p-Value Combination Method

This feature enables you to specify a method for combining p-values in each analysis group.

P-Value Combination Method1	Definition
minPvalue	• Takes the smallest p-value in the group and applies the Sidak correction to obtain the correct p-value
Fisher	• Replaces the p-value at the center of the sliding window with the p-value of the t-statistic.
Simes	• Replaces the p-value at the center of the sliding window with the p-value computed using Simes’ method2.
TPM	• Replaces the p-value at the center of the sliding window with the p-value computed using Zaykin’s method3. • The TPM is a variation of Fisher’s method that leads to a different alternative hypothesis. With the TPM, rejection of the null hypothesis implies that there is at least one false null hypothesis among those with p-values less than the specified tau value. Note: This method is equivalent to Fisher’s method when tau=1.

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1

Selected methods are not available in all processes.

2

Simes, R.J. (1986). An Improved Bonferroni Procedure for Multiple Tests of Significance. Biometrika 73: 751–754.

3

Zaykin, D.V., Zhivotovsky, L.A., Westfall, P.H., and Weir, B.S. (2002). Truncated Product Method for Combining p-Values. Genetic Epidemiology 22: 170–185.

To Specify a P-Value Combination Method:

Select a method from the drop-down menu.

For Additional Information

For more information about these methods, see the Methods of Smoothing p-Values in the SAS/Genetics User's Guide.