# Agreement Standard Deviation

In order to be able to compare the differences between the two sets of samples, regardless of their averages, it is more appropriate to consider the ratio between the pairs of measurements.  The transformation of the protocol (base 2) of the pre-analysis measurements allows the use of the standard approach. The presentation is therefore given by the following equation: the approach to the limits of concordance was introduced in 1983 by the English statisticians Martin Bland and Douglas Altman. The method became popular according to the authors` 1986 article in The Lancet. This second article is one of the most cited statistical articles since it has been cited more than 30,000 times. This is because the mean value is the absolute value of a standard root distribution (2/ft) and the mean of the absolute value of a normal distribution with a zero mean and the root sigma standard deviation (2/ft) is Sigma. We could use these regression equations to estimate the limits of 95% of the concordance as is currently the case: which is statistically significant (P<0.001). If we multiply these coefficients with the square root of (pi more than 2), we get an equation to predict the standard deviation of the differences: Bland JM, Altman DG. (1999) Measuring agreement in method comparison studies. Statistical Methods in Medical Research 8, 135-160. We can use this to model the relationship between the mean difference and blood sugar size. If we take the residues above this line, the differences between the observed difference and the difference predicted by the regression, we can use them to model the relationship between the standard deviation of the differences and the size of the blood glucose. We calculate the absolute values of the residues without warning signs, then we make a regression of these on the average glucose.

This is what emerges from the following regression equation: a primary application of the Bland Altman diagram is to compare two clinical measures that revealed an error in their measurements.  It can also be used to compare a new technique or method of measurement with a gold standard, because even a gold standard does not imply – and should not – that it is error-free.  See Analysis-it, MedCalc, NCSS, GraphPad Prism, R or StatsDirect for software that provides Bland Altman diagrams. If we predict the mean difference and standard deviation of these equations, we can estimate the mean minus or plus 1.96 SD for each glucose size: Myles & Cui. . . .