How to do Passing-Bablok regression?
Fit a Passing-Bablok regression to estimate the relationship between a test method and a reference or comparative method. Select a cell in the dataset. On the Analyse-it ribbon tab, in the Statistical Analyses group, click Method Comparison, and then click Passing-Bablok.
How do you interpret Passing-Bablok?
In short, the Passing-Bablok procedure fits the parameters a and b of the linear equation y = a + b x using non-parametric methods. The coefficient b is calculated by taking the median of all slopes of the straight lines between any two points, excluding lines for which b = 0 or b = ∞.
What is Deming regression analysis?
Deming regression is a technique for fitting a straight line to two-dimensional data where both variables, X and Y, are measured with error. Deming regression is often used for method comparison studies in clinical chemistry to look for systematic differences between two measurement methods.
What do Bland Altman plots show?
Bland–Altman plots allow identification of any systematic difference between the measurements (i.e., fixed bias) or possible outliers. The mean difference is the estimated bias, and the SD of the differences measures the random fluctuations around this mean.
How do you read a Bland Altman plot?
If the points on the Bland–Altman plot are scattered all over the place, above and below zero, then it suggests that there is no consistent bias of one approach versus the other. It is, therefore, a good first step for two measurement techniques of a variable.
What is YORK regression?
York’s (1969) method of regression, determining the best-fit line to data with errors in both. variables using a least-squares solution, has become an integral part of isotope geochemistry.
What is orthogonal distance regression?
Orthogonal distance regression (ODR) extends least squares data fitting to problems with independent variables that are not known exactly. The results indicate that, for the data and performance criteria considered, ODR never performs appreciably worse than OLS and often performs considerably better.
What is Passing Bablok regression?
Passing-Bablok regression is a linear regression procedure with no special assumptions regarding the distribution of the samples and the measurement errors (Passing & Bablok, 1983). The result does not depend on the assignment of the methods (or instruments) to X and Y.
What is the Passing-Bablok procedure?
The Passing-Bablok procedure fits the parameters a and b of the linear equation y = a + b x using non-parametric methods. The coefficient b is calculated by taking the shifted median of all slopes of the straight lines between any two points, disregarding lines for which the points are identical or b = -1.
What are outliers in Passing-Bablok regression?
Since it is in essence a non-parametric procedure, Passing-Bablok regression is not influenced by the presence of one or relative few outliers. Nevertheless, outliers – defined here as residuals outside the 4 SD limit – are plotted in a different color in the residuals plot.
Is the Passing-Bablok method comparable to the CUSUM test?
The Cusum test for linearity only tests the applicability of the Passing-Bablok method; it has no further interpretation with regards to comparability of the two laboratory methods. A small P value (P<0.05) indicates that there is no linear relationship between the two measurements and therefore the Passing-Bablok method is not applicable.