliorate these differences. The Tongueometer lingual measurements were consistently lower compared to the IOPI. Clinical use of values taken with the Tongueometer device should be compared to normative data published for each specific device. Available features of each device (e.g., display, bulb texture, technology/application) should be considered when selecting which device to use with an individual patient.

The telephone-based application of the modified fatigue impact scale in individuals with multiple sclerosis: An investigation of measurement properties

BackgroundFatigue is one of the most common symptoms reported by individuals with multiple sclerosis and it contributes to the reduction of the functionality. Therefore, it is important to assess the impact of fatigue on daily living of individuals with multiple sclerosis. The Modified Fatigue Impact Scale (MFIS) is an instrument to assess the perception of the impact of fatigue. However, there have been no investigations about the measurement properties of this instrument administered over the telephone for individuals with multiple sclerosis. ObjectivesTo verify the concurrent validity, the test-retest reliability, the standard error of measurement (SEM) and the minimal detectable change (MDC) of the MFIS applied over the telephone to assess the perception of the impact of fatigue of individuals with multiple sclerosis. MethodsThe MFIS, composed of 21 items covering three domains: physical, cognitive and psychosocial, was applied at three different moments with an interval of 5–7 days. To establish the concurrent criterion validity, the face-to-face application and the first evaluation by telephone were used. The two telephone assessments were used to assess the test-retest reliability The intraclass correlation coefficient (ICC) with 95 % confidence interval (CI) and the Bland-Altman method were used. The standard error of measurement (SEM) and the MDC was calculated according to reliability results. ResultsThirty individuals (40.83 ± 10.61, 60 % female) were included. The median score on the Expanded Disability Status Scale was 2.00 (±4.00). The majority of participants experienced fatigue (n = 17; 56.67 %). A significant and high magnitude correlation (0.70 ≤ ICC ≤ 0.87, p < 0.001) was found in the investigation of concurrent criterion validity. The Bland-Altman method showed a mean difference between 0.70 to 2.17 points between face-to-face and telephone-based application of the MFIS. For test-retest reliability, a significant and very high magnitude correlation (0.91 ≤ ICC ≤ 0.97, p < 0.001) was found. The Bland-Altman method showed a mean difference between -0.03 and -0.77 points between two telephone-based applications. The SEM and the MDC were 0.71 and 1.97 points. ConclusionThe telephone-based application of the MFIS to assess the perceived impact of fatigue in individuals with multiple sclerosis demonstrated adequate measurement properties, and may be a valuable tool to assess patients in clinical practice.

Saliva as a Diagnostic Tool for Early Detection of Exercise-Induced Oxidative Damage in Female Athletes.

Although blood still remains the most commonly utilized medium to detect increased levels of oxidative damage induced by exercise, saliva diagnostics have gained increasing popularity due to their non-invasive nature and athlete-friendly collection process. Given that the contribution of various phases of the menstrual cycle to the levels of oxidative damage may differ, the aim of this study was to evaluate an agreement between salivary and plasmatic levels of lipid peroxidation products in female swimmers in both the follicular (F) and luteal (L) phases of the menstrual cycle at rest and following exercise. Twelve well-trained female swimmers aged 19.6 ± 1.1 years old were examined. We measured diene conjugates (DCs), triene conjugates (TCs), and Schiff bases (SBs) in lipids immediately after their extraction from both saliva and blood plasma. All female swimmers were studied two times each, in the two different phases of one menstrual cycle, before and after high-intensity interval exercise (HIIE). Salivary and plasmatic levels of DCs, TCs, and SBs significantly increased post-exercise compared to pre-exercise, in both the F and L phases. A high positive correlation was observed between the concentrations of DCs, TCs, and SBs in the saliva and blood plasma of participants in the F and L phases, both at rest and following HIIE. Ordinary least products regression analysis indicates that there was no proportional and differential bias in the data. The Bland-Altman method also declares that there was no differential bias, since the line of equality was within the 95% confidence interval of the mean difference between salivary and plasmatic levels of DCs, TCs, and SBs in female swimmers, in both the F and L phases, before and after HIIE. There was also no proportional bias in the Bland-Altman plots. Thus, this is the first study to report a high agreement between the quantifications of DCs, TCs, and SBs in the saliva and blood plasma of female swimmers in both the F and L phases, at rest and following HIIE.

Evaluating Agility in Pre-Adolescent Basketball: A Comparative Analysis of CODAT, IAT, and RAT

Background: In basketball, agility is essential, characterized by the ability to change direction swiftly and accelerate. Traditional tests like the Illinois Agility Test (IAT) and the Reactive Agility Test (RAT) may not fully capture the agility demands specific to basketball. Purpose: This study aimed to introduce the Change of Direction and Acceleration Test (CODAT), designed specifically for young basketball players. It evaluates CODAT’s effectiveness by comparing it with IAT and RAT through comprehensive analysis. Methods: We assessed 87 pre-adolescent male basketball players, aged 9 to 13 years, with an average biological age of 11.2 years and an average estimated Peak Height Velocity (PHV) of 12.5 ± 0.5 years, using CODAT, IAT, and RAT. We employed regression analysis and the Bland–Altman method to determine CODAT’s reliability and validity. Results: The findings indicate that CODAT offers superior reliability and validity in measuring basketball-specific agility. Consistent scores highlight its potential as an effective tool for agility assessment in basketball training and talent identification. Conclusions: CODAT represents a significant advancement in agility assessment for young basketball players, advocating for its integration into sports science practices to better address the specialized demands of basketball agility.

Vertebral and Femoral Bone Mineral Density (BMD) Assessment with Dual-Energy CT versus DXA Scan in Postmenopausal Females.

This study aimed to demonstrate the potential role of dual-energy CT in assessing bone mineral density (BMD) using hydroxyapatite-fat material pairing in postmenopausal women. A retrospective study was conducted on 51 postmenopausal female patients who underwent DXA and DECT examinations for other clinical reasons. DECT images were acquired with spectral imaging using a 256-slice system. These images were processed and visualized using a HAP-fat material pair. Statistical analysis was performed using the Bland-Altman method to assess the agreement between DXA and DECT HAP-fat measurements. Mean BMD, vertebral, and femoral T-scores were obtained. For vertebral analysis, the Bland-Altman plot showed an inverse correlation (R2: -0.042; RMSE: 0.690) between T-scores and DECT HAP-fat values for measurements from L1 to L4, while a good linear correlation (R2: 0.341; RMSE: 0.589) was found for measurements at the femoral neck. In conclusion, we demonstrate the enhanced importance of BMD calculation through DECT, finding a statistically significant correlation only at the femoral neck where BMD results do not seem to be influenced by the overlap of the measurements on cortical and trabecular bone. This outcome could be beneficial in the future by reducing radiation exposure for patients already undergoing follow-up for chronic conditions.

Clinical Application of Automatic Assessment of Scoliosis Cobb Angle Based on Deep Learning.

A recently developed deep-learning-based automatic evaluation model provides reliable and efficient Cobb angle measurements for scoliosis diagnosis. However, few studies have explored its clinical application, and external validation is lacking. Therefore, this study aimed to explore the value of automated assessment models in clinical practice by comparing deep-learning models with manual measurement methods. The 481 spine radiographs from an open-source dataset were divided into training and validation sets, and 119 spine radiographs from a private dataset were used as the test set. The mean Cobb angle values assessed by three physicians in the hospital's PACS system served as the reference standard. The results of Seg4Reg, VFLDN, and manual measurement were statistically analyzed. The intra-class correlation coefficients (ICC) and the Pearson correlation coefficient (PCC) were used to compare their reliability and correlation. The Bland-Altman method was used to compare their agreement. The Kappa statistic was used to compare the consistency of Cobb angles at different severity levels. The mean Cobb angle values measured were 35.89° ± 9.33° with Seg4Reg, 31.54° ± 9.78° with VFLDN, and 32.23° ± 9.28° with manual measurement. The ICCs for the reliability of Seg4Reg and VFLDN were 0.809 and 0.974, respectively. The PCC and MAD between Seg4Reg and manual measurements were 0.731 (p<0.001) and 6.51°, while those between VFLDN and manual measurements were 0.952 (p<0.001) and 2.36°. The Kappa statistic indicated VFLDN (k= 0.686, p< 0.001) was superior to Seg4Reg and manual measurements for Cobb angle severity classification. The deep-learning-based automatic scoliosis Cobb angle assessment model is feasible in clinical practice. Specifically, the keypoint-based VFLDN is more valuable in actual clinical work with higher accuracy, transparency, and interpretability.

How well global dietary intake estimates agree: a case of sodium consumption.

Global dietary data repositories are key components of nutrition surveillance. The two most comprehensive databases, the Global Dietary Database (GDD) and the Global Burden Disease (GBD), provide national dietary intake estimates but use different data sources and models to generate estimates. To explore the agreement between GDD and GBD estimates, we compared country-specific average daily sodium intakes in 169 countries over a 28-year period using descriptive statistics, the Bland-Altman method, and prevalence exceeding the intake reference level of 2.3g/day. We detected a staggering 36% difference between GDD and GBD estimates of global mean intakes (2.68 ± 0.74 vs. 3.88 ± 1.15g/day, respectively; p < 0.0001). As 104 (61.5%) countries reported to have over-consumed sodium by both databases, the development of standardized approaches for national dietary intake estimation is critical for monitoring global sodium intake in a systematic and comprehensive way and for implementing global strategies to reduce sodium intake.

Analysis of mandibular jaw movements to assess ventilatory support management of children with obstructive sleep apnea syndrome treated with positive airway pressure therapies.

The polysomnography (PSG) is the gold-standard for obstructive sleep apnea (OSA) syndrome diagnosis and assessment under positive airway pressure (PAP) therapies in children. Recently, an innovative digital medicine solution, including a mandibular jaw movement (MJM) sensor coupled withautomated analysis, has been validated as an alternative to PSG for pediatric application. This study aimed to assess the reliability of MJMautomated analysis for the assessment of residual apnea/hypopnea events during sleep in children with OSA treated with noninvasive ventilation (NIV) or continuous PAP(CPAP). In this open-label prospective non-randomized multicentric trial, we included children aged from 5 to 18 years with a diagnosis of severe OSA. The children underwent in-laboratory PSG with simultaneous MJM monitoring and at-home recording with MJM monitoring 3 months later. Agreement between PSG and MJM analysis in measuring the residual apnea-hypopnea index (AHI) was evaluated by the Bland-Altman method. The treatment effect on residual AHI was estimated for both PSG and MJM analysis. Fifteen (60% males) children were included with a median age of 12 years [interquartile range 8-15]. Two (17%) were ventilated with NIV and 13 (83%) with CPAP. There was a good agreement between MJM-AHI and PSG-AHI with a median bias of -0.25 (95% CI: -3.40 to +2.04) events/h. The reduction in AHI under treatment was consistently significant across the three measurement methods: in-laboratory PSGand MJM recordings in the laboratory and at home. Automated analysis of MJM is a highly reliable alternative method to assess residual events in a small population treated with PAP therapies.

404 Mechanisms of a Dynamic Stability Protocol for Persons with Thumb Osteoarthritis

OBJECTIVES/GOALS: Our aims are to 1) describe changes in thumb Carpometacarpal (CMC1) joint stability following an 8-week clinic-based dynamic stability exercise program using computerized tomography (CAT) and 2) to evaluate the agreement between ultrasound and CAT (reference standard) when quantifying thumb CMC stability. METHODS/STUDY POPULATION: Aim 1: We have enrolled 13/49 participants in a prospective pre-post interventional study of an 8-week clinic-based occupational therapy dynamic stability program. The primary outcome will be change in stability (thumb metacarpal subluxation in mm) when forcefully loading the thumb as per CAT from pre-treatment to post-treatment at 9 weeks. Aim 2: Same 49 participants are undergoing a one-time ultrasound during baseline assessment. Agreement of ultrasound and CAT measurements (thumb metacarpal subluxation in mm) will be assessed by the Bland-Altman method. RESULTS/ANTICIPATED RESULTS: Exercise is a first-line treatment of CMC1 OA yet there is insufficient evidence to support this. Progression of CMC1 OA is characterized by altered joint mechanics. Joint replacement surgery may reduce pain but often worsens thumb mechanics and overall hand function. This study is the first to test the sustained biomechanical effects of non-invasive thumb exercises. Should these benefits exist, this will further support exercise as a first-tier intervention. Should ultrasound be a suitable proxy for CAT, therapists/physicians could monitor thumb CMC mechanics in response to treatment without risk of radiation exposure. We anticipate 1) a statistically significant reduction in thumb CMC subluxation at 9 weeks follow up and 2) high agreement between sonographic and CAT measures of thumb stability. DISCUSSION/SIGNIFICANCE: This study will lay the foundation for future work and may offer critical support for the use of a non-pharmacological and non-surgical approach as first-line treatment of a highly disabling disease. Future study should include controlled trials where hand function, activity limitation, disease progression, and costs are the outcomes in interest.

Development of Sample Size Formulas for Least Square Regression-Based Consistency Evaluation of Quantitative Indicators

Objective To develop and verify the sample size formulas for quantitative data consistency evaluation based on the least square regression method. Methods According to the principle of least square regression-based quantitative consistency evaluation,statistical inference,and formula derivation,we developed the formulas for calculating sample size based on regression constant and regression coefficient.Furthermore,the accuracy of the formulas was verified by the data of three examples,and the results were compared with those of the sample size formula established based on the Bland-Altman(BA)method. Results The sample size formulas for regression-based quantitative consistency evaluation were deduced,and the accuracy of the formulas was verified by three examples.In addition,the results obtained with this formula had differences compared with those of the sample size formula established based on the BA method.Furthermore,consistent conclusions could be obtained by regression analysis and BA analysis with the sample size calculated with the regression method.However,with the sample size calculated based on the BA method,the consistency conclusion of regression analysis and BA analysis was sometimes not valid. Conclusion A sample size formula for quantitative consistency evaluation based on the regression method was proposed for the first time,which provided methodological support for the research in this field.

Role of Imaging Modalities in the Quantitative Assessment of Atherosclerotic Plaques in the Thoracic Aorta.

Comparative analysis of the height of atherosclerotic plaques (AP) in the descending thoracic aorta (TA) according to two-dimensional (2D) and three-dimensional (3D) transesophageal echocardiography (TEE), and contrast-enhanced multislice computed tomography (MSCT). The TA was examined using 2D, 3D TEE and contrast-enhanced MSCT in 34 patients (20 men and 14 women aged 68 [62; 71] years). AP heights were compared using the Bland-Altman method and the Spearman correlation analysis. This was a blinded comparative study which assessed the AP morphometry using each of the radiation modalities without knowing the results of the method being compared. 100 APs were examined in the descending TA. The mean height of all analyzed APs in the descending TA was 2.2 mm [2; 2.7] for 2D TEE, 3.1 mm [2.7; 3.55] for 3D TEE, and 3.05 mm [2.55; 3.55] for MSCT. The AP heights measured with 2D TEE was statistically significantly smaller than the heights of similar APs measured either with 3D TEE or MSCT. The mean difference (bias) was 0.88±0.34 mm between 2D and 3D TEE, and 0.83±0.41 mm between 2D TEE and MSCT. The correlation coefficients for the AP heights were r=0.87 (p&lt;0.001) between 2D and 3D TEE and r=0.86 (p&lt;0.001) between 2D TEE and MSCT. There were no differences in the height of similar APs between 3D TEE and MSCT. The three-dimensional reconstruction of AP in the TA by TEE is more accurate for quantitative assessment of AP than a two-dimensional study.

Feasibility of the pitch efficiency rating: A novel tool for systematic assessment of pitching mechanics in developing throwing athletes.

Injuries in younger baseball athletes continue to increase despite work characterizing risk factors. Three-dimensional (3D) motion capture may identify suboptimal pitching mechanics that predispose an athlete to injury, but 3D-motion analysis is often inaccessible. Thus, there is a gap between the current biomechanics literature and its practical application in young athletes. The current study aims to assess the reliability of the pitch efficiency rating (PER) as a systematic tool to evaluate throwing mechanics in developing baseball pitchers. To determine the feasibility of application and reliability of a novel, scientifically informed tool (PER) for the assessment of pitching mechanics. Reliability study using Bland-Altman methods for assessing agreement between two raters. Academic medical center through community outreach. Pitching mechanics were assessed and rated with the PER for 40 athletes (26 high school, 14 Division III), average age 19.0 years old (range 15.3-23.7 years old). N/A. Interrater and intrarater reliability as calculated by intraclass correlation coefficient (ICC). For initial readings comparing interrater reliability between Rater 1 and Rater 2, the ICC was calculated at 0.80 (95% confidence interval [CI] 0.66-0.89) and 0.76 (95% CI 0.60-0.86) for the second set of ratings. Regarding intrarater reliability across reads, ICC was found to be 0.63 (95% CI 0.43-0.79) for Rater 1, and 0.91 for Rater 2 (95% CI 0.85-0.95). The present study introduces the PER as a potential tool for evaluating pitching mechanics. However, the intrarater reliability of the PER did not meet preestablished criteria in one of the two pilot raters. Further study is needed to continue to assess the reliability of the tool across diverse demographics.

An Innovative Mathematical Model of the Spine: Predicting Cobb and Intervertebral Angles Using the 3D Position of the Spinous Processes Measured by Vertebral Metrics

Back pain is regularly associated with biomechanical changes in the spine. The traditional methods to assess spine biomechanics use ionising radiation. Vertebral Metrics (VM) is a non-invasive instrument developed by the authors in previous research that assesses the spinous processes’ position. However, the spine model used by VM is not accurate. To overcome it, the present paper proposes a pioneering and simple articulated model of the spine built through the data collected by VM. The model is based on the spring–mass system and uses the Levenberg–Marquardt algorithm to find the arrangement of vertebral bodies. It represents the spine as rigid geometric transformations from one vertebra to the other when the extremity vertebrae are stationary. The validation process used the Bland–Altman method to compare the Cobb and the intervertebral angles computed by the model with the radiographic exams of eight patients diagnosed with Ankylosing Spondylitis. The results suggest that the model is valid; however, previous clinical information would improve outcomes by customising the lower and upper vertebrae positions, since the study revealed that the C6 rotation slightly influences the computed angles. Applying VM with the new model could make a difference in preventing, monitoring, and early diagnosing spinal disorders.