The weighted Kappa allows differences of opinion to be weighted differently and is particularly useful when codes are ordered. :66 Three matrixes are involved, the matrix of observed scores, the matrix of expected values based on random tuning and the weight matrix. The weight dies located on the diagonal (top left to bottom-to-right) are consistent and therefore contain zeroes. Off-diagonal cells contain weights that indicate the severity of this disagreement. Often, cells outside diagonal 1 are weighted, these two out of 2, etc. Cohens Kappa measures the agreement between two advisors who classify each of the N elements into C exclusion categories. The definition of « textstyle » is the distribution of cefazoline (left) and ceftriaxone (right) for escherichia coli (mic.eucast.org/Eucast2/SearchController/search.jsp?action=performSearch&BeginIndex=0&Micdif=mic&NumberIndex=50&Antib=-1&Specium=162). It is expected that the approval rates of categorials for cefazolin will be lower, as the stopping points are the wild-type mic bisect distribution. S, fragile; I, intermediate step; R, resilient. Kappa is an index that takes into account the agreement observed with regard to a basic agreement. However, investigators must carefully consider whether Kappa`s core agreement is relevant to the research issue.
Kappa`s baseline is often called random tuning, which is only partially correct. The basic agreement of Kappa is the agreement that could be expected because of the accidental allocation, given the quantities declared in quantity in the limit amounts of the square emergency table. Kappa – 0 if the observed attribution appears to be random, regardless of the quantitative opinion limited by the limit amounts. However, for many applications, investigators should be more interested in quantitative opinion in marginal amounts than in attribution opinion, as described in the supplementary information on the diagonal of the square emergency table. Kappa`s base is therefore more entertaining than illuminating for many applications. Take the following example: Among automated systems, MicroScan showed in this study the highest overall compliance with the results of micro-dilution of broth. This is consistent with the qi et al. ratio, which showed a strong correlation between the presence or absence of mutations in the RNA 23S r gene and the phenotype reported by the MicroScan system (18). VITEK 2 also had a high category agreement, provided that the advanced expert system, which reported all non-receptive linezolid staph as vulnerable, was not used. However, neither system gave a categorical result to strains classified as non-sensitive, leaving this gap in the report. This is potentially very confusing for prescribers.
Note that Cohen Kappa`s agreements are only concluded between two advisors.