Method Validation (Correlation)

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Determine the validity or correlation of recovered values of an analyte with a new method in comparison to the reference method.

CLIA Recommendation: Must be done to determine the correlation factor between two methodologies.

Method A (New Method):
Analyzer:  

Method B (Comparison Method):
Analyzer:  


Enter up to 30 values below:

















































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Number of Samples:
Range of Observation
Correlation Coefficient(r):
New Method Mean:
Comparison Method Mean:
Average Difference:
Slope:
Y-intercept:
Interpretation:


Correlation Graph
%Difference Plot

Definition of Terms:

Method validation is the process used to confirm that the analytical procedure employed for a specific test is suitable for its intended use. Results from method validation can be used to judge the quality, reliability and consistency of analytical results; it is an integral part of any good analytical practice.

Formula:

n = Number of points or dilutions
x-axis = Comparison or reference method
y-axis = New method
sumxy = sum of the products of the target & recovered values of a certain dilution
sumx = sum of all target values
sumy = sum of all recovered values
sumx2 = sum of all the squares of target values
sumy2 = sum of all the squares of recovered values
slope = ((n * sumxy) – (sumx * sumy))/((n * sumx2) – (sumx ²))
intercept = sumy – (slope * sumx)/n
correlation coefficient = ((n * sumxy) – (sumx * sumy)) / (((n * sumx2) – sumx² * ((n * sumy2) – sumy²)^0.5

Passing Criteria:

• Slope should be greater than 0.5
• Slope should be less than 1.5
• Correlation Coefficient should be equal or greater than 0.7

Please check out our list of calculators for Laboratory Statistics:

• Standard Deviation Calculator from Reference Range
• Standard Deviation Calculator using Data Points
• Calibration Verification and Linearity
• Method Validation and Correlation