For a testable hypothesis , you can request different Wald tests by using the DF= option in the MODEL statement.
Let
where is a contrast vector or matrix that you specify, is the vector of regression parameters, is the estimated regression coefficients, is the estimated covariance matrix of , and is a matrix such that the following are true:
has the same number of columns as .
has full row rank.
The rank of equals the rank of the matrix.
All rows of are estimable functions.
The Wald F statistic that is computed by using the matrix is equivalent to the Wald F statistic computed by using the matrix.
If is a fullrank matrix and all rows of are estimable functions, then is the same as . It is possible that such an matrix cannot be constructed for a given set of linear contrasts, in which case the contrasts are not testable. Let r be the rank of . The following table describes the Wald tests available in PROC SURVEYPHREG.
Numerator 
Denominator 


Value of DF= 
Test Request 
Test Statistic 
Degrees of Freedom 
Degrees of Freedom 
NONE 
Chisquare 
Q 
r 

v 
Customized F 
vQ/rd 
r 
v 
DESIGN 
Unadjusted F 
Q/r 
r 
d 
DESIGN (v) 
Unadjusted F 
Q/r 
r 
v 
PARMADJ 
Adjusted F 
(d–r+1)Q/rd 
r 
d–r+1 
PARMADJ (v) 
Adjusted F 
(v–r+1)Q/rv 
r 
v–r+1 
DESIGNADJ 
Adjusted F 
Q/r 
r 
d 