Agreement Of Different Methods Research Articles

Agreement Between Different Body Composition Methods And Dual-energy X-ray Absorptiometry In Adults

The assessment of body composition is often used in clinical practice for nutritional assessment and monitoring. The gold standard method, dual energy X-ray absorptiometry (DXA), is hardly feasible in routine clinical practice. The bioelectrical impedance analysis (BIA) method is a common applicable alternative because it is accessible and easy to use. In addition, methods that use artificial intelligence to assess body composition through photos (AI-Photo) began to emerge as cheaper alternatives than BIA. However, few studies have evaluated the agreement of different methods with DXA. PURPOSE: Evaluate the agreement between one IA-Photo method, three BIA devices and DXA for estimating body fat percent (BF%) in adults. METHODS: A total of 215 Brazilian adults, aged between 18 and 65 years, BMI from 18 to 35 kg/m2 and sedentary and physically active. Volunteers were evaluated by the IA-Photo method (Shaped, Rio de Janeiro, Brasil), bioimpedance scales of the inBody 270 (Biospace, California, USA), inBCA F-500 (Shenzhen, China), Omron HBF-514 (Kyoto, Japan) models and DXA (GE, Madison, USA) at an interval of 1 minute between the methods. The method of Bland-Altman (BA) was used to evaluate the identify the 95% limits of agreement and BIAS between IA-Photo method and BIA devices with DXA. Lin's Concordance Correlation Coefficient (CCC) was utilized to evaluate concordance between each method with DXA. RESULTS: Confidence interval values are represented by the dotted line and the BIAS by the dashed line (Figure 1). The BIAS value of the %error between methods and DXA ranged from 3.33 (Shaped) to 12.2 (inBody-270). CCC was 0.96; 0.93; 0.91 and 0.45 for the Shaped, Omron, inBody-270 and inBCA F-500 methods. The inBody and Omron model BIAs presented a significant p value for the linear regression in the BA plot, indicating a proportion bias in relation to the BF%. CONCLUSIONS: Shaped and Omron had greater agreement with the DXA compared to inBody-270 and inBCA F-500 for estimating BF%.

MEASURING OF ELASTIC MODULI BY MEANS OF SUB-SURFACE SOUNDING METHOD

The method of determination of elastic moduli for different materials by means of measuring of longitudinal and shear waves’ velocities is discussed in the paper. The velocities are measured by obtaining the time of flight between a pair of low frequency ultrasonic dry point contact transducers installed on the surface of the studied material sample. Factors defining the accuracy of such measurement are indicated which mainly consist of physical velocity frequency dispersion, fundamental although small differences between static and dynamic elastic moduli measurements, velocity dependence on temperature etc. Comparison between Young’s modulus and Poisson’s ratio, obtained experimentally and from table data, is given for various plastics and steel samples. It shows good agreement of different methods’ data and demonstrates the applicability of the suggested elastic moduli ultrasonic sub-surface measurement method.

Agreement of different methods for assessment of progesterone concentrations in beef cattle serum.

Progesterone (P4) is responsible for the main reproduction processes. Concentration of P4 varies widely among different determination methods, and interpretation of these values may be difficult. The objective of the current study was to assess the agreement of three different enzyme immunoassays (ELISA) in relation to radioimmunoassay (RIA) of P4 concentration assessment of beef cow serum samples. Samples were collected randomly considering high (pregnant cows) and low (non-pregnant cows) P4 concentrations. Depending on the P4 assessment method, four groups were created as follows: Group 1 - direct samples assessed by ELISA, Group 2 - extracted samples assessed by ELISA, Group 3 - samples assessed by automated ELISA, and Group 4 - samples assessed by RIA. The mean progesterone concentration was 4.50 ng/mL, 1.24 ng/mL, 4.07 ng/mL and 4.39 ng/mL from Group 1 to Group 4, respectively. The mean difference (MD) between Group 1, Group 2 and Group 3 individually compared with Group 4 was -0.10 ± 1.24 ng/mL, 3.15 ± 3.58 ng/mL and 0.33 ± 1.42 ng/mL, and the 95% confidence interval (CI) for the differences (s) was from -0.99 to 0.78 ng/mL, from 0.59 to 5.71 ng/mL, and from -0.69 to 1.34 ng/mL, respectively. The confidence interval for the lower and upper limit of the agreement ranged from -4.12 to -1.05 ng/mL and from 0.84 to 3.91 ng/mL between Group 1 and Group 4, from -8.45 to 0.42 ng/ mL and from 5.88 to 14.75 ng/mL between Group 2 and Group 4, from -4.29 to -0.76 ng/mL, and from 1.41 to 4.94 ng/mL between Group 3 and Group 4. Our findings show that the best agreement with RIA was observed for Group 1 and Group 3, while the agreement in the extraction method was least accurate.

Agreement of Different Methods for Tissue Based Detection of HER2 Signal in Invasive Breast Cancer.

Breast cancer is the second leading cause of cancer mortality amongst American women. The HER2 gene encodes a cell surface receptor that affects cell proliferation and has been recognized as a diagnostic factor in treatment selection for invasive breast cancer. Examine accuracy in HER2 detection between manual count, computer assisted, and automated tiling algorithm. 42 randomly selected invasive breast cancer specimens were enumerated by fluorescence in situ hybridization (FISH)for HER2 and CEP17 markers using the Vysis HER2 assay (AbbotLaboratory, North Chicago, IL). Specimens were tested using three methods: Manual, computer assisted nuclei selection (Tissue FISH MetaSystems, Newton, MA), and automated enumeration (MetaSystems, Newton, MA). The greatest bias and widest agreement limits for HER2 and CEP17 were seen in Automatic versus Manual, the gold standard. HER2 values greater than 6 possessed the greatest bias and widest agreement limits. CEP17 comparison showed similar bias and agreement limits for each comparison. Kappa values indicated good agreement for all methods although Tissue FISH and Manual possessed better agreement. Higher agreement at lower HER2 & CEP17 count maybe due to fewer chromosomal aberrations, in which selection of field of views has less variation between methods. Alternatively, increased background signals seen in polyploidy may be responsible for the variations in signal count. Manual and Tissue FISH demonstrated good agreement amongst by both Altman Bland and Cohen's Kappa. While the automatic method has good agreement at lower HER2, the sharp increase in variability at higher HER2 counts illustrates a limitation of the automatic method.

3D.09

Objective: Increased blood pressure (BP) variability is a possible independent risk factor for cardiovascular events. BP variability has been assessed with several methods of BP measurement in recent literature, although it is unclear whether these measurements of variability with varying timeframes reflect the same phenomenon. The aim of our study was to compare the agreement between ambulatory, home and office BP variability. Design and method: The study population consisted of 509 participants randomly drawn from the population register or recruited by general practitioners on the basis of newly diagnosed untreated hypertension. Ambulatory 24-h blood pressure monitoring, 28 home BP measurements (twice every morning and evening during 7 consecutive days) and 8 office BP measurements (duplicate measurements on 4 visits) were performed in all participants. 3 log-transformed variability indices (SD, standard deviation; CV, coefficient of variation and ARV, average real variability) were calculated for all measurement methods and Pearson's correlations between them were calculated. The agreement of different methods on the diagnoses of extreme BP variability (participants with variability above the highest decile) was also assessed with kappa coefficients. Results: Systolic/diastolic BP variability was greater in 24-h ambulatory (CV: 12.6 ± 2.8 /15.1 ± 3.4) than home (CV: 4.4 ± 1.8/4.7 ± 2.0, p < 0.001 versus ambulatory CV for both) and office (CV: 4.8 ± 2.6/5.3 ± 2.6, p < 0.001 versus ambulatory CV for both) measurements. Ambulatory daytime variability was greater than night-time variability (CV: 11.0 ± 2.8/13.1 ± 3.5 vs. 9.5 ± 3.8/12.8 ± 4.6, p < = 0.001 for both). Pearson's correlation coefficients for systolic/diastolic variability indices between different measurement methods were 0.08–0.34/0.03–0.26, indicating only negligible to weak positive relationship (Table). The agreement of ambulatory, home and office BP variability measures on diagnoses of extreme systolic/diastolic BP variability was only slight, with the kappa coefficients varying between 0.00–0.20/0.03–0.16. Extreme variability was diagnosed in only two persons with all three methods.Conclusions: Shorter-term and longer-term BP variability assessed with different methods of BP measurement seem to correlate only weakly with each other. Our study suggests that BP variability assessed by different methods and timeframes reflects various phenomena, not a single entity.

Agreement of different methods for assessing sleep characteristics: a comparison of two actigraphs, wrist and hip placement, and self-report with polysomnography

ObjectiveTo assess the agreement of sleep parameters measured by two actigraphs (SOMNOwatch plus®, ActiGraph GT3X+®) at two different placements (wrist, hip) and of self-reported sleep with polysomnography (PSG). MethodsWe estimated agreement with PSG for total sleep time (TST), sleep onset latency (SOL), wake after sleep onset (WASO), number of awakenings after sleep onset (NASO), and sleep efficiency (SE%) for 100 participants of the general population, aged 18–75 years by judging mean differences to PSG and intervals of agreement using Bland–Altman plots. ResultsMean difference to PSG for TST was 8.3 min (95% confidence intervals [CI] −7.4; 24.1) for SOMNOwatch plus® (wrist), 39.8 min (95% CI 24.3; 55.3) for self-report, −79.0 min (95% CI −89.0; −68.9) for SOMNOwatch plus® (hip), and −81.1 min (95% CI −91.9; −70.4) for GT3X+® (hip), respectively. The width of intervals of agreement differed with the placement of the devices. Mean differences to PSG were higher for hip-based measurements compared with wrist placement for most parameters. ConclusionsAgreement of sleep parameters assessed by actigraphy with PSG differs with the placement of the device and is limited for hip-based measurements. Agreement of self-report with PSG is comparable to that of actigraphy for some parameters.

Evaluation of the multifrequency electronic apex locator Joypex 5 in primary teeth

To evaluate ex vivo the accuracy of the multifrequency electronic apex locator (EAL) Joypex 5 in primary molars. Fourteen primary molars were selected for a total of 25 root canals. Working length measurements were performed by direct observation (DO), using a 15 K-file into the root canal until its tip was visible at the apical foramen and electronically using the EALs Joypex 5. Data were analysed statistically using the intraclass correlation coefficient (ICC). To assess whether a significant difference in accuracy of the electronic apex locator existed, the Student's t test was performed at 5% significance. No statistical difference was observed between the direct observation and the EAL measurement (p < 0.05). The ICC confirmed the agreement of different methods to measure canal length. The R(2) coefficient was close to 1, denoting a strong agreement between measures obtained with Joypex 5 and DO. The multifrequency EALs Joypex 5 showed adequate accuracy in the root length determination of primary teeth.

Inter-method comparison of salivary cortisol measurement

Abstract Background: Salivary cortisol is increasingly used in the diagnostic work-up of suspected Cushing’s disease as well as in stress research. In this study, the agreement of different methods for salivary cortisol measurement was assessed. Methods: Saliva samples from five healthy volunteers were distributed to three routine clinical chemistry laboratories. As a reference, all samples were also analyzed using liquid chromatography-tandem mass spectrometry involving stable isotope labeled cortisol for internal standardization in our laboratory. Results: All immunometric routine methods substantially overestimated salivary cortisol concentrations by approximately 50%. The agreement between these immunoassays was moderate with between-method coefficients of variation of up to 36% for individual samples. Conclusions: Standardization of salivary cortisol measurement requires substantial improvement, in particular by implementation of proficiency testing schemes, a defined reference method, and reference materials. Interpretation of salivary cortisol data in psycho-neuroendocrinological research has to consider the inappropriate level of standardization realized for salivary cortisol measurement to date.

Evaluation of the Joypex 5 and Root ZX II: an in vivo and ex vivo study

To evaluate in vivo and ex vivo the accuracy of the multifrequency electronic root canal length measurement device (ERCLMD) Joypex 5 and compare it with the Root ZX II. The ex vivo methodology for evaluation of the accuracy of ERCLMDs was also validated by comparison with in vivo results. Twenty single-rooted human teeth that were scheduled for extraction were selected. Working length measurements were performed in vivo with the Joypex 5 and Root ZX II. After the teeth were extracted, each canal was measured with the ERCLMDs ex vivo. Then, a size 15 K-file was used to determine the reference working length (RWL), which was established 0.5 mm from the major foramen by direct observation. The measurements of working length obtained with the different methods and ERCLMDs were compared by analysis of variance and Tukey's test at P < .05. Statistical correlations were also performed. No significant difference was observed between in vivo and ex vivo measurements or the different types of ERCLMDs. The Bland-Altman plot confirmed the agreement of different methods and ERCLMDs to measure canal length. The R(2) coefficient obtained in both situations, comparing the ERCLMDs, was close to 1, denoting a strong agreement between measurements obtained with the Joypex 5 and Root ZX II and between in vivo and ex vivo methodologies. The Joypex 5 and Root ZX II had similar accuracy in determining working length of root canals. The ex vivo methodology for evaluation of the accuracy of ERCLMDs was validated when compared with the in vivo results.

SU‐FF‐T‐345: Agreement of Different Methods of Measuring Relative Electron Cone Output

Purpose: To determine suitability of various methods of determining relative output factors of electron cones. Method and Materials: The electron cone factors of a Varian accelerator were measured by several different methods: the daily output check device (Atlas QA3), electron diode, scatter diode, 0.125 cc ion chamber and 0.6 cc Farmer chamber. The ion chambers were used in water and plastic water with both positive and negative polarities. The diodes were used on top of plastic water with added bolus and the scatter diode was also used in a water phantom. Results: All methods had variations in relative output factor of about 0.5%. They agreed with one another within about 1% as long as the size of the detector was small relative to the cone size. The Farmer chamber gave erroneously low results for a 4×4 cone size due to a portion of the ionization chamber being within the penumbra region. Conclusion: The practice of using the most convenient set‐up (daily output check device) for verifying cut‐out factors is justified by the good agreement with other methods. Very small cut‐outs require special considerations and may require diode or film measurements for good results.

Insufficient Standardization of a Direct Carbohydrate-Deficient Transferrin Immunoassay

Measurement of carbohydrate-deficient transferrin (CDT) can reveal alcohol-related changes in the serum transferrin glycosylation pattern. CDT is a more alcohol-specific indicator than liver-function tests and is used for identification and follow-up of chronic high alcohol consumption(1). Therefore stable calibration of the assays is very important. Comparison of CDT results between methods has often been hindered by method-dependent discrepancies in the definition of the measurand (the transferrin glycoforms covered) and the way results are expressed. With some methods there has been an increased risk for false-positive results(2). The lack of CDT standardization prompted initiation of a working group under the International Federation of Clinical Chemistry and Laboratory Medicine, whose aim was to define the measurand, select and validate a reference method, and work out procedures for the production of reference materials. The first recommendation was that the fraction of disialotransferrin to total transferrin (%disialotransferrin) should be the primary target for CDT testing, with HPLC as the candidate reference method(3). The performance of individual laboratories and agreement of different methods can be determined through external quality assessment (EQA). A Swedish EQA scheme for CDT has been run by EQUALIS (External …

How to best assess tumor response after curative chemoradiotherapy (CRT) for head and neck squamous cell carcinomas (HNSCC): RECIST or PET/CT?

6023 Background: Response evaluation criteria in solid tumors (RECIST) has questionable value when applied to potentially curable, locally advanced HNSCC. Combined functional and anatomical imaging offers potential advantages in response assessment. We previously showed that combined FDG-positron emission tomography/computed tomography (PET/CT) has higher accuracy in depicting head and neck cancer than CT or PET alone (Branstetter et al. Radiology 2005). Methods: We reviewed records of patients (pts) with previously untreated, stage III/IV HNSCC treated with primary CRT on 5 clinical trials from 2004–2007. All pts underwent PET/CT prior to treatment and approximately 8 weeks post CRT. The presence of a complete response (CR) was assessed by clinical exam, CT portion of PET/CT (RECIST) and PET portion of PET/CT. CR by PET was defined as complete disappearance of FDG activity attributable to tumor, without regard to the degree of CT response, as assessed on fused PET/CT. We evaluated the agreement of different methods in assessing CR and the correlation of CR with pt outcome. Results: 52 pts were analyzed. Median age was 54 years (20–74). Males 41 (79%). Stage III, 17%; IV, 83%. Primary sites: oropharynx (52%), oral cavity (6%), larynx (21%), hypopharynx (8%), nasopharynx (6%), unknown primary (8%). CRT regimens: cetuximab/cisplatin, 30; cetuximab/pemetrexed, 11; docetaxel/erlotinib, 9; cisplatin,1; carboplatin, 1. In addition, 28 pts received induction. Concordance between methods in assigning response as CR: CT and PET (62%), clinical exam and CT (43%); clinical exam and PET (51%). With a median follow up of 15 months, 1/27 of pts with CR by PET recurred vs 9/25 of pts without CR (p=0.004); 1/13 of pts with CR by CT recurred vs 9/39 of pts without CR (p=0.4); 8/42 of pts with CR by exam recurred vs 1/9 of pts without CR (p=0.5) Of 39 pts who did not achieve CR by CT (RECIST), 0/15 who had CR by PET progressed but 9/24 who had less than a CR by PET progressed (p=0.007). Conclusions: There is poor concordance between various methods of response assessment post CRT for HNSCC. Combined PET/CT is superior to CT (RECIST) and exam in predicting recurrence. PET negativity after CRT is a powerful predictor of outcome in HNSCC, regardless of response using RECIST. No significant financial relationships to disclose.

Bridging the morphological and biological species concepts: studies on the Bactrocera dorsalis (Hendel) complex (Diptera: Tephritidae: Dacinae) in South-east Asia

Defining species accurately is a critical need in fundamental disciplines such as ecology and evolutionary biology and in applied arenas such as pest management. The validity of species designations depends on agreement of different methods of species diagnosis for unique biological species. The Bactrocera dorsalis complex of fruit flies provide an excellent opportunity for such a test of the congruence of different techniques (e.g. morphological, molecular, host-plant based, chemotaxonomy) used for species diagnosis. The complex contains a large number of closely-related species, is distributed over a wide geographical range in South-east Asia and considerable information has been compiled on some species. In the present study, the morphological and biological species boundaries were compared using new data from morphometric analyses of reproductive and body parts, together with a review of data on morphology, chemistry of male pheromones that are important in courtship and mating, molecular analyses, and endemic rainforest host plants. For the populations studied (Bactrocera carambolae, Bactrocera dorsalis, Bactrocera occipitalis, Bactrocera papayae, Bactrocera philippinensis, Bactrocera kandiensis and Bactrocera invadens) there appears to be significant congruence between the morphological and biological species boundaries.