Intraobserver Variability (intraobserver + variability)

Distribution by Scientific Domains


Selected Abstracts


Interobserver and Intraobserver Variability of Flow-Mediated Vasodilatation of the Brachial Artery

ECHOCARDIOGRAPHY, Issue 1 2008
Iana Simova M.D.
Flow-mediated endothelial-dependent vasodilatation (FMD) of the brachial artery is a method capable of detecting endothelial dysfunction. In order to implement this method in future clinical research studies, its reproducibility and precision have to be assessed. The aim of the study is to evaluate the inter- and intraobserver variability of FMD performed in our department. We investigate 40 patients. FMD is measured by two independent observers to test the interobserver variability, and repeated by the first observer to test the intraobserver variability. We compare the baseline and post-ischemic diameter of the brachial artery and the percent dilatation. The correlation coefficients for these comparisons are high (>0.92) with a significance of less than 0.001. The inter- and intraobserver variability is further tested comparing the mean values of the baseline and post ischemic diameter of the brachial artery and the percent dilatation. The absolute values of the mean paired differences and the standard deviations (SDs) of the differences are 0.02850 0.05942, P = 0.004, 0.01175 0.08177, P = 0.369 and 0.28375 1.61561, P = 0.273, respectively for the interobserver variability and 0.00475 0.04663, P = 0.523, 0.00050 0.05267, P = 0.952 and 0.15725 1.19922, P = 0.412, respectively for the intraobserver variability. It can be concluded that the inter- and intraobserver variability for FMD performed in our department is acceptable. FMD can be performed precisely and accurately, with a satisfactory reproducibility and can be safely and reliably implemented in future clinical research studies. [source]


Observer variability in the sonographic evaluation of thyroid nodules

JOURNAL OF CLINICAL ULTRASOUND, Issue 6 2010
Chang Suk Park MD
Abstract Objective. Inter- and intraobserver variabilities in the description and diagnostic categorization of sonographic (US) features of thyroid nodules were evaluated. Methods. The current study was conducted on 72 malignant nodules and 61 benign nodules. The US findings for each thyroid nodule were analyzed twice at a 6-week interval by five radiologists. The analyses were in accordance with the guidelines proposed bythe Thyroid Study Group of the Korean Society of Neuroradiology and Head and Neck Radiology (TSGKSNRHNR). Inter- and intraobserver variabilities were calculated using Cohen's kappa statistics. The sensitivity, specificity, positive-predictive value, and negative-predictive value in the assessment of the diagnostic accuracy using these guidelines were calculated. Result. The interobserver agreement was fair to substantial for US features and categorization. Of the US features of the thyroid nodules, internal content (solid versus cystic) showed substantial agreement (k= 0.64). There was moderate agreement with regard to shape, echogenicity, calcification, and diagnostic categories (k = 0.42, 0.57, 0.55, and 0.55, respectively). There was fair agreement for margin, echotexture, and capsule invasion (k = 0.34, 0.26, and 0.32, respectively). With regard to intraobserver agreement, there was moderate to substantial agreement for all US features except for echotexture and capsule invasion, which showed fair agreement. In particular, there was moderate to almost perfect agreement for the diagnostic category. The sensitivity, specificity, positive-predictive value, and negative-predictive value were 65.3%,81.9%, 60.7%,68.9%, 69.7%,73.8%, and 66.6%,75.5%, respectively. Conclusion. There were high degrees of inter- and intraobserver agreement using the "Guidelines for diagnostic thyroid ultrasonography," of the TSGKSNRHNR in the description and categorization of thyroid nodules. 2010 Wiley Periodicals, Inc. J Clin Ultrasound, 2010 [source]


Interobserver and Intraobserver Variability of Flow-Mediated Vasodilatation of the Brachial Artery

ECHOCARDIOGRAPHY, Issue 1 2008
Iana Simova M.D.
Flow-mediated endothelial-dependent vasodilatation (FMD) of the brachial artery is a method capable of detecting endothelial dysfunction. In order to implement this method in future clinical research studies, its reproducibility and precision have to be assessed. The aim of the study is to evaluate the inter- and intraobserver variability of FMD performed in our department. We investigate 40 patients. FMD is measured by two independent observers to test the interobserver variability, and repeated by the first observer to test the intraobserver variability. We compare the baseline and post-ischemic diameter of the brachial artery and the percent dilatation. The correlation coefficients for these comparisons are high (>0.92) with a significance of less than 0.001. The inter- and intraobserver variability is further tested comparing the mean values of the baseline and post ischemic diameter of the brachial artery and the percent dilatation. The absolute values of the mean paired differences and the standard deviations (SDs) of the differences are 0.02850 0.05942, P = 0.004, 0.01175 0.08177, P = 0.369 and 0.28375 1.61561, P = 0.273, respectively for the interobserver variability and 0.00475 0.04663, P = 0.523, 0.00050 0.05267, P = 0.952 and 0.15725 1.19922, P = 0.412, respectively for the intraobserver variability. It can be concluded that the inter- and intraobserver variability for FMD performed in our department is acceptable. FMD can be performed precisely and accurately, with a satisfactory reproducibility and can be safely and reliably implemented in future clinical research studies. [source]


Amplitude and Velocity of Mitral Annulus Motion in Rabbits

ECHOCARDIOGRAPHY, Issue 4 2004
Li-ming Gan M.D., Ph.D.
Objective: During recent years, the amplitude and the maximal systolic velocity of the mitral annulus motion (MAM) have been established as indices of the left ventricular systolic function and the maximal diastolic velocity of the annulus motion has been suggested as an index of diastolic function. The main aims of the present study were to investigate the feasibility of these techniques in rabbits and to investigate age-related changes concerning these variables. Methods: Twenty-one New Zealand white rabbits were investigated by echocardiographic M-mode and pulsed tissue Doppler. One subgroup (I) included 11 still-growing, 3.0 0.2 month-old, animals and another group (II) included 10 young grown up rabbits, 12.1 1.5 months old. Results: The amplitude (4.8 0.6 and 3.5 0.3 mm, respectively) and maximal systolic (98 14 and 66 7 mm/s, respectively) and diastolic (111 21 and 80 12 mm/s, respectively) velocities of the MAM were significantly (P < 0.001) higher in group I than in group II, despite a bigger heart in the animals in the latter group. A coefficient of variation of <5% was found for both inter- and intraobserver variability for both amplitude and velocities. Conclusions: The amplitude and velocities of MAM are easily recorded in rabbits with excellent reproducibility and the changes with age seem to be very similar to those in humans. These noninvasive M-mode and tissue Doppler methods are therefore suitable for the investigation of left ventricular function in experimental studies in rabbits. (ECHOCARDIOGRAPHY, Volume 21, May 2004) [source]


Variation in identifying neonatal percutaneous central venous line position

JOURNAL OF PAEDIATRICS AND CHILD HEALTH, Issue 9-10 2004
DE Odd
Objective: The study objective was to obtain data on interpretation, including intra and interobserver variation and action taken for a given line tip location, for a series of radiographs demonstrating neonatal long lines. Methods: Nineteen radiographs taken to identify line tip position were digitized and published on an internet site. One film was included twice in order to assess intraobserver variation giving a total of 20 images. Fourteen used radio-opaque contrast and five no contrast. Australian and New Zealand Neonatal Network members and National Women's Hospital NICU staff were invited to participate in the study. For each radiograph, participants were asked to identify if long line tip could be identified, the likely anatomical position and desired action. Interobserver agreement was assessed by the maximum proportion of agreement per radiograph and by the number of different options selected. Intraobserver agreement was assessed by comparing the two reports from the duplicate radiograph. Results: Twenty-seven responses were received. Overall, 50% of the reports stated that the long line tips could be identified. The most commonly reported position was in the right atrium (31%) and most commonly reported action was to pull the line back (53%). The median agreement of whether the line was seen was 68%, agreement on position 62% and agreement on action 86%. On analysis of intraobserver variability, from the identical radiographs, 27% of respondents differed on whether the line tip could be visualized. Conclusion: Interobserver and intraobserver reliability was poor when using radiographs to assess long line tips. The major determinant of line repositioning was the perceived location. [source]