need help in creating formula for CKD-EPI equation

Question

I created the one mentioned below, but is somehow erroneous.

141 * Choose(
	(:Creat / :k) ^ If( :Sex == F/*###*/,
		-0.329,
		-0.411
	) < 1,
	1
) * Choose( (:Creat / :k) ^ (-1.209) > 1, 1 ) * 0.993
 ^ :Age * If( :Sex == F, 1.018, 1 ) *
If( :Race == B, 1.159, 1 )

Can someone please help me fix it?

Mark_Bailey · Answer

GFR = 141*Min(Scr/κ, 1)*α*Max(Scr/κ, 1) - 1.209*0.993*Age*If(:Name("RACE BLACK")==1,1.159,1)*If(:Sex=="F", 1.018, 1);

Drrads · Answer

Since I am using mg/dl, k= 0.7 and 0.9 for Female and male respectively

Drrads · Answer

141 * Choose( :Creat / :Name( "k (CKD EPI CONSTANT) F= 0.7, M=0.9" ) < 1, 1 ) ^ If(
	:Name( "k (CKD EPI CONSTANT) F= 0.7, M=0.9" ) == 0.7,
	-0.329,
	-0.411
) * Choose( :Creat / :Name( "k (CKD EPI CONSTANT) F= 0.7, M=0.9" ) > 1, 1 ) ^ (-1.209) * 0.993 ^ :Age *
If( :Name( "k (CKD EPI CONSTANT) F= 0.7, M=0.9" ) == 0.7,
	1.018,
	1
) * If( :Name( "RACE BLACK = 1, REST = 0" ) == 1,
	1.159,
	1

)

I did modify the code and it works, but my values do not match the ones using an online calculation. My formula is over-estimating the GFR.