Suppose you analyze data for a group of 50 people applying for a grant. Each grant proposal was read by two readers, and each reader said „yes“ or „no“ to the proposal. Suppose the data for the tally of differences of opinion were as follows, where A and B are readers, the data on the main diagonal of the matrix (a and d) count the number of chords and the non-diagonal data (b and c) count the number of disagreements: if we compare two observers, the concept behind the test resembles the Chi-Quadrat test. Two tables of 2 x 2 are created: one with the expected values, if there was a random agreement, and the other with your actual data. Kappa will indicate how much of your Interobserver agreement is due to chance. One of the most common methods for assessing vertebral fractures (VFA) is the semi-quantitative genant method , which assesses the shape of the deformity and its severity. So far, it has been found that this method has a fair to good reproducibility and reliability in lateral views of CT-Scout, x-rays or spinaldensitometry cephalometry -. Vertebral fractures may be more easily detectable on TDD than in conventional X-rays . In good conscience, intra- and interobserver variability in the evaluation of vertebral fracture of the Genant VFA method was not evaluated for multislice CT. Knowledge of reproducibility and reliability is a necessary condition for further study of the potentially important prognostic value of vertebral fractures on routine breast CT. In addition to Genant`s standard visual assessment of spinal height measurement, it showed match limits very close to the minimum altitude difference that a trained observer is likely to detect (13% ).
However, the reliability values (CCIs) were very different for observers. This indicates that the reliability of this VFA measurement may vary in the same way in clinical practice. This variability was also repeated for the presence of the green plane fracture (although the patient`s level did not have a fracture variable). In addition, some are low (>20%) Altitude loss values were noted for vortexes considered (usually slightly) broken during visual control. This may be due to the fact that the un fractured vertebrae were falsely classified as broken and/or are due to a poor measurement of the calliper. These problems, encountered by observers in quantification, which was also the longest part of the study, can be overcome in the future by automated measurements of the height of the vertebral body to the scanner. The dissent is 14/16 or 0.875. The disagreement is due to the quantity, because the assignment is optimal. Kappa is 0.01. To find the expected values, you will find the product of marginalized groups: if Cohens Kappa is accepted as an appropriate measure for the Interobserver agreement, as many judge it based on its widespread use, the corrections proposed here for Kappa`s negative values should be just as acceptable. Given that the expected divergences (or agreements) in the new coefficients naturally depend exclusively on the distribution of borders, some critics that Cohen`s coefficients were too dependent on the limit distributions would apply in the same way as the new coefficients. This concern is particularly important in the case of very uneven border distributions (uneven or „erroneous“).
However, if these distributions are fairly homogeneous (uniform), Cohens Kappa, and therefore the measures proposed in this document for the disappointment of Interobserver (negative agreement), seem to be reasonably acceptable measures against an agreement. In terms of fracture, intraobserver reliability was good to excellent (Kappa 0.73 (0.52-0.91) at 0.84 (0.63-1)) (Table 4). The Interobserver cappas ranged from 0.56 (0.29-0.79) to 0.81 (0.61-0.96), indicating a reliability of Interobserver just to excellent. For the worst level of fracture, intraobserver reliability (weighted kappa) ranged from 0.84 (0.68-0.93) to 0.9 (0.78-0.96), while Interobserver were 0.73 (0.45-0.88) at 0.88 (0.67-0.97), indicating significant reliability at the end of